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Clean up cnl_rt700 machine driver#2

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Clean up cnl_rt700 machine driver#2
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Clean up cnl_rt700 machine driver and add hdmi support.

bardliao added 2 commits June 20, 2019 17:51
Add rt700 matching table.

Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Clean up cnl_rt700 machine driver and add hdmi support.

Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
bardliao pushed a commit that referenced this pull request Jul 2, 2019
When receiving a deauthentication/disassociation frame from a TDLS
peer, a station should not disconnect the current AP, but only
disable the current TDLS link if it's enabled.

Without this change, a TDLS issue can be reproduced by following the
steps as below:

1. STA-1 and STA-2 are connected to AP, bidirection traffic is running
   between STA-1 and STA-2.
2. Set up TDLS link between STA-1 and STA-2, stay for a while, then
   teardown TDLS link.
3. Repeat step #2 and monitor the connection between STA and AP.

During the test, one STA may send a deauthentication/disassociation
frame to another, after TDLS teardown, with reason code 6/7, which
means: Class 2/3 frame received from nonassociated STA.

On receive this frame, the receiver STA will disconnect the current
AP and then reconnect. It's not a expected behavior, purpose of this
frame should be disabling the TDLS link, not the link with AP.

Cc: stable@vger.kernel.org
Signed-off-by: Yu Wang <yyuwang@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
bardliao pushed a commit that referenced this pull request Jul 2, 2019
struct dfl_feature_platform_data (and it's mutex) is used
by both fme and port devices, and when lockdep is enabled it
complains about nesting between these locks.  Tell lockdep about
the difference so it can track each class separately.

Here's the lockdep complaint:
[  409.680668] WARNING: possible recursive locking detected
[  409.685983] 5.1.0-rc3.fpga+ #1 Tainted: G            E
[  409.691469] --------------------------------------------
[  409.696779] fpgaconf/9348 is trying to acquire lock:
[  409.701746] 00000000a443fe2e (&pdata->lock){+.+.}, at: port_enable_set+0x24/0x60 [dfl_afu]
[  409.710006]
[  409.710006] but task is already holding lock:
[  409.715837] 0000000063b78782 (&pdata->lock){+.+.}, at: fme_pr_ioctl+0x21d/0x330 [dfl_fme]
[  409.724012]
[  409.724012] other info that might help us debug this:
[  409.730535]  Possible unsafe locking scenario:
[  409.730535]
[  409.736457]        CPU0
[  409.738910]        ----
[  409.741360]   lock(&pdata->lock);
[  409.744679]   lock(&pdata->lock);
[  409.747999]
[  409.747999]  *** DEADLOCK ***
[  409.747999]
[  409.753920]  May be due to missing lock nesting notation
[  409.753920]
[  409.760704] 4 locks held by fpgaconf/9348:
[  409.764805]  #0: 0000000063b78782 (&pdata->lock){+.+.}, at: fme_pr_ioctl+0x21d/0x330 [dfl_fme]
[  409.773408]  #1: 00000000213c8a66 (&region->mutex){+.+.}, at: fpga_region_program_fpga+0x24/0x200 [fpga_region]
[  409.783489]  #2: 00000000fe63afb9 (&mgr->ref_mutex){+.+.}, at: fpga_mgr_lock+0x15/0x40 [fpga_mgr]
[  409.792354]  #3: 000000000b2285c5 (&bridge->mutex){+.+.}, at: __fpga_bridge_get+0x26/0xa0 [fpga_bridge]
[  409.801740]
[  409.801740] stack backtrace:
[  409.806102] CPU: 45 PID: 9348 Comm: fpgaconf Kdump: loaded Tainted: G            E     5.1.0-rc3.fpga+ #1
[  409.815658] Hardware name: Intel Corporation S2600BT/S2600BT, BIOS SE5C620.86B.01.00.0763.022420181017 02/24/2018
[  409.825911] Call Trace:
[  409.828369]  dump_stack+0x5e/0x8b
[  409.831686]  __lock_acquire+0xf3d/0x10e0
[  409.835612]  ? find_held_lock+0x3c/0xa0
[  409.839451]  lock_acquire+0xbc/0x1d0
[  409.843030]  ? port_enable_set+0x24/0x60 [dfl_afu]
[  409.847823]  ? port_enable_set+0x24/0x60 [dfl_afu]
[  409.852616]  __mutex_lock+0x86/0x970
[  409.856195]  ? port_enable_set+0x24/0x60 [dfl_afu]
[  409.860989]  ? port_enable_set+0x24/0x60 [dfl_afu]
[  409.865777]  ? __mutex_unlock_slowpath+0x4b/0x290
[  409.870486]  port_enable_set+0x24/0x60 [dfl_afu]
[  409.875106]  fpga_bridges_disable+0x36/0x50 [fpga_bridge]
[  409.880502]  fpga_region_program_fpga+0xea/0x200 [fpga_region]
[  409.886338]  fme_pr_ioctl+0x13e/0x330 [dfl_fme]
[  409.890870]  fme_ioctl+0x66/0xe0 [dfl_fme]
[  409.894973]  do_vfs_ioctl+0xa9/0x720
[  409.898548]  ? lockdep_hardirqs_on+0xf0/0x1a0
[  409.902907]  ksys_ioctl+0x60/0x90
[  409.906225]  __x64_sys_ioctl+0x16/0x20
[  409.909981]  do_syscall_64+0x5a/0x220
[  409.913644]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  409.918698] RIP: 0033:0x7f9d31b9b8d7
[  409.922276] Code: 44 00 00 48 8b 05 b9 15 2d 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 89 15 2d 00 f7 d8 64 89 01 48
[  409.941020] RSP: 002b:00007ffe4cae0d68 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
[  409.948588] RAX: ffffffffffffffda RBX: 00007f9d32ade6a0 RCX: 00007f9d31b9b8d7
[  409.955719] RDX: 00007ffe4cae0df0 RSI: 000000000000b680 RDI: 0000000000000003
[  409.962852] RBP: 0000000000000003 R08: 00007f9d2b70a177 R09: 00007ffe4cae0e40
[  409.969984] R10: 00007ffe4cae0160 R11: 0000000000000202 R12: 00007ffe4cae0df0
[  409.977115] R13: 000000000000b680 R14: 0000000000000000 R15: 00007ffe4cae0f60

Signed-off-by: Scott Wood <swood@redhat.com>
Acked-by: Wu Hao <hao.wu@intel.com>
Acked-by: Alan Tull <atull@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bardliao pushed a commit that referenced this pull request Jul 2, 2019
ifmsh->csa is an RCU-protected pointer. The writer context
in ieee80211_mesh_finish_csa() is already mutually
exclusive with wdev->sdata.mtx, but the RCU checker did
not know this. Use rcu_dereference_protected() to avoid a
warning.

fixes the following warning:

[   12.519089] =============================
[   12.520042] WARNING: suspicious RCU usage
[   12.520652] 5.1.0-rc7-wt+ thesofproject#16 Tainted: G        W
[   12.521409] -----------------------------
[   12.521972] net/mac80211/mesh.c:1223 suspicious rcu_dereference_check() usage!
[   12.522928] other info that might help us debug this:
[   12.523984] rcu_scheduler_active = 2, debug_locks = 1
[   12.524855] 5 locks held by kworker/u8:2/152:
[   12.525438]  #0: 00000000057be08c ((wq_completion)phy0){+.+.}, at: process_one_work+0x1a2/0x620
[   12.526607]  #1: 0000000059c6b07a ((work_completion)(&sdata->csa_finalize_work)){+.+.}, at: process_one_work+0x1a2/0x620
[   12.528001]  #2: 00000000f184ba7d (&wdev->mtx){+.+.}, at: ieee80211_csa_finalize_work+0x2f/0x90
[   12.529116]  #3: 00000000831a1f54 (&local->mtx){+.+.}, at: ieee80211_csa_finalize_work+0x47/0x90
[   12.530233]  #4: 00000000fd06f988 (&local->chanctx_mtx){+.+.}, at: ieee80211_csa_finalize_work+0x51/0x90

Signed-off-by: Thomas Pedersen <thomas@eero.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
bardliao pushed a commit that referenced this pull request Jul 2, 2019
…utex

Remove circular lock dependency by using atomic version of interfaces
iterate in watch_dog_work(), hence avoid taking local->iflist_mtx
(rtw_vif_watch_dog_iter() only update some data, it can be called from
atomic context). Fixes below LOCKDEP warning:

[ 1157.219415] ======================================================
[ 1157.225772] [ INFO: possible circular locking dependency detected ]
[ 1157.232150] 3.10.0-1043.el7.sgruszka1.x86_64.debug #1 Not tainted
[ 1157.238346] -------------------------------------------------------
[ 1157.244635] kworker/u4:2/14490 is trying to acquire lock:
[ 1157.250194]  (&rtwdev->mutex){+.+.+.}, at: [<ffffffffc098322b>] rtw_ops_config+0x2b/0x90 [rtw88]
[ 1157.259151]
but task is already holding lock:
[ 1157.265085]  (&local->iflist_mtx){+.+...}, at: [<ffffffffc0b8ab7a>] ieee80211_mgd_probe_ap.part.28+0xca/0x160 [mac80211]
[ 1157.276169]
which lock already depends on the new lock.

[ 1157.284488]
the existing dependency chain (in reverse order) is:
[ 1157.292101]
-> #2 (&local->iflist_mtx){+.+...}:
[ 1157.296919]        [<ffffffffbc741a29>] lock_acquire+0x99/0x1e0
[ 1157.302955]        [<ffffffffbce72793>] mutex_lock_nested+0x93/0x410
[ 1157.309416]        [<ffffffffc0b6038f>] ieee80211_iterate_interfaces+0x2f/0x60 [mac80211]
[ 1157.317730]        [<ffffffffc09811ab>] rtw_watch_dog_work+0xcb/0x130 [rtw88]
[ 1157.325003]        [<ffffffffbc6d77bc>] process_one_work+0x22c/0x720
[ 1157.331481]        [<ffffffffbc6d7dd6>] worker_thread+0x126/0x3b0
[ 1157.337589]        [<ffffffffbc6e107f>] kthread+0xef/0x100
[ 1157.343260]        [<ffffffffbce848b7>] ret_from_fork_nospec_end+0x0/0x39
[ 1157.350091]
-> #1 ((&(&rtwdev->watch_dog_work)->work)){+.+...}:
[ 1157.356314]        [<ffffffffbc741a29>] lock_acquire+0x99/0x1e0
[ 1157.362427]        [<ffffffffbc6d570b>] flush_work+0x5b/0x310
[ 1157.368287]        [<ffffffffbc6d740e>] __cancel_work_timer+0xae/0x170
[ 1157.374940]        [<ffffffffbc6d7583>] cancel_delayed_work_sync+0x13/0x20
[ 1157.381930]        [<ffffffffc0982b49>] rtw_core_stop+0x29/0x50 [rtw88]
[ 1157.388679]        [<ffffffffc098bee6>] rtw_enter_ips+0x16/0x20 [rtw88]
[ 1157.395428]        [<ffffffffc0983242>] rtw_ops_config+0x42/0x90 [rtw88]
[ 1157.402173]        [<ffffffffc0b13343>] ieee80211_hw_config+0xc3/0x680 [mac80211]
[ 1157.409854]        [<ffffffffc0b3925b>] ieee80211_do_open+0x69b/0x9c0 [mac80211]
[ 1157.417418]        [<ffffffffc0b395e9>] ieee80211_open+0x69/0x70 [mac80211]
[ 1157.424496]        [<ffffffffbcd03442>] __dev_open+0xe2/0x160
[ 1157.430356]        [<ffffffffbcd03773>] __dev_change_flags+0xa3/0x180
[ 1157.436922]        [<ffffffffbcd03879>] dev_change_flags+0x29/0x60
[ 1157.443224]        [<ffffffffbcda14c4>] devinet_ioctl+0x794/0x890
[ 1157.449331]        [<ffffffffbcda27b5>] inet_ioctl+0x75/0xa0
[ 1157.455087]        [<ffffffffbccd54eb>] sock_do_ioctl+0x2b/0x60
[ 1157.461178]        [<ffffffffbccd5753>] sock_ioctl+0x233/0x310
[ 1157.467109]        [<ffffffffbc8bd820>] do_vfs_ioctl+0x410/0x6c0
[ 1157.473233]        [<ffffffffbc8bdb71>] SyS_ioctl+0xa1/0xc0
[ 1157.478914]        [<ffffffffbce84a5e>] system_call_fastpath+0x25/0x2a
[ 1157.485569]
-> #0 (&rtwdev->mutex){+.+.+.}:
[ 1157.490022]        [<ffffffffbc7409d1>] __lock_acquire+0xec1/0x1630
[ 1157.496305]        [<ffffffffbc741a29>] lock_acquire+0x99/0x1e0
[ 1157.502413]        [<ffffffffbce72793>] mutex_lock_nested+0x93/0x410
[ 1157.508890]        [<ffffffffc098322b>] rtw_ops_config+0x2b/0x90 [rtw88]
[ 1157.515724]        [<ffffffffc0b13343>] ieee80211_hw_config+0xc3/0x680 [mac80211]
[ 1157.523370]        [<ffffffffc0b8a4ca>] ieee80211_recalc_ps.part.27+0x9a/0x180 [mac80211]
[ 1157.531685]        [<ffffffffc0b8abc5>] ieee80211_mgd_probe_ap.part.28+0x115/0x160 [mac80211]
[ 1157.540353]        [<ffffffffc0b8b40d>] ieee80211_beacon_connection_loss_work+0x4d/0x80 [mac80211]
[ 1157.549513]        [<ffffffffbc6d77bc>] process_one_work+0x22c/0x720
[ 1157.555886]        [<ffffffffbc6d7dd6>] worker_thread+0x126/0x3b0
[ 1157.562170]        [<ffffffffbc6e107f>] kthread+0xef/0x100
[ 1157.567765]        [<ffffffffbce848b7>] ret_from_fork_nospec_end+0x0/0x39
[ 1157.574579]
other info that might help us debug this:

[ 1157.582788] Chain exists of:
  &rtwdev->mutex --> (&(&rtwdev->watch_dog_work)->work) --> &local->iflist_mtx

[ 1157.593024]  Possible unsafe locking scenario:

[ 1157.599046]        CPU0                    CPU1
[ 1157.603653]        ----                    ----
[ 1157.608258]   lock(&local->iflist_mtx);
[ 1157.612180]                                lock((&(&rtwdev->watch_dog_work)->work));
[ 1157.620074]                                lock(&local->iflist_mtx);
[ 1157.626555]   lock(&rtwdev->mutex);
[ 1157.630124]
 *** DEADLOCK ***

[ 1157.636148] 4 locks held by kworker/u4:2/14490:
[ 1157.640755]  #0:  (%s#6){.+.+.+}, at: [<ffffffffbc6d774a>] process_one_work+0x1ba/0x720
[ 1157.648965]  #1:  ((&ifmgd->beacon_connection_loss_work)){+.+.+.}, at: [<ffffffffbc6d774a>] process_one_work+0x1ba/0x720
[ 1157.659950]  #2:  (&wdev->mtx){+.+.+.}, at: [<ffffffffc0b8aad5>] ieee80211_mgd_probe_ap.part.28+0x25/0x160 [mac80211]
[ 1157.670901]  #3:  (&local->iflist_mtx){+.+...}, at: [<ffffffffc0b8ab7a>] ieee80211_mgd_probe_ap.part.28+0xca/0x160 [mac80211]
[ 1157.682466]

Fixes: e303748 ("rtw88: new Realtek 802.11ac driver")
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Yan-Hsuan Chuang <yhchuang@realtek.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
bardliao pushed a commit that referenced this pull request Jul 2, 2019
Booting with kernel parameter "rdt=cmt,mbmtotal,memlocal,l3cat,mba" and
executing "mount -t resctrl resctrl -o mba_MBps /sys/fs/resctrl" results in
a NULL pointer dereference on systems which do not have local MBM support
enabled..

BUG: kernel NULL pointer dereference, address: 0000000000000020
PGD 0 P4D 0
Oops: 0000 [#1] SMP PTI
CPU: 0 PID: 722 Comm: kworker/0:3 Not tainted 5.2.0-0.rc3.git0.1.el7_UNSUPPORTED.x86_64 #2
Workqueue: events mbm_handle_overflow
RIP: 0010:mbm_handle_overflow+0x150/0x2b0

Only enter the bandwith update loop if the system has local MBM enabled.

Fixes: de73f38 ("x86/intel_rdt/mba_sc: Feedback loop to dynamically update mem bandwidth")
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190610171544.13474-1-prarit@redhat.com
bardliao pushed a commit that referenced this pull request Jul 2, 2019
Ido Schimmel says:

====================
mlxsw: Various fixes

This patchset contains various fixes for mlxsw.

Patch #1 fixes an hash polarization problem when a nexthop device is a
LAG device. This is caused by the fact that the same seed is used for
the LAG and ECMP hash functions.

Patch #2 fixes an issue in which the driver fails to refresh a nexthop
neighbour after it becomes dead. This prevents the nexthop from ever
being written to the adjacency table and used to forward traffic. Patch

Patch #4 fixes a wrong extraction of TOS value in flower offload code.
Patch #5 is a test case.

Patch thesofproject#6 works around a buffer issue in Spectrum-2 by reducing the
default sizes of the shared buffer pools.

Patch thesofproject#7 prevents prio-tagged packets from entering the switch when PVID
is removed from the bridge port.

Please consider patches #2, #4 and thesofproject#6 for 5.1.y
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
bardliao pushed a commit that referenced this pull request Jul 2, 2019
…nux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm fixes for 5.2, take #2

- SVE cleanup killing a warning with ancient GCC versions
- Don't report non-existent system registers to userspace
- Fix memory leak when freeing the vgic ITS
- Properly lower the interrupt on the emulated physical timer
bardliao pushed a commit that referenced this pull request Aug 22, 2019
…OL_MF_STRICT were specified

When both MPOL_MF_MOVE* and MPOL_MF_STRICT was specified, mbind() should
try best to migrate misplaced pages, if some of the pages could not be
migrated, then return -EIO.

There are three different sub-cases:
 1. vma is not migratable
 2. vma is migratable, but there are unmovable pages
 3. vma is migratable, pages are movable, but migrate_pages() fails

If #1 happens, kernel would just abort immediately, then return -EIO,
after a7f40cf ("mm: mempolicy: make mbind() return -EIO when
MPOL_MF_STRICT is specified").

If #3 happens, kernel would set policy and migrate pages with
best-effort, but won't rollback the migrated pages and reset the policy
back.

Before that commit, they behaves in the same way.  It'd better to keep
their behavior consistent.  But, rolling back the migrated pages and
resetting the policy back sounds not feasible, so just make #1 behave as
same as #3.

Userspace will know that not everything was successfully migrated (via
-EIO), and can take whatever steps it deems necessary - attempt
rollback, determine which exact page(s) are violating the policy, etc.

Make queue_pages_range() return 1 to indicate there are unmovable pages
or vma is not migratable.

The #2 is not handled correctly in the current kernel, the following
patch will fix it.

[yang.shi@linux.alibaba.com: fix review comments from Vlastimil]
  Link: http://lkml.kernel.org/r/1563556862-54056-2-git-send-email-yang.shi@linux.alibaba.com
Link: http://lkml.kernel.org/r/1561162809-59140-2-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
bardliao pushed a commit that referenced this pull request Aug 22, 2019
When running syzkaller internally, we ran into the below bug on 4.9.x
kernel:

  kernel BUG at mm/huge_memory.c:2124!
  invalid opcode: 0000 [#1] SMP KASAN
  CPU: 0 PID: 1518 Comm: syz-executor107 Not tainted 4.9.168+ #2
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.5.1 01/01/2011
  task: ffff880067b34900 task.stack: ffff880068998000
  RIP: split_huge_page_to_list+0x8fb/0x1030 mm/huge_memory.c:2124
  Call Trace:
    split_huge_page include/linux/huge_mm.h:100 [inline]
    queue_pages_pte_range+0x7e1/0x1480 mm/mempolicy.c:538
    walk_pmd_range mm/pagewalk.c:50 [inline]
    walk_pud_range mm/pagewalk.c:90 [inline]
    walk_pgd_range mm/pagewalk.c:116 [inline]
    __walk_page_range+0x44a/0xdb0 mm/pagewalk.c:208
    walk_page_range+0x154/0x370 mm/pagewalk.c:285
    queue_pages_range+0x115/0x150 mm/mempolicy.c:694
    do_mbind mm/mempolicy.c:1241 [inline]
    SYSC_mbind+0x3c3/0x1030 mm/mempolicy.c:1370
    SyS_mbind+0x46/0x60 mm/mempolicy.c:1352
    do_syscall_64+0x1d2/0x600 arch/x86/entry/common.c:282
    entry_SYSCALL_64_after_swapgs+0x5d/0xdb
  Code: c7 80 1c 02 00 e8 26 0a 76 01 <0f> 0b 48 c7 c7 40 46 45 84 e8 4c
  RIP  [<ffffffff81895d6b>] split_huge_page_to_list+0x8fb/0x1030 mm/huge_memory.c:2124
   RSP <ffff88006899f980>

with the below test:

  uint64_t r[1] = {0xffffffffffffffff};

  int main(void)
  {
        syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
                                intptr_t res = 0;
        res = syscall(__NR_socket, 0x11, 3, 0x300);
        if (res != -1)
                r[0] = res;
        *(uint32_t*)0x20000040 = 0x10000;
        *(uint32_t*)0x20000044 = 1;
        *(uint32_t*)0x20000048 = 0xc520;
        *(uint32_t*)0x2000004c = 1;
        syscall(__NR_setsockopt, r[0], 0x107, 0xd, 0x20000040, 0x10);
        syscall(__NR_mmap, 0x20fed000, 0x10000, 0, 0x8811, r[0], 0);
        *(uint64_t*)0x20000340 = 2;
        syscall(__NR_mbind, 0x20ff9000, 0x4000, 0x4002, 0x20000340, 0x45d4, 3);
        return 0;
  }

Actually the test does:

  mmap(0x20000000, 16777216, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x20000000
  socket(AF_PACKET, SOCK_RAW, 768)        = 3
  setsockopt(3, SOL_PACKET, PACKET_TX_RING, {block_size=65536, block_nr=1, frame_size=50464, frame_nr=1}, 16) = 0
  mmap(0x20fed000, 65536, PROT_NONE, MAP_SHARED|MAP_FIXED|MAP_POPULATE|MAP_DENYWRITE, 3, 0) = 0x20fed000
  mbind(..., MPOL_MF_STRICT|MPOL_MF_MOVE) = 0

The setsockopt() would allocate compound pages (16 pages in this test)
for packet tx ring, then the mmap() would call packet_mmap() to map the
pages into the user address space specified by the mmap() call.

When calling mbind(), it would scan the vma to queue the pages for
migration to the new node.  It would split any huge page since 4.9
doesn't support THP migration, however, the packet tx ring compound
pages are not THP and even not movable.  So, the above bug is triggered.

However, the later kernel is not hit by this issue due to commit
d44d363 ("mm: don't assume anonymous pages have SwapBacked flag"),
which just removes the PageSwapBacked check for a different reason.

But, there is a deeper issue.  According to the semantic of mbind(), it
should return -EIO if MPOL_MF_MOVE or MPOL_MF_MOVE_ALL was specified and
MPOL_MF_STRICT was also specified, but the kernel was unable to move all
existing pages in the range.  The tx ring of the packet socket is
definitely not movable, however, mbind() returns success for this case.

Although the most socket file associates with non-movable pages, but XDP
may have movable pages from gup.  So, it sounds not fine to just check
the underlying file type of vma in vma_migratable().

Change migrate_page_add() to check if the page is movable or not, if it
is unmovable, just return -EIO.  But do not abort pte walk immediately,
since there may be pages off LRU temporarily.  We should migrate other
pages if MPOL_MF_MOVE* is specified.  Set has_unmovable flag if some
paged could not be not moved, then return -EIO for mbind() eventually.

With this change the above test would return -EIO as expected.

[yang.shi@linux.alibaba.com: fix review comments from Vlastimil]
  Link: http://lkml.kernel.org/r/1563556862-54056-3-git-send-email-yang.shi@linux.alibaba.com
Link: http://lkml.kernel.org/r/1561162809-59140-3-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
bardliao pushed a commit that referenced this pull request Aug 22, 2019
Since commit e1ab9a4 ("i2c: imx: improve the error handling in
i2c_imx_dma_request()") when booting with the DMA driver as module (such
as CONFIG_FSL_EDMA=m) the following endless clk warnings are seen:

[  153.077831] ------------[ cut here ]------------
[  153.082528] WARNING: CPU: 0 PID: 15 at drivers/clk/clk.c:924 clk_core_disable_lock+0x18/0x24
[  153.093077] i2c0 already disabled
[  153.096416] Modules linked in:
[  153.099521] CPU: 0 PID: 15 Comm: kworker/0:1 Tainted: G        W         5.2.0+ thesofproject#321
[  153.107290] Hardware name: Freescale Vybrid VF5xx/VF6xx (Device Tree)
[  153.113772] Workqueue: events deferred_probe_work_func
[  153.118979] [<c0019560>] (unwind_backtrace) from [<c0014734>] (show_stack+0x10/0x14)
[  153.126778] [<c0014734>] (show_stack) from [<c083f8dc>] (dump_stack+0x9c/0xd4)
[  153.134051] [<c083f8dc>] (dump_stack) from [<c0031154>] (__warn+0xf8/0x124)
[  153.141056] [<c0031154>] (__warn) from [<c0031248>] (warn_slowpath_fmt+0x38/0x48)
[  153.148580] [<c0031248>] (warn_slowpath_fmt) from [<c040fde0>] (clk_core_disable_lock+0x18/0x24)
[  153.157413] [<c040fde0>] (clk_core_disable_lock) from [<c058f520>] (i2c_imx_probe+0x554/0x6ec)
[  153.166076] [<c058f520>] (i2c_imx_probe) from [<c04b9178>] (platform_drv_probe+0x48/0x98)
[  153.174297] [<c04b9178>] (platform_drv_probe) from [<c04b7298>] (really_probe+0x1d8/0x2c0)
[  153.182605] [<c04b7298>] (really_probe) from [<c04b7554>] (driver_probe_device+0x5c/0x174)
[  153.190909] [<c04b7554>] (driver_probe_device) from [<c04b58c8>] (bus_for_each_drv+0x44/0x8c)
[  153.199480] [<c04b58c8>] (bus_for_each_drv) from [<c04b746c>] (__device_attach+0xa0/0x108)
[  153.207782] [<c04b746c>] (__device_attach) from [<c04b65a4>] (bus_probe_device+0x88/0x90)
[  153.215999] [<c04b65a4>] (bus_probe_device) from [<c04b6a04>] (deferred_probe_work_func+0x60/0x90)
[  153.225003] [<c04b6a04>] (deferred_probe_work_func) from [<c004f190>] (process_one_work+0x204/0x634)
[  153.234178] [<c004f190>] (process_one_work) from [<c004f618>] (worker_thread+0x20/0x484)
[  153.242315] [<c004f618>] (worker_thread) from [<c0055c2c>] (kthread+0x118/0x150)
[  153.249758] [<c0055c2c>] (kthread) from [<c00090b4>] (ret_from_fork+0x14/0x20)
[  153.257006] Exception stack(0xdde43fb0 to 0xdde43ff8)
[  153.262095] 3fa0:                                     00000000 00000000 00000000 00000000
[  153.270306] 3fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[  153.278520] 3fe0: 00000000 00000000 00000000 00000000 00000013 00000000
[  153.285159] irq event stamp: 3323022
[  153.288787] hardirqs last  enabled at (3323021): [<c0861c4c>] _raw_spin_unlock_irq+0x24/0x2c
[  153.297261] hardirqs last disabled at (3323022): [<c040d7a0>] clk_enable_lock+0x10/0x124
[  153.305392] softirqs last  enabled at (3322092): [<c000a504>] __do_softirq+0x344/0x540
[  153.313352] softirqs last disabled at (3322081): [<c00385c0>] irq_exit+0x10c/0x128
[  153.320946] ---[ end trace a506731ccd9bd703 ]---

This endless clk warnings behaviour is well explained by Andrey Smirnov:

"Allocating DMA after registering I2C adapter can lead to infinite
probing loop, for example, consider the following scenario:

    1. i2c_imx_probe() is called and successfully registers an I2C
       adapter via i2c_add_numbered_adapter()

    2. As a part of i2c_add_numbered_adapter() new I2C slave devices
       are added from DT which results in a call to
       driver_deferred_probe_trigger()

    3. i2c_imx_probe() continues and calls i2c_imx_dma_request() which
       due to lack of proper DMA driver returns -EPROBE_DEFER

    4. i2c_imx_probe() fails, removes I2C adapter and returns
       -EPROBE_DEFER, which places it into deferred probe list

    5. Deferred probe work triggered in #2 above kicks in and calls
       i2c_imx_probe() again thus bringing us to step #1"

So revert commit e1ab9a4 ("i2c: imx: improve the error handling in
i2c_imx_dma_request()") and restore the old behaviour, in order to
avoid regressions on existing setups.

Cc: <stable@vger.kernel.org>
Reported-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Reported-by: Russell King <linux@armlinux.org.uk>
Fixes: e1ab9a4 ("i2c: imx: improve the error handling in i2c_imx_dma_request()")
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
bardliao pushed a commit that referenced this pull request Sep 6, 2019
Revert the commit bd293d0. The proper
fix has been made available with commit d0a255e ("loop: set
PF_MEMALLOC_NOIO for the worker thread").

Note that the fix offered by commit bd293d0 doesn't really prevent
the deadlock from occuring - if we look at the stacktrace reported by
Junxiao Bi, we see that it hangs in bit_wait_io and not on the mutex -
i.e. it has already successfully taken the mutex. Changing the mutex
from mutex_lock to mutex_trylock won't help with deadlocks that happen
afterwards.

PID: 474    TASK: ffff8813e11f4600  CPU: 10  COMMAND: "kswapd0"
   #0 [ffff8813dedfb938] __schedule at ffffffff8173f405
   #1 [ffff8813dedfb990] schedule at ffffffff8173fa27
   #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec
   #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186
   #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f
   #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8
   thesofproject#6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81
   thesofproject#7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio]
   thesofproject#8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio]
   thesofproject#9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio]
  thesofproject#10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce
  thesofproject#11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778
  thesofproject#12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f
  thesofproject#13 [ffff8813dedfbec0] kthread at ffffffff810a8428
  thesofproject#14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Fixes: bd293d0 ("dm bufio: fix deadlock with loop device")
Depends-on: d0a255e ("loop: set PF_MEMALLOC_NOIO for the worker thread")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
bardliao pushed a commit that referenced this pull request Sep 6, 2019
Pablo Neira Ayuso says:

====================
flow_offload hardware priority fixes

This patchset contains two updates for the flow_offload users:

1) Pass the major tc priority to drivers so they do not have to
   lshift it. This is a preparation patch for the fix coming in
   patch #2.

2) Set the hardware priority from the netfilter basechain priority,
   some drivers break when using the existing hardware priority
   number that is set to zero.

v5: fix patch 2/2 to address a clang warning and to simplify
    the priority mapping.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
bardliao pushed a commit that referenced this pull request Sep 6, 2019
Calling ceph_buffer_put() in __ceph_setxattr() may end up freeing the
i_xattrs.prealloc_blob buffer while holding the i_ceph_lock.  This can be
fixed by postponing the call until later, when the lock is released.

The following backtrace was triggered by fstests generic/117.

  BUG: sleeping function called from invalid context at mm/vmalloc.c:2283
  in_atomic(): 1, irqs_disabled(): 0, pid: 650, name: fsstress
  3 locks held by fsstress/650:
   #0: 00000000870a0fe8 (sb_writers#8){.+.+}, at: mnt_want_write+0x20/0x50
   #1: 00000000ba0c4c74 (&type->i_mutex_dir_key#6){++++}, at: vfs_setxattr+0x55/0xa0
   #2: 000000008dfbb3f2 (&(&ci->i_ceph_lock)->rlock){+.+.}, at: __ceph_setxattr+0x297/0x810
  CPU: 1 PID: 650 Comm: fsstress Not tainted 5.2.0+ thesofproject#437
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58-prebuilt.qemu.org 04/01/2014
  Call Trace:
   dump_stack+0x67/0x90
   ___might_sleep.cold+0x9f/0xb1
   vfree+0x4b/0x60
   ceph_buffer_release+0x1b/0x60
   __ceph_setxattr+0x2b4/0x810
   __vfs_setxattr+0x66/0x80
   __vfs_setxattr_noperm+0x59/0xf0
   vfs_setxattr+0x81/0xa0
   setxattr+0x115/0x230
   ? filename_lookup+0xc9/0x140
   ? rcu_read_lock_sched_held+0x74/0x80
   ? rcu_sync_lockdep_assert+0x2e/0x60
   ? __sb_start_write+0x142/0x1a0
   ? mnt_want_write+0x20/0x50
   path_setxattr+0xba/0xd0
   __x64_sys_lsetxattr+0x24/0x30
   do_syscall_64+0x50/0x1c0
   entry_SYSCALL_64_after_hwframe+0x49/0xbe
  RIP: 0033:0x7ff23514359a

Signed-off-by: Luis Henriques <lhenriques@suse.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
bardliao pushed a commit that referenced this pull request Sep 6, 2019
…s_blob()

Calling ceph_buffer_put() in __ceph_build_xattrs_blob() may result in
freeing the i_xattrs.blob buffer while holding the i_ceph_lock.  This can
be fixed by having this function returning the old blob buffer and have
the callers of this function freeing it when the lock is released.

The following backtrace was triggered by fstests generic/117.

  BUG: sleeping function called from invalid context at mm/vmalloc.c:2283
  in_atomic(): 1, irqs_disabled(): 0, pid: 649, name: fsstress
  4 locks held by fsstress/649:
   #0: 00000000a7478e7e (&type->s_umount_key#19){++++}, at: iterate_supers+0x77/0xf0
   #1: 00000000f8de1423 (&(&ci->i_ceph_lock)->rlock){+.+.}, at: ceph_check_caps+0x7b/0xc60
   #2: 00000000562f2b27 (&s->s_mutex){+.+.}, at: ceph_check_caps+0x3bd/0xc60
   #3: 00000000f83ce16a (&mdsc->snap_rwsem){++++}, at: ceph_check_caps+0x3ed/0xc60
  CPU: 1 PID: 649 Comm: fsstress Not tainted 5.2.0+ thesofproject#439
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58-prebuilt.qemu.org 04/01/2014
  Call Trace:
   dump_stack+0x67/0x90
   ___might_sleep.cold+0x9f/0xb1
   vfree+0x4b/0x60
   ceph_buffer_release+0x1b/0x60
   __ceph_build_xattrs_blob+0x12b/0x170
   __send_cap+0x302/0x540
   ? __lock_acquire+0x23c/0x1e40
   ? __mark_caps_flushing+0x15c/0x280
   ? _raw_spin_unlock+0x24/0x30
   ceph_check_caps+0x5f0/0xc60
   ceph_flush_dirty_caps+0x7c/0x150
   ? __ia32_sys_fdatasync+0x20/0x20
   ceph_sync_fs+0x5a/0x130
   iterate_supers+0x8f/0xf0
   ksys_sync+0x4f/0xb0
   __ia32_sys_sync+0xa/0x10
   do_syscall_64+0x50/0x1c0
   entry_SYSCALL_64_after_hwframe+0x49/0xbe
  RIP: 0033:0x7fc6409ab617

Signed-off-by: Luis Henriques <lhenriques@suse.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
bardliao pushed a commit that referenced this pull request Sep 6, 2019
Calling ceph_buffer_put() in fill_inode() may result in freeing the
i_xattrs.blob buffer while holding the i_ceph_lock.  This can be fixed by
postponing the call until later, when the lock is released.

The following backtrace was triggered by fstests generic/070.

  BUG: sleeping function called from invalid context at mm/vmalloc.c:2283
  in_atomic(): 1, irqs_disabled(): 0, pid: 3852, name: kworker/0:4
  6 locks held by kworker/0:4/3852:
   #0: 000000004270f6bb ((wq_completion)ceph-msgr){+.+.}, at: process_one_work+0x1b8/0x5f0
   #1: 00000000eb420803 ((work_completion)(&(&con->work)->work)){+.+.}, at: process_one_work+0x1b8/0x5f0
   #2: 00000000be1c53a4 (&s->s_mutex){+.+.}, at: dispatch+0x288/0x1476
   #3: 00000000559cb958 (&mdsc->snap_rwsem){++++}, at: dispatch+0x2eb/0x1476
   #4: 000000000d5ebbae (&req->r_fill_mutex){+.+.}, at: dispatch+0x2fc/0x1476
   #5: 00000000a83d0514 (&(&ci->i_ceph_lock)->rlock){+.+.}, at: fill_inode.isra.0+0xf8/0xf70
  CPU: 0 PID: 3852 Comm: kworker/0:4 Not tainted 5.2.0+ thesofproject#441
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58-prebuilt.qemu.org 04/01/2014
  Workqueue: ceph-msgr ceph_con_workfn
  Call Trace:
   dump_stack+0x67/0x90
   ___might_sleep.cold+0x9f/0xb1
   vfree+0x4b/0x60
   ceph_buffer_release+0x1b/0x60
   fill_inode.isra.0+0xa9b/0xf70
   ceph_fill_trace+0x13b/0xc70
   ? dispatch+0x2eb/0x1476
   dispatch+0x320/0x1476
   ? __mutex_unlock_slowpath+0x4d/0x2a0
   ceph_con_workfn+0xc97/0x2ec0
   ? process_one_work+0x1b8/0x5f0
   process_one_work+0x244/0x5f0
   worker_thread+0x4d/0x3e0
   kthread+0x105/0x140
   ? process_one_work+0x5f0/0x5f0
   ? kthread_park+0x90/0x90
   ret_from_fork+0x3a/0x50

Signed-off-by: Luis Henriques <lhenriques@suse.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
bardliao pushed a commit that referenced this pull request Sep 6, 2019
Hayes Wang says:

====================
r8152: fix side effect

v3:
Update the commit message for patch #1.

v2:
Replace patch #2 with "r8152: remove calling netif_napi_del".

v1:
The commit 0ee1f47 ("r8152: napi hangup fix after disconnect")
add a check to avoid using napi_disable after netif_napi_del. However,
the commit ffa9fec ("r8152: set RTL8152_UNPLUG only for real
disconnection") let the check useless.

Therefore, I revert commit 0ee1f47 ("r8152: napi hangup fix
after disconnect") first, and add another patch to fix it.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
bardliao pushed a commit that referenced this pull request Sep 6, 2019
…#2]

When a local endpoint is ceases to be in use, such as when the kafs module
is unloaded, the kernel will emit an assertion failure if there are any
outstanding client connections:

	rxrpc: Assertion failed
	------------[ cut here ]------------
	kernel BUG at net/rxrpc/local_object.c:433!

and even beyond that, will evince other oopses if there are service
connections still present.

Fix this by:

 (1) Removing the triggering of connection reaping when an rxrpc socket is
     released.  These don't actually clean up the connections anyway - and
     further, the local endpoint may still be in use through another
     socket.

 (2) Mark the local endpoint as dead when we start the process of tearing
     it down.

 (3) When destroying a local endpoint, strip all of its client connections
     from the idle list and discard the ref on each that the list was
     holding.

 (4) When destroying a local endpoint, call the service connection reaper
     directly (rather than through a workqueue) to immediately kill off all
     outstanding service connections.

 (5) Make the service connection reaper reap connections for which the
     local endpoint is marked dead.

Only after destroying the connections can we close the socket lest we get
an oops in a workqueue that's looking at a connection or a peer.

Fixes: 3d18cbb ("rxrpc: Fix conn expiry timers")
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
bardliao pushed a commit that referenced this pull request Sep 6, 2019
Pull networking fixes from David Miller:

 1) Fix some length checks during OGM processing in batman-adv, from
    Sven Eckelmann.

 2) Fix regression that caused netfilter conntrack sysctls to not be
    per-netns any more. From Florian Westphal.

 3) Use after free in netpoll, from Feng Sun.

 4) Guard destruction of pfifo_fast per-cpu qdisc stats with
    qdisc_is_percpu_stats(), from Davide Caratti. Similar bug is fixed
    in pfifo_fast_enqueue().

 5) Fix memory leak in mld_del_delrec(), from Eric Dumazet.

 6) Handle neigh events on internal ports correctly in nfp, from John
    Hurley.

 7) Clear SKB timestamp in NF flow table code so that it does not
    confuse fq scheduler. From Florian Westphal.

 8) taprio destroy can crash if it is invoked in a failure path of
    taprio_init(), because the list head isn't setup properly yet and
    the list del is unconditional. Perform the list add earlier to
    address this. From Vladimir Oltean.

 9) Make sure to reapply vlan filters on device up, in aquantia driver.
    From Dmitry Bogdanov.

10) sgiseeq driver releases DMA memory using free_page() instead of
    dma_free_attrs(). From Christophe JAILLET.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (58 commits)
  net: seeq: Fix the function used to release some memory in an error handling path
  enetc: Add missing call to 'pci_free_irq_vectors()' in probe and remove functions
  net: bcmgenet: use ethtool_op_get_ts_info()
  tc-testing: don't hardcode 'ip' in nsPlugin.py
  net: dsa: microchip: add KSZ8563 compatibility string
  dt-bindings: net: dsa: document additional Microchip KSZ8563 switch
  net: aquantia: fix out of memory condition on rx side
  net: aquantia: linkstate irq should be oneshot
  net: aquantia: reapply vlan filters on up
  net: aquantia: fix limit of vlan filters
  net: aquantia: fix removal of vlan 0
  net/sched: cbs: Set default link speed to 10 Mbps in cbs_set_port_rate
  taprio: Set default link speed to 10 Mbps in taprio_set_picos_per_byte
  taprio: Fix kernel panic in taprio_destroy
  net: dsa: microchip: fill regmap_config name
  rxrpc: Fix lack of conn cleanup when local endpoint is cleaned up [ver #2]
  net: stmmac: dwmac-rk: Don't fail if phy regulator is absent
  amd-xgbe: Fix error path in xgbe_mod_init()
  netfilter: nft_meta_bridge: Fix get NFT_META_BRI_IIFVPROTO in network byteorder
  mac80211: Correctly set noencrypt for PAE frames
  ...
bardliao pushed a commit that referenced this pull request Oct 12, 2019
When a cpu requests broadcasting, before starting the tick broadcast
hrtimer, bc_set_next() checks if the timer callback (bc_handler) is active
using hrtimer_try_to_cancel(). But hrtimer_try_to_cancel() does not provide
the required synchronization when the callback is active on other core.

The callback could have already executed tick_handle_oneshot_broadcast()
and could have also returned. But still there is a small time window where
the hrtimer_try_to_cancel() returns -1. In that case bc_set_next() returns
without doing anything, but the next_event of the tick broadcast clock
device is already set to a timeout value.

In the race condition diagram below, CPU #1 is running the timer callback
and CPU #2 is entering idle state and so calls bc_set_next().

In the worst case, the next_event will contain an expiry time, but the
hrtimer will not be started which happens when the racing callback returns
HRTIMER_NORESTART. The hrtimer might never recover if all further requests
from the CPUs to subscribe to tick broadcast have timeout greater than the
next_event of tick broadcast clock device. This leads to cascading of
failures and finally noticed as rcu stall warnings

Here is a depiction of the race condition

CPU #1 (Running timer callback)                   CPU #2 (Enter idle
                                                  and subscribe to
                                                  tick broadcast)
---------------------                             ---------------------

__run_hrtimer()                                   tick_broadcast_enter()

  bc_handler()                                      __tick_broadcast_oneshot_control()

    tick_handle_oneshot_broadcast()

      raw_spin_lock(&tick_broadcast_lock);

      dev->next_event = KTIME_MAX;                  //wait for tick_broadcast_lock
      //next_event for tick broadcast clock
      set to KTIME_MAX since no other cores
      subscribed to tick broadcasting

      raw_spin_unlock(&tick_broadcast_lock);

    if (dev->next_event == KTIME_MAX)
      return HRTIMER_NORESTART
    // callback function exits without
       restarting the hrtimer                      //tick_broadcast_lock acquired
                                                   raw_spin_lock(&tick_broadcast_lock);

                                                   tick_broadcast_set_event()

                                                     clockevents_program_event()

                                                       dev->next_event = expires;

                                                       bc_set_next()

                                                         hrtimer_try_to_cancel()
                                                         //returns -1 since the timer
                                                         callback is active. Exits without
                                                         restarting the timer
  cpu_base->running = NULL;

The comment that hrtimer cannot be armed from within the callback is
wrong. It is fine to start the hrtimer from within the callback. Also it is
safe to start the hrtimer from the enter/exit idle code while the broadcast
handler is active. The enter/exit idle code and the broadcast handler are
synchronized using tick_broadcast_lock. So there is no need for the
existing try to cancel logic. All this can be removed which will eliminate
the race condition as well.

Fixes: 5d1638a ("tick: Introduce hrtimer based broadcast")
Originally-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Balasubramani Vivekanandan <balasubramani_vivekanandan@mentor.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190926135101.12102-2-balasubramani_vivekanandan@mentor.com
bardliao pushed a commit that referenced this pull request Oct 23, 2019
This patch fixes the lock inversion complaint:

============================================
WARNING: possible recursive locking detected
5.3.0-rc7-dbg+ #1 Not tainted
--------------------------------------------
kworker/u16:6/171 is trying to acquire lock:
00000000035c6e6c (&id_priv->handler_mutex){+.+.}, at: rdma_destroy_id+0x78/0x4a0 [rdma_cm]

but task is already holding lock:
00000000bc7c307d (&id_priv->handler_mutex){+.+.}, at: iw_conn_req_handler+0x151/0x680 [rdma_cm]

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&id_priv->handler_mutex);
  lock(&id_priv->handler_mutex);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

3 locks held by kworker/u16:6/171:
 #0: 00000000e2eaa773 ((wq_completion)iw_cm_wq){+.+.}, at: process_one_work+0x472/0xac0
 #1: 000000001efd357b ((work_completion)(&work->work)#3){+.+.}, at: process_one_work+0x476/0xac0
 #2: 00000000bc7c307d (&id_priv->handler_mutex){+.+.}, at: iw_conn_req_handler+0x151/0x680 [rdma_cm]

stack backtrace:
CPU: 3 PID: 171 Comm: kworker/u16:6 Not tainted 5.3.0-rc7-dbg+ #1
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
Workqueue: iw_cm_wq cm_work_handler [iw_cm]
Call Trace:
 dump_stack+0x8a/0xd6
 __lock_acquire.cold+0xe1/0x24d
 lock_acquire+0x106/0x240
 __mutex_lock+0x12e/0xcb0
 mutex_lock_nested+0x1f/0x30
 rdma_destroy_id+0x78/0x4a0 [rdma_cm]
 iw_conn_req_handler+0x5c9/0x680 [rdma_cm]
 cm_work_handler+0xe62/0x1100 [iw_cm]
 process_one_work+0x56d/0xac0
 worker_thread+0x7a/0x5d0
 kthread+0x1bc/0x210
 ret_from_fork+0x24/0x30

This is not a bug as there are actually two lock classes here.

Link: https://lore.kernel.org/r/20190930231707.48259-3-bvanassche@acm.org
Fixes: de910bd ("RDMA/cma: Simplify locking needed for serialization of callbacks")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
bardliao pushed a commit that referenced this pull request Oct 23, 2019
A user reported a lockdep splat

 ======================================================
 WARNING: possible circular locking dependency detected
 5.2.11-gentoo #2 Not tainted
 ------------------------------------------------------
 kswapd0/711 is trying to acquire lock:
 000000007777a663 (sb_internal){.+.+}, at: start_transaction+0x3a8/0x500

but task is already holding lock:
 000000000ba86300 (fs_reclaim){+.+.}, at: __fs_reclaim_acquire+0x0/0x30

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (fs_reclaim){+.+.}:
 kmem_cache_alloc+0x1f/0x1c0
 btrfs_alloc_inode+0x1f/0x260
 alloc_inode+0x16/0xa0
 new_inode+0xe/0xb0
 btrfs_new_inode+0x70/0x610
 btrfs_symlink+0xd0/0x420
 vfs_symlink+0x9c/0x100
 do_symlinkat+0x66/0xe0
 do_syscall_64+0x55/0x1c0
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

-> #0 (sb_internal){.+.+}:
 __sb_start_write+0xf6/0x150
 start_transaction+0x3a8/0x500
 btrfs_commit_inode_delayed_inode+0x59/0x110
 btrfs_evict_inode+0x19e/0x4c0
 evict+0xbc/0x1f0
 inode_lru_isolate+0x113/0x190
 __list_lru_walk_one.isra.4+0x5c/0x100
 list_lru_walk_one+0x32/0x50
 prune_icache_sb+0x36/0x80
 super_cache_scan+0x14a/0x1d0
 do_shrink_slab+0x131/0x320
 shrink_node+0xf7/0x380
 balance_pgdat+0x2d5/0x640
 kswapd+0x2ba/0x5e0
 kthread+0x147/0x160
 ret_from_fork+0x24/0x30

other info that might help us debug this:

 Possible unsafe locking scenario:

 CPU0 CPU1
 ---- ----
 lock(fs_reclaim);
 lock(sb_internal);
 lock(fs_reclaim);
 lock(sb_internal);
*** DEADLOCK ***

 3 locks held by kswapd0/711:
 #0: 000000000ba86300 (fs_reclaim){+.+.}, at: __fs_reclaim_acquire+0x0/0x30
 #1: 000000004a5100f8 (shrinker_rwsem){++++}, at: shrink_node+0x9a/0x380
 #2: 00000000f956fa46 (&type->s_umount_key#30){++++}, at: super_cache_scan+0x35/0x1d0

stack backtrace:
 CPU: 7 PID: 711 Comm: kswapd0 Not tainted 5.2.11-gentoo #2
 Hardware name: Dell Inc. Precision Tower 3620/0MWYPT, BIOS 2.4.2 09/29/2017
 Call Trace:
 dump_stack+0x85/0xc7
 print_circular_bug.cold.40+0x1d9/0x235
 __lock_acquire+0x18b1/0x1f00
 lock_acquire+0xa6/0x170
 ? start_transaction+0x3a8/0x500
 __sb_start_write+0xf6/0x150
 ? start_transaction+0x3a8/0x500
 start_transaction+0x3a8/0x500
 btrfs_commit_inode_delayed_inode+0x59/0x110
 btrfs_evict_inode+0x19e/0x4c0
 ? var_wake_function+0x20/0x20
 evict+0xbc/0x1f0
 inode_lru_isolate+0x113/0x190
 ? discard_new_inode+0xc0/0xc0
 __list_lru_walk_one.isra.4+0x5c/0x100
 ? discard_new_inode+0xc0/0xc0
 list_lru_walk_one+0x32/0x50
 prune_icache_sb+0x36/0x80
 super_cache_scan+0x14a/0x1d0
 do_shrink_slab+0x131/0x320
 shrink_node+0xf7/0x380
 balance_pgdat+0x2d5/0x640
 kswapd+0x2ba/0x5e0
 ? __wake_up_common_lock+0x90/0x90
 kthread+0x147/0x160
 ? balance_pgdat+0x640/0x640
 ? __kthread_create_on_node+0x160/0x160
 ret_from_fork+0x24/0x30

This is because btrfs_new_inode() calls new_inode() under the
transaction.  We could probably move the new_inode() outside of this but
for now just wrap it in memalloc_nofs_save().

Reported-by: Zdenek Sojka <zsojka@seznam.cz>
Fixes: 712e36c ("btrfs: use GFP_KERNEL in btrfs_alloc_inode")
CC: stable@vger.kernel.org # 4.16+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
bardliao pushed a commit that referenced this pull request Oct 30, 2019
On excessive bit errors for the FCP channel ingress fibre path, the channel
notifies us.  Previously, we only emitted a kernel message and a trace
record.  Since performance can become suboptimal with I/O timeouts due to
bit errors, we now stop using an FCP device by default on channel
notification so multipath on top can timely failover to other paths.  A new
module parameter zfcp.ber_stop can be used to get zfcp old behavior.

User explanation of new kernel message:

 * Description:
 * The FCP channel reported that its bit error threshold has been exceeded.
 * These errors might result from a problem with the physical components
 * of the local fibre link into the FCP channel.
 * The problem might be damage or malfunction of the cable or
 * cable connection between the FCP channel and
 * the adjacent fabric switch port or the point-to-point peer.
 * Find details about the errors in the HBA trace for the FCP device.
 * The zfcp device driver closed down the FCP device
 * to limit the performance impact from possible I/O command timeouts.
 * User action:
 * Check for problems on the local fibre link, ensure that fibre optics are
 * clean and functional, and all cables are properly plugged.
 * After the repair action, you can manually recover the FCP device by
 * writing "0" into its "failed" sysfs attribute.
 * If recovery through sysfs is not possible, set the CHPID of the device
 * offline and back online on the service element.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: <stable@vger.kernel.org> #2.6.30+
Link: https://lore.kernel.org/r/20191001104949.42810-1-maier@linux.ibm.com
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
bardliao pushed a commit that referenced this pull request Oct 30, 2019
A long time ago we fixed a similar deadlock in show_slab_objects() [1].
However, it is apparently due to the commits like 01fb58b ("slab:
remove synchronous synchronize_sched() from memcg cache deactivation
path") and 03afc0e ("slab: get_online_mems for
kmem_cache_{create,destroy,shrink}"), this kind of deadlock is back by
just reading files in /sys/kernel/slab which will generate a lockdep
splat below.

Since the "mem_hotplug_lock" here is only to obtain a stable online node
mask while racing with NUMA node hotplug, in the worst case, the results
may me miscalculated while doing NUMA node hotplug, but they shall be
corrected by later reads of the same files.

  WARNING: possible circular locking dependency detected
  ------------------------------------------------------
  cat/5224 is trying to acquire lock:
  ffff900012ac3120 (mem_hotplug_lock.rw_sem){++++}, at:
  show_slab_objects+0x94/0x3a8

  but task is already holding lock:
  b8ff009693eee398 (kn->count#45){++++}, at: kernfs_seq_start+0x44/0xf0

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #2 (kn->count#45){++++}:
         lock_acquire+0x31c/0x360
         __kernfs_remove+0x290/0x490
         kernfs_remove+0x30/0x44
         sysfs_remove_dir+0x70/0x88
         kobject_del+0x50/0xb0
         sysfs_slab_unlink+0x2c/0x38
         shutdown_cache+0xa0/0xf0
         kmemcg_cache_shutdown_fn+0x1c/0x34
         kmemcg_workfn+0x44/0x64
         process_one_work+0x4f4/0x950
         worker_thread+0x390/0x4bc
         kthread+0x1cc/0x1e8
         ret_from_fork+0x10/0x18

  -> #1 (slab_mutex){+.+.}:
         lock_acquire+0x31c/0x360
         __mutex_lock_common+0x16c/0xf78
         mutex_lock_nested+0x40/0x50
         memcg_create_kmem_cache+0x38/0x16c
         memcg_kmem_cache_create_func+0x3c/0x70
         process_one_work+0x4f4/0x950
         worker_thread+0x390/0x4bc
         kthread+0x1cc/0x1e8
         ret_from_fork+0x10/0x18

  -> #0 (mem_hotplug_lock.rw_sem){++++}:
         validate_chain+0xd10/0x2bcc
         __lock_acquire+0x7f4/0xb8c
         lock_acquire+0x31c/0x360
         get_online_mems+0x54/0x150
         show_slab_objects+0x94/0x3a8
         total_objects_show+0x28/0x34
         slab_attr_show+0x38/0x54
         sysfs_kf_seq_show+0x198/0x2d4
         kernfs_seq_show+0xa4/0xcc
         seq_read+0x30c/0x8a8
         kernfs_fop_read+0xa8/0x314
         __vfs_read+0x88/0x20c
         vfs_read+0xd8/0x10c
         ksys_read+0xb0/0x120
         __arm64_sys_read+0x54/0x88
         el0_svc_handler+0x170/0x240
         el0_svc+0x8/0xc

  other info that might help us debug this:

  Chain exists of:
    mem_hotplug_lock.rw_sem --> slab_mutex --> kn->count#45

   Possible unsafe locking scenario:

         CPU0                    CPU1
         ----                    ----
    lock(kn->count#45);
                                 lock(slab_mutex);
                                 lock(kn->count#45);
    lock(mem_hotplug_lock.rw_sem);

   *** DEADLOCK ***

  3 locks held by cat/5224:
   #0: 9eff00095b14b2a0 (&p->lock){+.+.}, at: seq_read+0x4c/0x8a8
   #1: 0eff008997041480 (&of->mutex){+.+.}, at: kernfs_seq_start+0x34/0xf0
   #2: b8ff009693eee398 (kn->count#45){++++}, at:
  kernfs_seq_start+0x44/0xf0

  stack backtrace:
  Call trace:
   dump_backtrace+0x0/0x248
   show_stack+0x20/0x2c
   dump_stack+0xd0/0x140
   print_circular_bug+0x368/0x380
   check_noncircular+0x248/0x250
   validate_chain+0xd10/0x2bcc
   __lock_acquire+0x7f4/0xb8c
   lock_acquire+0x31c/0x360
   get_online_mems+0x54/0x150
   show_slab_objects+0x94/0x3a8
   total_objects_show+0x28/0x34
   slab_attr_show+0x38/0x54
   sysfs_kf_seq_show+0x198/0x2d4
   kernfs_seq_show+0xa4/0xcc
   seq_read+0x30c/0x8a8
   kernfs_fop_read+0xa8/0x314
   __vfs_read+0x88/0x20c
   vfs_read+0xd8/0x10c
   ksys_read+0xb0/0x120
   __arm64_sys_read+0x54/0x88
   el0_svc_handler+0x170/0x240
   el0_svc+0x8/0xc

I think it is important to mention that this doesn't expose the
show_slab_objects to use-after-free.  There is only a single path that
might really race here and that is the slab hotplug notifier callback
__kmem_cache_shrink (via slab_mem_going_offline_callback) but that path
doesn't really destroy kmem_cache_node data structures.

[1] http://lkml.iu.edu/hypermail/linux/kernel/1101.0/02850.html

[akpm@linux-foundation.org: add comment explaining why we don't need mem_hotplug_lock]
Link: http://lkml.kernel.org/r/1570192309-10132-1-git-send-email-cai@lca.pw
Fixes: 01fb58b ("slab: remove synchronous synchronize_sched() from memcg cache deactivation path")
Fixes: 03afc0e ("slab: get_online_mems for kmem_cache_{create,destroy,shrink}")
Signed-off-by: Qian Cai <cai@lca.pw>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
bardliao pushed a commit that referenced this pull request Oct 30, 2019
Daniel Vetter uncovered a nasty cycle in using the mmu-notifiers to
invalidate userptr objects which also happen to be pulled into GGTT
mmaps. That is when we unbind the userptr object (on mmu invalidation),
we revoke all CPU mmaps, which may then recurse into mmu invalidation.

We looked for ways of breaking the cycle, but the revocation on
invalidation is required and cannot be avoided. The only solution we
could see was to not allow such GGTT bindings of userptr objects in the
first place. In practice, no one really wants to use a GGTT mmapping of
a CPU pointer...

Just before Daniel's explosive lockdep patches land in v5.4-rc1, we got
a genuine blip from CI:

<4>[  246.793958] ======================================================
<4>[  246.793972] WARNING: possible circular locking dependency detected
<4>[  246.793989] 5.3.0-gbd6c56f50d15-drmtip_372+ #1 Tainted: G     U
<4>[  246.794003] ------------------------------------------------------
<4>[  246.794017] kswapd0/145 is trying to acquire lock:
<4>[  246.794030] 000000003f565be6 (&dev->struct_mutex/1){+.+.}, at: userptr_mn_invalidate_range_start+0x18f/0x220 [i915]
<4>[  246.794250]
                  but task is already holding lock:
<4>[  246.794263] 000000001799cef9 (&anon_vma->rwsem){++++}, at: page_lock_anon_vma_read+0xe6/0x2a0
<4>[  246.794291]
                  which lock already depends on the new lock.

<4>[  246.794307]
                  the existing dependency chain (in reverse order) is:
<4>[  246.794322]
                  -> #3 (&anon_vma->rwsem){++++}:
<4>[  246.794344]        down_write+0x33/0x70
<4>[  246.794357]        __vma_adjust+0x3d9/0x7b0
<4>[  246.794370]        __split_vma+0x16a/0x180
<4>[  246.794385]        mprotect_fixup+0x2a5/0x320
<4>[  246.794399]        do_mprotect_pkey+0x208/0x2e0
<4>[  246.794413]        __x64_sys_mprotect+0x16/0x20
<4>[  246.794429]        do_syscall_64+0x55/0x1c0
<4>[  246.794443]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
<4>[  246.794456]
                  -> #2 (&mapping->i_mmap_rwsem){++++}:
<4>[  246.794478]        down_write+0x33/0x70
<4>[  246.794493]        unmap_mapping_pages+0x48/0x130
<4>[  246.794519]        i915_vma_revoke_mmap+0x81/0x1b0 [i915]
<4>[  246.794519]        i915_vma_unbind+0x11d/0x4a0 [i915]
<4>[  246.794519]        i915_vma_destroy+0x31/0x300 [i915]
<4>[  246.794519]        __i915_gem_free_objects+0xb8/0x4b0 [i915]
<4>[  246.794519]        drm_file_free.part.0+0x1e6/0x290
<4>[  246.794519]        drm_release+0xa6/0xe0
<4>[  246.794519]        __fput+0xc2/0x250
<4>[  246.794519]        task_work_run+0x82/0xb0
<4>[  246.794519]        do_exit+0x35b/0xdb0
<4>[  246.794519]        do_group_exit+0x34/0xb0
<4>[  246.794519]        __x64_sys_exit_group+0xf/0x10
<4>[  246.794519]        do_syscall_64+0x55/0x1c0
<4>[  246.794519]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
<4>[  246.794519]
                  -> #1 (&vm->mutex){+.+.}:
<4>[  246.794519]        i915_gem_shrinker_taints_mutex+0x6d/0xe0 [i915]
<4>[  246.794519]        i915_address_space_init+0x9f/0x160 [i915]
<4>[  246.794519]        i915_ggtt_init_hw+0x55/0x170 [i915]
<4>[  246.794519]        i915_driver_probe+0xc9f/0x1620 [i915]
<4>[  246.794519]        i915_pci_probe+0x43/0x1b0 [i915]
<4>[  246.794519]        pci_device_probe+0x9e/0x120
<4>[  246.794519]        really_probe+0xea/0x3d0
<4>[  246.794519]        driver_probe_device+0x10b/0x120
<4>[  246.794519]        device_driver_attach+0x4a/0x50
<4>[  246.794519]        __driver_attach+0x97/0x130
<4>[  246.794519]        bus_for_each_dev+0x74/0xc0
<4>[  246.794519]        bus_add_driver+0x13f/0x210
<4>[  246.794519]        driver_register+0x56/0xe0
<4>[  246.794519]        do_one_initcall+0x58/0x300
<4>[  246.794519]        do_init_module+0x56/0x1f6
<4>[  246.794519]        load_module+0x25bd/0x2a40
<4>[  246.794519]        __se_sys_finit_module+0xd3/0xf0
<4>[  246.794519]        do_syscall_64+0x55/0x1c0
<4>[  246.794519]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
<4>[  246.794519]
                  -> #0 (&dev->struct_mutex/1){+.+.}:
<4>[  246.794519]        __lock_acquire+0x15d8/0x1e90
<4>[  246.794519]        lock_acquire+0xa6/0x1c0
<4>[  246.794519]        __mutex_lock+0x9d/0x9b0
<4>[  246.794519]        userptr_mn_invalidate_range_start+0x18f/0x220 [i915]
<4>[  246.794519]        __mmu_notifier_invalidate_range_start+0x85/0x110
<4>[  246.794519]        try_to_unmap_one+0x76b/0x860
<4>[  246.794519]        rmap_walk_anon+0x104/0x280
<4>[  246.794519]        try_to_unmap+0xc0/0xf0
<4>[  246.794519]        shrink_page_list+0x561/0xc10
<4>[  246.794519]        shrink_inactive_list+0x220/0x440
<4>[  246.794519]        shrink_node_memcg+0x36e/0x740
<4>[  246.794519]        shrink_node+0xcb/0x490
<4>[  246.794519]        balance_pgdat+0x241/0x580
<4>[  246.794519]        kswapd+0x16c/0x530
<4>[  246.794519]        kthread+0x119/0x130
<4>[  246.794519]        ret_from_fork+0x24/0x50
<4>[  246.794519]
                  other info that might help us debug this:

<4>[  246.794519] Chain exists of:
                    &dev->struct_mutex/1 --> &mapping->i_mmap_rwsem --> &anon_vma->rwsem

<4>[  246.794519]  Possible unsafe locking scenario:

<4>[  246.794519]        CPU0                    CPU1
<4>[  246.794519]        ----                    ----
<4>[  246.794519]   lock(&anon_vma->rwsem);
<4>[  246.794519]                                lock(&mapping->i_mmap_rwsem);
<4>[  246.794519]                                lock(&anon_vma->rwsem);
<4>[  246.794519]   lock(&dev->struct_mutex/1);
<4>[  246.794519]
                   *** DEADLOCK ***

v2: Say no to mmap_ioctl

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=111744
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=111870
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@vger.kernel.org
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190928082546.3473-1-chris@chris-wilson.co.uk
(cherry picked from commit a431174)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
bardliao pushed a commit that referenced this pull request Nov 5, 2019
…kernel/git/kvmarm/kvmarm into HEAD

KVM/arm fixes for 5.4, take #2

Special PMU edition:

- Fix cycle counter truncation
- Fix cycle counter overflow limit on pure 64bit system
- Allow chained events to be actually functional
- Correct sample period after overflow
bardliao pushed a commit that referenced this pull request Nov 12, 2019
When lockdep is enabled, plugging Thunderbolt dock on Dominik's laptop
triggers following splat:

  ======================================================
  WARNING: possible circular locking dependency detected
  5.3.0-rc6+ #1 Tainted: G                T
  ------------------------------------------------------
  pool-/usr/lib/b/1258 is trying to acquire lock:
  000000005ab0ad43 (pci_rescan_remove_lock){+.+.}, at: authorized_store+0xe8/0x210

  but task is already holding lock:
  00000000bfb796b5 (&tb->lock){+.+.}, at: authorized_store+0x7c/0x210

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #1 (&tb->lock){+.+.}:
         __mutex_lock+0xac/0x9a0
         tb_domain_add+0x2d/0x130
         nhi_probe+0x1dd/0x330
         pci_device_probe+0xd2/0x150
         really_probe+0xee/0x280
         driver_probe_device+0x50/0xc0
         bus_for_each_drv+0x84/0xd0
         __device_attach+0xe4/0x150
         pci_bus_add_device+0x4e/0x70
         pci_bus_add_devices+0x2e/0x66
         pci_bus_add_devices+0x59/0x66
         pci_bus_add_devices+0x59/0x66
         enable_slot+0x344/0x450
         acpiphp_check_bridge.part.0+0x119/0x150
         acpiphp_hotplug_notify+0xaa/0x140
         acpi_device_hotplug+0xa2/0x3f0
         acpi_hotplug_work_fn+0x1a/0x30
         process_one_work+0x234/0x580
         worker_thread+0x50/0x3b0
         kthread+0x10a/0x140
         ret_from_fork+0x3a/0x50

  -> #0 (pci_rescan_remove_lock){+.+.}:
         __lock_acquire+0xe54/0x1ac0
         lock_acquire+0xb8/0x1b0
         __mutex_lock+0xac/0x9a0
         authorized_store+0xe8/0x210
         kernfs_fop_write+0x125/0x1b0
         vfs_write+0xc2/0x1d0
         ksys_write+0x6c/0xf0
         do_syscall_64+0x50/0x180
         entry_SYSCALL_64_after_hwframe+0x49/0xbe

  other info that might help us debug this:
   Possible unsafe locking scenario:
         CPU0                    CPU1
         ----                    ----
    lock(&tb->lock);
                                 lock(pci_rescan_remove_lock);
                                 lock(&tb->lock);
    lock(pci_rescan_remove_lock);

   *** DEADLOCK ***
  5 locks held by pool-/usr/lib/b/1258:
   #0: 000000003df1a1ad (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x4d/0x60
   #1: 0000000095a40b02 (sb_writers#6){.+.+}, at: vfs_write+0x185/0x1d0
   #2: 0000000017a7d714 (&of->mutex){+.+.}, at: kernfs_fop_write+0xf2/0x1b0
   #3: 000000004f262981 (kn->count#208){.+.+}, at: kernfs_fop_write+0xfa/0x1b0
   #4: 00000000bfb796b5 (&tb->lock){+.+.}, at: authorized_store+0x7c/0x210

  stack backtrace:
  CPU: 0 PID: 1258 Comm: pool-/usr/lib/b Tainted: G                T 5.3.0-rc6+ #1

On an system using ACPI hotplug the host router gets hotplugged first and then
the firmware starts sending notifications about connected devices so the above
scenario should not happen in reality. However, after taking a second
look at commit a03e828 ("thunderbolt: Serialize PCIe tunnel
creation with PCI rescan") that introduced the locking, I don't think it
is actually correct. It may have cured the symptom but probably the real
root cause was somewhere closer to PCI stack and possibly is already
fixed with recent kernels. I also tried to reproduce the original issue
with the commit reverted but could not.

So to keep lockdep happy and the code bit less complex drop calls to
pci_lock_rescan_remove()/pci_unlock_rescan_remove() in
tb_switch_set_authorized() effectively reverting a03e828.

Link: https://lkml.org/lkml/2019/8/30/513
Fixes: a03e828 ("thunderbolt: Serialize PCIe tunnel creation with PCI rescan")
Reported-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
bardliao pushed a commit that referenced this pull request Nov 12, 2019
Original version of g920_get_config() contained two kind of actions:

    1. Device specific communication to query/set some parameters
       which requires active communication channel with the device,
       or, put in other way, for the call to be sandwiched between
       hid_device_io_start() and hid_device_io_stop().

    2. Input subsystem specific FF controller initialization which, in
       order to access a valid 'struct hid_input' via
       'hid->inputs.next', requires claimed hidinput which means be
       executed after the call to hid_hw_start() with connect_mask
       containing HID_CONNECT_HIDINPUT.

Location of g920_get_config() can only fulfill requirements for #1 and
not #2, which might result in following backtrace:

[   88.312258] logitech-hidpp-device 0003:046D:C262.0005: HID++ 4.2 device connected.
[   88.320298] BUG: kernel NULL pointer dereference, address: 0000000000000018
[   88.320304] #PF: supervisor read access in kernel mode
[   88.320307] #PF: error_code(0x0000) - not-present page
[   88.320309] PGD 0 P4D 0
[   88.320315] Oops: 0000 [#1] SMP PTI
[   88.320320] CPU: 1 PID: 3080 Comm: systemd-udevd Not tainted 5.4.0-rc1+ thesofproject#31
[   88.320322] Hardware name: Apple Inc. MacBookPro11,1/Mac-189A3D4F975D5FFC, BIOS 149.0.0.0.0 09/17/2018
[   88.320334] RIP: 0010:hidpp_probe+0x61f/0x948 [hid_logitech_hidpp]
[   88.320338] Code: 81 00 00 48 89 ef e8 f0 d6 ff ff 41 89 c6 85 c0 75 b5 0f b6 44 24 28 48 8b 5d 00 88 44 24 1e 89 44 24 0c 48 8b 83 18 1c 00 00 <48> 8b 48 18 48 8b 83 10 19 00 00 48 8b 40 40 48 89 0c 24 0f b7 80
[   88.320341] RSP: 0018:ffffb0a6824aba68 EFLAGS: 00010246
[   88.320345] RAX: 0000000000000000 RBX: ffff93a50756e000 RCX: 0000000000010408
[   88.320347] RDX: 0000000000000000 RSI: ffff93a51f0ad0a0 RDI: 000000000002d0a0
[   88.320350] RBP: ffff93a50416da28 R08: ffff93a50416da70 R09: ffff93a50416da70
[   88.320352] R10: 000000148ae9e60c R11: 00000000000f1525 R12: ffff93a50756e000
[   88.320354] R13: ffff93a50756f8d0 R14: 0000000000000000 R15: ffff93a50756fc38
[   88.320358] FS:  00007f8d8c1e0940(0000) GS:ffff93a51f080000(0000) knlGS:0000000000000000
[   88.320361] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   88.320363] CR2: 0000000000000018 CR3: 00000003996d8003 CR4: 00000000001606e0
[   88.320366] Call Trace:
[   88.320377]  ? _cond_resched+0x15/0x30
[   88.320387]  ? create_pinctrl+0x2f/0x3c0
[   88.320393]  ? kernfs_link_sibling+0x94/0xe0
[   88.320398]  ? _cond_resched+0x15/0x30
[   88.320402]  ? kernfs_activate+0x5f/0x80
[   88.320406]  ? kernfs_add_one+0xe2/0x130
[   88.320411]  hid_device_probe+0x106/0x170
[   88.320419]  really_probe+0x147/0x3c0
[   88.320424]  driver_probe_device+0xb6/0x100
[   88.320428]  device_driver_attach+0x53/0x60
[   88.320433]  __driver_attach+0x8a/0x150
[   88.320437]  ? device_driver_attach+0x60/0x60
[   88.320440]  bus_for_each_dev+0x78/0xc0
[   88.320445]  bus_add_driver+0x14d/0x1f0
[   88.320450]  driver_register+0x6c/0xc0
[   88.320453]  ? 0xffffffffc0d67000
[   88.320457]  __hid_register_driver+0x4c/0x80
[   88.320464]  do_one_initcall+0x46/0x1f4
[   88.320469]  ? _cond_resched+0x15/0x30
[   88.320474]  ? kmem_cache_alloc_trace+0x162/0x220
[   88.320481]  ? do_init_module+0x23/0x230
[   88.320486]  do_init_module+0x5c/0x230
[   88.320491]  load_module+0x26e1/0x2990
[   88.320502]  ? ima_post_read_file+0xf0/0x100
[   88.320508]  ? __do_sys_finit_module+0xaa/0x110
[   88.320512]  __do_sys_finit_module+0xaa/0x110
[   88.320520]  do_syscall_64+0x5b/0x180
[   88.320525]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   88.320528] RIP: 0033:0x7f8d8d1f01fd
[   88.320532] Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 5b 8c 0c 00 f7 d8 64 89 01 48
[   88.320535] RSP: 002b:00007ffefa3bb068 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
[   88.320539] RAX: ffffffffffffffda RBX: 000055922040cb40 RCX: 00007f8d8d1f01fd
[   88.320541] RDX: 0000000000000000 RSI: 00007f8d8ce4984d RDI: 0000000000000006
[   88.320543] RBP: 0000000000020000 R08: 0000000000000000 R09: 0000000000000007
[   88.320545] R10: 0000000000000006 R11: 0000000000000246 R12: 00007f8d8ce4984d
[   88.320547] R13: 0000000000000000 R14: 000055922040efc0 R15: 000055922040cb40
[   88.320551] Modules linked in: hid_logitech_hidpp(+) fuse rfcomm ccm xt_CHECKSUM xt_MASQUERADE bridge stp llc nf_nat_tftp nf_conntrack_tftp nf_conntrack_netbios_ns nf_conntrack_broadcast xt_CT ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntrack ebtable_nat ip6table_nat ip6table_mangle ip6table_raw ip6table_security iptable_nat nf_nat tun iptable_mangle iptable_raw iptable_security nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 libcrc32c ip_set nfnetlink ebtable_filter ebtables ip6table_filter ip6_tables cmac bnep sunrpc dm_crypt nls_utf8 hfsplus intel_rapl_msr intel_rapl_common ath9k_htc ath9k_common x86_pkg_temp_thermal intel_powerclamp b43 ath9k_hw coretemp snd_hda_codec_hdmi cordic kvm_intel snd_hda_codec_cirrus mac80211 snd_hda_codec_generic ledtrig_audio kvm snd_hda_intel snd_intel_nhlt irqbypass snd_hda_codec btusb btrtl snd_hda_core ath btbcm ssb snd_hwdep btintel snd_seq crct10dif_pclmul iTCO_wdt snd_seq_device crc32_pclmul bluetooth mmc_core iTCO_vendor_support joydev cfg80211
[   88.320602]  applesmc ghash_clmulni_intel ecdh_generic snd_pcm input_polldev intel_cstate ecc intel_uncore thunderbolt snd_timer i2c_i801 libarc4 rfkill intel_rapl_perf lpc_ich mei_me pcspkr bcm5974 snd bcma mei soundcore acpi_als sbs kfifo_buf sbshc industrialio apple_bl i915 i2c_algo_bit drm_kms_helper drm uas crc32c_intel usb_storage video hid_apple
[   88.320630] CR2: 0000000000000018
[   88.320633] ---[ end trace 933491c8a4fadeb7 ]---
[   88.320642] RIP: 0010:hidpp_probe+0x61f/0x948 [hid_logitech_hidpp]
[   88.320645] Code: 81 00 00 48 89 ef e8 f0 d6 ff ff 41 89 c6 85 c0 75 b5 0f b6 44 24 28 48 8b 5d 00 88 44 24 1e 89 44 24 0c 48 8b 83 18 1c 00 00 <48> 8b 48 18 48 8b 83 10 19 00 00 48 8b 40 40 48 89 0c 24 0f b7 80
[   88.320647] RSP: 0018:ffffb0a6824aba68 EFLAGS: 00010246
[   88.320650] RAX: 0000000000000000 RBX: ffff93a50756e000 RCX: 0000000000010408
[   88.320652] RDX: 0000000000000000 RSI: ffff93a51f0ad0a0 RDI: 000000000002d0a0
[   88.320655] RBP: ffff93a50416da28 R08: ffff93a50416da70 R09: ffff93a50416da70
[   88.320657] R10: 000000148ae9e60c R11: 00000000000f1525 R12: ffff93a50756e000
[   88.320659] R13: ffff93a50756f8d0 R14: 0000000000000000 R15: ffff93a50756fc38
[   88.320662] FS:  00007f8d8c1e0940(0000) GS:ffff93a51f080000(0000) knlGS:0000000000000000
[   88.320664] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   88.320667] CR2: 0000000000000018 CR3: 00000003996d8003 CR4: 00000000001606e0

To solve this issue:

   1. Split g920_get_config() such that all of the device specific
      communication remains a part of the function and input subsystem
      initialization bits go to hidpp_ff_init()

   2. Move call to hidpp_ff_init() from being a part of
      g920_get_config() to be the last step of .probe(), right after a
      call to hid_hw_start() with connect_mask containing
      HID_CONNECT_HIDINPUT.

Fixes: 91cf9a9 ("HID: logitech-hidpp: make .probe usbhid capable")
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Tested-by: Sam Bazley <sambazley@fastmail.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: Henrik Rydberg <rydberg@bitmath.org>
Cc: Pierre-Loup A. Griffais <pgriffais@valvesoftware.com>
Cc: Austin Palmer <austinp@valvesoftware.com>
Cc: linux-input@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org # 5.2+
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
bardliao pushed a commit that referenced this pull request Nov 12, 2019
All bonding device has same lockdep key and subclass is initialized with
nest_level.
But actual nest_level value can be changed when a lower device is attached.
And at this moment, the subclass should be updated but it seems to be
unsafe.
So this patch makes bonding use dynamic lockdep key instead of the
subclass.

Test commands:
    ip link add bond0 type bond

    for i in {1..5}
    do
	    let A=$i-1
	    ip link add bond$i type bond
	    ip link set bond$i master bond$A
    done
    ip link set bond5 master bond0

Splat looks like:
[  307.992912] WARNING: possible recursive locking detected
[  307.993656] 5.4.0-rc3+ thesofproject#96 Tainted: G        W
[  307.994367] --------------------------------------------
[  307.995092] ip/761 is trying to acquire lock:
[  307.995710] ffff8880513aac60 (&(&bond->stats_lock)->rlock#2/2){+.+.}, at: bond_get_stats+0xb8/0x500 [bonding]
[  307.997045]
	       but task is already holding lock:
[  307.997923] ffff88805fcbac60 (&(&bond->stats_lock)->rlock#2/2){+.+.}, at: bond_get_stats+0xb8/0x500 [bonding]
[  307.999215]
	       other info that might help us debug this:
[  308.000251]  Possible unsafe locking scenario:

[  308.001137]        CPU0
[  308.001533]        ----
[  308.001915]   lock(&(&bond->stats_lock)->rlock#2/2);
[  308.002609]   lock(&(&bond->stats_lock)->rlock#2/2);
[  308.003302]
		*** DEADLOCK ***

[  308.004310]  May be due to missing lock nesting notation

[  308.005319] 3 locks held by ip/761:
[  308.005830]  #0: ffffffff9fcc42b0 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x466/0x8a0
[  308.006894]  #1: ffff88805fcbac60 (&(&bond->stats_lock)->rlock#2/2){+.+.}, at: bond_get_stats+0xb8/0x500 [bonding]
[  308.008243]  #2: ffffffff9f9219c0 (rcu_read_lock){....}, at: bond_get_stats+0x9f/0x500 [bonding]
[  308.009422]
	       stack backtrace:
[  308.010124] CPU: 0 PID: 761 Comm: ip Tainted: G        W         5.4.0-rc3+ thesofproject#96
[  308.011097] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[  308.012179] Call Trace:
[  308.012601]  dump_stack+0x7c/0xbb
[  308.013089]  __lock_acquire+0x269d/0x3de0
[  308.013669]  ? register_lock_class+0x14d0/0x14d0
[  308.014318]  lock_acquire+0x164/0x3b0
[  308.014858]  ? bond_get_stats+0xb8/0x500 [bonding]
[  308.015520]  _raw_spin_lock_nested+0x2e/0x60
[  308.016129]  ? bond_get_stats+0xb8/0x500 [bonding]
[  308.017215]  bond_get_stats+0xb8/0x500 [bonding]
[  308.018454]  ? bond_arp_rcv+0xf10/0xf10 [bonding]
[  308.019710]  ? rcu_read_lock_held+0x90/0xa0
[  308.020605]  ? rcu_read_lock_sched_held+0xc0/0xc0
[  308.021286]  ? bond_get_stats+0x9f/0x500 [bonding]
[  308.021953]  dev_get_stats+0x1ec/0x270
[  308.022508]  bond_get_stats+0x1d1/0x500 [bonding]

Fixes: d3fff6c ("net: add netdev_lockdep_set_classes() helper")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
bardliao pushed a commit that referenced this pull request Jan 6, 2020
Target creation triggers a new BUG_ON introduced in in commit 4d43d39
("workqueue: Try to catch flush_work() without INIT_WORK().").  The BUG_ON
reveals an attempt to flush free_work in qla24xx_do_nack_work before it's
initialized in qlt_unreg_sess:

  WARNING: CPU: 7 PID: 211 at kernel/workqueue.c:3031 __flush_work.isra.38+0x40/0x2e0
  CPU: 7 PID: 211 Comm: kworker/7:1 Kdump: loaded Tainted: G            E     5.3.0-rc7-vanilla+ #2
  Workqueue: qla2xxx_wq qla2x00_iocb_work_fn [qla2xxx]
  NIP:  c000000000159620 LR: c0080000009d91b0 CTR: c0000000001598c0
  REGS: c000000005f3f730 TRAP: 0700   Tainted: G            E      (5.3.0-rc7-vanilla+)
  MSR:  800000000282b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE>  CR: 24002222  XER: 00000000
  CFAR: c0000000001598d0 IRQMASK: 0
  GPR00: c0080000009d91b0 c000000005f3f9c0 c000000001670a00 c0000003f8655ca8
  GPR04: c0000003f8655c00 000000000000ffff 0000000000000011 ffffffffffffffff
  GPR08: c008000000949228 0000000000000000 0000000000000001 c0080000009e7780
  GPR12: 0000000000002200 c00000003fff6200 c000000000161bc8 0000000000000004
  GPR16: c0000003f9d68280 0000000002000000 0000000000000005 0000000000000003
  GPR20: 0000000000000002 000000000000ffff 0000000000000000 fffffffffffffef7
  GPR24: c000000004f73848 c000000004f73838 c000000004f73f28 c000000005f3fb60
  GPR28: c000000004f73e48 c000000004f73c80 c000000004f73818 c0000003f9d68280
  NIP [c000000000159620] __flush_work.isra.38+0x40/0x2e0
  LR [c0080000009d91b0] qla24xx_do_nack_work+0x88/0x180 [qla2xxx]
  Call Trace:
  [c000000005f3f9c0] [c000000000159644] __flush_work.isra.38+0x64/0x2e0 (unreliable)
  [c000000005f3fa50] [c0080000009d91a0] qla24xx_do_nack_work+0x78/0x180 [qla2xxx]
  [c000000005f3fae0] [c0080000009496ec] qla2x00_do_work+0x604/0xb90 [qla2xxx]
  [c000000005f3fc40] [c008000000949cd8] qla2x00_iocb_work_fn+0x60/0xe0 [qla2xxx]
  [c000000005f3fc80] [c000000000157bb8] process_one_work+0x2c8/0x5b0
  [c000000005f3fd10] [c000000000157f28] worker_thread+0x88/0x660
  [c000000005f3fdb0] [c000000000161d64] kthread+0x1a4/0x1b0
  [c000000005f3fe20] [c00000000000b960] ret_from_kernel_thread+0x5c/0x7c
  Instruction dump:
  3d22001d 892966b1 7d908026 91810008 f821ff71 69290001 0b090000 2e290000
  40920200 e9230018 7d2a0074 794ad182 <0b0a0000> 2fa90000 419e01e8 7c0802a6
  ---[ end trace 5ccf335d4f90fcb8 ]---

Fixes: 1021f0b ("scsi: qla2xxx: allow session delete to finish before create.")
Cc: Quinn Tran <qutran@marvell.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20191125165702.1013-4-r.bolshakov@yadro.com
Acked-by: Himanshu Madhani <hmadhani@marvell.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
bardliao pushed a commit that referenced this pull request Jan 6, 2020
Each AFS mountpoint has strings that define the target to be mounted.  This
is required to end in a dot that is supposed to be stripped off.  The
string can include suffixes of ".readonly" or ".backup" - which are
supposed to come before the terminal dot.  To add to the confusion, the "fs
lsmount" afs utility does not show the terminal dot when displaying the
string.

The kernel mount source string parser, however, assumes that the terminal
dot marks the suffix and that the suffix is always "" and is thus ignored.
In most cases, there is no suffix and this is not a problem - but if there
is a suffix, it is lost and this affects the ability to mount the correct
volume.

The command line mount command, on the other hand, is expected not to
include a terminal dot - so the problem doesn't arise there.

Fix this by making sure that the dot exists and then stripping it when
passing the string to the mount configuration.

Fixes: bec5eb6 ("AFS: Implement an autocell mount capability [ver #2]")
Reported-by: Jonathan Billings <jsbillings@jsbillings.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
Tested-by: Jonathan Billings <jsbillings@jsbillings.org>
bardliao pushed a commit that referenced this pull request Jan 8, 2020
When commit:

  69c1f39 ("efi/x86: Convert x86 EFI earlyprintk into generic earlycon implementation")

moved the x86 specific EFI earlyprintk implementation to a shared location,
it also tweaked the behaviour. In particular, it dropped a trick with full
framebuffer remapping after page initialization, leading to two regressions:

  1) very slow scrolling after page initialization,
  2) kernel hang when the 'keep_bootcon' command line argument is passed.

Putting the tweak back fixes #2 and mitigates #1, i.e., it limits the slow
behavior to the early boot stages, presumably due to eliminating heavy
map()/unmap() operations per each pixel line on the screen.

 [ ardb: ensure efifb is unmapped again unless keep_bootcon is in effect. ]
 [ mingo: speling fixes. ]

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Bhupesh Sharma <bhsharma@redhat.com>
Cc: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Cc: linux-efi@vger.kernel.org
Fixes: 69c1f39 ("efi/x86: Convert x86 EFI earlyprintk into generic earlycon implementation")
Link: https://lkml.kernel.org/r/20191206165542.31469-7-ardb@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
bardliao pushed a commit that referenced this pull request Jan 8, 2020
The current rbtree for service ranges in the name table is built based
on the 'lower' & 'upper' range values resulting in a flaw in the rbtree
searching. Some issues have been observed in case of range overlapping:

Case #1: unable to withdraw a name entry:
After some name services are bound, all of them are withdrawn by user
but one remains in the name table forever. This corrupts the table and
that service becomes dummy i.e. no real port.
E.g.

                /
           {22, 22}
              /
             /
   --->  {10, 50}
           /  \
          /    \
    {10, 30}  {20, 60}

The node {10, 30} cannot be removed since the rbtree searching stops at
the node's ancestor i.e. {10, 50}, so starting from it will never reach
the finding node.

Case #2: failed to send data in some cases:
E.g. Two service ranges: {20, 60}, {10, 50} are bound. The rbtree for
this service will be one of the two cases below depending on the order
of the bindings:

        {20, 60}             {10, 50} <--
          /  \                 /  \
         /    \               /    \
    {10, 50}  NIL <--       NIL  {20, 60}

          (a)                    (b)

Now, try to send some data to service {30}, there will be two results:
(a): Failed, no route to host.
(b): Ok.

The reason is that the rbtree searching will stop at the pointing node
as shown above.

Case #3: Same as case #2b above but if the data sending's scope is
local and the {10, 50} is published by a peer node, then it will result
in 'no route to host' even though the other {20, 60} is for example on
the local node which should be able to get the data.

The issues are actually due to the way we built the rbtree. This commit
fixes it by introducing an additional field to each node - named 'max',
which is the largest 'upper' of that node subtree. The 'max' value for
each subtrees will be propagated correctly whenever a node is inserted/
removed or the tree is rebalanced by the augmented rbtree callbacks.

By this way, we can change the rbtree searching appoarch to solve the
issues above. Another benefit from this is that we can now improve the
searching for a next range matching e.g. in case of multicast, so get
rid of the unneeded looping over all nodes in the tree.

Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
bardliao pushed a commit that referenced this pull request Jan 8, 2020
No error code was being set on this error path.

Cc: stable@vger.kernel.org
Fixes: ad4b1eb ("KEYS: asym_tpm: Implement encryption operation [ver #2]")
Fixes: c08fed7 ("KEYS: Implement encrypt, decrypt and sign for software asymmetric key [ver #2]")
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
bardliao pushed a commit that referenced this pull request Jan 8, 2020
We got another syzbot report [1] that tells us we must use
write_lock_irq()/write_unlock_irq() to avoid possible deadlock.

[1]

WARNING: inconsistent lock state
5.5.0-rc1-syzkaller #0 Not tainted
--------------------------------
inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-R} usage.
syz-executor826/9605 [HC1[1]:SC0[0]:HE0:SE1] takes:
ffffffff8a128718 (disc_data_lock){+-..}, at: sp_get.isra.0+0x1d/0xf0 drivers/net/ppp/ppp_synctty.c:138
{HARDIRQ-ON-W} state was registered at:
  lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4485
  __raw_write_lock_bh include/linux/rwlock_api_smp.h:203 [inline]
  _raw_write_lock_bh+0x33/0x50 kernel/locking/spinlock.c:319
  sixpack_close+0x1d/0x250 drivers/net/hamradio/6pack.c:657
  tty_ldisc_close.isra.0+0x119/0x1a0 drivers/tty/tty_ldisc.c:489
  tty_set_ldisc+0x230/0x6b0 drivers/tty/tty_ldisc.c:585
  tiocsetd drivers/tty/tty_io.c:2337 [inline]
  tty_ioctl+0xe8d/0x14f0 drivers/tty/tty_io.c:2597
  vfs_ioctl fs/ioctl.c:47 [inline]
  file_ioctl fs/ioctl.c:545 [inline]
  do_vfs_ioctl+0x977/0x14e0 fs/ioctl.c:732
  ksys_ioctl+0xab/0xd0 fs/ioctl.c:749
  __do_sys_ioctl fs/ioctl.c:756 [inline]
  __se_sys_ioctl fs/ioctl.c:754 [inline]
  __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:754
  do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
irq event stamp: 3946
hardirqs last  enabled at (3945): [<ffffffff87c86e43>] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline]
hardirqs last  enabled at (3945): [<ffffffff87c86e43>] _raw_spin_unlock_irq+0x23/0x80 kernel/locking/spinlock.c:199
hardirqs last disabled at (3946): [<ffffffff8100675f>] trace_hardirqs_off_thunk+0x1a/0x1c arch/x86/entry/thunk_64.S:42
softirqs last  enabled at (2658): [<ffffffff86a8b4df>] spin_unlock_bh include/linux/spinlock.h:383 [inline]
softirqs last  enabled at (2658): [<ffffffff86a8b4df>] clusterip_netdev_event+0x46f/0x670 net/ipv4/netfilter/ipt_CLUSTERIP.c:222
softirqs last disabled at (2656): [<ffffffff86a8b22b>] spin_lock_bh include/linux/spinlock.h:343 [inline]
softirqs last disabled at (2656): [<ffffffff86a8b22b>] clusterip_netdev_event+0x1bb/0x670 net/ipv4/netfilter/ipt_CLUSTERIP.c:196

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(disc_data_lock);
  <Interrupt>
    lock(disc_data_lock);

 *** DEADLOCK ***

5 locks held by syz-executor826/9605:
 #0: ffff8880a905e198 (&tty->legacy_mutex){+.+.}, at: tty_lock+0xc7/0x130 drivers/tty/tty_mutex.c:19
 #1: ffffffff899a56c0 (rcu_read_lock){....}, at: mutex_spin_on_owner+0x0/0x330 kernel/locking/mutex.c:413
 #2: ffff8880a496a2b0 (&(&i->lock)->rlock){-.-.}, at: spin_lock include/linux/spinlock.h:338 [inline]
 #2: ffff8880a496a2b0 (&(&i->lock)->rlock){-.-.}, at: serial8250_interrupt+0x2d/0x1a0 drivers/tty/serial/8250/8250_core.c:116
 #3: ffffffff8c104048 (&port_lock_key){-.-.}, at: serial8250_handle_irq.part.0+0x24/0x330 drivers/tty/serial/8250/8250_port.c:1823
 #4: ffff8880a905e090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref+0x22/0x90 drivers/tty/tty_ldisc.c:288

stack backtrace:
CPU: 1 PID: 9605 Comm: syz-executor826 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x197/0x210 lib/dump_stack.c:118
 print_usage_bug.cold+0x327/0x378 kernel/locking/lockdep.c:3101
 valid_state kernel/locking/lockdep.c:3112 [inline]
 mark_lock_irq kernel/locking/lockdep.c:3309 [inline]
 mark_lock+0xbb4/0x1220 kernel/locking/lockdep.c:3666
 mark_usage kernel/locking/lockdep.c:3554 [inline]
 __lock_acquire+0x1e55/0x4a00 kernel/locking/lockdep.c:3909
 lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4485
 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline]
 _raw_read_lock+0x32/0x50 kernel/locking/spinlock.c:223
 sp_get.isra.0+0x1d/0xf0 drivers/net/ppp/ppp_synctty.c:138
 sixpack_write_wakeup+0x25/0x340 drivers/net/hamradio/6pack.c:402
 tty_wakeup+0xe9/0x120 drivers/tty/tty_io.c:536
 tty_port_default_wakeup+0x2b/0x40 drivers/tty/tty_port.c:50
 tty_port_tty_wakeup+0x57/0x70 drivers/tty/tty_port.c:387
 uart_write_wakeup+0x46/0x70 drivers/tty/serial/serial_core.c:104
 serial8250_tx_chars+0x495/0xaf0 drivers/tty/serial/8250/8250_port.c:1761
 serial8250_handle_irq.part.0+0x2a2/0x330 drivers/tty/serial/8250/8250_port.c:1834
 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1820 [inline]
 serial8250_default_handle_irq+0xc0/0x150 drivers/tty/serial/8250/8250_port.c:1850
 serial8250_interrupt+0xf1/0x1a0 drivers/tty/serial/8250/8250_core.c:126
 __handle_irq_event_percpu+0x15d/0x970 kernel/irq/handle.c:149
 handle_irq_event_percpu+0x74/0x160 kernel/irq/handle.c:189
 handle_irq_event+0xa7/0x134 kernel/irq/handle.c:206
 handle_edge_irq+0x25e/0x8d0 kernel/irq/chip.c:830
 generic_handle_irq_desc include/linux/irqdesc.h:156 [inline]
 do_IRQ+0xde/0x280 arch/x86/kernel/irq.c:250
 common_interrupt+0xf/0xf arch/x86/entry/entry_64.S:607
 </IRQ>
RIP: 0010:cpu_relax arch/x86/include/asm/processor.h:685 [inline]
RIP: 0010:mutex_spin_on_owner+0x247/0x330 kernel/locking/mutex.c:579
Code: c3 be 08 00 00 00 4c 89 e7 e8 e5 06 59 00 4c 89 e0 48 c1 e8 03 42 80 3c 38 00 0f 85 e1 00 00 00 49 8b 04 24 a8 01 75 96 f3 90 <e9> 2f fe ff ff 0f 0b e8 0d 19 09 00 84 c0 0f 85 ff fd ff ff 48 c7
RSP: 0018:ffffc90001eafa20 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffd7
RAX: 0000000000000000 RBX: ffff88809fd9e0c0 RCX: 1ffffffff13266dd
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000000
RBP: ffffc90001eafa60 R08: 1ffff11013d22898 R09: ffffed1013d22899
R10: ffffed1013d22898 R11: ffff88809e9144c7 R12: ffff8880a905e138
R13: ffff88809e9144c0 R14: 0000000000000000 R15: dffffc0000000000
 mutex_optimistic_spin kernel/locking/mutex.c:673 [inline]
 __mutex_lock_common kernel/locking/mutex.c:962 [inline]
 __mutex_lock+0x32b/0x13c0 kernel/locking/mutex.c:1106
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1121
 tty_lock+0xc7/0x130 drivers/tty/tty_mutex.c:19
 tty_release+0xb5/0xe90 drivers/tty/tty_io.c:1665
 __fput+0x2ff/0x890 fs/file_table.c:280
 ____fput+0x16/0x20 fs/file_table.c:313
 task_work_run+0x145/0x1c0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x8e7/0x2ef0 kernel/exit.c:797
 do_group_exit+0x135/0x360 kernel/exit.c:895
 __do_sys_exit_group kernel/exit.c:906 [inline]
 __se_sys_exit_group kernel/exit.c:904 [inline]
 __x64_sys_exit_group+0x44/0x50 kernel/exit.c:904
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x43fef8
Code: Bad RIP value.
RSP: 002b:00007ffdb07d2338 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043fef8
RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000
RBP: 00000000004bf730 R08: 00000000000000e7 R09: ffffffffffffffd0
R10: 00000000004002c8 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000006d1180 R14: 0000000000000000 R15: 0000000000000000

Fixes: 6e4e2f8 ("6pack,mkiss: fix lock inconsistency")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
bardliao pushed a commit that referenced this pull request Jan 8, 2020
Ido Schimmel says:

====================
mlxsw: Couple of fixes

This patch set contains two fixes for mlxsw. Please consider both for
stable.

Patch #1 from Amit fixes a wrong check during MAC validation when
creating router interfaces (RIFs). Given a particular order of
configuration this can result in the driver refusing to create new RIFs.

Patch #2 fixes a wrong trap configuration in which VRRP packets and
routing exceptions were policed by the same policer towards the CPU. In
certain situations this can prevent VRRP packets from reaching the CPU.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
bardliao pushed a commit that referenced this pull request Jan 14, 2020
Petr Machata says:

====================
When ungrafting from PRIO, replace child with FIFO

When a child Qdisc is removed from one of the PRIO Qdisc's bands, it is
replaced unconditionally by a NOOP qdisc. As a result, any traffic hitting
that band gets dropped. That is incorrect--no Qdisc was explicitly added
when PRIO was created, and after removal, none should have to be added
either.

In patch #2, this problem is fixed for PRIO by first attempting to create a
default Qdisc and only falling back to noop when that fails. This pattern
of attempting to create an invisible FIFO, using NOOP only as a fallback,
is also seen in some other Qdiscs.

The only driver currently offloading PRIO (and thus presumably the only one
impacted by this) is mlxsw. Therefore patch #1 extends mlxsw to handle the
replacement by an invisible FIFO gracefully.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
bardliao pushed a commit that referenced this pull request Feb 12, 2020
Ido Schimmel says:

====================
mlxsw: Various fixes

This patch set contains various fixes for mlxsw.

Patch #1 splits the init() callback between Spectrum-2 and Spectrum-3 in
order to avoid enforcing the same firmware version for both ASICs, as
this can't possibly work. Without this patch the driver cannot boot with
the Spectrum-3 ASIC.

Patches #2-#3 fix a long standing race condition that was recently
exposed while testing the driver on an emulator, which is very slow
compared to the actual hardware. The problem is explained in detail in
the commit messages.

Patch #4 fixes a selftest.

Patch #5 prevents offloaded qdiscs from presenting a non-zero backlog to
the user when the netdev is down. This is done by clearing the cached
backlog in the driver when the netdev goes down.

Patch thesofproject#6 fixes qdisc statistics (backlog and tail drops) to also take
into account the multicast traffic classes.

v2:
* Patches #2-#3: use skb_cow_head() instead of skb_unshare() as
  suggested by Jakub. Remove unnecessary check regarding headroom
* Patches #5-thesofproject#6: new
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
bardliao pushed a commit that referenced this pull request Feb 21, 2020
Turning on CONFIG_DMA_API_DEBUG_SG results in the following error:

[   12.078665] msm ae00000.mdss: DMA-API: mapping sg segment longer than device claims to support [len=3526656] [max=65536]
[   12.089870] WARNING: CPU: 6 PID: 334 at /mnt/host/source/src/third_party/kernel/v4.19/kernel/dma/debug.c:1301 debug_dma_map_sg+0x1dc/0x318
[   12.102655] Modules linked in: joydev
[   12.106442] CPU: 6 PID: 334 Comm: frecon Not tainted 4.19.0 #2
[   12.112450] Hardware name: Google Cheza (rev3+) (DT)
[   12.117566] pstate: 60400009 (nZCv daif +PAN -UAO)
[   12.122506] pc : debug_dma_map_sg+0x1dc/0x318
[   12.126995] lr : debug_dma_map_sg+0x1dc/0x318
[   12.131487] sp : ffffff800cc3ba80
[   12.134913] x29: ffffff800cc3ba80 x28: 0000000000000000
[   12.140395] x27: 0000000000000004 x26: 0000000000000004
[   12.145868] x25: ffffff8008e55b18 x24: 0000000000000000
[   12.151337] x23: 00000000ffffffff x22: ffffff800921c000
[   12.156809] x21: ffffffc0fa75b080 x20: ffffffc0f7195090
[   12.162280] x19: ffffffc0f1c53280 x18: 0000000000000000
[   12.167749] x17: 0000000000000000 x16: 0000000000000000
[   12.173218] x15: 0000000000000000 x14: 0720072007200720
[   12.178689] x13: 0720072007200720 x12: 0720072007200720
[   12.184161] x11: 0720072007200720 x10: 0720072007200720
[   12.189641] x9 : ffffffc0f1fc6b60 x8 : 0000000000000000
[   12.195110] x7 : ffffff8008132ce0 x6 : 0000000000000000
[   12.200585] x5 : 0000000000000000 x4 : ffffff8008134734
[   12.206058] x3 : ffffff800cc3b830 x2 : ffffffc0f1fc6240
[   12.211532] x1 : 25045a74f48a7400 x0 : 25045a74f48a7400
[   12.217006] Call trace:
[   12.219535]  debug_dma_map_sg+0x1dc/0x318
[   12.223671]  get_pages+0x19c/0x20c
[   12.227177]  msm_gem_fault+0x64/0xfc
[   12.230874]  __do_fault+0x3c/0x140
[   12.234383]  __handle_mm_fault+0x70c/0xdb8
[   12.238603]  handle_mm_fault+0xac/0xc4
[   12.242473]  do_page_fault+0x1bc/0x3d4
[   12.246342]  do_translation_fault+0x54/0x88
[   12.250652]  do_mem_abort+0x60/0xf0
[   12.254250]  el0_da+0x20/0x24
[   12.257317] irq event stamp: 67260
[   12.260828] hardirqs last  enabled at (67259): [<ffffff8008132d0c>] console_unlock+0x214/0x608
[   12.269693] hardirqs last disabled at (67260): [<ffffff8008080e0c>] do_debug_exception+0x5c/0x178
[   12.278820] softirqs last  enabled at (67256): [<ffffff8008081664>] __do_softirq+0x4d4/0x520
[   12.287510] softirqs last disabled at (67249): [<ffffff80080be574>] irq_exit+0xa8/0x100
[   12.295742] ---[ end trace e63cfc40c313ffab ]---

The root of the problem is that the default segment size for sgt is
(UINT_MAX & PAGE_MASK), and the default segment size for device dma is
64K. As such, if you compare the 2, you would deduce that the sg segment
will overflow the device's capacity. In reality, the hardware can
accommodate the larger sg segments, it's just not initializing its max
segment properly. This patch initializes the max segment size for the
mdss device, which gets rid of that pesky warning.

Reported-by: Stephen Boyd <swboyd@chromium.org>
Tested-by: Stephen Boyd <swboyd@chromium.org>
Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200121111813.REPOST.1.I92c66a35fb13f368095b05287bdabdbe88ca6922@changeid
bardliao pushed a commit that referenced this pull request Feb 21, 2020
I see the following lockdep splat in the qcom pinctrl driver when
attempting to suspend the device.

 WARNING: possible recursive locking detected
 5.4.11 #3 Tainted: G        W
 --------------------------------------------
 cat/3074 is trying to acquire lock:
 ffffff81f49804c0 (&irq_desc_lock_class){-.-.}, at: __irq_get_desc_lock+0x64/0x94

 but task is already holding lock:
 ffffff81f1cc10c0 (&irq_desc_lock_class){-.-.}, at: __irq_get_desc_lock+0x64/0x94

 other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(&irq_desc_lock_class);
   lock(&irq_desc_lock_class);

  *** DEADLOCK ***

  May be due to missing lock nesting notation

 6 locks held by cat/3074:
  #0: ffffff81f01d9420 (sb_writers#7){.+.+}, at: vfs_write+0xd0/0x1a4
  #1: ffffff81bd7d2080 (&of->mutex){+.+.}, at: kernfs_fop_write+0x12c/0x1fc
  #2: ffffff81f4c322f0 (kn->count#337){.+.+}, at: kernfs_fop_write+0x134/0x1fc
  #3: ffffffe411a41d60 (system_transition_mutex){+.+.}, at: pm_suspend+0x108/0x348
  #4: ffffff81f1c5e970 (&dev->mutex){....}, at: __device_suspend+0x168/0x41c
  #5: ffffff81f1cc10c0 (&irq_desc_lock_class){-.-.}, at: __irq_get_desc_lock+0x64/0x94

 stack backtrace:
 CPU: 5 PID: 3074 Comm: cat Tainted: G        W         5.4.11 #3
 Hardware name: Google Cheza (rev3+) (DT)
 Call trace:
  dump_backtrace+0x0/0x174
  show_stack+0x20/0x2c
  dump_stack+0xc8/0x124
  __lock_acquire+0x460/0x2388
  lock_acquire+0x1cc/0x210
  _raw_spin_lock_irqsave+0x64/0x80
  __irq_get_desc_lock+0x64/0x94
  irq_set_irq_wake+0x40/0x144
  qpnpint_irq_set_wake+0x28/0x34
  set_irq_wake_real+0x40/0x5c
  irq_set_irq_wake+0x70/0x144
  pm8941_pwrkey_suspend+0x34/0x44
  platform_pm_suspend+0x34/0x60
  dpm_run_callback+0x64/0xcc
  __device_suspend+0x310/0x41c
  dpm_suspend+0xf8/0x298
  dpm_suspend_start+0x84/0xb4
  suspend_devices_and_enter+0xbc/0x620
  pm_suspend+0x210/0x348
  state_store+0xb0/0x108
  kobj_attr_store+0x14/0x24
  sysfs_kf_write+0x4c/0x64
  kernfs_fop_write+0x15c/0x1fc
  __vfs_write+0x54/0x18c
  vfs_write+0xe4/0x1a4
  ksys_write+0x7c/0xe4
  __arm64_sys_write+0x20/0x2c
  el0_svc_common+0xa8/0x160
  el0_svc_handler+0x7c/0x98
  el0_svc+0x8/0xc

Set a lockdep class when we map the irq so that irq_set_wake() doesn't
warn about a lockdep bug that doesn't exist.

Fixes: 12a9eea ("spmi: pmic-arb: convert to v2 irq interfaces to support hierarchical IRQ chips")
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Brian Masney <masneyb@onstation.org>
Cc: Lina Iyer <ilina@codeaurora.org>
Cc: Maulik Shah <mkshah@codeaurora.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20200121183748.68662-1-swboyd@chromium.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
bardliao pushed a commit that referenced this pull request Feb 21, 2020
Add a check that the size specified in the flow spec header doesn't cause
an overflow when calculating the filter size, and thus prevent access to
invalid memory.  The following crash from syzkaller revealed it.

  kasan: CONFIG_KASAN_INLINE enabled
  kasan: GPF could be caused by NULL-ptr deref or user memory access
  general protection fault: 0000 [#1] SMP KASAN PTI
  CPU: 1 PID: 17834 Comm: syz-executor.3 Not tainted 5.5.0-rc5 #2
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
  rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
  RIP: 0010:memchr_inv+0xd3/0x330
  Code: 89 f9 89 f5 83 e1 07 0f 85 f9 00 00 00 49 89 d5 49 c1 ed 03 45 85
  ed 74 6f 48 89 d9 48 b8 00 00 00 00 00 fc ff df 48 c1 e9 03 <80> 3c 01
  00 0f 85 0d 02 00 00 44 0f b6 e5 48 b8 01 01 01 01 01 01
  RSP: 0018:ffffc9000a13fa50 EFLAGS: 00010202
  RAX: dffffc0000000000 RBX: 7fff88810de9d820 RCX: 0ffff11021bd3b04
  RDX: 000000000000fff8 RSI: 0000000000000000 RDI: 7fff88810de9d820
  RBP: 0000000000000000 R08: ffff888110d69018 R09: 0000000000000009
  R10: 0000000000000001 R11: ffffed10236267cc R12: 0000000000000004
  R13: 0000000000001fff R14: ffff88810de9d820 R15: 0000000000000040
  FS:  00007f9ee0e51700(0000) GS:ffff88811b100000(0000)
  knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000000 CR3: 0000000115ea0006 CR4: 0000000000360ee0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   spec_filter_size.part.16+0x34/0x50
   ib_uverbs_kern_spec_to_ib_spec_filter+0x691/0x770
   ib_uverbs_ex_create_flow+0x9ea/0x1b40
   ib_uverbs_write+0xaa5/0xdf0
   __vfs_write+0x7c/0x100
   vfs_write+0x168/0x4a0
   ksys_write+0xc8/0x200
   do_syscall_64+0x9c/0x390
   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  RIP: 0033:0x465b49
  Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8 48 89
  f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01
  f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
  RSP: 002b:00007f9ee0e50c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
  RAX: ffffffffffffffda RBX: 000000000073bf00 RCX: 0000000000465b49
  RDX: 00000000000003a0 RSI: 00000000200007c0 RDI: 0000000000000004
  RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9ee0e516bc
  R13: 00000000004ca2da R14: 000000000070deb8 R15: 00000000ffffffff
  Modules linked in:
  Dumping ftrace buffer:
     (ftrace buffer empty)

Fixes: 94e03f1 ("IB/uverbs: Add support for flow tag")
Link: https://lore.kernel.org/r/20200126171500.4623-1-leon@kernel.org
Signed-off-by: Avihai Horon <avihaih@mellanox.com>
Reviewed-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
bardliao pushed a commit that referenced this pull request Feb 21, 2020
We don't need to set pkey as valid in case that user set only one of pkey
index or port number, otherwise it will be resulted in NULL pointer
dereference while accessing to uninitialized pkey list.  The following
crash from Syzkaller revealed it.

  kasan: CONFIG_KASAN_INLINE enabled
  kasan: GPF could be caused by NULL-ptr deref or user memory access
  general protection fault: 0000 [#1] SMP KASAN PTI
  CPU: 1 PID: 14753 Comm: syz-executor.2 Not tainted 5.5.0-rc5 #2
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
  rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
  RIP: 0010:get_pkey_idx_qp_list+0x161/0x2d0
  Code: 01 00 00 49 8b 5e 20 4c 39 e3 0f 84 b9 00 00 00 e8 e4 42 6e fe 48
  8d 7b 10 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04
  02 84 c0 74 08 3c 01 0f 8e d0 00 00 00 48 8d 7d 04 48 b8
  RSP: 0018:ffffc9000bc6f950 EFLAGS: 00010202
  RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff82c8bdec
  RDX: 0000000000000002 RSI: ffffc900030a8000 RDI: 0000000000000010
  RBP: ffff888112c8ce80 R08: 0000000000000004 R09: fffff5200178df1f
  R10: 0000000000000001 R11: fffff5200178df1f R12: ffff888115dc4430
  R13: ffff888115da8498 R14: ffff888115dc4410 R15: ffff888115da8000
  FS:  00007f20777de700(0000) GS:ffff88811b100000(0000)
  knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000001b2f721000 CR3: 00000001173ca002 CR4: 0000000000360ee0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   port_pkey_list_insert+0xd7/0x7c0
   ib_security_modify_qp+0x6fa/0xfc0
   _ib_modify_qp+0x8c4/0xbf0
   modify_qp+0x10da/0x16d0
   ib_uverbs_modify_qp+0x9a/0x100
   ib_uverbs_write+0xaa5/0xdf0
   __vfs_write+0x7c/0x100
   vfs_write+0x168/0x4a0
   ksys_write+0xc8/0x200
   do_syscall_64+0x9c/0x390
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: d291f1a ("IB/core: Enforce PKey security on QPs")
Link: https://lore.kernel.org/r/20200212080651.GB679970@unreal
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Message-Id: <20200212080651.GB679970@unreal>
bardliao pushed a commit that referenced this pull request Feb 25, 2020
After bond_release(), netdev_update_lockdep_key() should be called.
But both ioctl path and attribute path don't call
netdev_update_lockdep_key().
This patch adds missing netdev_update_lockdep_key().

Test commands:
    ip link add bond0 type bond
    ip link add bond1 type bond
    ifenslave bond0 bond1
    ifenslave -d bond0 bond1
    ifenslave bond1 bond0

Splat looks like:
[   29.501182][ T1046] WARNING: possible circular locking dependency detected
[   29.501945][ T1039] hardirqs last disabled at (1962): [<ffffffffac6c807f>] handle_mm_fault+0x13f/0x700
[   29.503442][ T1046] 5.5.0+ thesofproject#322 Not tainted
[   29.503447][ T1046] ------------------------------------------------------
[   29.504277][ T1039] softirqs last  enabled at (1180): [<ffffffffade00678>] __do_softirq+0x678/0x981
[   29.505443][ T1046] ifenslave/1046 is trying to acquire lock:
[   29.505886][ T1039] softirqs last disabled at (1169): [<ffffffffac19c18a>] irq_exit+0x17a/0x1a0
[   29.509997][ T1046] ffff88805d5da280 (&dev->addr_list_lock_key#3){+...}, at: dev_mc_sync_multiple+0x95/0x120
[   29.511243][ T1046]
[   29.511243][ T1046] but task is already holding lock:
[   29.512192][ T1046] ffff8880460f2280 (&dev->addr_list_lock_key#4){+...}, at: bond_enslave+0x4482/0x47b0 [bonding]
[   29.514124][ T1046]
[   29.514124][ T1046] which lock already depends on the new lock.
[   29.514124][ T1046]
[   29.517297][ T1046]
[   29.517297][ T1046] the existing dependency chain (in reverse order) is:
[   29.518231][ T1046]
[   29.518231][ T1046] -> #1 (&dev->addr_list_lock_key#4){+...}:
[   29.519076][ T1046]        _raw_spin_lock+0x30/0x70
[   29.519588][ T1046]        dev_mc_sync_multiple+0x95/0x120
[   29.520208][ T1046]        bond_enslave+0x448d/0x47b0 [bonding]
[   29.520862][ T1046]        bond_option_slaves_set+0x1a3/0x370 [bonding]
[   29.521640][ T1046]        __bond_opt_set+0x1ff/0xbb0 [bonding]
[   29.522438][ T1046]        __bond_opt_set_notify+0x2b/0xf0 [bonding]
[   29.523251][ T1046]        bond_opt_tryset_rtnl+0x92/0xf0 [bonding]
[   29.524082][ T1046]        bonding_sysfs_store_option+0x8a/0xf0 [bonding]
[   29.524959][ T1046]        kernfs_fop_write+0x276/0x410
[   29.525620][ T1046]        vfs_write+0x197/0x4a0
[   29.526218][ T1046]        ksys_write+0x141/0x1d0
[   29.526818][ T1046]        do_syscall_64+0x99/0x4f0
[   29.527430][ T1046]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   29.528265][ T1046]
[   29.528265][ T1046] -> #0 (&dev->addr_list_lock_key#3){+...}:
[   29.529272][ T1046]        __lock_acquire+0x2d8d/0x3de0
[   29.529935][ T1046]        lock_acquire+0x164/0x3b0
[   29.530638][ T1046]        _raw_spin_lock+0x30/0x70
[   29.531187][ T1046]        dev_mc_sync_multiple+0x95/0x120
[   29.531790][ T1046]        bond_enslave+0x448d/0x47b0 [bonding]
[   29.532451][ T1046]        bond_option_slaves_set+0x1a3/0x370 [bonding]
[   29.533163][ T1046]        __bond_opt_set+0x1ff/0xbb0 [bonding]
[   29.533789][ T1046]        __bond_opt_set_notify+0x2b/0xf0 [bonding]
[   29.534595][ T1046]        bond_opt_tryset_rtnl+0x92/0xf0 [bonding]
[   29.535500][ T1046]        bonding_sysfs_store_option+0x8a/0xf0 [bonding]
[   29.536379][ T1046]        kernfs_fop_write+0x276/0x410
[   29.537057][ T1046]        vfs_write+0x197/0x4a0
[   29.537640][ T1046]        ksys_write+0x141/0x1d0
[   29.538251][ T1046]        do_syscall_64+0x99/0x4f0
[   29.538870][ T1046]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   29.539659][ T1046]
[   29.539659][ T1046] other info that might help us debug this:
[   29.539659][ T1046]
[   29.540953][ T1046]  Possible unsafe locking scenario:
[   29.540953][ T1046]
[   29.541883][ T1046]        CPU0                    CPU1
[   29.542540][ T1046]        ----                    ----
[   29.543209][ T1046]   lock(&dev->addr_list_lock_key#4);
[   29.543880][ T1046]                                lock(&dev->addr_list_lock_key#3);
[   29.544873][ T1046]                                lock(&dev->addr_list_lock_key#4);
[   29.545863][ T1046]   lock(&dev->addr_list_lock_key#3);
[   29.546525][ T1046]
[   29.546525][ T1046]  *** DEADLOCK ***
[   29.546525][ T1046]
[   29.547542][ T1046] 5 locks held by ifenslave/1046:
[   29.548196][ T1046]  #0: ffff88806044c478 (sb_writers#5){.+.+}, at: vfs_write+0x3bb/0x4a0
[   29.549248][ T1046]  #1: ffff88805af00890 (&of->mutex){+.+.}, at: kernfs_fop_write+0x1cf/0x410
[   29.550343][ T1046]  #2: ffff88805b8b54b0 (kn->count#157){.+.+}, at: kernfs_fop_write+0x1f2/0x410
[   29.551575][ T1046]  #3: ffffffffaecf4cf0 (rtnl_mutex){+.+.}, at: bond_opt_tryset_rtnl+0x5f/0xf0 [bonding]
[   29.552819][ T1046]  #4: ffff8880460f2280 (&dev->addr_list_lock_key#4){+...}, at: bond_enslave+0x4482/0x47b0 [bonding]
[   29.554175][ T1046]
[   29.554175][ T1046] stack backtrace:
[   29.554907][ T1046] CPU: 0 PID: 1046 Comm: ifenslave Not tainted 5.5.0+ thesofproject#322
[   29.555854][ T1046] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[   29.557064][ T1046] Call Trace:
[   29.557504][ T1046]  dump_stack+0x96/0xdb
[   29.558054][ T1046]  check_noncircular+0x371/0x450
[   29.558723][ T1046]  ? print_circular_bug.isra.35+0x310/0x310
[   29.559486][ T1046]  ? hlock_class+0x130/0x130
[   29.560100][ T1046]  ? __lock_acquire+0x2d8d/0x3de0
[   29.560761][ T1046]  __lock_acquire+0x2d8d/0x3de0
[   29.561366][ T1046]  ? register_lock_class+0x14d0/0x14d0
[   29.562045][ T1046]  ? find_held_lock+0x39/0x1d0
[   29.562641][ T1046]  lock_acquire+0x164/0x3b0
[   29.563199][ T1046]  ? dev_mc_sync_multiple+0x95/0x120
[   29.563872][ T1046]  _raw_spin_lock+0x30/0x70
[   29.564464][ T1046]  ? dev_mc_sync_multiple+0x95/0x120
[   29.565146][ T1046]  dev_mc_sync_multiple+0x95/0x120
[   29.565793][ T1046]  bond_enslave+0x448d/0x47b0 [bonding]
[   29.566487][ T1046]  ? bond_update_slave_arr+0x940/0x940 [bonding]
[   29.567279][ T1046]  ? bstr_printf+0xc20/0xc20
[   29.567857][ T1046]  ? stack_trace_consume_entry+0x160/0x160
[   29.568614][ T1046]  ? deactivate_slab.isra.77+0x2c5/0x800
[   29.569320][ T1046]  ? check_chain_key+0x236/0x5d0
[   29.569939][ T1046]  ? sscanf+0x93/0xc0
[   29.570442][ T1046]  ? vsscanf+0x1e20/0x1e20
[   29.571003][ T1046]  bond_option_slaves_set+0x1a3/0x370 [bonding]
[ ... ]

Fixes: ab92d68 ("net: core: add generic lockdep keys")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
bardliao pushed a commit that referenced this pull request Feb 25, 2020
In the "struct bonding", there is stats_lock.
This lock protects "bond_stats" in the "struct bonding".
bond_stats is updated in the bond_get_stats() and this function would be
executed concurrently. So, the lock is needed.

Bonding interfaces would be nested.
So, either stats_lock should use dynamic lockdep class key or stats_lock
should be used by spin_lock_nested(). In the current code, stats_lock is
using a dynamic lockdep class key.
But there is no updating stats_lock_key routine So, lockdep warning
will occur.

Test commands:
    ip link add bond0 type bond
    ip link add bond1 type bond
    ip link set bond0 master bond1
    ip link set bond0 nomaster
    ip link set bond1 master bond0

Splat looks like:
[   38.420603][  T957] 5.5.0+ thesofproject#394 Not tainted
[   38.421074][  T957] ------------------------------------------------------
[   38.421837][  T957] ip/957 is trying to acquire lock:
[   38.422399][  T957] ffff888063262cd8 (&bond->stats_lock_key#2){+.+.}, at: bond_get_stats+0x90/0x4d0 [bonding]
[   38.423528][  T957]
[   38.423528][  T957] but task is already holding lock:
[   38.424526][  T957] ffff888065fd2cd8 (&bond->stats_lock_key){+.+.}, at: bond_get_stats+0x90/0x4d0 [bonding]
[   38.426075][  T957]
[   38.426075][  T957] which lock already depends on the new lock.
[   38.426075][  T957]
[   38.428536][  T957]
[   38.428536][  T957] the existing dependency chain (in reverse order) is:
[   38.429475][  T957]
[   38.429475][  T957] -> #1 (&bond->stats_lock_key){+.+.}:
[   38.430273][  T957]        _raw_spin_lock+0x30/0x70
[   38.430812][  T957]        bond_get_stats+0x90/0x4d0 [bonding]
[   38.431451][  T957]        dev_get_stats+0x1ec/0x270
[   38.432088][  T957]        bond_get_stats+0x1a5/0x4d0 [bonding]
[   38.432767][  T957]        dev_get_stats+0x1ec/0x270
[   38.433322][  T957]        rtnl_fill_stats+0x44/0xbe0
[   38.433866][  T957]        rtnl_fill_ifinfo+0xeb2/0x3720
[   38.434474][  T957]        rtmsg_ifinfo_build_skb+0xca/0x170
[   38.435081][  T957]        rtmsg_ifinfo_event.part.33+0x1b/0xb0
[   38.436848][  T957]        rtnetlink_event+0xcd/0x120
[   38.437455][  T957]        notifier_call_chain+0x90/0x160
[   38.438067][  T957]        netdev_change_features+0x74/0xa0
[   38.438708][  T957]        bond_compute_features.isra.45+0x4e6/0x6f0 [bonding]
[   38.439522][  T957]        bond_enslave+0x3639/0x47b0 [bonding]
[   38.440225][  T957]        do_setlink+0xaab/0x2ef0
[   38.440786][  T957]        __rtnl_newlink+0x9c5/0x1270
[   38.441463][  T957]        rtnl_newlink+0x65/0x90
[   38.442075][  T957]        rtnetlink_rcv_msg+0x4a8/0x890
[   38.442774][  T957]        netlink_rcv_skb+0x121/0x350
[   38.443451][  T957]        netlink_unicast+0x42e/0x610
[   38.444282][  T957]        netlink_sendmsg+0x65a/0xb90
[   38.444992][  T957]        ____sys_sendmsg+0x5ce/0x7a0
[   38.445679][  T957]        ___sys_sendmsg+0x10f/0x1b0
[   38.446365][  T957]        __sys_sendmsg+0xc6/0x150
[   38.447007][  T957]        do_syscall_64+0x99/0x4f0
[   38.447668][  T957]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   38.448538][  T957]
[   38.448538][  T957] -> #0 (&bond->stats_lock_key#2){+.+.}:
[   38.449554][  T957]        __lock_acquire+0x2d8d/0x3de0
[   38.450148][  T957]        lock_acquire+0x164/0x3b0
[   38.450711][  T957]        _raw_spin_lock+0x30/0x70
[   38.451292][  T957]        bond_get_stats+0x90/0x4d0 [bonding]
[   38.451950][  T957]        dev_get_stats+0x1ec/0x270
[   38.452425][  T957]        bond_get_stats+0x1a5/0x4d0 [bonding]
[   38.453362][  T957]        dev_get_stats+0x1ec/0x270
[   38.453825][  T957]        rtnl_fill_stats+0x44/0xbe0
[   38.454390][  T957]        rtnl_fill_ifinfo+0xeb2/0x3720
[   38.456257][  T957]        rtmsg_ifinfo_build_skb+0xca/0x170
[   38.456998][  T957]        rtmsg_ifinfo_event.part.33+0x1b/0xb0
[   38.459351][  T957]        rtnetlink_event+0xcd/0x120
[   38.460086][  T957]        notifier_call_chain+0x90/0x160
[   38.460829][  T957]        netdev_change_features+0x74/0xa0
[   38.461752][  T957]        bond_compute_features.isra.45+0x4e6/0x6f0 [bonding]
[   38.462705][  T957]        bond_enslave+0x3639/0x47b0 [bonding]
[   38.463476][  T957]        do_setlink+0xaab/0x2ef0
[   38.464141][  T957]        __rtnl_newlink+0x9c5/0x1270
[   38.464897][  T957]        rtnl_newlink+0x65/0x90
[   38.465522][  T957]        rtnetlink_rcv_msg+0x4a8/0x890
[   38.466215][  T957]        netlink_rcv_skb+0x121/0x350
[   38.466895][  T957]        netlink_unicast+0x42e/0x610
[   38.467583][  T957]        netlink_sendmsg+0x65a/0xb90
[   38.468285][  T957]        ____sys_sendmsg+0x5ce/0x7a0
[   38.469202][  T957]        ___sys_sendmsg+0x10f/0x1b0
[   38.469884][  T957]        __sys_sendmsg+0xc6/0x150
[   38.470587][  T957]        do_syscall_64+0x99/0x4f0
[   38.471245][  T957]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   38.472093][  T957]
[   38.472093][  T957] other info that might help us debug this:
[   38.472093][  T957]
[   38.473438][  T957]  Possible unsafe locking scenario:
[   38.473438][  T957]
[   38.474898][  T957]        CPU0                    CPU1
[   38.476234][  T957]        ----                    ----
[   38.480171][  T957]   lock(&bond->stats_lock_key);
[   38.480808][  T957]                                lock(&bond->stats_lock_key#2);
[   38.481791][  T957]                                lock(&bond->stats_lock_key);
[   38.482754][  T957]   lock(&bond->stats_lock_key#2);
[   38.483416][  T957]
[   38.483416][  T957]  *** DEADLOCK ***
[   38.483416][  T957]
[   38.484505][  T957] 3 locks held by ip/957:
[   38.485048][  T957]  #0: ffffffffbccf6230 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x457/0x890
[   38.486198][  T957]  #1: ffff888065fd2cd8 (&bond->stats_lock_key){+.+.}, at: bond_get_stats+0x90/0x4d0 [bonding]
[   38.487625][  T957]  #2: ffffffffbc9254c0 (rcu_read_lock){....}, at: bond_get_stats+0x5/0x4d0 [bonding]
[   38.488897][  T957]
[   38.488897][  T957] stack backtrace:
[   38.489646][  T957] CPU: 1 PID: 957 Comm: ip Not tainted 5.5.0+ thesofproject#394
[   38.490497][  T957] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[   38.492810][  T957] Call Trace:
[   38.493219][  T957]  dump_stack+0x96/0xdb
[   38.493709][  T957]  check_noncircular+0x371/0x450
[   38.494344][  T957]  ? lookup_address+0x60/0x60
[   38.494923][  T957]  ? print_circular_bug.isra.35+0x310/0x310
[   38.495699][  T957]  ? hlock_class+0x130/0x130
[   38.496334][  T957]  ? __lock_acquire+0x2d8d/0x3de0
[   38.496979][  T957]  __lock_acquire+0x2d8d/0x3de0
[   38.497607][  T957]  ? register_lock_class+0x14d0/0x14d0
[   38.498333][  T957]  ? check_chain_key+0x236/0x5d0
[   38.499003][  T957]  lock_acquire+0x164/0x3b0
[   38.499800][  T957]  ? bond_get_stats+0x90/0x4d0 [bonding]
[   38.500706][  T957]  _raw_spin_lock+0x30/0x70
[   38.501435][  T957]  ? bond_get_stats+0x90/0x4d0 [bonding]
[   38.502311][  T957]  bond_get_stats+0x90/0x4d0 [bonding]
[ ... ]

But, there is another problem.
The dynamic lockdep class key is protected by RTNL, but bond_get_stats()
would be called outside of RTNL.
So, it would use an invalid dynamic lockdep class key.

In order to fix this issue, stats_lock uses spin_lock_nested() instead of
a dynamic lockdep key.
The bond_get_stats() calls bond_get_lowest_level_rcu() to get the correct
nest level value, which will be used by spin_lock_nested().
The "dev->lower_level" indicates lower nest level value, but this value
is invalid outside of RTNL.
So, bond_get_lowest_level_rcu() returns valid lower nest level value in
the RCU critical section.
bond_get_lowest_level_rcu() will be work only when LOCKDEP is enabled.

Fixes: 089bca2 ("bonding: use dynamic lockdep key instead of subclass")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
bardliao pushed a commit that referenced this pull request Feb 25, 2020
The only time we actually leave the path spinning is if we're truncating
a small amount and don't actually free an extent, which is not a common
occurrence.  We have to set the path blocking in order to add the
delayed ref anyway, so the first extent we find we set the path to
blocking and stay blocking for the duration of the operation.  With the
upcoming file extent map stuff there will be another case that we have
to have the path blocking, so just swap to blocking always.

Note: this patch also fixes a warning after 28553fa ("Btrfs: fix
race between shrinking truncate and fiemap") got merged that inserts
extent locks around truncation so the path must not leave spinning locks
after btrfs_search_slot.

  [70.794783] BUG: sleeping function called from invalid context at mm/slab.h:565
  [70.794834] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1141, name: rsync
  [70.794863] 5 locks held by rsync/1141:
  [70.794876]  #0: ffff888417b9c408 (sb_writers#17){.+.+}, at: mnt_want_write+0x20/0x50
  [70.795030]  #1: ffff888428de28e8 (&type->i_mutex_dir_key#13/1){+.+.}, at: lock_rename+0xf1/0x100
  [70.795051]  #2: ffff888417b9c608 (sb_internal#2){.+.+}, at: start_transaction+0x394/0x560
  [70.795124]  #3: ffff888403081768 (btrfs-fs-01){++++}, at: btrfs_try_tree_write_lock+0x2f/0x160
  [70.795203]  #4: ffff888403086568 (btrfs-fs-00){++++}, at: btrfs_try_tree_write_lock+0x2f/0x160
  [70.795222] CPU: 5 PID: 1141 Comm: rsync Not tainted 5.6.0-rc2-backup+ #2
  [70.795362] Call Trace:
  [70.795374]  dump_stack+0x71/0xa0
  [70.795445]  ___might_sleep.part.96.cold.106+0xa6/0xb6
  [70.795459]  kmem_cache_alloc+0x1d3/0x290
  [70.795471]  alloc_extent_state+0x22/0x1c0
  [70.795544]  __clear_extent_bit+0x3ba/0x580
  [70.795557]  ? _raw_spin_unlock_irq+0x24/0x30
  [70.795569]  btrfs_truncate_inode_items+0x339/0xe50
  [70.795647]  btrfs_evict_inode+0x269/0x540
  [70.795659]  ? dput.part.38+0x29/0x460
  [70.795671]  evict+0xcd/0x190
  [70.795682]  __dentry_kill+0xd6/0x180
  [70.795754]  dput.part.38+0x2ad/0x460
  [70.795765]  do_renameat2+0x3cb/0x540
  [70.795777]  __x64_sys_rename+0x1c/0x20

Reported-by: Dave Jones <davej@codemonkey.org.uk>
Fixes: 28553fa ("Btrfs: fix race between shrinking truncate and fiemap")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add note ]
Signed-off-by: David Sterba <dsterba@suse.com>
bardliao pushed a commit that referenced this pull request Feb 25, 2020
Commit 0579963 ("bpf: Add batch ops to all htab bpf map")
added lookup_and_delete batch operation for hash table.
The current implementation has bpf_lru_push_free() inside
the bucket lock, which may cause a deadlock.

syzbot reports:
   -> #2 (&htab->buckets[i].lock#2){....}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:159
       htab_lru_map_delete_node+0xce/0x2f0 kernel/bpf/hashtab.c:593
       __bpf_lru_list_shrink_inactive kernel/bpf/bpf_lru_list.c:220 [inline]
       __bpf_lru_list_shrink+0xf9/0x470 kernel/bpf/bpf_lru_list.c:266
       bpf_lru_list_pop_free_to_local kernel/bpf/bpf_lru_list.c:340 [inline]
       bpf_common_lru_pop_free kernel/bpf/bpf_lru_list.c:447 [inline]
       bpf_lru_pop_free+0x87c/0x1670 kernel/bpf/bpf_lru_list.c:499
       prealloc_lru_pop+0x2c/0xa0 kernel/bpf/hashtab.c:132
       __htab_lru_percpu_map_update_elem+0x67e/0xa90 kernel/bpf/hashtab.c:1069
       bpf_percpu_hash_update+0x16e/0x210 kernel/bpf/hashtab.c:1585
       bpf_map_update_value.isra.0+0x2d7/0x8e0 kernel/bpf/syscall.c:181
       generic_map_update_batch+0x41f/0x610 kernel/bpf/syscall.c:1319
       bpf_map_do_batch+0x3f5/0x510 kernel/bpf/syscall.c:3348
       __do_sys_bpf+0x9b7/0x41e0 kernel/bpf/syscall.c:3460
       __se_sys_bpf kernel/bpf/syscall.c:3355 [inline]
       __x64_sys_bpf+0x73/0xb0 kernel/bpf/syscall.c:3355
       do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

   -> #0 (&loc_l->lock){....}:
       check_prev_add kernel/locking/lockdep.c:2475 [inline]
       check_prevs_add kernel/locking/lockdep.c:2580 [inline]
       validate_chain kernel/locking/lockdep.c:2970 [inline]
       __lock_acquire+0x2596/0x4a00 kernel/locking/lockdep.c:3954
       lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4484
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:159
       bpf_common_lru_push_free kernel/bpf/bpf_lru_list.c:516 [inline]
       bpf_lru_push_free+0x250/0x5b0 kernel/bpf/bpf_lru_list.c:555
       __htab_map_lookup_and_delete_batch+0x8d4/0x1540 kernel/bpf/hashtab.c:1374
       htab_lru_map_lookup_and_delete_batch+0x34/0x40 kernel/bpf/hashtab.c:1491
       bpf_map_do_batch+0x3f5/0x510 kernel/bpf/syscall.c:3348
       __do_sys_bpf+0x1f7d/0x41e0 kernel/bpf/syscall.c:3456
       __se_sys_bpf kernel/bpf/syscall.c:3355 [inline]
       __x64_sys_bpf+0x73/0xb0 kernel/bpf/syscall.c:3355
       do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

    Possible unsafe locking scenario:

          CPU0                    CPU2
          ----                    ----
     lock(&htab->buckets[i].lock#2);
                                  lock(&l->lock);
                                  lock(&htab->buckets[i].lock#2);
     lock(&loc_l->lock);

    *** DEADLOCK ***

To fix the issue, for htab_lru_map_lookup_and_delete_batch() in CPU0,
let us do bpf_lru_push_free() out of the htab bucket lock. This can
avoid the above deadlock scenario.

Fixes: 0579963 ("bpf: Add batch ops to all htab bpf map")
Reported-by: syzbot+a38ff3d9356388f2fb83@syzkaller.appspotmail.com
Reported-by: syzbot+122b5421d14e68f29cd1@syzkaller.appspotmail.com
Suggested-by: Hillf Danton <hdanton@sina.com>
Suggested-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: Brian Vazquez <brianvv@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200219234757.3544014-1-yhs@fb.com
bardliao pushed a commit that referenced this pull request Feb 25, 2020
Damien Le Moal reports a lockdep splat with the acpi_power_meter,
observed with Linux v5.5 and later.

======================================================
WARNING: possible circular locking dependency detected
5.6.0-rc2+ thesofproject#629 Not tainted
------------------------------------------------------
python/1397 is trying to acquire lock:
ffff888619080070 (&resource->lock){+.+.}, at: show_power+0x3c/0xa0 [acpi_power_meter]

               but task is already holding lock:
ffff88881643f188 (kn->count#119){++++}, at: kernfs_seq_start+0x6a/0x160

               which lock already depends on the new lock.

               the existing dependency chain (in reverse order) is:

               -> #1 (kn->count#119){++++}:
       __kernfs_remove+0x626/0x7e0
       kernfs_remove_by_name_ns+0x41/0x80
       remove_attrs+0xcb/0x3c0 [acpi_power_meter]
       acpi_power_meter_notify+0x1f7/0x310 [acpi_power_meter]
       acpi_ev_notify_dispatch+0x198/0x1f3
       acpi_os_execute_deferred+0x4d/0x70
       process_one_work+0x7c8/0x1340
       worker_thread+0x94/0xc70
       kthread+0x2ed/0x3f0
       ret_from_fork+0x24/0x30

               -> #0 (&resource->lock){+.+.}:
       __lock_acquire+0x20be/0x49b0
       lock_acquire+0x127/0x340
       __mutex_lock+0x15b/0x1350
       show_power+0x3c/0xa0 [acpi_power_meter]
       dev_attr_show+0x3f/0x80
       sysfs_kf_seq_show+0x216/0x410
       seq_read+0x407/0xf90
       vfs_read+0x152/0x2c0
       ksys_read+0xf3/0x1d0
       do_syscall_64+0x95/0x1010
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

               other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(kn->count#119);
                               lock(&resource->lock);
                               lock(kn->count#119);
  lock(&resource->lock);

                *** DEADLOCK ***
4 locks held by python/1397:
 #0: ffff8890242d64e0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x9b/0xb0
 #1: ffff889040be74e0 (&p->lock){+.+.}, at: seq_read+0x6b/0xf90
 #2: ffff8890448eb880 (&of->mutex){+.+.}, at: kernfs_seq_start+0x47/0x160
 #3: ffff88881643f188 (kn->count#119){++++}, at: kernfs_seq_start+0x6a/0x160

               stack backtrace:
CPU: 10 PID: 1397 Comm: python Not tainted 5.6.0-rc2+ thesofproject#629
Hardware name: Supermicro Super Server/X11DPL-i, BIOS 3.1 05/21/2019
Call Trace:
 dump_stack+0x97/0xe0
 check_noncircular+0x32e/0x3e0
 ? print_circular_bug.isra.0+0x1e0/0x1e0
 ? unwind_next_frame+0xb9a/0x1890
 ? entry_SYSCALL_64_after_hwframe+0x49/0xbe
 ? graph_lock+0x79/0x170
 ? __lockdep_reset_lock+0x3c0/0x3c0
 ? mark_lock+0xbc/0x1150
 __lock_acquire+0x20be/0x49b0
 ? mark_held_locks+0xe0/0xe0
 ? stack_trace_save+0x91/0xc0
 lock_acquire+0x127/0x340
 ? show_power+0x3c/0xa0 [acpi_power_meter]
 ? device_remove_bin_file+0x10/0x10
 ? device_remove_bin_file+0x10/0x10
 __mutex_lock+0x15b/0x1350
 ? show_power+0x3c/0xa0 [acpi_power_meter]
 ? show_power+0x3c/0xa0 [acpi_power_meter]
 ? mutex_lock_io_nested+0x11f0/0x11f0
 ? lock_downgrade+0x6a0/0x6a0
 ? kernfs_seq_start+0x47/0x160
 ? lock_acquire+0x127/0x340
 ? kernfs_seq_start+0x6a/0x160
 ? device_remove_bin_file+0x10/0x10
 ? show_power+0x3c/0xa0 [acpi_power_meter]
 show_power+0x3c/0xa0 [acpi_power_meter]
 dev_attr_show+0x3f/0x80
 ? memset+0x20/0x40
 sysfs_kf_seq_show+0x216/0x410
 seq_read+0x407/0xf90
 ? security_file_permission+0x16f/0x2c0
 vfs_read+0x152/0x2c0

Problem is that reading an attribute takes the kernfs lock in the kernfs
code, then resource->lock in the driver. During an ACPI notification, the
opposite happens: The resource lock is taken first, followed by the kernfs
lock when sysfs attributes are removed and re-created. Presumably this is
now seen due to some locking related changes in kernfs after v5.4, but it
was likely always a problem.

Fix the problem by not blindly acquiring the lock in the notification
function. It is only needed to protect the various update functions.
However, those update functions are called anyway when sysfs attributes
are read. This means that we can just stop calling those functions from
the notifier, and the resource lock in the notifier function is no longer
needed.

That leaves two situations:

First, METER_NOTIFY_CONFIG removes and re-allocates capability strings.
While it did so under the resource lock, _displaying_ those strings was not
protected, creating a race condition. To solve this problem, selectively
protect both removal/creation and reporting of capability attributes with
the resource lock.

Second, removing and re-creating the attribute files is no longer protected
by the resource lock. That doesn't matter since access to each individual
attribute is protected by the kernfs lock. Userspace may get messed up if
attributes disappear and reappear under its nose, but that is not different
than today, and there is nothing we can do about it without major driver
restructuring.

Last but not least, when removing the driver, remove attribute functions
first, then release capability strings. This avoids yet another race
condition.

Reported-by: Damien Le Moal <Damien.LeMoal@wdc.com>
Cc: Damien Le Moal <Damien.LeMoal@wdc.com>
Cc: stable@vger.kernel.org # v5.5+
Tested-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
bardliao pushed a commit that referenced this pull request Mar 16, 2020
Luo bin says:

====================
hinic: BugFixes

the bug fixed in patch #2 has been present since the first commit.
the bugs fixed in patch #1 and patch #3 have been present since the
following commits:
patch #1: 352f58b ("net-next/hinic: Set Rxq irq to specific cpu for NUMA")
patch #3: 421e952 ("hinic: add rss support")
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
bardliao pushed a commit that referenced this pull request Mar 16, 2020
rmnet_get_port() internally calls rcu_dereference_rtnl(),
which checks RTNL.
But rmnet_get_port() could be called by packet path.
The packet path is not protected by RTNL.
So, the suspicious RCU usage problem occurs.

Test commands:
    modprobe rmnet
    ip netns add nst
    ip link add veth0 type veth peer name veth1
    ip link set veth1 netns nst
    ip link add rmnet0 link veth0 type rmnet mux_id 1
    ip netns exec nst ip link add rmnet1 link veth1 type rmnet mux_id 1
    ip netns exec nst ip link set veth1 up
    ip netns exec nst ip link set rmnet1 up
    ip netns exec nst ip a a 192.168.100.2/24 dev rmnet1
    ip link set veth0 up
    ip link set rmnet0 up
    ip a a 192.168.100.1/24 dev rmnet0
    ping 192.168.100.2

Splat looks like:
[  146.630958][ T1174] WARNING: suspicious RCU usage
[  146.631735][ T1174] 5.6.0-rc1+ thesofproject#447 Not tainted
[  146.632387][ T1174] -----------------------------
[  146.633151][ T1174] drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c:386 suspicious rcu_dereference_check() !
[  146.634742][ T1174]
[  146.634742][ T1174] other info that might help us debug this:
[  146.634742][ T1174]
[  146.645992][ T1174]
[  146.645992][ T1174] rcu_scheduler_active = 2, debug_locks = 1
[  146.646937][ T1174] 5 locks held by ping/1174:
[  146.647609][ T1174]  #0: ffff8880c31dea70 (sk_lock-AF_INET){+.+.}, at: raw_sendmsg+0xab8/0x2980
[  146.662463][ T1174]  #1: ffffffff93925660 (rcu_read_lock_bh){....}, at: ip_finish_output2+0x243/0x2150
[  146.671696][ T1174]  #2: ffffffff93925660 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x213/0x2940
[  146.673064][ T1174]  #3: ffff8880c19ecd58 (&dev->qdisc_running_key#7){+...}, at: ip_finish_output2+0x714/0x2150
[  146.690358][ T1174]  #4: ffff8880c5796898 (&dev->qdisc_xmit_lock_key#3){+.-.}, at: sch_direct_xmit+0x1e2/0x1020
[  146.699875][ T1174]
[  146.699875][ T1174] stack backtrace:
[  146.701091][ T1174] CPU: 0 PID: 1174 Comm: ping Not tainted 5.6.0-rc1+ thesofproject#447
[  146.705215][ T1174] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[  146.706565][ T1174] Call Trace:
[  146.707102][ T1174]  dump_stack+0x96/0xdb
[  146.708007][ T1174]  rmnet_get_port.part.9+0x76/0x80 [rmnet]
[  146.709233][ T1174]  rmnet_egress_handler+0x107/0x420 [rmnet]
[  146.710492][ T1174]  ? sch_direct_xmit+0x1e2/0x1020
[  146.716193][ T1174]  rmnet_vnd_start_xmit+0x3d/0xa0 [rmnet]
[  146.717012][ T1174]  dev_hard_start_xmit+0x160/0x740
[  146.717854][ T1174]  sch_direct_xmit+0x265/0x1020
[  146.718577][ T1174]  ? register_lock_class+0x14d0/0x14d0
[  146.719429][ T1174]  ? dev_watchdog+0xac0/0xac0
[  146.723738][ T1174]  ? __dev_queue_xmit+0x15fd/0x2940
[  146.724469][ T1174]  ? lock_acquire+0x164/0x3b0
[  146.725172][ T1174]  __dev_queue_xmit+0x20c7/0x2940
[ ... ]

Fixes: ceed73a ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
bardliao pushed a commit that referenced this pull request Mar 16, 2020
sel_lock cannot nest in the console lock. Thanks to syzkaller, the
kernel states firmly:

> WARNING: possible circular locking dependency detected
> 5.6.0-rc3-syzkaller #0 Not tainted
> ------------------------------------------------------
> syz-executor.4/20336 is trying to acquire lock:
> ffff8880a2e952a0 (&tty->termios_rwsem){++++}, at: tty_unthrottle+0x22/0x100 drivers/tty/tty_ioctl.c:136
>
> but task is already holding lock:
> ffffffff89462e70 (sel_lock){+.+.}, at: paste_selection+0x118/0x470 drivers/tty/vt/selection.c:374
>
> which lock already depends on the new lock.
>
> the existing dependency chain (in reverse order) is:
>
> -> #2 (sel_lock){+.+.}:
>        mutex_lock_nested+0x1b/0x30 kernel/locking/mutex.c:1118
>        set_selection_kernel+0x3b8/0x18a0 drivers/tty/vt/selection.c:217
>        set_selection_user+0x63/0x80 drivers/tty/vt/selection.c:181
>        tioclinux+0x103/0x530 drivers/tty/vt/vt.c:3050
>        vt_ioctl+0x3f1/0x3a30 drivers/tty/vt/vt_ioctl.c:364

This is ioctl(TIOCL_SETSEL).
Locks held on the path: console_lock -> sel_lock

> -> #1 (console_lock){+.+.}:
>        console_lock+0x46/0x70 kernel/printk/printk.c:2289
>        con_flush_chars+0x50/0x650 drivers/tty/vt/vt.c:3223
>        n_tty_write+0xeae/0x1200 drivers/tty/n_tty.c:2350
>        do_tty_write drivers/tty/tty_io.c:962 [inline]
>        tty_write+0x5a1/0x950 drivers/tty/tty_io.c:1046

This is write().
Locks held on the path: termios_rwsem -> console_lock

> -> #0 (&tty->termios_rwsem){++++}:
>        down_write+0x57/0x140 kernel/locking/rwsem.c:1534
>        tty_unthrottle+0x22/0x100 drivers/tty/tty_ioctl.c:136
>        mkiss_receive_buf+0x12aa/0x1340 drivers/net/hamradio/mkiss.c:902
>        tty_ldisc_receive_buf+0x12f/0x170 drivers/tty/tty_buffer.c:465
>        paste_selection+0x346/0x470 drivers/tty/vt/selection.c:389
>        tioclinux+0x121/0x530 drivers/tty/vt/vt.c:3055
>        vt_ioctl+0x3f1/0x3a30 drivers/tty/vt/vt_ioctl.c:364

This is ioctl(TIOCL_PASTESEL).
Locks held on the path: sel_lock -> termios_rwsem

> other info that might help us debug this:
>
> Chain exists of:
>   &tty->termios_rwsem --> console_lock --> sel_lock

Clearly. From the above, we have:
 console_lock -> sel_lock
 sel_lock -> termios_rwsem
 termios_rwsem -> console_lock

Fix this by reversing the console_lock -> sel_lock dependency in
ioctl(TIOCL_SETSEL). First, lock sel_lock, then console_lock.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Reported-by: syzbot+26183d9746e62da329b8@syzkaller.appspotmail.com
Fixes: 07e6124 ("vt: selection, close sel_buffer race")
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200228115406.5735-2-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bardliao pushed a commit that referenced this pull request Mar 16, 2020
journal_head::b_transaction and journal_head::b_next_transaction could
be accessed concurrently as noticed by KCSAN,

 LTP: starting fsync04
 /dev/zero: Can't open blockdev
 EXT4-fs (loop0): mounting ext3 file system using the ext4 subsystem
 EXT4-fs (loop0): mounted filesystem with ordered data mode. Opts: (null)
 ==================================================================
 BUG: KCSAN: data-race in __jbd2_journal_refile_buffer [jbd2] / jbd2_write_access_granted [jbd2]

 write to 0xffff99f9b1bd0e30 of 8 bytes by task 25721 on cpu 70:
  __jbd2_journal_refile_buffer+0xdd/0x210 [jbd2]
  __jbd2_journal_refile_buffer at fs/jbd2/transaction.c:2569
  jbd2_journal_commit_transaction+0x2d15/0x3f20 [jbd2]
  (inlined by) jbd2_journal_commit_transaction at fs/jbd2/commit.c:1034
  kjournald2+0x13b/0x450 [jbd2]
  kthread+0x1cd/0x1f0
  ret_from_fork+0x27/0x50

 read to 0xffff99f9b1bd0e30 of 8 bytes by task 25724 on cpu 68:
  jbd2_write_access_granted+0x1b2/0x250 [jbd2]
  jbd2_write_access_granted at fs/jbd2/transaction.c:1155
  jbd2_journal_get_write_access+0x2c/0x60 [jbd2]
  __ext4_journal_get_write_access+0x50/0x90 [ext4]
  ext4_mb_mark_diskspace_used+0x158/0x620 [ext4]
  ext4_mb_new_blocks+0x54f/0xca0 [ext4]
  ext4_ind_map_blocks+0xc79/0x1b40 [ext4]
  ext4_map_blocks+0x3b4/0x950 [ext4]
  _ext4_get_block+0xfc/0x270 [ext4]
  ext4_get_block+0x3b/0x50 [ext4]
  __block_write_begin_int+0x22e/0xae0
  __block_write_begin+0x39/0x50
  ext4_write_begin+0x388/0xb50 [ext4]
  generic_perform_write+0x15d/0x290
  ext4_buffered_write_iter+0x11f/0x210 [ext4]
  ext4_file_write_iter+0xce/0x9e0 [ext4]
  new_sync_write+0x29c/0x3b0
  __vfs_write+0x92/0xa0
  vfs_write+0x103/0x260
  ksys_write+0x9d/0x130
  __x64_sys_write+0x4c/0x60
  do_syscall_64+0x91/0xb05
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

 5 locks held by fsync04/25724:
  #0: ffff99f9911093f8 (sb_writers#13){.+.+}, at: vfs_write+0x21c/0x260
  #1: ffff99f9db4c0348 (&sb->s_type->i_mutex_key#15){+.+.}, at: ext4_buffered_write_iter+0x65/0x210 [ext4]
  #2: ffff99f5e7dfcf58 (jbd2_handle){++++}, at: start_this_handle+0x1c1/0x9d0 [jbd2]
  #3: ffff99f9db4c0168 (&ei->i_data_sem){++++}, at: ext4_map_blocks+0x176/0x950 [ext4]
  #4: ffffffff99086b40 (rcu_read_lock){....}, at: jbd2_write_access_granted+0x4e/0x250 [jbd2]
 irq event stamp: 1407125
 hardirqs last  enabled at (1407125): [<ffffffff980da9b7>] __find_get_block+0x107/0x790
 hardirqs last disabled at (1407124): [<ffffffff980da8f9>] __find_get_block+0x49/0x790
 softirqs last  enabled at (1405528): [<ffffffff98a0034c>] __do_softirq+0x34c/0x57c
 softirqs last disabled at (1405521): [<ffffffff97cc67a2>] irq_exit+0xa2/0xc0

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 68 PID: 25724 Comm: fsync04 Tainted: G L 5.6.0-rc2-next-20200221+ thesofproject#7
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019

The plain reads are outside of jh->b_state_lock critical section which result
in data races. Fix them by adding pairs of READ|WRITE_ONCE().

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Qian Cai <cai@lca.pw>
Link: https://lore.kernel.org/r/20200222043111.2227-1-cai@lca.pw
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
bardliao pushed a commit that referenced this pull request Mar 16, 2020
Fix NULL pointer dereference in the error flow of ib_create_qp_user
when accessing to uninitialized list pointers - rdma_mrs and sig_mrs.
The following crash from syzkaller revealed it.

  kasan: GPF could be caused by NULL-ptr deref or user memory access
  general protection fault: 0000 [#1] SMP KASAN PTI
  CPU: 1 PID: 23167 Comm: syz-executor.1 Not tainted 5.5.0-rc5 #2
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
  rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
  RIP: 0010:ib_mr_pool_destroy+0x81/0x1f0
  Code: 00 00 fc ff df 49 c1 ec 03 4d 01 fc e8 a8 ea 72 fe 41 80 3c 24 00
  0f 85 62 01 00 00 48 8b 13 48 89 d6 4c 8d 6a c8 48 c1 ee 03 <42> 80 3c
  3e 00 0f 85 34 01 00 00 48 8d 7a 08 4c 8b 02 48 89 fe 48
  RSP: 0018:ffffc9000951f8b0 EFLAGS: 00010046
  RAX: 0000000000040000 RBX: ffff88810f268038 RCX: ffffffff82c41628
  RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc9000951f850
  RBP: ffff88810f268020 R08: 0000000000000004 R09: fffff520012a3f0a
  R10: 0000000000000001 R11: fffff520012a3f0a R12: ffffed1021e4d007
  R13: ffffffffffffffc8 R14: 0000000000000246 R15: dffffc0000000000
  FS:  00007f54bc788700(0000) GS:ffff88811b100000(0000)
  knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000000 CR3: 0000000116920002 CR4: 0000000000360ee0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   rdma_rw_cleanup_mrs+0x15/0x30
   ib_destroy_qp_user+0x674/0x7d0
   ib_create_qp_user+0xb01/0x11c0
   create_qp+0x1517/0x2130
   ib_uverbs_create_qp+0x13e/0x190
   ib_uverbs_write+0xaa5/0xdf0
   __vfs_write+0x7c/0x100
   vfs_write+0x168/0x4a0
   ksys_write+0xc8/0x200
   do_syscall_64+0x9c/0x390
   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  RIP: 0033:0x465b49
  Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8 48 89
  f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01
  f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
  RSP: 002b:00007f54bc787c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
  RAX: ffffffffffffffda RBX: 000000000073bf00 RCX: 0000000000465b49
  RDX: 0000000000000040 RSI: 0000000020000540 RDI: 0000000000000003
  RBP: 00007f54bc787c70 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00007f54bc7886bc
  R13: 00000000004ca2ec R14: 000000000070ded0 R15: 0000000000000005

Fixes: a060b56 ("IB/core: generic RDMA READ/WRITE API")
Link: https://lore.kernel.org/r/20200227112708.93023-1-leon@kernel.org
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
bardliao pushed a commit that referenced this pull request Mar 27, 2020
Sigh, this is mostly my fault for not giving commit cd82d82
("drm/dp_mst: Add branch bandwidth validation to MST atomic check")
enough scrutiny during review. The way we're checking bandwidth
limitations here is mostly wrong:

For starters, drm_dp_mst_atomic_check_bw_limit() determines the
pbn_limit of a branch by simply scanning each port on the current branch
device, then uses the last non-zero full_pbn value that it finds. It
then counts the sum of the PBN used on each branch device for that
level, and compares against the full_pbn value it found before.

This is wrong because ports can and will have different PBN limitations
on many hubs, especially since a number of DisplayPort hubs out there
will be clever and only use the smallest link rate required for each
downstream sink - potentially giving every port a different full_pbn
value depending on what link rate it's trained at. This means with our
current code, which max PBN value we end up with is not well defined.

Additionally, we also need to remember when checking bandwidth
limitations that the top-most device in any MST topology is a branch
device, not a port. This means that the first level of a topology
doesn't technically have a full_pbn value that needs to be checked.
Instead, we should assume that so long as our VCPI allocations fit we're
within the bandwidth limitations of the primary MSTB.

We do however, want to check full_pbn on every port including those of
the primary MSTB. However, it's important to keep in mind that this
value represents the minimum link rate /between a port's sink or mstb,
and the mstb itself/. A quick diagram to explain:

                                MSTB #1
                               /       \
                              /         \
                           Port #1    Port #2
       full_pbn for Port #1 → |          | ← full_pbn for Port #2
                           Sink #1    MSTB #2
                                         |
                                       etc...

Note that in the above diagram, the combined PBN from all VCPI
allocations on said hub should not exceed the full_pbn value of port #2,
and the display configuration on sink #1 should not exceed the full_pbn
value of port #1. However, port #1 and port #2 can otherwise consume as
much bandwidth as they want so long as their VCPI allocations still fit.

And finally - our current bandwidth checking code also makes the mistake
of not checking whether something is an end device or not before trying
to traverse down it.

So, let's fix it by rewriting our bandwidth checking helpers. We split
the function into one part for handling branches which simply adds up
the total PBN on each branch and returns it, and one for checking each
port to ensure we're not going over its PBN limit. Phew.

This should fix regressions seen, where we erroneously reject display
configurations due to thinking they're going over our bandwidth limits
when they're not.

Changes since v1:
* Took an even closer look at how PBN limitations are supposed to be
  handled, and did some experimenting with Sean Paul. Ended up rewriting
  these helpers again, but this time they should actually be correct!
Changes since v2:
* Small indenting fix
* Fix pbn_used check in drm_dp_mst_atomic_check_port_bw_limit()

Signed-off-by: Lyude Paul <lyude@redhat.com>
Fixes: cd82d82 ("drm/dp_mst: Add branch bandwidth validation to MST atomic check")
Cc: Sean Paul <seanpaul@google.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Mikita Lipski <mikita.lipski@amd.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200309210131.1497545-1-lyude@redhat.com
bardliao pushed a commit that referenced this pull request Mar 27, 2020
The vector management code assumes that managed interrupts cannot be
migrated away from an online CPU. free_moved_vector() has a WARN_ON_ONCE()
which triggers when a managed interrupt vector association on a online CPU
is cleared. The CPU offline code uses a different mechanism which cannot
trigger this.

This assumption is not longer correct because the new CPU isolation feature
which affects the placement of managed interrupts must be able to move a
managed interrupt away from an online CPU.

There are two reasons why this can happen:

  1) When the interrupt is activated the affinity mask which was
     established in irq_create_affinity_masks() is handed in to
     the vector allocation code. This mask contains all CPUs to which
     the interrupt can be made affine to, but this does not take the
     CPU isolation 'managed_irq' mask into account.

     When the interrupt is finally requested by the device driver then the
     affinity is checked again and the CPU isolation 'managed_irq' mask is
     taken into account, which moves the interrupt to a non-isolated CPU if
     possible.

  2) The interrupt can be affine to an isolated CPU because the
     non-isolated CPUs in the calculated affinity mask are not online.

     Once a non-isolated CPU which is in the mask comes online the
     interrupt is migrated to this non-isolated CPU

In both cases the regular online migration mechanism is used which triggers
the WARN_ON_ONCE() in free_moved_vector().

Case #1 could have been addressed by taking the isolation mask into
account, but that would require a massive code change in the activation
logic and the eventual migration event was accepted as a reasonable
tradeoff when the isolation feature was developed. But even if #1 would be
addressed, #2 would still trigger it.

Of course the warning in free_moved_vector() was overlooked at that time
and the above two cases which have been discussed during patch review have
obviously never been tested before the final submission.

So keep it simple and remove the warning.

[ tglx: Rewrote changelog and added a comment to free_moved_vector() ]

Fixes: 11ea68f ("genirq, sched/isolation: Isolate from handling managed interrupts")
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>                                                                                                                                                                       
Link: https://lkml.kernel.org/r/20200312205830.81796-1-peterx@redhat.com
bardliao pushed a commit that referenced this pull request Apr 10, 2020
It is safe to traverse mm->notifier_subscriptions->list either under
SRCU read lock or mm->notifier_subscriptions->lock using
hlist_for_each_entry_rcu().  Silence the PROVE_RCU_LIST false positives,
for example,

  WARNING: suspicious RCU usage
  -----------------------------
  mm/mmu_notifier.c:484 RCU-list traversed in non-reader section!!

  other info that might help us debug this:

  rcu_scheduler_active = 2, debug_locks = 1
  3 locks held by libvirtd/802:
   #0: ffff9321e3f58148 (&mm->mmap_sem#2){++++}, at: do_mprotect_pkey+0xe1/0x3e0
   #1: ffffffff91ae6160 (mmu_notifier_invalidate_range_start){+.+.}, at: change_p4d_range+0x5fa/0x800
   #2: ffffffff91ae6e08 (srcu){....}, at: __mmu_notifier_invalidate_range_start+0x178/0x460

  stack backtrace:
  CPU: 7 PID: 802 Comm: libvirtd Tainted: G          I       5.6.0-rc6-next-20200317+ #2
  Hardware name: HP ProLiant BL460c Gen8, BIOS I31 11/02/2014
  Call Trace:
    dump_stack+0xa4/0xfe
    lockdep_rcu_suspicious+0xeb/0xf5
    __mmu_notifier_invalidate_range_start+0x3ff/0x460
    change_p4d_range+0x746/0x800
    change_protection+0x1df/0x300
    mprotect_fixup+0x245/0x3e0
    do_mprotect_pkey+0x23b/0x3e0
    __x64_sys_mprotect+0x51/0x70
    do_syscall_64+0x91/0xae8
    entry_SYSCALL_64_after_hwframe+0x49/0xb3

Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Link: http://lkml.kernel.org/r/20200317175640.2047-1-cai@lca.pw
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
bardliao pushed a commit that referenced this pull request Apr 23, 2020
Similar to commit 0266d81 ("acpi/processor: Prevent cpu hotplug
deadlock") except this is for acpi_processor_ffh_cstate_probe():

"The problem is that the work is scheduled on the current CPU from the
hotplug thread associated with that CPU.

It's not required to invoke these functions via the workqueue because
the hotplug thread runs on the target CPU already.

Check whether current is a per cpu thread pinned on the target CPU and
invoke the function directly to avoid the workqueue."

 WARNING: possible circular locking dependency detected
 ------------------------------------------------------
 cpuhp/1/15 is trying to acquire lock:
 ffffc90003447a28 ((work_completion)(&wfc.work)){+.+.}-{0:0}, at: __flush_work+0x4c6/0x630

 but task is already holding lock:
 ffffffffafa1c0e8 (cpuidle_lock){+.+.}-{3:3}, at: cpuidle_pause_and_lock+0x17/0x20

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #1 (cpu_hotplug_lock){++++}-{0:0}:
 cpus_read_lock+0x3e/0xc0
 irq_calc_affinity_vectors+0x5f/0x91
 __pci_enable_msix_range+0x10f/0x9a0
 pci_alloc_irq_vectors_affinity+0x13e/0x1f0
 pci_alloc_irq_vectors_affinity at drivers/pci/msi.c:1208
 pqi_ctrl_init+0x72f/0x1618 [smartpqi]
 pqi_pci_probe.cold.63+0x882/0x892 [smartpqi]
 local_pci_probe+0x7a/0xc0
 work_for_cpu_fn+0x2e/0x50
 process_one_work+0x57e/0xb90
 worker_thread+0x363/0x5b0
 kthread+0x1f4/0x220
 ret_from_fork+0x27/0x50

 -> #0 ((work_completion)(&wfc.work)){+.+.}-{0:0}:
 __lock_acquire+0x2244/0x32a0
 lock_acquire+0x1a2/0x680
 __flush_work+0x4e6/0x630
 work_on_cpu+0x114/0x160
 acpi_processor_ffh_cstate_probe+0x129/0x250
 acpi_processor_evaluate_cst+0x4c8/0x580
 acpi_processor_get_power_info+0x86/0x740
 acpi_processor_hotplug+0xc3/0x140
 acpi_soft_cpu_online+0x102/0x1d0
 cpuhp_invoke_callback+0x197/0x1120
 cpuhp_thread_fun+0x252/0x2f0
 smpboot_thread_fn+0x255/0x440
 kthread+0x1f4/0x220
 ret_from_fork+0x27/0x50

 other info that might help us debug this:

 Chain exists of:
 (work_completion)(&wfc.work) --> cpuhp_state-up --> cpuidle_lock

 Possible unsafe locking scenario:

 CPU0                    CPU1
 ----                    ----
 lock(cpuidle_lock);
                         lock(cpuhp_state-up);
                         lock(cpuidle_lock);
 lock((work_completion)(&wfc.work));

 *** DEADLOCK ***

 3 locks held by cpuhp/1/15:
 #0: ffffffffaf51ab10 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x69/0x2f0
 #1: ffffffffaf51ad40 (cpuhp_state-up){+.+.}-{0:0}, at: cpuhp_thread_fun+0x69/0x2f0
 #2: ffffffffafa1c0e8 (cpuidle_lock){+.+.}-{3:3}, at: cpuidle_pause_and_lock+0x17/0x20

 Call Trace:
 dump_stack+0xa0/0xea
 print_circular_bug.cold.52+0x147/0x14c
 check_noncircular+0x295/0x2d0
 __lock_acquire+0x2244/0x32a0
 lock_acquire+0x1a2/0x680
 __flush_work+0x4e6/0x630
 work_on_cpu+0x114/0x160
 acpi_processor_ffh_cstate_probe+0x129/0x250
 acpi_processor_evaluate_cst+0x4c8/0x580
 acpi_processor_get_power_info+0x86/0x740
 acpi_processor_hotplug+0xc3/0x140
 acpi_soft_cpu_online+0x102/0x1d0
 cpuhp_invoke_callback+0x197/0x1120
 cpuhp_thread_fun+0x252/0x2f0
 smpboot_thread_fn+0x255/0x440
 kthread+0x1f4/0x220
 ret_from_fork+0x27/0x50

Signed-off-by: Qian Cai <cai@lca.pw>
Tested-by: Borislav Petkov <bp@suse.de>
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
bardliao pushed a commit that referenced this pull request Apr 23, 2020
Patch series "mm: Fix misuse of parent anon_vma in dup_mmap path".

This patchset fixes the misuse of parenet anon_vma, which mainly caused by
child vma's vm_next and vm_prev are left same as its parent after
duplicate vma.  Finally, code reached parent vma's neighbor by referring
pointer of child vma and executed wrong logic.

The first two patches fix relevant issues, and the third patch sets
vm_next and vm_prev to NULL when duplicate vma to prevent potential misuse
in future.

Effects of the first bug is that causes rmap code to check both parent and
child's page table, although a page couldn't be mapped by both parent and
child, because child vma has WIPEONFORK so all pages mapped by child are
'new' and not relevant to parent.

Effects of the second bug is that the relationship of anon_vma of parent
and child are totallyconvoluted.  It would cause 'son', 'grandson', ...,
etc, to share 'parent' anon_vma, which disobey the design rule of reusing
anon_vma (the rule to be followed is that reusing should among vma of same
process, and vma should not gone through fork).

So, both issues should cause unnecessary rmap walking and have unexpected
complexity.

These two issues would not be directly visible, I used debugging code to
check the anon_vma pointers of parent and child when inspecting the
suspicious implementation of issue #2, then find the problem.

This patch (of 3):

In dup_mmap(), anon_vma_prepare() is called for vma has VM_WIPEONFORK, and
parameter 'tmp' (i.e., the new vma of child) has same ->vm_next and
->vm_prev as its parent vma.  That allows anon_vma used by parent been
mistakenly shared by child (find_mergeable_anon_vma() will do this reuse
work).

Besides this issue, call anon_vma_prepare() should be avoided because we
don't copy page for this vma.  Preparing anon_vma will be handled during
fault.

Fixes: d2cd9ed ("mm,fork: introduce MADV_WIPEONFORK")
Signed-off-by: Li Xinhai <lixinhai.lxh@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Link: http://lkml.kernel.org/r/1581150928-3214-2-git-send-email-lixinhai.lxh@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
bardliao pushed a commit that referenced this pull request May 8, 2020
FuzzUSB (a variant of syzkaller) found a free-while-still-in-use bug
in the USB scatter-gather library:

BUG: KASAN: use-after-free in atomic_read
include/asm-generic/atomic-instrumented.h:26 [inline]
BUG: KASAN: use-after-free in usb_hcd_unlink_urb+0x5f/0x170
drivers/usb/core/hcd.c:1607
Read of size 4 at addr ffff888065379610 by task kworker/u4:1/27

CPU: 1 PID: 27 Comm: kworker/u4:1 Not tainted 5.5.11 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.10.2-1ubuntu1 04/01/2014
Workqueue: scsi_tmf_2 scmd_eh_abort_handler
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0xce/0x128 lib/dump_stack.c:118
 print_address_description.constprop.4+0x21/0x3c0 mm/kasan/report.c:374
 __kasan_report+0x153/0x1cb mm/kasan/report.c:506
 kasan_report+0x12/0x20 mm/kasan/common.c:639
 check_memory_region_inline mm/kasan/generic.c:185 [inline]
 check_memory_region+0x152/0x1b0 mm/kasan/generic.c:192
 __kasan_check_read+0x11/0x20 mm/kasan/common.c:95
 atomic_read include/asm-generic/atomic-instrumented.h:26 [inline]
 usb_hcd_unlink_urb+0x5f/0x170 drivers/usb/core/hcd.c:1607
 usb_unlink_urb+0x72/0xb0 drivers/usb/core/urb.c:657
 usb_sg_cancel+0x14e/0x290 drivers/usb/core/message.c:602
 usb_stor_stop_transport+0x5e/0xa0 drivers/usb/storage/transport.c:937

This bug occurs when cancellation of the S-G transfer races with
transfer completion.  When that happens, usb_sg_cancel() may continue
to access the transfer's URBs after usb_sg_wait() has freed them.

The bug is caused by the fact that usb_sg_cancel() does not take any
sort of reference to the transfer, and so there is nothing to prevent
the URBs from being deallocated while the routine is trying to use
them.  The fix is to take such a reference by incrementing the
transfer's io->count field while the cancellation is in progres and
decrementing it afterward.  The transfer's URBs are not deallocated
until io->complete is triggered, which happens when io->count reaches
zero.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: Kyungtae Kim <kt0755@gmail.com>
CC: <stable@vger.kernel.org>

Link: https://lore.kernel.org/r/Pine.LNX.4.44L0.2003281615140.14837-100000@netrider.rowland.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bardliao pushed a commit that referenced this pull request May 18, 2020
…f fs_info::journal_info

[BUG]
One run of btrfs/063 triggered the following lockdep warning:
  ============================================
  WARNING: possible recursive locking detected
  5.6.0-rc7-custom+ thesofproject#48 Not tainted
  --------------------------------------------
  kworker/u24:0/7 is trying to acquire lock:
  ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]

  but task is already holding lock:
  ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(sb_internal#2);
    lock(sb_internal#2);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  4 locks held by kworker/u24:0/7:
   #0: ffff88817b495948 ((wq_completion)btrfs-endio-write){+.+.}, at: process_one_work+0x557/0xb80
   #1: ffff888189ea7db8 ((work_completion)(&work->normal_work)){+.+.}, at: process_one_work+0x557/0xb80
   #2: ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs]
   #3: ffff888174ca4da8 (&fs_info->reloc_mutex){+.+.}, at: btrfs_record_root_in_trans+0x83/0xd0 [btrfs]

  stack backtrace:
  CPU: 0 PID: 7 Comm: kworker/u24:0 Not tainted 5.6.0-rc7-custom+ thesofproject#48
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  Workqueue: btrfs-endio-write btrfs_work_helper [btrfs]
  Call Trace:
   dump_stack+0xc2/0x11a
   __lock_acquire.cold+0xce/0x214
   lock_acquire+0xe6/0x210
   __sb_start_write+0x14e/0x290
   start_transaction+0x66c/0x890 [btrfs]
   btrfs_join_transaction+0x1d/0x20 [btrfs]
   find_free_extent+0x1504/0x1a50 [btrfs]
   btrfs_reserve_extent+0xd5/0x1f0 [btrfs]
   btrfs_alloc_tree_block+0x1ac/0x570 [btrfs]
   btrfs_copy_root+0x213/0x580 [btrfs]
   create_reloc_root+0x3bd/0x470 [btrfs]
   btrfs_init_reloc_root+0x2d2/0x310 [btrfs]
   record_root_in_trans+0x191/0x1d0 [btrfs]
   btrfs_record_root_in_trans+0x90/0xd0 [btrfs]
   start_transaction+0x16e/0x890 [btrfs]
   btrfs_join_transaction+0x1d/0x20 [btrfs]
   btrfs_finish_ordered_io+0x55d/0xcd0 [btrfs]
   finish_ordered_fn+0x15/0x20 [btrfs]
   btrfs_work_helper+0x116/0x9a0 [btrfs]
   process_one_work+0x632/0xb80
   worker_thread+0x80/0x690
   kthread+0x1a3/0x1f0
   ret_from_fork+0x27/0x50

It's pretty hard to reproduce, only one hit so far.

[CAUSE]
This is because we're calling btrfs_join_transaction() without re-using
the current running one:

btrfs_finish_ordered_io()
|- btrfs_join_transaction()		<<< Call #1
   |- btrfs_record_root_in_trans()
      |- btrfs_reserve_extent()
	 |- btrfs_join_transaction()	<<< Call #2

Normally such btrfs_join_transaction() call should re-use the existing
one, without trying to re-start a transaction.

But the problem is, in btrfs_join_transaction() call #1, we call
btrfs_record_root_in_trans() before initializing current::journal_info.

And in btrfs_join_transaction() call #2, we're relying on
current::journal_info to avoid such deadlock.

[FIX]
Call btrfs_record_root_in_trans() after we have initialized
current::journal_info.

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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