The existing CPUSet type is a fixed-size array limited to 1024 CPUs,
which makes it problematic to use for large systems (such as Google's
X4 instances with 1440 and 1920 vCPUs), see e.g.
opencontainers/runc#5023.

Introduce CPUSetDynamic type and NewCPUSet constructor to support large
systems. The bit-managing routines (set/clear/isset/fill/count) are
separated and reused.

Add variants of SchedGetaffinity, SchedSetaffinity and SetMemPolicy
that accept the new type.

Amend the documentation for CPUSet.

Amend the existing TestSchedSetaffinity to:
 - test set.Fill;
 - use t.Cleanup to restore the affinity.

Add tests for new functionality (mostly a copy of existing tests).

This is an alternative to CL 727540 / CL 727541.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
Change-Id: I51bba0305b8dfa7a88a4e7fb8758d73f798574f1
Reviewed-on: https://go-review.googlesource.com/c/sys/+/735380
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

Passing a nil buf *Utimbuf to Utime on linux/{arm,arm64,loong64,riscv64}
will cause a nil pointer dereference. Check buf explicitly to avoid this
case.

Change-Id: Ifb719f83029002f043919daa066af6b1fb4ebe03
Reviewed-on: https://go-review.googlesource.com/c/sys/+/764562
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: David Chase <drchase@google.com>

When GOOS=linux, mkall.sh creates a container to run linux/mkall.go.  It does not
remove this container before exiting.  Therefore each time you run mkall.sh on Linux
you end up with a new stopped container that must be manually deleted with docker rm.
This is cumbersome as it may take several runs of mkall.sh to develop and test a patch
for golang/x/sys/unix resulting in multiple containers that require manual removal.
It's also a little counterintuitive as the user doesn't invoke the docker command directly
so it's not obvious that manual cleanup is required after mkall.sh completes.  The
leftover containers aren't even that useful for debugging as they have an entrypoint
set.

Change-Id: I92a94ae53078f0095d3ddf1d95c4879f1bc1cb2a
Reviewed-on: https://go-review.googlesource.com/c/sys/+/513335
Auto-Submit: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Florian Lehner <lehner.florian86@gmail.com>
Reviewed-by: Junyang Shao <shaojunyang@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>

This CL started as revert of CL 757482.

Fixes golang/go#76791

Change-Id: Iaa78c73a6dde8d735e74e2c57c86375ccd5902c7
Reviewed-on: https://go-review.googlesource.com/c/sys/+/758960
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Quim Muntal <quimmuntal@gmail.com>
LUCI-TryBot-Result: golang-scoped@luci-project-accounts.iam.gserviceaccount.com <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

…AddressTable

GetIfTable2Ex retrieves the MIB-II interface table.

GetIpInterfaceEntry retrieves IP information for the specified interface.

GetIpInterfaceTable retrieves the IP interface entries.

GetUnicastIpAddressTable retrieves the unicast IP address table.

Change-Id: If9f619cb48da204da3bac8b429b3231432337b0a
Reviewed-on: https://go-review.googlesource.com/c/sys/+/744880
LUCI-TryBot-Result: golang-scoped@luci-project-accounts.iam.gserviceaccount.com <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>

Fixes CVE-2026-39824
Fixes #78916

Change-Id: I344518a17d59fd81c4bb39da0b3e13be6a6a6964
Reviewed-on: https://go-review.googlesource.com/c/sys/+/770080
Reviewed-by: Neal Patel <nealpatel@google.com>
Reviewed-by: Quim Muntal <quimmuntal@gmail.com>
LUCI-TryBot-Result: golang-scoped@luci-project-accounts.iam.gserviceaccount.com <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Damien Neil <dneil@google.com>