OCaml 4.13 memory leak in caml_setup_stack_overflow_detection #10698
Description
Run any ocamlopt-compiled program under valgrind --leak-check=full and you will see:
==2560078== 8,192 bytes in 1 blocks are definitely lost in loss record 25 of 33
==2560078== at 0x484086F: malloc (vg_replace_malloc.c:380)
==2560078== by 0x13C969: caml_setup_stack_overflow_detection (in /var/tmp/test)
==2560078== by 0x13C9E3: caml_init_signals (in /var/tmp/test)
==2560078== by 0x13B684: caml_startup_common (in /var/tmp/test)
==2560078== by 0x13B76E: caml_main (in /var/tmp/test)
==2560078== by 0x11C6D1: main (in /var/tmp/test)
This leak seems to be new in OCaml 4.13.1.
In nbdkit we maintain a set of valgrind suppressions for OCaml, and the only ones we expect are functions matching caml_stat_alloc*: https://gitlab.com/nbdkit/nbdkit/-/blob/master/valgrind/ocaml.suppressions