CVS commit: src/sys/kern

["Taylor R Campbell" <riastradh%netbsd.org@localhost>]

Module Name:    src
Committed By:   riastradh
Date:           Mon May  4 13:58:48 UTC 2020

Modified Files:
        src/sys/kern: uipc_sem.c

Log Message:
Release the collision if we find one.

Candidate fix for:

panic: lock error: Mutex: mutex_vector_enter,542: locking against myself: lock 0xffff8f611abd37e0 cpu 8 lwp 0xffff8f60a3c6a040
cpu8: Begin traceback...
vpanic() at netbsd:vpanic+0x178
snprintf() at netbsd:snprintf
lockdebug_abort() at netbsd:lockdebug_abort+0xe6
mutex_vector_enter() at netbsd:mutex_vector_enter+0x3c1
ksem_close_fop() at netbsd:ksem_close_fop+0x17
closef() at netbsd:closef+0x69
fd_free() at netbsd:fd_free+0x101
exit1() at netbsd:exit1+0x118
sys_exit() at netbsd:sys_exit+0x3d
syscall() at netbsd:syscall+0x299

Would be nice to have an automatic test for this.  Since semids are
only 24 bits, we only need to create a few thousand of them to have a
high probability of collision.  Maybe we should bump default semmax
while here...


To generate a diff of this commit:
cvs rdiff -u -r1.58 -r1.59 src/sys/kern/uipc_sem.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.