Author: asomers Date: Wed Jul 11 19:38:42 2018 New Revision: 336205 URL: https://svnweb.freebsd.org/changeset/base/336205
Log: Don't acquire evclass_lock with a spinlock held When the "pc" audit class is enabled and auditd is running, witness will panic during thread exit because au_event_class tries to lock an rwlock while holding a spinlock acquired upstack by thread_exit. To fix this, move AUDIT_SYSCALL_EXIT futher upstack, before the spinlock is acquired. Of thread_exit's 16 callers, it's only necessary to call AUDIT_SYSCALL_EXIT from two, exit1 (for exiting processes) and kern_thr_exit (for exiting threads). The other callers are all kernel threads, which needen't call AUDIT_SYSCALL_EXIT because since they can't make syscalls there will be nothing to audit. And exit1 already does call AUDIT_SYSCALL_EXIT, making the second call in thread_exit redundant for that case. PR: 228444 Reported by: aniketp Reviewed by: aniketp, kib MFC after: 2 weeks Differential Revision: https://reviews.freebsd.org/D16210 Modified: head/sys/kern/kern_thr.c head/sys/kern/kern_thread.c Modified: head/sys/kern/kern_thr.c ============================================================================== --- head/sys/kern/kern_thr.c Wed Jul 11 19:23:11 2018 (r336204) +++ head/sys/kern/kern_thr.c Wed Jul 11 19:38:42 2018 (r336205) @@ -374,6 +374,11 @@ kern_thr_exit(struct thread *td) KASSERT(p->p_numthreads > 1, ("too few threads")); racct_sub(p, RACCT_NTHR, 1); tdsigcleanup(td); + +#ifdef AUDIT + AUDIT_SYSCALL_EXIT(0, td); +#endif + PROC_SLOCK(p); thread_stopped(p); thread_exit(); Modified: head/sys/kern/kern_thread.c ============================================================================== --- head/sys/kern/kern_thread.c Wed Jul 11 19:23:11 2018 (r336204) +++ head/sys/kern/kern_thread.c Wed Jul 11 19:38:42 2018 (r336205) @@ -532,9 +532,6 @@ thread_exit(void) SDT_PROBE0(proc, , , lwp__exit); KASSERT(TAILQ_EMPTY(&td->td_sigqueue.sq_list), ("signal pending")); -#ifdef AUDIT - AUDIT_SYSCALL_EXIT(0, td); -#endif /* * drop FPU & debug register state storage, or any other * architecture specific resources that _______________________________________________ email@example.com mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"