diff options
| author | kib <kib@FreeBSD.org> | 2016-08-01 06:35:35 +0000 |
|---|---|---|
| committer | kib <kib@FreeBSD.org> | 2016-08-01 06:35:35 +0000 |
| commit | 36e8256d894d8e6473f9f42eefff0f7e32fd868a (patch) | |
| tree | e4e823b502a8488f97f0cf838503d24798de65df /sys/kern/subr_trap.c | |
| parent | fd5fb6ea0d0460e476248d5d425c067d846c2c3d (diff) | |
| download | FreeBSD-src-36e8256d894d8e6473f9f42eefff0f7e32fd868a.zip FreeBSD-src-36e8256d894d8e6473f9f42eefff0f7e32fd868a.tar.gz | |
MFC r302614:
Revive the check, disabled in r197963.
MFC r302999:
On first exec after vfork(), call signotify() to handle pending
reenabled signals.
Diffstat (limited to 'sys/kern/subr_trap.c')
| -rw-r--r-- | sys/kern/subr_trap.c | 55 |
1 files changed, 45 insertions, 10 deletions
diff --git a/sys/kern/subr_trap.c b/sys/kern/subr_trap.c index 0b5d380b..bc2e294 100644 --- a/sys/kern/subr_trap.c +++ b/sys/kern/subr_trap.c @@ -108,17 +108,29 @@ userret(struct thread *td, struct trapframe *frame) td->td_name); KASSERT((p->p_flag & P_WEXIT) == 0, ("Exiting process returns to usermode")); -#if 0 #ifdef DIAGNOSTIC - /* Check that we called signotify() enough. */ - PROC_LOCK(p); - thread_lock(td); - if (SIGPENDING(td) && ((td->td_flags & TDF_NEEDSIGCHK) == 0 || - (td->td_flags & TDF_ASTPENDING) == 0)) - printf("failed to set signal flags properly for ast()\n"); - thread_unlock(td); - PROC_UNLOCK(p); -#endif + /* + * Check that we called signotify() enough. For + * multi-threaded processes, where signal distribution might + * change due to other threads changing sigmask, the check is + * racy and cannot be performed reliably. + * If current process is vfork child, indicated by P_PPWAIT, then + * issignal() ignores stops, so we block the check to avoid + * classifying pending signals. + */ + if (p->p_numthreads == 1) { + PROC_LOCK(p); + thread_lock(td); + if ((p->p_flag & P_PPWAIT) == 0) { + KASSERT(!SIGPENDING(td) || (td->td_flags & + (TDF_NEEDSIGCHK | TDF_ASTPENDING)) == + (TDF_NEEDSIGCHK | TDF_ASTPENDING), + ("failed to set signal flags for ast p %p " + "td %p fl %x", p, td, td->td_flags)); + } + thread_unlock(td); + PROC_UNLOCK(p); + } #endif #ifdef KTRACE KTRUSERRET(td); @@ -268,6 +280,29 @@ ast(struct trapframe *framep) #endif } +#ifdef DIAGNOSTIC + if (p->p_numthreads == 1 && (flags & TDF_NEEDSIGCHK) == 0) { + PROC_LOCK(p); + thread_lock(td); + /* + * Note that TDF_NEEDSIGCHK should be re-read from + * td_flags, since signal might have been delivered + * after we cleared td_flags above. This is one of + * the reason for looping check for AST condition. + * See comment in userret() about P_PPWAIT. + */ + if ((p->p_flag & P_PPWAIT) == 0) { + KASSERT(!SIGPENDING(td) || (td->td_flags & + (TDF_NEEDSIGCHK | TDF_ASTPENDING)) == + (TDF_NEEDSIGCHK | TDF_ASTPENDING), + ("failed2 to set signal flags for ast p %p td %p " + "fl %x %x", p, td, flags, td->td_flags)); + } + thread_unlock(td); + PROC_UNLOCK(p); + } +#endif + /* * Check for signals. Unlocked reads of p_pendingcnt or * p_siglist might cause process-directed signal to be handled |
