From 279b97daea47b784fa8af7f9e6174384c141cdff Mon Sep 17 00:00:00 2001 From: attilio Date: Tue, 30 Oct 2012 15:10:50 +0000 Subject: Fixup r240246: hwpmc needs to retain the pinning until ASTs are not executed. This means past the point where userret() is generally executed. Skip the td_pinned check if a callchain tracing is currently happening and add a more robust check to pmc_capture_user_callchain() in order to catch td_pinned leak past ast() in hwpmc case. Reported and tested by: fabient MFC after: 1 week X-MFC: r240246 --- sys/kern/subr_trap.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'sys/kern/subr_trap.c') diff --git a/sys/kern/subr_trap.c b/sys/kern/subr_trap.c index 70df8a1..22cabcb 100644 --- a/sys/kern/subr_trap.c +++ b/sys/kern/subr_trap.c @@ -145,6 +145,11 @@ userret(struct thread *td, struct trapframe *frame) /* * Check for misbehavior. + * + * In case there is a callchain tracing ongoing because of + * hwpmc(4), skip the scheduler pinning check. + * hwpmc(4) subsystem, infact, will collect callchain informations + * at ast() checkpoint, which is past userret(). */ WITNESS_WARN(WARN_PANIC, NULL, "userret: returning"); KASSERT(td->td_critnest == 0, @@ -155,7 +160,7 @@ userret(struct thread *td, struct trapframe *frame) ("userret: Returning with pagefaults disabled")); KASSERT((td->td_pflags & TDP_NOSLEEPING) == 0, ("userret: Returning with sleep disabled")); - KASSERT(td->td_pinned == 0, + KASSERT(td->td_pinned == 0 || (td->td_pflags & TDP_CALLCHAIN) != 0, ("userret: Returning with with pinned thread")); KASSERT(td->td_vp_reserv == 0, ("userret: Returning while holding vnode reservation")); -- cgit v1.1