Date: Fri, 11 Dec 2015 20:05:07 +0000 (UTC) From: Mark Johnston <markj@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r292117 - in head/sys: kern vm Message-ID: <201512112005.tBBK576W086543@repo.freebsd.org>
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Author: markj Date: Fri Dec 11 20:05:07 2015 New Revision: 292117 URL: https://svnweb.freebsd.org/changeset/base/292117 Log: Don't make assertions about td_critnest when the scheduler is stopped. A panicking thread always executes with a critical section held, so any attempt to allocate or free memory while dumping will otherwise cause a second panic. This can occur, for example, if xpt_polled_action() completes non-dump I/O that was pending at the time of the panic. The fact that this can occur is itself a bug, but asserting in this case does little but reduce the reliability of kernel dumps. Suggested by: kib Reported by: pho Modified: head/sys/kern/kern_malloc.c head/sys/vm/uma_core.c Modified: head/sys/kern/kern_malloc.c ============================================================================== --- head/sys/kern/kern_malloc.c Fri Dec 11 18:47:41 2015 (r292116) +++ head/sys/kern/kern_malloc.c Fri Dec 11 20:05:07 2015 (r292117) @@ -475,8 +475,7 @@ malloc(unsigned long size, struct malloc if (flags & M_WAITOK) KASSERT(curthread->td_intr_nesting_level == 0, ("malloc(M_WAITOK) in interrupt context")); - - KASSERT(curthread->td_critnest == 0, + KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(), ("malloc: called with spinlock or critical section held")); #ifdef DEBUG_MEMGUARD @@ -544,8 +543,7 @@ free(void *addr, struct malloc_type *mtp u_long size; KASSERT(mtp->ks_magic == M_MAGIC, ("free: bad malloc type magic")); - - KASSERT(curthread->td_critnest == 0, + KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(), ("free: called with spinlock or critical section held")); /* free(NULL, ...) does nothing */ @@ -610,8 +608,7 @@ realloc(void *addr, unsigned long size, KASSERT(mtp->ks_magic == M_MAGIC, ("realloc: bad malloc type magic")); - - KASSERT(curthread->td_critnest == 0, + KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(), ("realloc: called with spinlock or critical section held")); /* realloc(NULL, ...) is equivalent to malloc(...) */ Modified: head/sys/vm/uma_core.c ============================================================================== --- head/sys/vm/uma_core.c Fri Dec 11 18:47:41 2015 (r292116) +++ head/sys/vm/uma_core.c Fri Dec 11 20:05:07 2015 (r292117) @@ -2149,8 +2149,7 @@ uma_zalloc_arg(uma_zone_t zone, void *ud WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "uma_zalloc_arg: zone \"%s\"", zone->uz_name); } - - KASSERT(curthread->td_critnest == 0, + KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(), ("uma_zalloc_arg: called with spinlock or critical section held")); #ifdef DEBUG_MEMGUARD @@ -2690,7 +2689,7 @@ uma_zfree_arg(uma_zone_t zone, void *ite CTR2(KTR_UMA, "uma_zfree_arg thread %x zone %s", curthread, zone->uz_name); - KASSERT(curthread->td_critnest == 0, + KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(), ("uma_zfree_arg: called with spinlock or critical section held")); /* uma_zfree(..., NULL) does nothing, to match free(9). */
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