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| author | Rainer Gerhards <rgerhards@adiscon.com> | 2009-01-30 13:49:41 +0100 |
|---|---|---|
| committer | Rainer Gerhards <rgerhards@adiscon.com> | 2009-01-30 13:49:41 +0100 |
| commit | 2cfaf5f86a4fb40cc37ae71118c506f1d924df13 (patch) | |
| tree | 4ddc545b4d091885404f04c7fa06cc199e752c8e /runtime | |
| parent | ce11f7bdb8db977a8b00b28d9b84d1b1c924f3c3 (diff) | |
| download | rsyslog-2cfaf5f86a4fb40cc37ae71118c506f1d924df13.tar.gz rsyslog-2cfaf5f86a4fb40cc37ae71118c506f1d924df13.tar.bz2 rsyslog-2cfaf5f86a4fb40cc37ae71118c506f1d924df13.zip | |
bugfix: inconsistent use of mutex/atomic operations could cause segfault
details are too many, for full analysis see blog post at:
http://blog.gerhards.net/2009/01/rsyslog-data-race-analysis.html
Diffstat (limited to 'runtime')
| -rw-r--r-- | runtime/atomic.h | 2 | ||||
| -rw-r--r-- | runtime/msg.c | 13 |
2 files changed, 8 insertions, 7 deletions
diff --git a/runtime/atomic.h b/runtime/atomic.h index 2dbe7f52..2c20e0c3 100644 --- a/runtime/atomic.h +++ b/runtime/atomic.h @@ -46,7 +46,7 @@ # define ATOMIC_FETCH_32BIT(data) ((unsigned) __sync_fetch_and_and(&(data), 0xffffffff)) # define ATOMIC_STORE_1_TO_32BIT(data) __sync_lock_test_and_set(&(data), 1) #else -# warning "atomic builtins not available, using nul operations" +# warning "atomic builtins not available, using nul operations - rsyslogd will probably be racy!" # define ATOMIC_INC(data) (++(data)) # define ATOMIC_DEC_AND_FETCH(data) (--(data)) # define ATOMIC_FETCH_32BIT(data) (data) diff --git a/runtime/msg.c b/runtime/msg.c index 3073fc5f..038e002a 100644 --- a/runtime/msg.c +++ b/runtime/msg.c @@ -281,14 +281,13 @@ finalize_it: BEGINobjDestruct(msg) /* be sure to specify the object type also in END and CODESTART macros! */ int currRefCount; CODESTARTobjDestruct(msg) - /* DEV Debugging only ! dbgprintf("msgDestruct\t0x%lx, Ref now: %d\n", (unsigned long)pM, pM->iRefCount - 1); */ -//# ifdef DO_HAVE_ATOMICS -// currRefCount = ATOMIC_DEC_AND_FETCH(pThis->iRefCount); -//# else + /* DEV Debugging only ! dbgprintf("msgDestruct\t0x%lx, Ref now: %d\n", (unsigned long)pThis, pThis->iRefCount - 1); */ +# ifdef HAVE_ATOMIC_BUILTINS + currRefCount = ATOMIC_DEC_AND_FETCH(pThis->iRefCount); +# else MsgLock(pThis); currRefCount = --pThis->iRefCount; -//# endif -// we need a mutex, because we may be suspended after getting the refcount but before +# endif if(currRefCount == 0) { /* DEV Debugging Only! dbgprintf("msgDestruct\t0x%lx, RefCount now 0, doing DESTROY\n", (unsigned long)pThis); */ @@ -348,7 +347,9 @@ CODESTARTobjDestruct(msg) rsCStrDestruct(&pThis->pCSPROCID); if(pThis->pCSMSGID != NULL) rsCStrDestruct(&pThis->pCSMSGID); +# ifndef HAVE_ATOMIC_BUILTINS MsgUnlock(pThis); +# endif funcDeleteMutex(pThis); } else { MsgUnlock(pThis); |