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| author | Jesper Juhl <jesper.juhl@gmail.com> | 2008-03-04 14:29:00 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2008-03-04 16:35:14 -0800 |
| commit | 544adb41077a10d299a1094f12ec55a5843a9bdb (patch) | |
| tree | c865b4792e67fcd96171a514c3a649fcce0cde39 /kernel/marker.c | |
| parent | 7088655477b51a5a248fa54190388e1283ba7ebf (diff) | |
| download | lwn-544adb41077a10d299a1094f12ec55a5843a9bdb.tar.gz lwn-544adb41077a10d299a1094f12ec55a5843a9bdb.zip | |
markers: don't risk NULL deref in marker
get_marker() may return NULL, so test for it.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/marker.c')
| -rw-r--r-- | kernel/marker.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/kernel/marker.c b/kernel/marker.c index 50effc01d9a2..48a4ea5afffd 100644 --- a/kernel/marker.c +++ b/kernel/marker.c @@ -698,14 +698,12 @@ int marker_probe_unregister(const char *name, { struct marker_entry *entry; struct marker_probe_closure *old; - int ret = 0; + int ret = -ENOENT; mutex_lock(&markers_mutex); entry = get_marker(name); - if (!entry) { - ret = -ENOENT; + if (!entry) goto end; - } if (entry->rcu_pending) rcu_barrier(); old = marker_entry_remove_probe(entry, probe, probe_private); @@ -713,12 +711,15 @@ int marker_probe_unregister(const char *name, marker_update_probes(); /* may update entry */ mutex_lock(&markers_mutex); entry = get_marker(name); + if (!entry) + goto end; entry->oldptr = old; entry->rcu_pending = 1; /* write rcu_pending before calling the RCU callback */ smp_wmb(); call_rcu(&entry->rcu, free_old_closure); remove_marker(name); /* Ignore busy error message */ + ret = 0; end: mutex_unlock(&markers_mutex); return ret; |