path: root/kernel
diff options
authorLinus Torvalds <torvalds@linux-foundation.org>2015-04-19 04:56:03 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2015-04-19 13:19:23 -0700
commit5224b9613b91d937c6948fe977023247afbcc04e (patch)
treebee9cc7cfcb2c338d06bb933c1e76c2d3cf68a46 /kernel
parent64fb1d0e975e92e012802d371e417266d6531676 (diff)
smp: Fix error case handling in smp_call_function_*()
Commit 8053871d0f7f ("smp: Fix smp_call_function_single_async() locking") fixed the locking for the asynchronous smp-call case, but in the process of moving the lock handling around, one of the error cases ended up not unlocking the call data at all. This went unnoticed on x86, because this is a "caller is buggy" case, where the caller is trying to call a non-existent CPU. But apparently ARM does that (at least under qemu-arm). Bindly doing cross-cpu calls to random CPU's that aren't even online seems a bit fishy, but the error handling was clearly not correct. Simply add the missing "csd_unlock()" to the error path. Reported-and-tested-by: Guenter Roeck <linux@roeck-us.net> Analyzed-by: Rabin Vincent <rabin@rab.in> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/smp.c b/kernel/smp.c
index 2aaac2c47683..07854477c164 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -159,8 +159,10 @@ static int generic_exec_single(int cpu, struct call_single_data *csd,
- if ((unsigned)cpu >= nr_cpu_ids || !cpu_online(cpu))
+ if ((unsigned)cpu >= nr_cpu_ids || !cpu_online(cpu)) {
+ csd_unlock(csd);
return -ENXIO;
+ }
csd->func = func;
csd->info = info;

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