Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx>
* Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
On Sun, Apr 19, 2015 at 4:48 AM, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
Does that smaller patch work equally well?
.. and here's a properly formatted email and patch.
Linus
kernel/smp.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
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;
+ }
Acked-by: Ingo Molnar <mingo@xxxxxxxxxx>
Btw., in this case we should probably also generate a WARN_ONCE()Not really; at least the online cpu part is an absolutely normal use
warning?
I _think_ most such callers calling an SMP function call for offline
or out of range CPUs are at minimum racy.