[tip:sched/urgent] sched: Fix sched_getaffinity()

From: tip-bot for Anton Blanchard
Date: Tue Apr 06 2010 - 04:32:56 EST

Commit-ID: 84fba5ec91f11c0efb27d0ed6098f7447491f0df
Gitweb: http://git.kernel.org/tip/84fba5ec91f11c0efb27d0ed6098f7447491f0df
Author: Anton Blanchard <anton@xxxxxxxxx>
AuthorDate: Tue, 6 Apr 2010 17:02:19 +1000
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Tue, 6 Apr 2010 10:01:35 +0200

sched: Fix sched_getaffinity()

taskset on 2.6.34-rc3 fails on one of my ppc64 test boxes with
the following error:

sched_getaffinity(0, 16, 0x10029650030) = -1 EINVAL (Invalid argument)

This box has 128 threads and 16 bytes is enough to cover it.

Commit cd3d8031eb4311e516329aee03c79a08333141f1 (sched:
sched_getaffinity(): Allow less than NR_CPUS length) is
comparing this 16 bytes agains nr_cpu_ids.

Fix it by comparing nr_cpu_ids to the number of bits in the
cpumask we pass in.

Signed-off-by: Anton Blanchard <anton@xxxxxxxxx>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Sharyathi Nagesh <sharyath@xxxxxxxxxx>
Cc: Ulrich Drepper <drepper@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Jack Steiner <steiner@xxxxxxx>
Cc: Russ Anderson <rja@xxxxxxx>
Cc: Mike Travis <travis@xxxxxxx>
LKML-Reference: <20100406070218.GM5594@kryten>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
kernel/sched.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kernel/sched.c b/kernel/sched.c
index 528a105..eaf5c73 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4902,7 +4902,7 @@ SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len,
int ret;
cpumask_var_t mask;

- if (len < nr_cpu_ids)
+ if ((len * BITS_PER_BYTE) < nr_cpu_ids)
return -EINVAL;
if (len & (sizeof(unsigned long)-1))
return -EINVAL;
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/