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| author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2014-04-13 09:34:53 -0400 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2014-06-20 17:33:50 +0200 |
| commit | 21af1041b8943eabe04ba00e247c0bda7091a9f1 (patch) | |
| tree | 17c48ab02727633e1304d1f2e12164e462323cca | |
| parent | 4801cb6ba3527f1cbb2078e23d3fdbe03ebcc7e7 (diff) | |
| download | lwn-21af1041b8943eabe04ba00e247c0bda7091a9f1.tar.gz lwn-21af1041b8943eabe04ba00e247c0bda7091a9f1.zip | |
sched: Use CPUPRI_NR_PRIORITIES instead of MAX_RT_PRIO in cpupri check
commit 6227cb00cc120f9a43ce8313bb0475ddabcb7d01 upstream.
The check at the beginning of cpupri_find() makes sure that the task_pri
variable does not exceed the cp->pri_to_cpu array length. But that length
is CPUPRI_NR_PRIORITIES not MAX_RT_PRIO, where it will miss the last two
priorities in that array.
As task_pri is computed from convert_prio() which should never be bigger
than CPUPRI_NR_PRIORITIES, if the check should cause a panic if it is
hit.
Reported-by: Mike Galbraith <umgwanakikbuti@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1397015410.5212.13.camel@marge.simpson.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
| -rw-r--r-- | kernel/sched/cpupri.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/kernel/sched/cpupri.c b/kernel/sched/cpupri.c index 8b836b376d91..3031bac8aa3e 100644 --- a/kernel/sched/cpupri.c +++ b/kernel/sched/cpupri.c @@ -70,8 +70,7 @@ int cpupri_find(struct cpupri *cp, struct task_struct *p, int idx = 0; int task_pri = convert_prio(p->prio); - if (task_pri >= MAX_RT_PRIO) - return 0; + BUG_ON(task_pri >= CPUPRI_NR_PRIORITIES); for (idx = 0; idx < task_pri; idx++) { struct cpupri_vec *vec = &cp->pri_to_cpu[idx]; |