Messages in this thread Patch in this message | | | From | Kamal Mostafa <> | Subject | [PATCH 3.8 28/65] sched: Use CPUPRI_NR_PRIORITIES instead of MAX_RT_PRIO in cpupri check | Date | Tue, 24 Jun 2014 13:29:48 -0700 |
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3.8.13.25 -stable review patch. If anyone has any objections, please let me know.
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From: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org>
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: Kamal Mostafa <kamal@canonical.com> --- kernel/sched/cpupri.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/kernel/sched/cpupri.c b/kernel/sched/cpupri.c index 23aa789..8ea0f2e 100644 --- a/kernel/sched/cpupri.c +++ b/kernel/sched/cpupri.c @@ -68,8 +68,7 @@ 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]; -- 1.9.1
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