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authorLinus Torvalds <torvalds@linux-foundation.org>2014-09-19 10:31:36 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-09-19 10:31:36 -0700
commit598a0c7d0932e385486b173768f03d95bf5507c8 (patch)
treed528410bffc0297c205b55dbb2b4a012243089d7
parent7a5e87867e9fe043c3067a864124caf2b8e7fb99 (diff)
parent3577af70a2ce4853d58e57d832e687d739281479 (diff)
Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar: "Two kernel side fixes: a kprobes fix and a perf_remove_from_context() fix (which does not yet fix the migration bug which is WIP)" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Fix a race condition in perf_remove_from_context() kprobes/x86: Free 'optinsn' cache when range check fails
-rw-r--r--arch/x86/kernel/kprobes/opt.c4
-rw-r--r--kernel/events/core.c10
2 files changed, 13 insertions, 1 deletions
diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c
index f304773285ae..f1314d0bcf0a 100644
--- a/arch/x86/kernel/kprobes/opt.c
+++ b/arch/x86/kernel/kprobes/opt.c
@@ -338,8 +338,10 @@ int arch_prepare_optimized_kprobe(struct optimized_kprobe *op)
* a relative jump.
*/
rel = (long)op->optinsn.insn - (long)op->kp.addr + RELATIVEJUMP_SIZE;
- if (abs(rel) > 0x7fffffff)
+ if (abs(rel) > 0x7fffffff) {
+ __arch_remove_optimized_kprobe(op, 0);
return -ERANGE;
+ }
buf = (u8 *)op->optinsn.insn;
diff --git a/kernel/events/core.c b/kernel/events/core.c
index f9c1ed002dbc..d640a8b4dcbc 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -1524,6 +1524,11 @@ retry:
*/
if (ctx->is_active) {
raw_spin_unlock_irq(&ctx->lock);
+ /*
+ * Reload the task pointer, it might have been changed by
+ * a concurrent perf_event_context_sched_out().
+ */
+ task = ctx->task;
goto retry;
}
@@ -1967,6 +1972,11 @@ retry:
*/
if (ctx->is_active) {
raw_spin_unlock_irq(&ctx->lock);
+ /*
+ * Reload the task pointer, it might have been changed by
+ * a concurrent perf_event_context_sched_out().
+ */
+ task = ctx->task;
goto retry;
}