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authorMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>2010-12-03 10:54:09 +0100
committerIngo Molnar <mingo@elte.hu>2010-12-06 17:59:30 +0100
commit6274de4984a630b45c6934b3ee62e5692c745328 (patch)
treedfe66f06596b0165c87a75d800fa83acb6201d1b /arch/x86/kernel/kprobes.c
parentkprobes: Separate kprobe optimizing code from optimizer (diff)
downloadlinux-6274de4984a630b45c6934b3ee62e5692c745328.tar.xz
linux-6274de4984a630b45c6934b3ee62e5692c745328.zip
kprobes: Support delayed unoptimizing
Unoptimization occurs when a probe is unregistered or disabled, and is heavy because it recovers instructions by using stop_machine(). This patch delays unoptimization operations and unoptimize several probes at once by using text_poke_smp_batch(). This can avoid unexpected system slowdown coming from stop_machine(). Changes in v5: - Split this patch into several cleanup patches and this patch. - Fix some text_mutex lock miss. - Use bool instead of int for behavior flags. - Add additional comment for (un)optimizing path. Changes in v2: - Use dynamic allocated buffers and params. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jason Baron <jbaron@redhat.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: 2nddept-manager@sdl.hitachi.co.jp LKML-Reference: <20101203095409.2961.82733.stgit@ltc236.sdl.hitachi.co.jp> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/kprobes.c')
-rw-r--r--arch/x86/kernel/kprobes.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c
index 1cbd54c0df99..da51dc8e77cb 100644
--- a/arch/x86/kernel/kprobes.c
+++ b/arch/x86/kernel/kprobes.c
@@ -1184,6 +1184,10 @@ static void __kprobes optimized_callback(struct optimized_kprobe *op,
{
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+ /* This is possible if op is under delayed unoptimizing */
+ if (kprobe_disabled(&op->kp))
+ return;
+
preempt_disable();
if (kprobe_running()) {
kprobes_inc_nmissed_count(&op->kp);