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| author | Masami Hiramatsu <mhiramat@kernel.org> | 2017-09-19 12:02:20 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-09-28 09:25:50 +0200 |
| commit | a19b2e3d783964d48d2b494439648e929bcdc976 (patch) | |
| tree | e9937278cf4c1555e28853edbfdb0c6de25ff68d /arch/x86/kernel/kprobes/opt.c | |
| parent | kprobes/x86: Disable preemption in ftrace-based jprobes (diff) | |
| download | linux-a19b2e3d783964d48d2b494439648e929bcdc976.tar.xz linux-a19b2e3d783964d48d2b494439648e929bcdc976.zip | |
kprobes/x86: Remove IRQ disabling from ftrace-based/optimized kprobes
Kkprobes don't need to disable IRQs if they are called from the
ftrace/jump trampoline code, because Documentation/kprobes.txt says:
-----
Probe handlers are run with preemption disabled. Depending on the
architecture and optimization state, handlers may also run with
interrupts disabled (e.g., kretprobe handlers and optimized kprobe
handlers run without interrupt disabled on x86/x86-64).
-----
So let's remove IRQ disabling from those handlers.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E . McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/150581534039.32348.11331736206004264553.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to '')
| -rw-r--r-- | arch/x86/kernel/kprobes/opt.c | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c index 32c35cb3550c..e941136e24d8 100644 --- a/arch/x86/kernel/kprobes/opt.c +++ b/arch/x86/kernel/kprobes/opt.c @@ -154,13 +154,10 @@ STACK_FRAME_NON_STANDARD(optprobe_template_func); static void optimized_callback(struct optimized_kprobe *op, struct pt_regs *regs) { - unsigned long flags; - /* This is possible if op is under delayed unoptimizing */ if (kprobe_disabled(&op->kp)) return; - local_irq_save(flags); preempt_disable(); if (kprobe_running()) { kprobes_inc_nmissed_count(&op->kp); @@ -182,7 +179,6 @@ optimized_callback(struct optimized_kprobe *op, struct pt_regs *regs) __this_cpu_write(current_kprobe, NULL); } preempt_enable_no_resched(); - local_irq_restore(flags); } NOKPROBE_SYMBOL(optimized_callback); |