Commit 9a09f261 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Ingo Molnar

kprobes/x86: Disable preemption in optprobe

Disable preemption in optprobe handler as described
in Documentation/kprobes.txt, which says:

  "Probe handlers are run with preemption disabled."
Signed-off-by: default avatarMasami 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/150581525942.32348.6359217983269060829.stgit@devboxSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent e863d539
...@@ -161,6 +161,7 @@ optimized_callback(struct optimized_kprobe *op, struct pt_regs *regs) ...@@ -161,6 +161,7 @@ optimized_callback(struct optimized_kprobe *op, struct pt_regs *regs)
return; return;
local_irq_save(flags); local_irq_save(flags);
preempt_disable();
if (kprobe_running()) { if (kprobe_running()) {
kprobes_inc_nmissed_count(&op->kp); kprobes_inc_nmissed_count(&op->kp);
} else { } else {
...@@ -180,6 +181,7 @@ optimized_callback(struct optimized_kprobe *op, struct pt_regs *regs) ...@@ -180,6 +181,7 @@ optimized_callback(struct optimized_kprobe *op, struct pt_regs *regs)
opt_pre_handler(&op->kp, regs); opt_pre_handler(&op->kp, regs);
__this_cpu_write(current_kprobe, NULL); __this_cpu_write(current_kprobe, NULL);
} }
preempt_enable_no_resched();
local_irq_restore(flags); local_irq_restore(flags);
} }
NOKPROBE_SYMBOL(optimized_callback); NOKPROBE_SYMBOL(optimized_callback);
......
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