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authorMasami Hiramatsu <mhiramat@kernel.org>2018-10-20 18:47:53 +0900
committerIngo Molnar <mingo@kernel.org>2018-10-22 03:31:01 +0200
commit2e62024c265aa69315ed02835623740030435380 (patch)
tree365d4638504642c2ed30f261c0cd2f8bcf62e835
parentc2712b858187f5bcd7b042fe4daa3ba3a12635c0 (diff)
kprobes/x86: Use preempt_enable() in optimized_callback()
The following commit: a19b2e3d7839 ("kprobes/x86: Remove IRQ disabling from ftrace-based/optimized kprobes”) removed local_irq_save/restore() from optimized_callback(), the handler might be interrupted by the rescheduling interrupt and might be rescheduled - so we must not use the preempt_enable_no_resched() macro. Use preempt_enable() instead, to not lose preemption events. [ mingo: Improved the changelog. ] Reported-by: Nadav Amit <namit@vmware.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@vger.kernel.org> Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dwmw@amazon.co.uk Fixes: a19b2e3d7839 ("kprobes/x86: Remove IRQ disabling from ftrace-based/optimized kprobes”) Link: http://lkml.kernel.org/r/154002887331.7627.10194920925792947001.stgit@devbox Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--arch/x86/kernel/kprobes/opt.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c
index eaf02f2e7300..40b16b270656 100644
--- a/arch/x86/kernel/kprobes/opt.c
+++ b/arch/x86/kernel/kprobes/opt.c
@@ -179,7 +179,7 @@ optimized_callback(struct optimized_kprobe *op, struct pt_regs *regs)
opt_pre_handler(&op->kp, regs);
__this_cpu_write(current_kprobe, NULL);
}
- preempt_enable_no_resched();
+ preempt_enable();
}
NOKPROBE_SYMBOL(optimized_callback);