Messages in this thread | | | Date | Mon, 12 Mar 2018 00:05:22 +0900 | From | Masami Hiramatsu <> | Subject | Re: [RFC PATCH -tip 8/9] error-injection: Fix to not enabling preemption in pre_handler |
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On Sat, 10 Mar 2018 09:22:48 +0100 Ingo Molnar <mingo@kernel.org> wrote:
> > * Masami Hiramatsu <mhiramat@kernel.org> wrote: > > > Since kprobes pre_handler doesn't need to recover preemption > > even if it modifies regs->ip anymore, this fixes to remove > > the preempt_enable_no_resched() from pre_handler. > > > > Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> > > --- > > kernel/fail_function.c | 1 - > > 1 file changed, 1 deletion(-) > > > > diff --git a/kernel/fail_function.c b/kernel/fail_function.c > > index 21b0122cb39c..b1713521f096 100644 > > --- a/kernel/fail_function.c > > +++ b/kernel/fail_function.c > > @@ -176,7 +176,6 @@ static int fei_kprobe_handler(struct kprobe *kp, struct pt_regs *regs) > > override_function_with_return(regs); > > /* Kprobe specific fixup */ > > reset_current_kprobe(); > > - preempt_enable_no_resched(); > > return 1; > > } > > So where did the matching preempt_disable() get removed? If it's the 6/9 patch, > then this patch (and 8/9) should very much be part of it.
It is 7/9, in kprobe_int3_handler() and kprobe_ftrace_handler(). The latter is a bit tricky, originally it enable preemption only when the pre_handler returns 0, but 7/9 changes it always enables preemption.
> > There should be no bisection breakage in the series.
OK, I will merge 7/9-9/9 (anyway those are currently only support x86).
Thanks,
> > Thanks, > > Ingo
-- Masami Hiramatsu <mhiramat@kernel.org>
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