Messages in this thread | | | Date | Fri, 11 Oct 2019 17:43:19 +0100 | From | Will Deacon <> | Subject | Re: [PATCH] ARM/hw_breakpoint: modify dead code for breakpoint_handler() |
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On Wed, Oct 09, 2019 at 05:27:00PM +0800, wangxu wrote: > From: Wang Xu <wangxu72@huawei.com> > > In perf_event_alloc(), event->overflow_handler is initialized to a > non-null value, which makes enable_single_step(bp, addr) in > breakpoint_handler() never be executed. > > As a matter of fact, the branch condition has been updated to > is_default_overflow_handler(). > > Signed-off-by: Wang Xu <wangxu72@huawei.com> > --- > arch/arm/kernel/hw_breakpoint.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c > index b0c195e..586a587 100644 > --- a/arch/arm/kernel/hw_breakpoint.c > +++ b/arch/arm/kernel/hw_breakpoint.c > @@ -822,7 +822,7 @@ static void breakpoint_handler(unsigned long unknown, struct pt_regs *regs) > info->trigger = addr; > pr_debug("breakpoint fired: address = 0x%x\n", addr); > perf_bp_event(bp, regs); > - if (!bp->overflow_handler) > + if (is_default_overflow_handler(bp)) > enable_single_step(bp, addr); > goto unlock;
Seems to match what we do on arm64, so:
Acked-by: Will Deacon <will@kernel.org>
You'll need to put this into rmk's patch system [1].
Will
[1] https://www.arm.linux.org.uk/developer/
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