[PATCH] ARM/hw_breakpoint: modify dead code for breakpoint_handler()

From: wangxu
Date: Wed Oct 09 2019 - 05:27:10 EST


From: Wang Xu <wangxu72@xxxxxxxxxx>

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@xxxxxxxxxx>
---
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;
}
--
1.8.5.6