Re: [PATCH 2/2] arm64: Fix watchpoint recursion when single-step is wrongly triggered in irq

From: Wangnan (F)
Date: Mon Mar 21 2016 - 06:41:59 EST




On 2016/3/21 18:24, Pratyush Anand wrote:
On 21/03/2016:08:37:50 AM, He Kuang wrote:
On arm64, watchpoint handler enables single-step to bypass the next
instruction for not recursive enter. If an irq is triggered right
after the watchpoint, a single-step will be wrongly triggered in irq
handler, which causes the watchpoint address not stepped over and
system hang.
Does patch [1] resolves this issue as well? I hope it should. Patch[1] has still
not been sent for review. Your test result will be helpful.

~Pratyush

[1] https://github.com/pratyushanand/linux/commit/7623c8099ac22eaa00e7e0f52430f7a4bd154652

Could you please provide a test program for your case so we can test
it on our devices? I guess setting breakpoint on a "copy_from_user()"
accessing an invalid address can trigger this problem?

Thank you.