Re: [PATCH 3/6] x86: clean up _TIF_SYSCALL_EMU handling using ptrace_syscall_enter hook
From: Haibo Xu (Arm Technology China) <hidden>
Date: 2019-03-05 02:14:54
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linux-arm-kernel, lkml
On 2019/3/4 18:12, Sudeep Holla wrote:
On Mon, Mar 04, 2019 at 08:25:28AM +0000, Haibo Xu (Arm Technology China) wrote:quoted
On 2019/3/1 2:32, Sudeep Holla wrote:quoted
Now that we have a new hook ptrace_syscall_enter that can be called from syscall entry code and it handles PTRACE_SYSEMU in generic code, we can do some cleanup using the same in syscall_trace_enter. Further the extra logic to find single stepping PTRACE_SYSEMU_SINGLESTEP in syscall_slow_exit_work seems unnecessary. Let's remove the same.I think we should not change the logic here. Is so, it will double the report of syscall when PTRACE_SYSEMU_SINGLESTEP is enabled.I don't think that should happen, but I may be missing something. Can you explain how ? -- Regards, Sudeep
When PTRACE_SYSEMU_SINGLESTEP is enabled, both the _TIF_SYSCALL_EMU and _TIF_SINGLESTEP flags are set, but ptrace only need to report(send SIGTRAP) at the entry of a system call, no need to report at the exit of a system call. Regards, Haibo IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.