From: Alex LIU <alex.liu@st.com>
To: "'Andries Brouwer'" <aebr@win.tue.nl>, "'Pavel Machek'" <pavel@ucw.cz>
Cc: <linux-kernel@vger.kernel.org>
Subject: RE: The purpose of PT_TRACESYSGOOD
Date: Tue, 11 Jan 2005 14:28:33 +0800 [thread overview]
Message-ID: <00ac01c4f7a6$c79e03f0$ac655e0a@sha.st.com> (raw)
In-Reply-To: <20050111023003.GA2760@pclin040.win.tue.nl>
Then I think the tracing thread should call the ptrace_request to set
PTRACE_O_TRACESYSGOOD flag of the traced thread first before
ptrace(PTRACE_SYSCALL...) ,right?
Thanks a lot!
Alex
Andries Brouwer wrote:
>> What's the effect of PT_TRACESYSGOOD flag? I found it's used only set
>> in ptrace_setoptions, which is called in the function ptrace_request.
>> And the PT_TRACESYSGOOD flag will be requested in do_syscall_trace.
>> What's the purpose of that flag?
>/*
> * A child stopped at a syscall has status as if it received SIGTRAP.
> * In order to distinguish between SIGTRAP and syscall, some kernel
> * versions have the PTRACE_O_TRACESYSGOOD option, that sets an extra
> * bit 0x80 in the syscall case.
> */
next prev parent reply other threads:[~2005-01-11 6:36 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-01-10 3:58 The purpose of PT_TRACESYSGOOD Alex LIU
2005-01-10 20:24 ` Pavel Machek
2005-01-11 2:30 ` Andries Brouwer
2005-01-11 6:28 ` Alex LIU [this message]
2005-01-11 11:10 ` Andries Brouwer
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