From: Oleg Nesterov <oleg@redhat.com>
To: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>,
Peter Zijlstra <peterz@infradead.org>,
Frederic Weisbecker <fweisbec@gmail.com>,
linux-kernel@vger.kernel.org,
Steven Rostedt <rostedt@goodmis.org>,
Jiaying Zhang <jiayingz@google.com>,
Martin Bligh <mbligh@google.com>,
utrace-devel@redhat.com
Subject: Re: [RFC][PATCH 1/2] tracing/ftrace: syscall tracing infrastructure
Date: Tue, 17 Mar 2009 06:24:42 +0100 [thread overview]
Message-ID: <20090317052442.GA32674@redhat.com> (raw)
In-Reply-To: <20090316214526.GA15119@Krystal>
On 03/16, Mathieu Desnoyers wrote:
>
> utrace_add_engine()
> set_notify_resume(target);
>
> ok, so this is where the TIF_NOTIFY_RESUME thread flag is set. I notice
> that it is set asynchronously with the execution of the target thread
> (as I do with my TIF_KERNEL_TRACE thread flag).
>
> However, on x86_64, _TIF_DO_NOTIFY_MASK is only tested in
> entry_64.S
>
> int_signal:
> and
> retint_signal:
>
> code paths. However, if there is no syscall tracing to do upon syscall
> entry, the thread flags are not re-read at syscall exit and you will
> miss the syscall exit returning from your target thread if this thread
> was blocked while you set its TIF_NOTIFY_RESUME.
Afaics, TIF_NOTIFY_RESUME is not needed to trace syscall entry/exit.
If engine wants the syscall tracing, utrace_set_events(UTRACE_SYSCALL_xxx)
sets TIF_SYSCALL_TRACE. And syscall_trace_enter/syscall_trace_leave call
tracehook_report_syscall_xxx().
Oleg.
next prev parent reply other threads:[~2009-03-17 5:28 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-07 4:52 [RFC][PATCH 0/2] Syscalls tracing Frederic Weisbecker
2009-03-07 4:52 ` [RFC][PATCH 1/2] tracing/ftrace: syscall tracing infrastructure Frederic Weisbecker
2009-03-07 7:49 ` Frederic Weisbecker
2009-03-09 13:52 ` Steven Rostedt
2009-03-09 20:47 ` Frederic Weisbecker
2009-03-10 0:52 ` Steven Rostedt
2009-03-10 10:08 ` Frederic Weisbecker
2009-03-08 16:24 ` Ingo Molnar
2009-03-09 20:40 ` Frederic Weisbecker
2009-03-09 13:44 ` Steven Rostedt
2009-03-09 20:42 ` Frederic Weisbecker
2009-03-13 4:27 ` [tip:tracing/syscalls] tracing/ftrace: syscall tracing infrastructure, basics Frederic Weisbecker
2009-03-16 19:36 ` [RFC][PATCH 1/2] tracing/ftrace: syscall tracing infrastructure Masami Hiramatsu
2009-03-16 20:15 ` Frederic Weisbecker
2009-03-16 20:38 ` Masami Hiramatsu
2009-03-16 21:45 ` Mathieu Desnoyers
2009-03-16 22:18 ` Frank Ch. Eigler
2009-03-16 23:46 ` Frederic Weisbecker
2009-03-23 16:42 ` Mathieu Desnoyers
2009-03-23 16:52 ` Frank Ch. Eigler
2009-03-23 17:03 ` Mathieu Desnoyers
2009-03-17 5:24 ` Oleg Nesterov [this message]
2009-03-17 16:00 ` Mathieu Desnoyers
2009-03-19 10:34 ` Roland McGrath
2009-03-23 17:33 ` Mathieu Desnoyers
2009-03-07 4:53 ` [RFC][PATCH 2/2] tracing/x86: basic implementation of syscall tracing for x86-64 Frederic Weisbecker
2009-03-13 4:27 ` [tip:tracing/syscalls] tracing/x86: basic implementation of syscall tracing for x86 Frederic Weisbecker
2009-03-13 16:09 ` [tip:tracing/syscalls] tracing/syscalls: support for syscalls tracing on x86, fix Ingo Molnar
2009-03-13 16:32 ` [RFC][PATCH 2/2] tracing/x86: basic implementation of syscall tracing for x86-64 Mathieu Desnoyers
2009-03-13 16:37 ` Ingo Molnar
2009-03-13 16:50 ` Mathieu Desnoyers
2009-03-15 4:44 ` Ingo Molnar
2009-03-15 15:16 ` Frederic Weisbecker
2009-03-15 19:22 ` Mathieu Desnoyers
2009-03-07 12:15 ` [RFC][PATCH 0/2] Syscalls tracing Peter Zijlstra
2009-03-07 16:02 ` Frederic Weisbecker
2009-03-08 11:24 ` Frederic Weisbecker
2009-03-08 11:28 ` Frederic Weisbecker
2009-03-07 20:26 ` Frank Ch. Eigler
2009-03-07 21:53 ` Frederic Weisbecker
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20090317052442.GA32674@redhat.com \
--to=oleg@redhat.com \
--cc=fweisbec@gmail.com \
--cc=jiayingz@google.com \
--cc=laijs@cn.fujitsu.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mathieu.desnoyers@polymtl.ca \
--cc=mbligh@google.com \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
--cc=utrace-devel@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox