From: Ross Zwisler <zwisler@google.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
Masami Hiramatsu <mhiramat@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Tom Zanussi <zanussi@kernel.org>,
Zheng Yejian <zhengyejian1@huawei.com>
Subject: Re: [PATCH 1/2] tracing: Add a way to filter function addresses to function names
Date: Mon, 19 Dec 2022 13:57:18 -0700 [thread overview]
Message-ID: <Y6DQLgVYHedPB+F+@google.com> (raw)
In-Reply-To: <20221219183213.916833763@goodmis.org>
On Mon, Dec 19, 2022 at 01:31:07PM -0500, Steven Rostedt wrote:
> From: "Steven Rostedt (Google)" <rostedt@goodmis.org>
>
> There's been several times where an event records a function address in
> its field and I needed to filter on that address for a specific function
> name. It required looking up the function in kallsyms, finding its size,
> and doing a compare of "field >= function_start && field < function_end".
>
> But this would change from boot to boot and is unreliable in scripts.
> Also, it is useful to have this at boot up, where the addresses will not
> be known. For example, on the boot command line:
>
> trace_trigger="initcall_finish.traceoff if func.function == acpi_init"
>
> To implement this, add a ".function" prefix, that will check that the
> field is of size long, and the only operations allowed (so far) are "=="
> and "!=".
>
> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Reviewed-by: Ross Zwisler <zwisler@google.com>
next prev parent reply other threads:[~2022-12-19 20:57 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-19 18:31 [PATCH 0/2] tracing: Add a way to filter function addresses to function names Steven Rostedt
2022-12-19 18:31 ` [PATCH 1/2] " Steven Rostedt
2022-12-19 20:57 ` Ross Zwisler [this message]
2022-12-19 18:31 ` [PATCH 2/2] tracing/selftests: Add test for event filtering on function name Steven Rostedt
2022-12-19 20:57 ` Ross Zwisler
2022-12-19 22:11 ` Shuah Khan
2022-12-19 22:35 ` Steven Rostedt
2022-12-20 0:20 ` Shuah Khan
2022-12-20 1:21 ` Steven Rostedt
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=Y6DQLgVYHedPB+F+@google.com \
--to=zwisler@google.com \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-trace-kernel@vger.kernel.org \
--cc=mhiramat@kernel.org \
--cc=rostedt@goodmis.org \
--cc=zanussi@kernel.org \
--cc=zhengyejian1@huawei.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;
as well as URLs for NNTP newsgroup(s).