From: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
To: Andrew Morton <akpm@linux-foundation.org>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Thomas Meyer <thomas@m3y3r.de>, Ingo Molnar <mingo@kernel.org>,
"Steven Rostedt (VMware)" <rostedt@goodmis.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Paul Gortmaker <paul.gortmaker@windriver.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
<linux-kernel@vger.kernel.org>
Cc: <linux-mips@linux-mips.org>,
Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Subject: [PATCH] kernel/extable.c: mark core_kernel_text notrace
Date: Wed, 21 Jun 2017 09:03:26 +0200 [thread overview]
Message-ID: <1498028607-6765-1-git-send-email-marcin.nowakowski@imgtec.com> (raw)
core_kernel_text is used by MIPS in its function graph trace processing,
so having this method traced leads to an infinite set of recursive calls
such as:
[ 2.972075] Call Trace:
[ 2.972111]
[ 2.976731] [<80506584>] ftrace_return_to_handler+0x50/0x128
[ 2.983379] [<8045478c>] core_kernel_text+0x10/0x1b8
[ 2.989146] [<804119b8>] prepare_ftrace_return+0x6c/0x114
[ 2.995402] [<80411b2c>] ftrace_graph_caller+0x20/0x44
[ 3.001362] [<80411b60>] return_to_handler+0x10/0x30
[ 3.007159] [<80411b50>] return_to_handler+0x0/0x30
[ 3.012827] [<80411b50>] return_to_handler+0x0/0x30
[ 3.018621] [<804e589c>] ftrace_ops_no_ops+0x114/0x1bc
[ 3.024602] [<8045478c>] core_kernel_text+0x10/0x1b8
[ 3.030377] [<8045478c>] core_kernel_text+0x10/0x1b8
[ 3.036140] [<8045478c>] core_kernel_text+0x10/0x1b8
[ 3.041915] [<804e589c>] ftrace_ops_no_ops+0x114/0x1bc
[ 3.047923] [<8045478c>] core_kernel_text+0x10/0x1b8
[ 3.053682] [<804119b8>] prepare_ftrace_return+0x6c/0x114
[ 3.059938] [<80411b2c>] ftrace_graph_caller+0x20/0x44
(...)
Mark the function notrace to avoid it being traced.
Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
---
kernel/extable.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/extable.c b/kernel/extable.c
index 2676d7f..4efaf26 100644
--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -70,7 +70,7 @@ static inline int init_kernel_text(unsigned long addr)
return 0;
}
-int core_kernel_text(unsigned long addr)
+int notrace core_kernel_text(unsigned long addr)
{
if (addr >= (unsigned long)_stext &&
addr < (unsigned long)_etext)
--
2.7.4
next reply other threads:[~2017-06-21 7:03 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-21 7:03 Marcin Nowakowski [this message]
2017-06-22 10:24 ` Masami Hiramatsu
2017-06-22 22:10 ` Steven Rostedt
2017-06-22 22:16 ` Thomas Gleixner
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=1498028607-6765-1-git-send-email-marcin.nowakowski@imgtec.com \
--to=marcin.nowakowski@imgtec.com \
--cc=akpm@linux-foundation.org \
--cc=daniel@iogearbox.net \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mips@linux-mips.org \
--cc=mhiramat@kernel.org \
--cc=mingo@kernel.org \
--cc=paul.gortmaker@windriver.com \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
--cc=thomas@m3y3r.de \
/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
all inboxes | Powered by JetHome®