From: Matt Fleming <matt@codeblueprint.co.uk>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Namhyung Kim <namhyung@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@kernel.org>,
x86@kernel.org, Borislav Petkov <bp@suse.de>
Subject: Re: [PATCH] ftrace/x86: Fix function graph tracer reset path
Date: Sun, 15 May 2016 22:41:01 +0100 [thread overview]
Message-ID: <20160515214101.GA6574@codeblueprint.co.uk> (raw)
In-Reply-To: <20160513100610.1a90ea6f@gandalf.local.home>
On Fri, 13 May, at 10:06:10AM, Steven Rostedt wrote:
> Matt,
>
> This bug looks very similar to what you were hitting with the function
> profiler. Can you apply this patch and see if it fixes the issue for
> you.
Yep, this patch fixes it for me.
For the record, this is what objdump tells me (with patch applied),
00000000000000b6 <ftrace_epilogue>:
b6: eb 03 jmp bb <ftrace_stub>
b8: 90 nop
b9: 90 nop
ba: 90 nop
So my toolchain is definitely generating a short jump. This is
binutils 2.26.
But on one of my other test machines with binutils 2.24 I see this,
00000000000000aa <ftrace_epilogue>:
aa: e9 00 00 00 00 jmpq af <ftrace_stub>
ab: R_X86_64_PC32 ftrace_stub-0x4
i.e. a near jump.
next prev parent reply other threads:[~2016-05-15 21:41 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-13 13:53 [PATCH] ftrace/x86: Fix function graph tracer reset path Namhyung Kim
2016-05-13 14:06 ` Steven Rostedt
2016-05-15 21:41 ` Matt Fleming [this message]
2016-05-15 0:41 ` Masami Hiramatsu
2016-05-15 13:06 ` Namhyung Kim
[not found] ` <20160516175614.53e0ceed3ec0880526fa1799@kernel.org>
2016-05-16 12:32 ` Namhyung Kim
2016-05-16 13:58 ` Steven Rostedt
2016-05-16 14:24 ` Namhyung Kim
2016-05-16 19:03 ` Borislav Petkov
2016-05-16 19:13 ` Steven Rostedt
2016-05-16 19:19 ` Borislav Petkov
2016-05-16 19:23 ` Steven Rostedt
2016-05-16 19:52 ` Matt Fleming
2016-05-16 22:08 ` Masami Hiramatsu
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