From: Anton Blanchard <anton@samba.org>
To: rostedt@goodmis.org, fweisbec@gmail.com, mingo@redhat.com
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH] tracing/trace_stack: Fix stack trace on ppc64
Date: Wed, 25 Aug 2010 11:32:38 +1000 [thread overview]
Message-ID: <20100825013238.GE28360@kryten> (raw)
save_stack_trace() stores the instruction pointer, not the function
descriptor. On ppc64 the trace stack code currently dereferences the
instruction pointer and shows 8 bytes of instructions in our backtraces:
# cat /sys/kernel/debug/tracing/stack_trace
Depth Size Location (26 entries)
----- ---- --------
0) 5424 112 0x6000000048000004
1) 5312 160 0x60000000ebad01b0
2) 5152 160 0x2c23000041c20030
3) 4992 240 0x600000007c781b79
4) 4752 160 0xe84100284800000c
5) 4592 192 0x600000002fa30000
6) 4400 256 0x7f1800347b7407e0
7) 4144 208 0xe89f0108f87f0070
8) 3936 272 0xe84100282fa30000
Since we aren't dealing with function descriptors, use %pS instead of %pF
to fix it:
# cat /sys/kernel/debug/tracing/stack_trace
Depth Size Location (26 entries)
----- ---- --------
0) 5424 112 ftrace_call+0x4/0x8
1) 5312 160 .current_io_context+0x28/0x74
2) 5152 160 .get_io_context+0x48/0xa0
3) 4992 240 .cfq_set_request+0x94/0x4c4
4) 4752 160 .elv_set_request+0x60/0x84
5) 4592 192 .get_request+0x2d4/0x468
6) 4400 256 .get_request_wait+0x7c/0x258
7) 4144 208 .__make_request+0x49c/0x610
8) 3936 272 .generic_make_request+0x390/0x434
Signed-off-by: Anton Blanchard <anton@samba.org>
---
Index: powerpc.git/kernel/trace/trace_stack.c
===================================================================
--- powerpc.git.orig/kernel/trace/trace_stack.c 2010-08-25 11:03:52.337982567 +1000
+++ powerpc.git/kernel/trace/trace_stack.c 2010-08-25 11:03:55.018371055 +1000
@@ -249,7 +249,7 @@ static int trace_lookup_stack(struct seq
{
unsigned long addr = stack_dump_trace[i];
- return seq_printf(m, "%pF\n", (void *)addr);
+ return seq_printf(m, "%pS\n", (void *)addr);
}
static void print_disabled(struct seq_file *m)
next reply other threads:[~2010-08-25 1:34 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-25 1:32 Anton Blanchard [this message]
2010-08-25 12:58 ` [tip:perf/urgent] tracing/trace_stack: Fix stack trace on ppc64 tip-bot for Anton Blanchard
2010-08-31 1:31 ` [PATCH] " Steven Rostedt
2010-08-31 14:21 ` Frederic Weisbecker
2010-08-31 14:58 ` Steven Rostedt
2010-08-31 15:14 ` Frederic Weisbecker
2010-08-31 17:36 ` Ingo Molnar
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=20100825013238.GE28360@kryten \
--to=anton@samba.org \
--cc=fweisbec@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=rostedt@goodmis.org \
/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