Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932420Ab0HaPOo (ORCPT ); Tue, 31 Aug 2010 11:14:44 -0400 Received: from mail-wy0-f174.google.com ([74.125.82.174]:35701 "EHLO mail-wy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932309Ab0HaPOn (ORCPT ); Tue, 31 Aug 2010 11:14:43 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=VoR/8RWyaWzEZh8uPVdyEtohy9AgH4qyxmocIqx6ILnGP0nvas8OrtrR5C9BwhN0eX M0odugZ16xTnJ3BQwTf0Vl3hir0MZCh7LlX5q3TnUVR5+nLRTTOrkQ9sxtcOz20EdAb6 1mZce0ZrPz2vT+PZfx3IgUVrvxiA0dZKVdm8w= Date: Tue, 31 Aug 2010 17:14:41 +0200 From: Frederic Weisbecker To: Steven Rostedt Cc: Anton Blanchard , mingo@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] tracing/trace_stack: Fix stack trace on ppc64 Message-ID: <20100831151439.GC5259@nowhere> References: <20100825013238.GE28360@kryten> <1283218310.1377.50.camel@gandalf.stny.rr.com> <20100831142111.GA5259@nowhere> <1283266722.1377.80.camel@gandalf.stny.rr.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1283266722.1377.80.camel@gandalf.stny.rr.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3208 Lines: 92 On Tue, Aug 31, 2010 at 10:58:42AM -0400, Steven Rostedt wrote: > Hmm, I never saw the tip-bot reply :-( > > I guess it only sends to the Cc tags. > > -- Steve > > We were in the commit Cc tags but somehow they didn't make it in the email tags. Here is the tip-bot email: --- Commit-ID: 151772dbfad4dbe81721e40f9b3d588ea77bb7aa Gitweb: http://git.kernel.org/tip/151772dbfad4dbe81721e40f9b3d588ea77bb7aa Author: Anton Blanchard AuthorDate: Wed, 25 Aug 2010 11:32:38 +1000 Committer: Ingo Molnar CommitDate: Wed, 25 Aug 2010 13:08:48 +0200 tracing/trace_stack: Fix stack trace on ppc64 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 Cc: rostedt@goodmis.org Cc: fweisbec@gmail.com LKML-Reference: <20100825013238.GE28360@kryten> Signed-off-by: Ingo Molnar --- kernel/trace/trace_stack.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 056468e..a6b7e0e 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -249,7 +249,7 @@ static int trace_lookup_stack(struct seq_file *m, long i) { 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) -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/