Patch "tracing/stacktrace: Show entire trace if passed in function not found" has been added to the 4.4-stable tree

Patch "tracing/stacktrace: Show entire trace if passed in function not found" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    tracing/stacktrace: Show entire trace if passed in function not found

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     tracing-stacktrace-show-entire-trace-if-passed-in-function-not-found.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 6ccd83714a009ee301b50c15f6c3a5dc1f30164c Mon Sep 17 00:00:00 2001
From: Steven Rostedt <rostedt@goodmis.org>
Date: Fri, 29 Jan 2016 10:22:41 -0500
Subject: tracing/stacktrace: Show entire trace if passed in function not found

From: Steven Rostedt <rostedt@goodmis.org>

commit 6ccd83714a009ee301b50c15f6c3a5dc1f30164c upstream.

When a max stack trace is discovered, the stack dump is saved. In order to
not record the overhead of the stack tracer, the ip of the traced function
is looked for within the dump. The trace is started from the location of
that function. But if for some reason the ip is not found, the entire stack
trace is then truncated. That's not very useful. Instead, print everything
if the ip of the traced function is not found within the trace.

This issue showed up on s390.

Link: http://lkml.kernel.org/r/20160129102241.1b3c9c04@gandalf.local.home

Fixes: 72ac426a5bb0 ("tracing: Clean up stack tracing and fix fentry updates")
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 kernel/trace/trace_stack.c |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -126,6 +126,13 @@ check_stack(unsigned long ip, unsigned l
 	}
 
 	/*
+	 * Some archs may not have the passed in ip in the dump.
+	 * If that happens, we need to show everything.
+	 */
+	if (i == stack_trace_max.nr_entries)
+		i = 0;
+
+	/*
 	 * Now find where in the stack these are.
 	 */
 	x = 0;


Patches currently in stable-queue which might be from rostedt@goodmis.org are

queue-4.4/tracing-fix-stacktrace-skip-depth-in-trace_buffer_unlock_commit_regs.patch
queue-4.4/tracing-stacktrace-show-entire-trace-if-passed-in-function-not-found.patch