linux-kernel - [PATCH 3.12 44/64] scripts/recordmcount.pl: support data in text section on powerpc

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Date:	Thu, 11 Feb 2016 14:59:20 +0100
From:	Jiri Slaby <jslaby@...e.cz>
To:	stable@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org,
	Ulrich Weigand <ulrich.weigand@...ibm.com>,
	Michael Ellerman <mpe@...erman.id.au>,
	Jiri Slaby <jslaby@...e.cz>
Subject: [PATCH 3.12 44/64] scripts/recordmcount.pl: support data in text section on powerpc

From: Ulrich Weigand <ulrich.weigand@...ibm.com>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

commit 2e50c4bef77511b42cc226865d6bc568fa7f8769 upstream.

If a text section starts out with a data blob before the first
function start label, disassembly parsing doing in recordmcount.pl
gets confused on powerpc, leading to creation of corrupted module
objects.

This was not a problem so far since the compiler would never create
such text sections.  However, this has changed with a recent change
in GCC 6 to support distances of > 2GB between a function and its
assoicated TOC in the ELFv2 ABI, exposing this problem.

There is already code in recordmcount.pl to handle such data blobs
on the sparc64 platform.  This patch uses the same method to handle
those on powerpc as well.

Acked-by: Steven Rostedt <rostedt@...dmis.org>
Signed-off-by: Ulrich Weigand <ulrich.weigand@...ibm.com>
Signed-off-by: Michael Ellerman <mpe@...erman.id.au>
Signed-off-by: Jiri Slaby <jslaby@...e.cz>
---
 scripts/recordmcount.pl | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/scripts/recordmcount.pl b/scripts/recordmcount.pl
index a27134fc3f76..efe7567d6225 100755
--- a/scripts/recordmcount.pl
+++ b/scripts/recordmcount.pl
@@ -265,7 +265,8 @@ if ($arch eq "x86_64") {

 } elsif ($arch eq "powerpc") {
     $local_regex = "^[0-9a-fA-F]+\\s+t\\s+(\\.?\\S+)";
-    $function_regex = "^([0-9a-fA-F]+)\\s+<(\\.?.*?)>:";
+    # See comment in the sparc64 section for why we use '\w'.
+    $function_regex = "^([0-9a-fA-F]+)\\s+<(\\.?\\w*?)>:";
     $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s\\.?_mcount\$";

     if ($bits == 64) {
-- 
2.7.1