Patch "PM / sleep: declare __tracedata symbols as char[] rather than char" has been added to the 4.4-stable tree

Patch "PM / sleep: declare __tracedata symbols as char[] rather than char" 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

    PM / sleep: declare __tracedata symbols as char[] rather than char

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:
     pm-sleep-declare-__tracedata-symbols-as-char-rather-than-char.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 f97238373b8662a6d580e204df2e7bcbfa43e27a Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers3@gmail.com>
Date: Sun, 24 Jan 2016 20:08:52 -0600
Subject: PM / sleep: declare __tracedata symbols as char[] rather than char

From: Eric Biggers <ebiggers3@gmail.com>

commit f97238373b8662a6d580e204df2e7bcbfa43e27a upstream.

Accessing more than one byte from a symbol declared simply 'char' is undefined
behavior, as reported by UBSAN:

	UBSAN: Undefined behaviour in drivers/base/power/trace.c:178:18
	load of address ffffffff8203fc78 with insufficient space
	for an object of type 'char'

Avoid this by declaring the symbols as arrays.

Signed-off-by: Eric Biggers <ebiggers3@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/base/power/trace.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/base/power/trace.c
+++ b/drivers/base/power/trace.c
@@ -166,14 +166,14 @@ void generate_pm_trace(const void *trace
 }
 EXPORT_SYMBOL(generate_pm_trace);
 
-extern char __tracedata_start, __tracedata_end;
+extern char __tracedata_start[], __tracedata_end[];
 static int show_file_hash(unsigned int value)
 {
 	int match;
 	char *tracedata;
 
 	match = 0;
-	for (tracedata = &__tracedata_start ; tracedata < &__tracedata_end ;
+	for (tracedata = __tracedata_start ; tracedata < __tracedata_end ;
 			tracedata += 2 + sizeof(unsigned long)) {
 		unsigned short lineno = *(unsigned short *)tracedata;
 		const char *file = *(const char **)(tracedata + 2);


Patches currently in stable-queue which might be from ebiggers3@gmail.com are

queue-4.4/pm-sleep-declare-__tracedata-symbols-as-char-rather-than-char.patch