Patch "powerpc/perf: Cap 64bit userspace backtraces to PERF_MAX_STACK_DEPTH" has been added to the 4.0-stable tree

Patch "powerpc/perf: Cap 64bit userspace backtraces to PERF_MAX_STACK_DEPTH" has been added to the 4.0-stable tree

[gregkh]

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

    powerpc/perf: Cap 64bit userspace backtraces to PERF_MAX_STACK_DEPTH

to the 4.0-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:
     powerpc-perf-cap-64bit-userspace-backtraces-to-perf_max_stack_depth.patch
and it can be found in the queue-4.0 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 9a5cbce421a283e6aea3c4007f141735bf9da8c3 Mon Sep 17 00:00:00 2001
From: Anton Blanchard <anton@samba.org>
Date: Tue, 14 Apr 2015 07:51:03 +1000
Subject: powerpc/perf: Cap 64bit userspace backtraces to PERF_MAX_STACK_DEPTH

From: Anton Blanchard <anton@samba.org>

commit 9a5cbce421a283e6aea3c4007f141735bf9da8c3 upstream.

We cap 32bit userspace backtraces to PERF_MAX_STACK_DEPTH
(currently 127), but we forgot to do the same for 64bit backtraces.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/powerpc/perf/callchain.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/powerpc/perf/callchain.c
+++ b/arch/powerpc/perf/callchain.c
@@ -243,7 +243,7 @@ static void perf_callchain_user_64(struc
 	sp = regs->gpr[1];
 	perf_callchain_store(entry, next_ip);
 
-	for (;;) {
+	while (entry->nr < PERF_MAX_STACK_DEPTH) {
 		fp = (unsigned long __user *) sp;
 		if (!valid_user_sp(sp, 1) || read_user_stack_64(fp, &next_sp))
 			return;


Patches currently in stable-queue which might be from anton@samba.org are

queue-4.0/powerpc-perf-cap-64bit-userspace-backtraces-to-perf_max_stack_depth.patch
queue-4.0/powerpc-jump_label-include-linux-jump_label.h-to-get-have_jump_label-define.patch
queue-4.0/perf-symbols-define-stt_gnu_ifunc-for-glibc-2.9-and-older.patch