This is a note to let you know that I've just added the patch titled
powerpc/32: Fix boot failure with CONFIG_STACKPROTECTOR
to the 5.12-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-32-fix-boot-failure-with-config_stackprotector.patch
and it can be found in the queue-5.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From f5668260b872e89b8d3942a8b7d4278aa9c2c981 Mon Sep 17 00:00:00 2001
From: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Date: Thu, 29 Apr 2021 16:52:09 +0000
Subject: powerpc/32: Fix boot failure with CONFIG_STACKPROTECTOR
From: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
commit f5668260b872e89b8d3942a8b7d4278aa9c2c981 upstream.
Commit 7c95d8893fb5 ("powerpc: Change calling convention for
create_branch() et. al.") complexified the frame of function
do_feature_fixups(), leading to GCC setting up a stack
guard when CONFIG_STACKPROTECTOR is selected.
The problem is that do_feature_fixups() is called very early
while 'current' in r2 is not set up yet and the code is still
not at the final address used at link time.
So, like other instrumentation, stack protection needs to be
deactivated for feature-fixups.c and code-patching.c
Fixes: 7c95d8893fb5 ("powerpc: Change calling convention for create_branch() et. al.")
Cc: stable@xxxxxxxxxxxxxxx # v5.8+
Reported-by: Jonathan Neuschaefer <j.neuschaefer@xxxxxxx>
Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Tested-by: Jonathan Neuschaefer <j.neuschaefer@xxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/b688fe82927b330349d9e44553363fa451ea4d95.1619715114.git.christophe.leroy@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/lib/Makefile | 3 +++
1 file changed, 3 insertions(+)
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -5,6 +5,9 @@
ccflags-$(CONFIG_PPC64) := $(NO_MINIMAL_TOC)
+CFLAGS_code-patching.o += -fno-stack-protector
+CFLAGS_feature-fixups.o += -fno-stack-protector
+
CFLAGS_REMOVE_code-patching.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_feature-fixups.o = $(CC_FLAGS_FTRACE)
Patches currently in stable-queue which might be from christophe.leroy@xxxxxxxxxx are
queue-5.12/powerpc-vdso-separate-vvar-vma-from-vdso.patch
queue-5.12/powerpc-32-fix-boot-failure-with-config_stackprotector.patch
