powerpc/32: Fix boot failure with CONFIG_STACKPROTECTOR

Commit 7c95d8893f ("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: 7c95d8893f ("powerpc: Change calling convention for create_branch() et. al.")
Cc: stable@vger.kernel.org # v5.8+
Reported-by: Jonathan Neuschaefer <j.neuschaefer@gmx.net>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Tested-by: Jonathan Neuschaefer <j.neuschaefer@gmx.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b688fe82927b330349d9e44553363fa451ea4d95.1619715114.git.christophe.leroy@csgroup.eu
This commit is contained in:
Christophe Leroy 2021-04-29 16:52:09 +00:00 committed by Michael Ellerman
parent b910fcbada
commit f5668260b8

View file

@ -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)