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s390/vdso: filter out -mstack-guard and -mstack-size

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When CONFIG_VMAP_STACK is disabled, the user can enable CONFIG_STACK_CHECK,
which adds a stack overflow check to each C function in the kernel. This is
also done for functions in the vdso page. These functions are run in user
context and user stack sizes are usually different to what the kernel uses.
This might trigger the stack check although the stack size is valid.
Therefore filter the -mstack-guard and -mstack-size flags when compiling
vdso C files.

Cc: stable@kernel.org # 5.10+
Fixes: 4bff8cb545 ("s390: convert to GENERIC_VDSO")
Reported-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
This commit is contained in:
Sven Schnelle 2021-11-11 10:58:26 +01:00 committed by Heiko Carstens
parent 7b737adc10
commit 00b55eaf45
2 changed files with 9 additions and 6 deletions
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10
arch/s390/Makefile
View File

@ -77,10 +77,12 @@ KBUILD_AFLAGS_DECOMPRESSOR += $(aflags-y)
KBUILD_CFLAGS_DECOMPRESSOR += $(cflags-y)
ifneq ($(call cc-option,-mstack-size=8192 -mstack-guard=128),)
cflags-$(CONFIG_CHECK_STACK) += -mstack-size=$(STACK_SIZE)
ifeq ($(call cc-option,-mstack-size=8192),)
cflags-$(CONFIG_CHECK_STACK) += -mstack-guard=$(CONFIG_STACK_GUARD)
endif
CC_FLAGS_CHECK_STACK := -mstack-size=$(STACK_SIZE)
ifeq ($(call cc-option,-mstack-size=8192),)
CC_FLAGS_CHECK_STACK += -mstack-guard=$(CONFIG_STACK_GUARD)
endif
export CC_FLAGS_CHECK_STACK
cflags-$(CONFIG_CHECK_STACK) += $(CC_FLAGS_CHECK_STACK)
endif
ifdef CONFIG_EXPOLINE

5
arch/s390/kernel/vdso64/Makefile
View File

@ -8,8 +8,9 @@ ARCH_REL_TYPE_ABS += R_390_GOT|R_390_PLT
include $(srctree)/lib/vdso/Makefile
obj-vdso64 = vdso_user_wrapper.o note.o
obj-cvdso64 = vdso64_generic.o getcpu.o
CFLAGS_REMOVE_getcpu.o = -pg $(CC_FLAGS_FTRACE) $(CC_FLAGS_EXPOLINE)
CFLAGS_REMOVE_vdso64_generic.o = -pg $(CC_FLAGS_FTRACE) $(CC_FLAGS_EXPOLINE)
VDSO_CFLAGS_REMOVE := -pg $(CC_FLAGS_FTRACE) $(CC_FLAGS_EXPOLINE) $(CC_FLAGS_CHECK_STACK)
CFLAGS_REMOVE_getcpu.o = $(VDSO_CFLAGS_REMOVE)
CFLAGS_REMOVE_vdso64_generic.o = $(VDSO_CFLAGS_REMOVE)
# Build rules