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authorSven Schnelle <svens@linux.ibm.com>2021-11-11 12:58:26 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-11-25 11:48:45 +0300
commitcc8b2e0d5bd75b67d7ee24de2685d2ee3d28e2d9 (patch)
tree82aa1ac2c77f52632881e4f702eda824f863dfe0 /arch/s390
parent44b6cc4367cc6f9c3803bd19df509ae7c1e3496e (diff)
downloadlinux-cc8b2e0d5bd75b67d7ee24de2685d2ee3d28e2d9.tar.xz
s390/vdso: filter out -mstack-guard and -mstack-size
commit 00b55eaf45549ce26424224d069a091c7e5d8bac upstream. 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: 4bff8cb54502 ("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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/Makefile10
-rw-r--r--arch/s390/kernel/vdso64/Makefile5
2 files changed, 9 insertions, 6 deletions
diff --git a/arch/s390/Makefile b/arch/s390/Makefile
index 450b351dfa8e..d4fd1426a822 100644
--- a/arch/s390/Makefile
+++ b/arch/s390/Makefile
@@ -79,10 +79,12 @@ 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
diff --git a/arch/s390/kernel/vdso64/Makefile b/arch/s390/kernel/vdso64/Makefile
index 6568de236701..0dea82b87e54 100644
--- a/arch/s390/kernel/vdso64/Makefile
+++ b/arch/s390/kernel/vdso64/Makefile
@@ -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