s390: add support for FORTIFY_SOURCE

This is the quite trivial backend for s390 which is required to enable
FORTIFY_SOURCE support.

See commit 6974f0c4555e ("include/linux/string.h: add the option of
fortified string.h functions") for more details.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 2784ca9..4edc91e 100644 (file)
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -67,6 +67,7 @@ config S390
        select ARCH_BINFMT_ELF_STATE
        select ARCH_HAS_DEVMEM_IS_ALLOWED
        select ARCH_HAS_ELF_RANDOMIZE
+       select ARCH_HAS_FORTIFY_SOURCE
        select ARCH_HAS_GCOV_PROFILE_ALL
        select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
        select ARCH_HAS_KCOV

diff --git a/arch/s390/boot/compressed/Makefile b/arch/s390/boot/compressed/Makefile
index f7e4c83..ec63b58 100644 (file)
--- a/arch/s390/boot/compressed/Makefile
+++ b/arch/s390/boot/compressed/Makefile
@@ -11,7 +11,7 @@ targets += vmlinux.bin.xz vmlinux.bin.lzma vmlinux.bin.lzo vmlinux.bin.lz4
 targets += misc.o piggy.o sizes.h head.o
 
 KBUILD_CFLAGS := -m64 -D__KERNEL__ -O2
-KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING
+KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING -D__NO_FORTIFY
 KBUILD_CFLAGS += $(cflags-y) -fno-delete-null-pointer-checks -msoft-float
 KBUILD_CFLAGS += $(call cc-option,-mpacked-stack)
 KBUILD_CFLAGS += $(call cc-option,-ffreestanding)

diff --git a/arch/s390/include/asm/string.h b/arch/s390/include/asm/string.h
index e5f5c70..8fb4331 100644 (file)
--- a/arch/s390/include/asm/string.h
+++ b/arch/s390/include/asm/string.h
@@ -49,7 +49,7 @@ extern char *strstr(const char *, const char *);
 #undef __HAVE_ARCH_STRSEP
 #undef __HAVE_ARCH_STRSPN
 
-#if !defined(IN_ARCH_STRING_C)
+#if !defined(IN_ARCH_STRING_C) && (!defined(CONFIG_FORTIFY_SOURCE) || defined(__NO_FORTIFY))
 
 static inline void *memchr(const void * s, int c, size_t n)
 {

diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index adb3fe2..9118e62 100644 (file)
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -33,6 +33,8 @@ AFLAGS_REMOVE_head.o  += $(CC_FLAGS_MARCH)
 AFLAGS_head.o          += -march=z900
 endif
 
+CFLAGS_als.o           += -D__NO_FORTIFY
+
 #
 # Passing null pointers is ok for smp code, since we access the lowcore here.
 #