ARM: 8749/1: Kconfig: Add ARCH_HAS_FORTIFY_SOURCE

CONFIG_FORTIFY_SOURCE detects various overflows at compile-time.
(6974f0c455 ("include/linux/string.h:
add the option of fortified string.h functions)

ARCH_HAS_FORTIFY_SOURCE means that the architecture can be built and
run with CONFIG_FORTIFY_SOURCE.

Since ARM can be built and run with that flag like other architectures,
select ARCH_HAS_FORTIFY_SOURCE as default.

Acked-by: Kees Cook <[email protected]>
Signed-off-by: Jinbum Park <[email protected]>
Signed-off-by: Russell King <[email protected]>

arch/arm/Kconfig

@@ -7,6 +7,7 @@ config ARM
 	select ARCH_HAS_DEBUG_VIRTUAL if MMU
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_ELF_RANDOMIZE
+	select ARCH_HAS_FORTIFY_SOURCE
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_PHYS_TO_DMA
 	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL

arch/arm/boot/compressed/misc.c

@@ -167,3 +167,8 @@ decompress_kernel(unsigned long output_start, unsigned long free_mem_ptr_p,
 	else
 		putstr(" done, booting the kernel.\n");
 }
+
+void fortify_panic(const char *name)
+{
+	error("detected buffer overflow");
+}