From c633544a6154146a210cf158157a1ae7c55473b6 Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Sun, 3 Dec 2017 13:28:52 -0800 Subject: xtensa: add support for KASAN Cover kernel addresses above 0x90000000 by the shadow map. Enable HAVE_ARCH_KASAN when MMU is enabled. Provide kasan_early_init that fills shadow map with writable copies of kasan_zero_page. Call kasan_early_init right after mmu initialization in the setup_arch. Provide kasan_init that allocates proper shadow map pages from the memblock and puts these pages into the shadow map for addresses from VMALLOC area to the end of KSEG. Call kasan_init right after memblock initialization. Don't use KASAN for the boot code, MMU and KASAN initialization and page fault handler. Make kernel stack size 4 times larger when KASAN is enabled to avoid stack overflows. GCC 7.3, 8 or newer is required to build the xtensa kernel with KASAN. Signed-off-by: Max Filippov --- arch/xtensa/boot/lib/Makefile | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/xtensa/boot') diff --git a/arch/xtensa/boot/lib/Makefile b/arch/xtensa/boot/lib/Makefile index 2fe182915b63..355127faade1 100644 --- a/arch/xtensa/boot/lib/Makefile +++ b/arch/xtensa/boot/lib/Makefile @@ -15,6 +15,8 @@ CFLAGS_REMOVE_inftrees.o = -pg CFLAGS_REMOVE_inffast.o = -pg endif +KASAN_SANITIZE := n + CFLAGS_REMOVE_inflate.o += -fstack-protector -fstack-protector-strong CFLAGS_REMOVE_zmem.o += -fstack-protector -fstack-protector-strong CFLAGS_REMOVE_inftrees.o += -fstack-protector -fstack-protector-strong -- cgit v1.2.3