Unverified Commit 54c5639d authored Oct 29, 2021 by Alexandre Ghiti Committed by Palmer Dabbelt Oct 29, 2021

riscv: Fix asan-stack clang build



Nathan reported that because KASAN_SHADOW_OFFSET was not defined in
Kconfig, it prevents asan-stack from getting disabled with clang even
when CONFIG_KASAN_STACK is disabled: fix this by defining the
corresponding config.

Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Fixes: 8ad8b727 ("riscv: Add KASAN support")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

parent cf11d011

arch/riscv/Kconfig

+6 −0

Original line number	Diff line number	Diff line
		@@ -163,6 +163,12 @@ config PAGE_OFFSET
		default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
		default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB

		config KASAN_SHADOW_OFFSET
		hex
		depends on KASAN_GENERIC
		default 0xdfffffc800000000 if 64BIT
		default 0xffffffff if 32BIT

		config ARCH_FLATMEM_ENABLE
		def_bool !NUMA

arch/riscv/include/asm/kasan.h

+1 −2

Original line number	Diff line number	Diff line
		@@ -30,8 +30,7 @@
		#define KASAN_SHADOW_SIZE (UL(1) << ((CONFIG_VA_BITS - 1) - KASAN_SHADOW_SCALE_SHIFT))
		#define KASAN_SHADOW_START KERN_VIRT_START
		#define KASAN_SHADOW_END (KASAN_SHADOW_START + KASAN_SHADOW_SIZE)
		#define KASAN_SHADOW_OFFSET (KASAN_SHADOW_END - (1ULL << \
		(64 - KASAN_SHADOW_SCALE_SHIFT)))
		#define KASAN_SHADOW_OFFSET _AC(CONFIG_KASAN_SHADOW_OFFSET, UL)

		void kasan_init(void);
		asmlinkage void kasan_early_init(void);

arch/riscv/mm/kasan_init.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -17,6 +17,9 @@ asmlinkage void __init kasan_early_init(void)
		uintptr_t i;
		pgd_t *pgd = early_pg_dir + pgd_index(KASAN_SHADOW_START);

		BUILD_BUG_ON(KASAN_SHADOW_OFFSET !=
		KASAN_SHADOW_END - (1UL << (64 - KASAN_SHADOW_SCALE_SHIFT)));

		for (i = 0; i < PTRS_PER_PTE; ++i)
		set_pte(kasan_early_shadow_pte + i,
		mk_pte(virt_to_page(kasan_early_shadow_page),