Currently, KASAN on LoongArch assume the CPU VA bits is 48, which is true for Loongson-3 series, but not for Loongson-2 series (only 40 or lower), this patch fix that issue and make KASAN usable for variable cpu_vabits.
1. Define XRANGE_SHADOW_SHIFT which means valid address length from VA_BITS to min(cpu_vabits, VA_BITS). 2. In kasan_mem_to_shadow() let DMW addresses which exceed XRANGE_SIZE to return kasan_early_shadow_page.
Cc: stable@vger.kernel.org Signed-off-by: Kanglong Wang wangkanglong@loongson.cn Signed-off-by: Huacai Chen chenhuacai@loongson.cn --- arch/loongarch/include/asm/kasan.h | 2 +- arch/loongarch/mm/kasan_init.c | 4 ++++ 2 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/loongarch/include/asm/kasan.h b/arch/loongarch/include/asm/kasan.h index cd6084f4e153..c6bce5fbff57 100644 --- a/arch/loongarch/include/asm/kasan.h +++ b/arch/loongarch/include/asm/kasan.h @@ -16,7 +16,7 @@ #define XRANGE_SHIFT (48)
/* Valid address length */ -#define XRANGE_SHADOW_SHIFT (PGDIR_SHIFT + PAGE_SHIFT - 3) +#define XRANGE_SHADOW_SHIFT min(cpu_vabits, VA_BITS) /* Used for taking out the valid address */ #define XRANGE_SHADOW_MASK GENMASK_ULL(XRANGE_SHADOW_SHIFT - 1, 0) /* One segment whole address space size */ diff --git a/arch/loongarch/mm/kasan_init.c b/arch/loongarch/mm/kasan_init.c index 427d6b1aec09..e5ecc8c12034 100644 --- a/arch/loongarch/mm/kasan_init.c +++ b/arch/loongarch/mm/kasan_init.c @@ -48,6 +48,10 @@ void *kasan_mem_to_shadow(const void *addr) return (void *)(kasan_early_shadow_page);
maddr &= XRANGE_SHADOW_MASK; + + if (maddr >= XRANGE_SIZE) + return (void *)(kasan_early_shadow_page); + switch (xrange) { case XKPRANGE_CC_SEG: offset = XKPRANGE_CC_SHADOW_OFFSET;