[PATCH v6 09/18] khwasan, arm64: fix up fault handling logic
From: Andrey Konovalov <hidden>
Date: 2018-08-29 11:35:46
Also in:
linux-doc, linux-kbuild, linux-mm, lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
show_pte in arm64 fault handling relies on the fact that the top byte of a kernel pointer is 0xff, which isn't always the case with KHWASAN enabled. Reset the top byte. Signed-off-by: Andrey Konovalov <redacted> --- arch/arm64/mm/fault.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 50b30ff30de4..35feee78a9bd 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c@@ -32,6 +32,7 @@ #include <linux/perf_event.h> #include <linux/preempt.h> #include <linux/hugetlb.h> +#include <linux/kasan.h> #include <asm/bug.h> #include <asm/cmpxchg.h>
@@ -134,6 +135,8 @@ void show_pte(unsigned long addr) pgd_t *pgdp; pgd_t pgd; + addr = (unsigned long)khwasan_reset_tag((void *)addr); + if (addr < TASK_SIZE) { /* TTBR0 */ mm = current->active_mm;
--
2.19.0.rc0.228.g281dcd1b4d0-goog