diff mbox series

[v8,11/20] kasan, arm64: fix up fault handling logic

Message ID ca97a9434ecb703456cc06d9f17fd45e2e0b46ce.1537383101.git.andreyknvl@google.com (mailing list archive)
State New, archived
Headers show
Series kasan: add software tag-based mode for arm64 | expand

Commit Message

Andrey Konovalov Sept. 19, 2018, 6:54 p.m. UTC 
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 tag-based
KASAN.

This patch resets the top byte in show_pte.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
 arch/arm64/mm/fault.c | 3 +++
 1 file changed, 3 insertions(+)
diff mbox series

Patch

diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 50b30ff30de4..78328c864d01 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)kasan_reset_tag((void *)addr);
+
 	if (addr < TASK_SIZE) {
 		/* TTBR0 */
 		mm = current->active_mm;