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-rw-r--r--mm/kfence/kfence.h10
1 files changed, 9 insertions, 1 deletions
diff --git a/mm/kfence/kfence.h b/mm/kfence/kfence.h
index 600f2e2431d6..2aafc46a4aaf 100644
--- a/mm/kfence/kfence.h
+++ b/mm/kfence/kfence.h
@@ -21,7 +21,15 @@
* lower 3 bits of the address, to detect memory corruptions with higher
* probability, where similar constants are used.
*/
-#define KFENCE_CANARY_PATTERN(addr) ((u8)0xaa ^ (u8)((unsigned long)(addr) & 0x7))
+#define KFENCE_CANARY_PATTERN_U8(addr) ((u8)0xaa ^ (u8)((unsigned long)(addr) & 0x7))
+
+/*
+ * Define a continuous 8-byte canary starting from a multiple of 8. The canary
+ * of each byte is only related to the lowest three bits of its address, so the
+ * canary of every 8 bytes is the same. 64-bit memory can be filled and checked
+ * at a time instead of byte by byte to improve performance.
+ */
+#define KFENCE_CANARY_PATTERN_U64 ((u64)0xaaaaaaaaaaaaaaaa ^ (u64)(0x0706050403020100))
/* Maximum stack depth for reports. */
#define KFENCE_STACK_DEPTH 64