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authorKalle Valo <kvalo@kernel.org>2023-01-17 13:36:25 +0200
committerKalle Valo <kvalo@kernel.org>2023-01-17 13:36:25 +0200
commitd0e99511834b6828c960e978d9a8cb6e5731250d (patch)
treee7b062c1f9d28a55083477a1462286a7923a57fd /include/linux/stackprotector.h
parentde7d0ff301fccc75281d7d8eb98c4a47faacf32d (diff)
parent80f8a66dede0a4b4e9e846765a97809c6fe49ce5 (diff)
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Merge wireless into wireless-next
Due to the two cherry picked commits from wireless to wireless-next we have several conflicts in mt76. To avoid any bugs with conflicts merge wireless into wireless-next. 96f134dc1964 wifi: mt76: handle possible mt76_rx_token_consume failures fe13dad8992b wifi: mt76: dma: do not increment queue head if mt76_dma_add_buf fails
Diffstat (limited to 'include/linux/stackprotector.h')
-rw-r--r--include/linux/stackprotector.h19
1 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/stackprotector.h b/include/linux/stackprotector.h
index 4c678c4fec58..9c88707d9a0f 100644
--- a/include/linux/stackprotector.h
+++ b/include/linux/stackprotector.h
@@ -6,6 +6,25 @@
#include <linux/sched.h>
#include <linux/random.h>
+/*
+ * On 64-bit architectures, protect against non-terminated C string overflows
+ * by zeroing out the first byte of the canary; this leaves 56 bits of entropy.
+ */
+#ifdef CONFIG_64BIT
+# ifdef __LITTLE_ENDIAN
+# define CANARY_MASK 0xffffffffffffff00UL
+# else /* big endian, 64 bits: */
+# define CANARY_MASK 0x00ffffffffffffffUL
+# endif
+#else /* 32 bits: */
+# define CANARY_MASK 0xffffffffUL
+#endif
+
+static inline unsigned long get_random_canary(void)
+{
+ return get_random_long() & CANARY_MASK;
+}
+
#if defined(CONFIG_STACKPROTECTOR) || defined(CONFIG_ARM64_PTR_AUTH)
# include <asm/stackprotector.h>
#else