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| author | Jani Nikula <jani.nikula@intel.com> | 2023-01-02 12:31:03 +0300 |
|---|---|---|
| committer | Jani Nikula <jani.nikula@intel.com> | 2023-01-02 12:31:03 +0300 |
| commit | 0d8eae7b124e2ddaee00f186fe922450faad0ed7 (patch) | |
| tree | 5acf7a7a4300665c26b128d9afd1843b402e8b8e /include/linux/stackprotector.h | |
| parent | be3ad78dfed2af3c293e01f3c5f13ee1af3395c3 (diff) | |
| parent | 1b929c02afd37871d5afb9d498426f83432e71c2 (diff) | |
| download | linux-0d8eae7b124e2ddaee00f186fe922450faad0ed7.tar.xz | |
Merge drm/drm-next into drm-intel-next
Sync up with v6.2-rc1.
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Diffstat (limited to 'include/linux/stackprotector.h')
| -rw-r--r-- | include/linux/stackprotector.h | 19 |
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 |