diff options
| author | Arnaldo Carvalho de Melo <[email protected]> | 2022-12-16 09:53:53 -0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <[email protected]> | 2022-12-16 09:53:53 -0300 |
| commit | 1a931707ad4a46e79d4ecfee56d8f6e8cc8d4f28 (patch) | |
| tree | c3ed4dafca580360da63eef576b35eb67eb2e5a2 /include/linux/stackprotector.h | |
| parent | 818448e9cf92e5c6b3c10320372eefcbe4174e4f (diff) | |
| parent | 84e57d292203a45c96dbcb2e6be9dd80961d981a (diff) | |
Merge remote-tracking branch 'torvalds/master' into perf/core
To resolve a trivial merge conflict with c302378bc157f6a7 ("libbpf:
Hashmap interface update to allow both long and void* keys/values"),
where a function present upstream was removed in the perf tools
development tree.
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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 |