diff options
| author | Mel Gorman <mgorman@techsingularity.net> | 2025-01-24 01:11:14 +0300 |
|---|---|---|
| committer | Kees Cook <kees@kernel.org> | 2025-02-28 22:51:31 +0300 |
| commit | 496d2d23886436f7c651bf4c14950eb002815c61 (patch) | |
| tree | 523dfc03bdca78d94eb22f1b93e29d6f34b48f28 /include/linux | |
| parent | d2132f453e3308adc82ab7c101bd5220a9a34167 (diff) | |
| download | linux-496d2d23886436f7c651bf4c14950eb002815c61.tar.xz | |
mm: security: Check early if HARDENED_USERCOPY is enabled
HARDENED_USERCOPY is checked within a function so even if disabled, the
function overhead still exists. Move the static check inline.
This is at best a micro-optimisation and any difference in performance
was within noise but it is relatively consistent with the init_on_*
implementations.
Suggested-by: Kees Cook <kees@kernel.org>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Link: https://lore.kernel.org/r/20250123221115.19722-4-mgorman@techsingularity.net
Signed-off-by: Kees Cook <kees@kernel.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/ucopysize.h | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/include/linux/ucopysize.h b/include/linux/ucopysize.h index b3e1b875d565..41c2d9720466 100644 --- a/include/linux/ucopysize.h +++ b/include/linux/ucopysize.h @@ -6,14 +6,21 @@ #include <linux/bug.h> #ifdef CONFIG_HARDENED_USERCOPY +#include <linux/jump_label.h> extern void __check_object_size(const void *ptr, unsigned long n, bool to_user); +DECLARE_STATIC_KEY_MAYBE(CONFIG_HARDENED_USERCOPY_DEFAULT_ON, + validate_usercopy_range); + static __always_inline void check_object_size(const void *ptr, unsigned long n, bool to_user) { - if (!__builtin_constant_p(n)) + if (!__builtin_constant_p(n) && + static_branch_maybe(CONFIG_HARDENED_USERCOPY_DEFAULT_ON, + &validate_usercopy_range)) { __check_object_size(ptr, n, to_user); + } } #else static inline void check_object_size(const void *ptr, unsigned long n, |