diff options
| author | Kees Cook <kees@kernel.org> | 2024-08-05 14:43:44 -0700 |
|---|---|---|
| committer | Kees Cook <kees@kernel.org> | 2024-08-22 17:04:43 -0700 |
| commit | 559048d156ff3391c4b793779a824c9193e20442 (patch) | |
| tree | a05e8cf71ae1b3814c1c59f8f316beb1e9b58ebf /include/linux/compiler.h | |
| parent | 32ef4b710cbe1a8901534033872a5bc6b1618bbc (diff) | |
string: Check for "nonstring" attribute on strscpy() arguments
GCC already checks for arguments that are marked with the "nonstring"[1]
attribute when used on standard C String API functions (e.g. strcpy). Gain
this compile-time checking also for the kernel's primary string copying
function, strscpy().
Note that Clang has neither "nonstring" nor __builtin_has_attribute().
Link: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-nonstring-variable-attribute [1]
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Tested-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://lore.kernel.org/r/20240805214340.work.339-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
Diffstat (limited to 'include/linux/compiler.h')
| -rw-r--r-- | include/linux/compiler.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 2df665fa2964..ec55bcce4146 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -242,6 +242,9 @@ static inline void *offset_to_ptr(const int *off) /* &a[0] degrades to a pointer: a different type from an array */ #define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0])) +/* Require C Strings (i.e. NUL-terminated) lack the "nonstring" attribute. */ +#define __must_be_cstr(p) BUILD_BUG_ON_ZERO(__annotated(p, nonstring)) + /* * This returns a constant expression while determining if an argument is * a constant expression, most importantly without evaluating the argument. |