diff options
Diffstat (limited to 'include/linux/fortify-string.h')
| -rw-r--r-- | include/linux/fortify-string.h | 24 |
1 files changed, 17 insertions, 7 deletions
diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h index 0d99bf11d260..171982e53c9a 100644 --- a/include/linux/fortify-string.h +++ b/include/linux/fortify-string.h @@ -2,7 +2,6 @@ #ifndef _LINUX_FORTIFY_STRING_H_ #define _LINUX_FORTIFY_STRING_H_ -#include <linux/bitfield.h> #include <linux/bug.h> #include <linux/const.h> #include <linux/limits.h> @@ -10,10 +9,9 @@ #define __FORTIFY_INLINE extern __always_inline __gnu_inline __overloadable #define __RENAME(x) __asm__(#x) -#define FORTIFY_REASON_DIR(r) FIELD_GET(BIT(0), r) -#define FORTIFY_REASON_FUNC(r) FIELD_GET(GENMASK(7, 1), r) -#define FORTIFY_REASON(func, write) (FIELD_PREP(BIT(0), write) | \ - FIELD_PREP(GENMASK(7, 1), func)) +#define FORTIFY_REASON_DIR(r) ((r) & 1) +#define FORTIFY_REASON_FUNC(r) ((r) >> 1) +#define FORTIFY_REASON(func, write) ((func) << 1 | (write)) /* Overridden by KUnit tests. */ #ifndef fortify_panic @@ -596,7 +594,7 @@ __FORTIFY_INLINE bool fortify_memcpy_chk(__kernel_size_t size, if (p_size != SIZE_MAX && p_size < size) fortify_panic(func, FORTIFY_WRITE, p_size, size, true); else if (q_size != SIZE_MAX && q_size < size) - fortify_panic(func, FORTIFY_READ, p_size, size, true); + fortify_panic(func, FORTIFY_READ, q_size, size, true); /* * Warn when writing beyond destination field size. @@ -616,6 +614,12 @@ __FORTIFY_INLINE bool fortify_memcpy_chk(__kernel_size_t size, return false; } +/* + * To work around what seems to be an optimizer bug, the macro arguments + * need to have const copies or the values end up changed by the time they + * reach fortify_warn_once(). See commit 6f7630b1b5bc ("fortify: Capture + * __bos() results in const temp vars") for more details. + */ #define __fortify_memcpy_chk(p, q, size, p_size, q_size, \ p_size_field, q_size_field, op) ({ \ const size_t __fortify_size = (size_t)(size); \ @@ -623,6 +627,8 @@ __FORTIFY_INLINE bool fortify_memcpy_chk(__kernel_size_t size, const size_t __q_size = (q_size); \ const size_t __p_size_field = (p_size_field); \ const size_t __q_size_field = (q_size_field); \ + /* Keep a mutable version of the size for the final copy. */ \ + size_t __copy_size = __fortify_size; \ fortify_warn_once(fortify_memcpy_chk(__fortify_size, __p_size, \ __q_size, __p_size_field, \ __q_size_field, FORTIFY_FUNC_ ##op), \ @@ -630,7 +636,11 @@ __FORTIFY_INLINE bool fortify_memcpy_chk(__kernel_size_t size, __fortify_size, \ "field \"" #p "\" at " FILE_LINE, \ __p_size_field); \ - __underlying_##op(p, q, __fortify_size); \ + /* Hide only the run-time size from value range tracking to */ \ + /* silence compile-time false positive bounds warnings. */ \ + if (!__builtin_constant_p(__copy_size)) \ + OPTIMIZER_HIDE_VAR(__copy_size); \ + __underlying_##op(p, q, __copy_size); \ }) /* |