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authorNamhyung Kim <namhyung@kernel.org>2025-02-05 14:57:18 -0800
committerNamhyung Kim <namhyung@kernel.org>2025-02-05 14:57:18 -0800
commit9e676a024fa1fa2bd8150c2d2ba85478280353bc (patch)
tree5cf0e1d4ab27002fcafdc7dc5bdfdd9ff3f3c9f1 /include/linux/fortify-string.h
parent357b965deba9fb71467413e473764ec4e1694d8d (diff)
parent2014c95afecee3e76ca4a56956a936e23283f05b (diff)
Merge tag 'v6.14-rc1' into perf-tools-next
To get the various fixes in the current master. Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Diffstat (limited to 'include/linux/fortify-string.h')
-rw-r--r--include/linux/fortify-string.h14
1 files changed, 13 insertions, 1 deletions
diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h
index 0d99bf11d260..e4ce1cae03bf 100644
--- a/include/linux/fortify-string.h
+++ b/include/linux/fortify-string.h
@@ -616,6 +616,12 @@ __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 +629,8 @@ __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 +638,11 @@ __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); \
})
/*