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From: Sam James <sam@gentoo.org>
Date: Tue, 24 May 2022 23:21:50 +0100
Subject: [PATCH] Revert "Support -D_FORTIFY_SOURCE=3 by using
__builtin_dynamic_object_size."
Breaks Clang (even without F_S=3).
This reverts commit 0bd292567a543d124cd303f7dd61169a209cae64.
Bug: https://bugs.gentoo.org/841770
Bug: https://github.com/systemd/systemd/issues/23150
--- a/src/basic/alloc-util.h
+++ b/src/basic/alloc-util.h
@@ -174,23 +174,13 @@ void* greedy_realloc0(void **p, size_t need, size_t size);
* is compatible with _FORTIFY_SOURCES. If _FORTIFY_SOURCES is used many memory operations will take the
* object size as returned by __builtin_object_size() into account. Hence, let's return the smaller size of
* malloc_usable_size() and __builtin_object_size() here, so that we definitely operate in safe territory by
- * both the compiler's and libc's standards. Note that _FORTIFY_SOURCES=3 handles also dynamically allocated
- * objects and thus it's safer using __builtin_dynamic_object_size if _FORTIFY_SOURCES=3 is used (#22801).
- * Moreover, when NULL is passed malloc_usable_size() is documented to return zero, and
+ * both the compiler's and libc's standards. Note that __builtin_object_size() evaluates to SIZE_MAX if the
+ * size cannot be determined, hence the MIN() expression should be safe with dynamically sized memory,
+ * too. Moreover, when NULL is passed malloc_usable_size() is documented to return zero, and
* __builtin_object_size() returns SIZE_MAX too, hence we also return a sensible value of 0 in this corner
* case. */
-
-#if defined __has_builtin
-# if __has_builtin(__builtin_dynamic_object_size)
-# define MALLOC_SIZEOF_SAFE(x) \
- MIN(malloc_usable_size(x), __builtin_dynamic_object_size(x, 0))
-# endif
-#endif
-
-#ifndef MALLOC_SIZEOF_SAFE
#define MALLOC_SIZEOF_SAFE(x) \
MIN(malloc_usable_size(x), __builtin_object_size(x, 0))
-#endif
/* Inspired by ELEMENTSOF() but operates on malloc()'ed memory areas: typesafely returns the number of items
* that fit into the specified memory block */
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