From e998c9d7c1a52ab02ff6e9c363c1cfe0b76cd6f4 Mon Sep 17 00:00:00 2001 From: Siddhesh Poyarekar Date: Sat, 7 Jan 2023 19:30:32 -0500 Subject: [PATCH 5/5] alloc-util: Disallow inlining of expand_to_usable Explicitly set __attribute__ ((noinline)) so that the compiler does not attempt to inline expand_to_usable, even with LTO. (cherry picked from commit 4f79f545b3c46c358666c9f5f2b384fe50aac4b4) --- src/basic/alloc-util.h | 7 ++++--- src/fundamental/macro-fundamental.h | 1 + 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/src/basic/alloc-util.h b/src/basic/alloc-util.h index eb53aae6f3..bf783b15a2 100644 --- a/src/basic/alloc-util.h +++ b/src/basic/alloc-util.h @@ -186,10 +186,11 @@ void* greedy_realloc0(void **p, size_t need, size_t size); #endif /* Dummy allocator to tell the compiler that the new size of p is newsize. The implementation returns the - * pointer as is; the only reason for its existence is as a conduit for the _alloc_ attribute. This cannot be - * a static inline because gcc then loses the attributes on the function. + * pointer as is; the only reason for its existence is as a conduit for the _alloc_ attribute. This must not + * be inlined (hence a non-static function with _noinline_ because LTO otherwise tries to inline it) because + * gcc then loses the attributes on the function. * See: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96503 */ -void *expand_to_usable(void *p, size_t newsize) _alloc_(2) _returns_nonnull_; +void *expand_to_usable(void *p, size_t newsize) _alloc_(2) _returns_nonnull_ _noinline_; static inline size_t malloc_sizeof_safe(void **xp) { if (_unlikely_(!xp || !*xp)) diff --git a/src/fundamental/macro-fundamental.h b/src/fundamental/macro-fundamental.h index c11a5b15f4..e73174a593 100644 --- a/src/fundamental/macro-fundamental.h +++ b/src/fundamental/macro-fundamental.h @@ -20,6 +20,7 @@ #define _hidden_ __attribute__((__visibility__("hidden"))) #define _likely_(x) (__builtin_expect(!!(x), 1)) #define _malloc_ __attribute__((__malloc__)) +#define _noinline_ __attribute__((noinline)) #define _noreturn_ _Noreturn #define _packed_ __attribute__((__packed__)) #define _printf_(a, b) __attribute__((__format__(printf, a, b))) -- 2.39.1