commit 51da74a97e0f024fd89b57304b3ab010a3cfaef1
Author: Sam James <sam@gentoo.org>
Date:   Mon Dec 9 23:11:25 2024 +0000

    malloc: add indirection for malloc(-like) functions in tests [BZ #32366]
    
    GCC 15 introduces allocation dead code removal (DCE) for PR117370 in
    r15-5255-g7828dc070510f8. This breaks various glibc tests which want
    to assert various properties of the allocator without doing anything
    obviously useful with the allocated memory.
    
    Alexander Monakov rightly pointed out that we can and should do better
    than passing -fno-malloc-dce to paper over the problem. Not least because
    GCC 14 already does such DCE where there's no testing of malloc's return
    value against NULL, and LLVM has such optimisations too.
    
    Handle this by providing malloc (and friends) wrappers with a volatile
    function pointer to obscure that we're calling malloc (et. al) from the
    compiler.
    
    Reviewed-by: Paul Eggert <eggert@cs.ucla.edu>
    (cherry picked from commit a9944a52c967ce76a5894c30d0274b824df43c7a)

diff --git a/malloc/tst-aligned-alloc.c b/malloc/tst-aligned-alloc.c
index 91167d1392c0e626..b0f05a8fec78d5e8 100644
--- a/malloc/tst-aligned-alloc.c
+++ b/malloc/tst-aligned-alloc.c
@@ -25,6 +25,8 @@
 #include <libc-diag.h>
 #include <support/check.h>
 
+#include "tst-malloc-aux.h"
+
 static int
 do_test (void)
 {
diff --git a/malloc/tst-compathooks-off.c b/malloc/tst-compathooks-off.c
index d0106f3fb74ff3b1..4cce6e5a8076f6b6 100644
--- a/malloc/tst-compathooks-off.c
+++ b/malloc/tst-compathooks-off.c
@@ -25,6 +25,8 @@
 #include <support/check.h>
 #include <support/support.h>
 
+#include "tst-malloc-aux.h"
+
 extern void (*volatile __free_hook) (void *, const void *);
 extern void *(*volatile __malloc_hook)(size_t, const void *);
 extern void *(*volatile __realloc_hook)(void *, size_t, const void *);
diff --git a/malloc/tst-malloc-aux.h b/malloc/tst-malloc-aux.h
new file mode 100644
index 0000000000000000..54908b4a2464d510
--- /dev/null
+++ b/malloc/tst-malloc-aux.h
@@ -0,0 +1,41 @@
+/* Wrappers for malloc-like functions to allow testing the implementation
+   without optimization.
+   Copyright (C) 2024 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <https://www.gnu.org/licenses/>.  */
+
+#ifndef TST_MALLOC_AUX_H
+#define TST_MALLOC_AUX_H
+
+#include <stddef.h>
+#include <stdlib.h>
+
+static void *(*volatile aligned_alloc_indirect)(size_t, size_t) = aligned_alloc;
+static void *(*volatile calloc_indirect)(size_t, size_t) = calloc;
+static void *(*volatile malloc_indirect)(size_t) = malloc;
+static void *(*volatile realloc_indirect)(void*, size_t) = realloc;
+
+#undef aligned_alloc
+#undef calloc
+#undef malloc
+#undef realloc
+
+#define aligned_alloc aligned_alloc_indirect
+#define calloc calloc_indirect
+#define malloc malloc_indirect
+#define realloc realloc_indirect
+
+#endif /* TST_MALLOC_AUX_H */
diff --git a/malloc/tst-malloc-check.c b/malloc/tst-malloc-check.c
index fde8863ad7561a71..cc88bff3b39a421c 100644
--- a/malloc/tst-malloc-check.c
+++ b/malloc/tst-malloc-check.c
@@ -20,6 +20,8 @@
 #include <stdlib.h>
 #include <libc-diag.h>
 
+#include "tst-malloc-aux.h"
+
 static int errors = 0;
 
 static void
diff --git a/malloc/tst-malloc-too-large.c b/malloc/tst-malloc-too-large.c
index 8e9e0d5fa2b4b907..2b91377e54cdc485 100644
--- a/malloc/tst-malloc-too-large.c
+++ b/malloc/tst-malloc-too-large.c
@@ -43,6 +43,7 @@
 #include <unistd.h>
 #include <sys/param.h>
 
+#include "tst-malloc-aux.h"
 
 /* This function prepares for each 'too-large memory allocation' test by
    performing a small successful malloc/free and resetting errno prior to
diff --git a/malloc/tst-malloc.c b/malloc/tst-malloc.c
index f7a6e4654c374d01..68af399022543111 100644
--- a/malloc/tst-malloc.c
+++ b/malloc/tst-malloc.c
@@ -22,6 +22,8 @@
 #include <libc-diag.h>
 #include <time.h>
 
+#include "tst-malloc-aux.h"
+
 static int errors = 0;
 
 static void
diff --git a/malloc/tst-realloc.c b/malloc/tst-realloc.c
index f50499ecb114d574..74a28fb45ed80bf5 100644
--- a/malloc/tst-realloc.c
+++ b/malloc/tst-realloc.c
@@ -23,6 +23,8 @@
 #include <libc-diag.h>
 #include <support/check.h>
 
+#include "tst-malloc-aux.h"
+
 static int
 do_test (void)
 {
diff --git a/support/support.h b/support/support.h
index ba21ec9b5add7c02..1a77f7979330d60c 100644
--- a/support/support.h
+++ b/support/support.h
@@ -113,7 +113,7 @@ void *xposix_memalign (size_t alignment, size_t n)
   __attribute_malloc__ __attribute_alloc_align__ ((1))
   __attribute_alloc_size__ ((2)) __attr_dealloc_free __returns_nonnull;
 char *xasprintf (const char *format, ...)
-  __attribute__ ((format (printf, 1, 2), malloc)) __attr_dealloc_free
+  __attribute__ ((format (printf, 1, 2), __malloc__)) __attr_dealloc_free
   __returns_nonnull;
 char *xstrdup (const char *) __attr_dealloc_free __returns_nonnull;
 char *xstrndup (const char *, size_t) __attr_dealloc_free __returns_nonnull;
diff --git a/test-skeleton.c b/test-skeleton.c
index ae185a4f2821de00..690f26e7cf229622 100644
--- a/test-skeleton.c
+++ b/test-skeleton.c
@@ -27,7 +27,6 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <getopt.h>
-#include <malloc.h>
 #include <paths.h>
 #include <search.h>
 #include <signal.h>