Remove malloc hooks [BZ #23328]

Make malloc hooks symbols compat-only so that new applications cannot
link against them and remove the declarations from the API.  Also
remove the unused malloc-hooks.h.

Finally, mark all symbols in libc_malloc_debug.so as compat so that
the library cannot be linked against.

Add a note about the deprecation in NEWS.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>

4 files changed, 41 insertions, 41 deletions

diff --git a/malloc/hooks.c b/malloc/hooks.c
index 8e1afe55e5..2761e4739b 100644
--- a/malloc/hooks.c
+++ b/malloc/hooks.c
@@ -32,12 +32,16 @@ void weak_variable (*__after_morecore_hook) (void) = NULL;
 compat_symbol (libc, __after_morecore_hook, __after_morecore_hook, GLIBC_2_0);
 void *(*__morecore)(ptrdiff_t);
 compat_symbol (libc, __morecore, __morecore, GLIBC_2_0);
-#endif
 
 void weak_variable (*__free_hook) (void *, const void *) = NULL;
 void *weak_variable (*__malloc_hook) (size_t, const void *) = NULL;
 void *weak_variable (*__realloc_hook) (void *, size_t, const void *) = NULL;
 void *weak_variable (*__memalign_hook) (size_t, size_t, const void *) = NULL;
+compat_symbol (libc, __free_hook, __free_hook, GLIBC_2_0);
+compat_symbol (libc, __malloc_hook, __malloc_hook, GLIBC_2_0);
+compat_symbol (libc, __realloc_hook, __realloc_hook, GLIBC_2_0);
+compat_symbol (libc, __memalign_hook, __memalign_hook, GLIBC_2_0);
+#endif
 
 /*
  * Local variables:
diff --git a/malloc/malloc-debug.c b/malloc/malloc-debug.c
index b7744460e9..34523b0cc3 100644
--- a/malloc/malloc-debug.c
+++ b/malloc/malloc-debug.c
@@ -23,6 +23,7 @@
 #include <unistd.h>
 #include <sys/param.h>
 
+#if SHLIB_COMPAT (libc_malloc_debug, GLIBC_2_0, GLIBC_2_34)
 /* Support only the glibc allocators.  */
 extern void *__libc_malloc (size_t);
 extern void __libc_free (void *);
@@ -76,9 +77,11 @@ __malloc_debug_disable (enum malloc_debug_hooks flag)
 #include "mtrace.c"
 #include "malloc-check.c"
 
+#if SHLIB_COMPAT (libc_malloc_debug, GLIBC_2_0, GLIBC_2_24)
 extern void (*__malloc_initialize_hook) (void);
 compat_symbol_reference (libc, __malloc_initialize_hook,
 			 __malloc_initialize_hook, GLIBC_2_0);
+#endif
 
 static void *malloc_hook_ini (size_t, const void *) __THROW;
 static void *realloc_hook_ini (void *, size_t, const void *) __THROW;
@@ -115,9 +118,11 @@ generic_hook_ini (void)
        will not try to optimize it away.  */
     __libc_free (__libc_malloc (0));
 
+#if SHLIB_COMPAT (libc_malloc_debug, GLIBC_2_0, GLIBC_2_24)
   void (*hook) (void) = __malloc_initialize_hook;
   if (hook != NULL)
     (*hook)();
+#endif
 
   debug_initialized = 1;
 }
@@ -631,3 +636,34 @@ malloc_set_state (void *msptr)
 compat_symbol (libc_malloc_debug, malloc_set_state, malloc_set_state,
 	       GLIBC_2_0);
 #endif
+
+/* Do not allow linking against the library.  */
+compat_symbol (libc_malloc_debug, aligned_alloc, aligned_alloc, GLIBC_2_16);
+compat_symbol (libc_malloc_debug, calloc, calloc, GLIBC_2_0);
+compat_symbol (libc_malloc_debug, free, free, GLIBC_2_0);
+compat_symbol (libc_malloc_debug, mallinfo2, mallinfo2, GLIBC_2_33);
+compat_symbol (libc_malloc_debug, mallinfo, mallinfo, GLIBC_2_0);
+compat_symbol (libc_malloc_debug, malloc_info, malloc_info, GLIBC_2_10);
+compat_symbol (libc_malloc_debug, malloc, malloc, GLIBC_2_0);
+compat_symbol (libc_malloc_debug, malloc_stats, malloc_stats, GLIBC_2_0);
+compat_symbol (libc_malloc_debug, malloc_trim, malloc_trim, GLIBC_2_0);
+compat_symbol (libc_malloc_debug, malloc_usable_size, malloc_usable_size,
+	       GLIBC_2_0);
+compat_symbol (libc_malloc_debug, mallopt, mallopt, GLIBC_2_0);
+compat_symbol (libc_malloc_debug, mcheck_check_all, mcheck_check_all,
+	       GLIBC_2_2);
+compat_symbol (libc_malloc_debug, mcheck, mcheck, GLIBC_2_0);
+compat_symbol (libc_malloc_debug, mcheck_pedantic, mcheck_pedantic, GLIBC_2_2);
+compat_symbol (libc_malloc_debug, memalign, memalign, GLIBC_2_0);
+compat_symbol (libc_malloc_debug, mprobe, mprobe, GLIBC_2_0);
+compat_symbol (libc_malloc_debug, mtrace, mtrace, GLIBC_2_0);
+compat_symbol (libc_malloc_debug, muntrace, muntrace, GLIBC_2_0);
+compat_symbol (libc_malloc_debug, posix_memalign, posix_memalign, GLIBC_2_2);
+compat_symbol (libc_malloc_debug, pvalloc, pvalloc, GLIBC_2_0);
+compat_symbol (libc_malloc_debug, realloc, realloc, GLIBC_2_0);
+compat_symbol (libc_malloc_debug, valloc, valloc, GLIBC_2_0);
+compat_symbol (libc_malloc_debug, __free_hook, __free_hook, GLIBC_2_0);
+compat_symbol (libc_malloc_debug, __malloc_hook, __malloc_hook, GLIBC_2_0);
+compat_symbol (libc_malloc_debug, __realloc_hook, __realloc_hook, GLIBC_2_0);
+compat_symbol (libc_malloc_debug, __memalign_hook, __memalign_hook, GLIBC_2_0);
+#endif
diff --git a/malloc/malloc-hooks.h b/malloc/malloc-hooks.h
deleted file mode 100644
index 0133331b83..0000000000
--- a/malloc/malloc-hooks.h
+++ /dev/null
@@ -1,24 +0,0 @@
-/* Internal declarations of malloc hooks no longer in the public API.
-   Copyright (C) 2016-2021 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 _MALLOC_HOOKS_H
-#define _MALLOC_HOOKS_H
-
-void (*__malloc_initialize_hook) (void);
-
-#endif  /* _MALLOC_HOOKS_H */
diff --git a/malloc/malloc.h b/malloc/malloc.h
index 17ab9ee345..2df0b38050 100644
--- a/malloc/malloc.h
+++ b/malloc/malloc.h
@@ -156,21 +156,5 @@ extern void malloc_stats (void) __THROW;
 /* Output information about state of allocator to stream FP.  */
 extern int malloc_info (int __options, FILE *__fp) __THROW;
 
-/* Hooks for debugging and user-defined versions. */
-extern void (*__MALLOC_HOOK_VOLATILE __free_hook) (void *__ptr,
-                                                   const void *)
-__MALLOC_DEPRECATED;
-extern void *(*__MALLOC_HOOK_VOLATILE __malloc_hook)(size_t __size,
-                                                     const void *)
-__MALLOC_DEPRECATED;
-extern void *(*__MALLOC_HOOK_VOLATILE __realloc_hook)(void *__ptr,
-                                                      size_t __size,
-                                                      const void *)
-__MALLOC_DEPRECATED;
-extern void *(*__MALLOC_HOOK_VOLATILE __memalign_hook)(size_t __alignment,
-                                                       size_t __size,
-                                                       const void *)
-__MALLOC_DEPRECATED;
-
 __END_DECLS
 #endif /* malloc.h */