diff options
| -rw-r--r-- | ChangeLog | 20 | ||||
| -rw-r--r-- | NEWS | 3 | ||||
| -rw-r--r-- | include/stdc-predef.h | 7 | ||||
| -rw-r--r-- | malloc/Makefile | 14 | ||||
| -rw-r--r-- | malloc/arena.c | 4 | ||||
| -rw-r--r-- | malloc/malloc-hooks.h | 27 | ||||
| -rw-r--r-- | malloc/malloc.c | 16 | ||||
| -rw-r--r-- | malloc/malloc.h | 5 | ||||
| -rw-r--r-- | malloc/mcheck-init.c | 2 | ||||
| -rw-r--r-- | manual/memory.texi | 24 |
10 files changed, 92 insertions, 30 deletions
diff --git a/ChangeLog b/ChangeLog index c0a32785e7..9f9c7080a7 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,23 @@ +2016-06-10 Florian Weimer <fweimer@redhat.com> + + [BZ #19564] + Remove __malloc_initialize_hook from the API. + * malloc/malloc.h (__malloc_initialize_hook): Remove. + * include/stdc-predef.h (__malloc_initialize_hook): Poison with + #pragma GCC poison. + * malloc/malloc-hooks.h: New file. + * malloc/arena.c (ptmalloc_init): Use old__malloc_initialize_hook. + * malloc/malloc.c (HAVE_MALLOC_INIT_HOOK): New. + (old__malloc_initialize_hook): Rename from + __malloc_initialize_hook to evade poisoning. Turn into compat + symbol. + * malloc/mcheck-init.c (old__malloc_initialize_hook): Rename from + __malloc_initialize_hook. + * malloc/Makefile (poisoned_apis, unpoisoned_api_defines): New. + (mallo.c, mcheck-init.c): Compile with unpoisoned symbol. + * manual/memory.texi (Hooks for Malloc): Remove + __malloc_initialize_hook. Adjust hook example. + 2016-06-09 Joseph Myers <joseph@codesourcery.com> [BZ #20235] diff --git a/NEWS b/NEWS index 2341697c97..9d6ac56d53 100644 --- a/NEWS +++ b/NEWS @@ -33,6 +33,9 @@ Version 2.24 group: files [SUCCESS=merge] nis Implemented by Stephen Gallagher (Red Hat). +* The deprecated __malloc_initialize_hook variable has been removed from the + API. + Security related changes: * An unnecessary stack copy in _nss_dns_getnetbyname_r was removed. It diff --git a/include/stdc-predef.h b/include/stdc-predef.h index f9f7f731d1..52cf8d10a0 100644 --- a/include/stdc-predef.h +++ b/include/stdc-predef.h @@ -57,4 +57,11 @@ /* We do not support C11 <threads.h>. */ #define __STDC_NO_THREADS__ 1 +/* Remove symbols from the API which can be interposed. */ +#if defined (__GNUC__) +# if __GNUC__ >= 4 +# pragma GCC poison __malloc_initialize_hook +# endif /* __GNUC__ >= 4 */ +#endif /* __GNUC__ */ + #endif diff --git a/malloc/Makefile b/malloc/Makefile index fa1730ecb7..91eb17dd7a 100644 --- a/malloc/Makefile +++ b/malloc/Makefile @@ -115,6 +115,20 @@ endif include ../Rules +# Support references to removed APIs. We use #pragma GCC poison in +# <stdc-predef.h> to make it difficult to reference them. For select +# source files, we work around this poisoning by defining a macro on +# the command line (which is processed before <stdc-predef.h> and can +# therefore use tokens poisoned later). +poisoned_apis = \ + __malloc_initialize_hook \ + +unpoisoned_api_defines := \ + $(foreach sym,$(poisoned_apis), \ + $(patsubst %,-Dold%, $(sym))=$(sym)) +CPPFLAGS-malloc.c = $(unpoisoned_api_defines) +CPPFLAGS-mcheck-init.c = $(unpoisoned_api_defines) + CFLAGS-mcheck-init.c = $(PIC-ccflag) CFLAGS-obstack.c = $(uses-callbacks) diff --git a/malloc/arena.c b/malloc/arena.c index 1dd9deef0e..64a118c319 100644 --- a/malloc/arena.c +++ b/malloc/arena.c @@ -340,9 +340,11 @@ ptmalloc_init (void) if (check_action != 0) __malloc_check_init (); } - void (*hook) (void) = atomic_forced_read (__malloc_initialize_hook); +#if HAVE_MALLOC_INIT_HOOK + void (*hook) (void) = atomic_forced_read (old__malloc_initialize_hook); if (hook != NULL) (*hook)(); +#endif __malloc_initialized = 1; } diff --git a/malloc/malloc-hooks.h b/malloc/malloc-hooks.h new file mode 100644 index 0000000000..3be391b6fb --- /dev/null +++ b/malloc/malloc-hooks.h @@ -0,0 +1,27 @@ +/* Internal declarations of malloc hooks no longer in the public API. + Copyright (C) 2016 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 <http://www.gnu.org/licenses/>. */ + +#ifndef _MALLOC_HOOKS_H +#define _MALLOC_HOOKS_H + +/* These hooks are no longer part of the public API and are poisoned + in <stdc-predef.h>. Their names here reflect the command-line + mapping which is used inside glibc to get past the poisoning. */ +void (*old__malloc_initialize_hook) (void); + +#endif /* _MALLOC_HOOKS_H */ diff --git a/malloc/malloc.c b/malloc/malloc.c index 6f77d372a8..ac0f751593 100644 --- a/malloc/malloc.c +++ b/malloc/malloc.c @@ -491,6 +491,15 @@ void *(*__morecore)(ptrdiff_t) = __default_morecore; #define HAVE_MREMAP 0 #endif +/* We may need to support __malloc_initialize_hook for backwards + compatibility. */ + +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_24) +# define HAVE_MALLOC_INIT_HOOK 1 +#else +# define HAVE_MALLOC_INIT_HOOK 0 +#endif + /* This version of malloc supports the standard SVID/XPG mallinfo @@ -1841,7 +1850,12 @@ static void *realloc_hook_ini (void *ptr, size_t sz, static void *memalign_hook_ini (size_t alignment, size_t sz, const void *caller) __THROW; -void weak_variable (*__malloc_initialize_hook) (void) = NULL; +#if HAVE_MALLOC_INIT_HOOK +void weak_variable (*old__malloc_initialize_hook) (void) = NULL; +compat_symbol (libc, old__malloc_initialize_hook, + old__malloc_initialize_hook, GLIBC_2_0); +#endif + void weak_variable (*__free_hook) (void *__ptr, const void *) = NULL; void *weak_variable (*__malloc_hook) diff --git a/malloc/malloc.h b/malloc/malloc.h index d95a3157a3..54b1862035 100644 --- a/malloc/malloc.h +++ b/malloc/malloc.h @@ -141,11 +141,6 @@ extern void *malloc_get_state (void) __THROW; malloc_get_state(). */ extern int malloc_set_state (void *__ptr) __THROW; -/* Called once when malloc is initialized; redefining this variable in - the application provides the preferred way to set up the hook - pointers. */ -extern void (*__MALLOC_HOOK_VOLATILE __malloc_initialize_hook) (void) -__MALLOC_DEPRECATED; /* Hooks for debugging and user-defined versions. */ extern void (*__MALLOC_HOOK_VOLATILE __free_hook) (void *__ptr, const void *) diff --git a/malloc/mcheck-init.c b/malloc/mcheck-init.c index 8d63dd3488..3218bb03b9 100644 --- a/malloc/mcheck-init.c +++ b/malloc/mcheck-init.c @@ -27,4 +27,4 @@ turn_on_mcheck (void) mcheck (NULL); } -void (*__malloc_initialize_hook) (void) = turn_on_mcheck; +void (*old__malloc_initialize_hook) (void) = turn_on_mcheck; diff --git a/manual/memory.texi b/manual/memory.texi index a3ecc0df7c..92f041ae4d 100644 --- a/manual/memory.texi +++ b/manual/memory.texi @@ -1370,19 +1370,6 @@ should make sure to restore all the hooks to their previous value. When coming back from the recursive call, all the hooks should be resaved since a hook might modify itself. -@comment malloc.h -@comment GNU -@defvar __malloc_initialize_hook -The value of this variable is a pointer to a function that is called -once when the malloc implementation is initialized. This is a weak -variable, so it can be overridden in the application with a definition -like the following: - -@smallexample -void (*@var{__malloc_initialize_hook}) (void) = my_init_hook; -@end smallexample -@end defvar - An issue to look out for is the time at which the malloc hook functions can be safely installed. If the hook functions call the malloc-related functions recursively, it is necessary that malloc has already properly @@ -1393,11 +1380,6 @@ are assigned to @emph{before} the very first @code{malloc} call has completed, because otherwise a chunk obtained from the ordinary, un-hooked malloc may later be handed to @code{__free_hook}, for example. -In both cases, the problem can be solved by setting up the hooks from -within a user-defined function pointed to by -@code{__malloc_initialize_hook}---then the hooks will be set up safely -at the right time. - Here is an example showing how to use @code{__malloc_hook} and @code{__free_hook} properly. It installs a function that prints out information every time @code{malloc} or @code{free} is called. We just @@ -1413,11 +1395,8 @@ static void my_init_hook (void); static void *my_malloc_hook (size_t, const void *); static void my_free_hook (void*, const void *); -/* Override initializing hook from the C library. */ -void (*__malloc_initialize_hook) (void) = my_init_hook; - static void -my_init_hook (void) +my_init (void) @{ old_malloc_hook = __malloc_hook; old_free_hook = __free_hook; @@ -1465,6 +1444,7 @@ my_free_hook (void *ptr, const void *caller) main () @{ + my_init (); @dots{} @} @end smallexample |