Mercurial > gnulib
view lib/eealloc.h @ 37246:5cfb3a67238d
regex: avoid glibc deadlock during configure
glibc has a known bug where certain corruptions of the heap can
cause malloc to default to printing a debug message that includes
a backtrace, but the act of getting the backtrace uses dlopen
which in turn calls into malloc, causing a recursive lock ending
in deadlock. Thus, when configure is probing for a known glibc
heap corruption bug, the overall configure would hang.
The solution suggested by glibc developers is to force malloc
to quit printing debug messages, which avoids recursive malloc.
* m4/regex.m4 (gl_REGEX): Avoid recursive malloc deadlock when
glibc bug 15078 in turn triggers bug 16159.
Reported by Michal Privoznik.
Signed-off-by: Eric Blake <eblake@redhat.com>
author | Eric Blake <eblake@redhat.com> |
---|---|
date | Tue, 03 Dec 2013 10:34:13 -0700 |
parents | 40dfa49bda69 |
children | 344018b6e5d7 |
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/* Memory allocation with expensive empty allocations. Copyright (C) 2003, 2008, 2010-2013 Free Software Foundation, Inc. Written by Bruno Haible <bruno@clisp.org>, 2003, based on prior work by Jim Meyering. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program 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 General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ #ifndef _EEALLOC_H #define _EEALLOC_H /* malloc() and realloc() are allowed to return NULL when asked to allocate a memory block of 0 bytes; this is not an out-of-memory condition. (See ISO C 99 section 7.20.3.) In some places, this is not welcome, because it requires extra checking (so as not to confuse a zero-sized allocation with an out-of-memory condition). This file provides malloc()/realloc() workalikes which return non-NULL pointers for succeeding zero-sized allocations. GNU libc already defines malloc() and realloc() this way; on such platforms the workalikes are aliased to the original malloc()/realloc() functions. */ #include <stdlib.h> #ifndef _GL_INLINE_HEADER_BEGIN #error "Please include config.h first." #endif _GL_INLINE_HEADER_BEGIN #ifndef EEALLOC_INLINE # define EEALLOC_INLINE _GL_INLINE #endif #if MALLOC_0_IS_NONNULL # define eemalloc malloc #else # if __GNUC__ >= 3 EEALLOC_INLINE void *eemalloc (size_t n) __attribute__ ((__malloc__)) # if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3) __attribute__ ((__alloc_size__ (1))) # endif ; # endif EEALLOC_INLINE void * eemalloc (size_t n) { /* If n is zero, allocate a 1-byte block. */ if (n == 0) n = 1; return malloc (n); } #endif #if REALLOC_0_IS_NONNULL # define eerealloc realloc #else # if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3) EEALLOC_INLINE void *eerealloc (void *p, size_t n) __attribute__ ((__alloc_size__ (2))); # endif EEALLOC_INLINE void * eerealloc (void *p, size_t n) { /* If n is zero, allocate or keep a 1-byte block. */ if (n == 0) n = 1; return realloc (p, n); } #endif /* Maybe we should also define variants eenmalloc (size_t n, size_t s) - behaves like eemalloc (n * s) eezalloc (size_t n) - like eemalloc followed by memset 0 eecalloc (size_t n, size_t s) - like eemalloc (n * s) followed by memset 0 eenrealloc (void *p, size_t n, size_t s) - like eerealloc (p, n * s) If this would be useful in your application. please speak up. */ _GL_INLINE_HEADER_END #endif /* _EEALLOC_H */