Mercurial > gnulib
view lib/fd-safer.c @ 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 | c741bc27922a |
children | 344018b6e5d7 |
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/* Return a safer copy of a file descriptor. Copyright (C) 2005-2006, 2009-2013 Free Software Foundation, Inc. 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/>. */ /* Written by Paul Eggert. */ #include <config.h> #include "unistd-safer.h" #include <errno.h> #include <unistd.h> /* Return FD, unless FD would be a copy of standard input, output, or error; in that case, return a duplicate of FD, closing FD. On failure to duplicate, close FD, set errno, and return -1. Preserve errno if FD is negative, so that the caller can always inspect errno when the returned value is negative. This function is usefully wrapped around functions that return file descriptors, e.g., fd_safer (open ("file", O_RDONLY)). */ int fd_safer (int fd) { if (STDIN_FILENO <= fd && fd <= STDERR_FILENO) { int f = dup_safer (fd); int e = errno; close (fd); errno = e; fd = f; } return fd; }