Mercurial > gnulib
view lib/cloexec.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 |
line wrap: on
line source
/* closexec.c - set or clear the close-on-exec descriptor flag Copyright (C) 1991, 2004-2006, 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/>. The code is taken from glibc/manual/llio.texi */ #include <config.h> #include "cloexec.h" #include <errno.h> #include <fcntl.h> #include <unistd.h> /* Set the 'FD_CLOEXEC' flag of DESC if VALUE is true, or clear the flag if VALUE is false. Return 0 on success, or -1 on error with 'errno' set. Note that on MingW, this function does NOT protect DESC from being inherited into spawned children. Instead, either use dup_cloexec followed by closing the original DESC, or use interfaces such as open or pipe2 that accept flags like O_CLOEXEC to create DESC non-inheritable in the first place. */ int set_cloexec_flag (int desc, bool value) { #ifdef F_SETFD int flags = fcntl (desc, F_GETFD, 0); if (0 <= flags) { int newflags = (value ? flags | FD_CLOEXEC : flags & ~FD_CLOEXEC); if (flags == newflags || fcntl (desc, F_SETFD, newflags) != -1) return 0; } return -1; #else /* !F_SETFD */ /* Use dup2 to reject invalid file descriptors; the cloexec flag will be unaffected. */ if (desc < 0) { errno = EBADF; return -1; } if (dup2 (desc, desc) < 0) /* errno is EBADF here. */ return -1; /* There is nothing we can do on this kind of platform. Punt. */ return 0; #endif /* !F_SETFD */ } /* Duplicates a file handle FD, while marking the copy to be closed prior to exec or spawn. Returns -1 and sets errno if FD could not be duplicated. */ int dup_cloexec (int fd) { return fcntl (fd, F_DUPFD_CLOEXEC, 0); }