Mercurial > gnulib
view lib/ftello.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
/* An ftello() function that works around platform bugs. Copyright (C) 2007, 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/>. */ #include <config.h> /* Specification. */ #include <stdio.h> /* Get lseek. */ #include <unistd.h> #include "stdio-impl.h" off_t ftello (FILE *fp) #undef ftello #if !HAVE_FTELLO # undef ftell # define ftello ftell #endif #if _GL_WINDOWS_64_BIT_OFF_T # undef ftello # if HAVE__FTELLI64 /* msvc, mingw64 */ # define ftello _ftelli64 # else /* mingw */ # define ftello ftello64 # endif #endif { #if LSEEK_PIPE_BROKEN /* mingw gives bogus answers rather than failure on non-seekable files. */ if (lseek (fileno (fp), 0, SEEK_CUR) == -1) return -1; #endif #if FTELLO_BROKEN_AFTER_SWITCHING_FROM_READ_TO_WRITE /* Solaris */ /* The Solaris stdio leaves the _IOREAD flag set after reading from a file reaches EOF and the program then starts writing to the file. ftello gets confused by this. */ if (fp_->_flag & _IOWRT) { off_t pos; /* Call ftello nevertheless, for the side effects that it does on fp. */ ftello (fp); /* Compute the file position ourselves. */ pos = lseek (fileno (fp), (off_t) 0, SEEK_CUR); if (pos >= 0) { if ((fp_->_flag & _IONBF) == 0 && fp_->_base != NULL) pos += fp_->_ptr - fp_->_base; } return pos; } #endif #if defined __SL64 && defined __SCLE /* Cygwin */ if ((fp->_flags & __SL64) == 0) { /* Cygwin 1.5.0 through 1.5.24 failed to open stdin in 64-bit mode; but has an ftello that requires 64-bit mode. */ FILE *tmp = fopen ("/dev/null", "r"); if (!tmp) return -1; fp->_flags |= __SL64; fp->_seek64 = tmp->_seek64; fclose (tmp); } #endif return ftello (fp); }