Mercurial > gnulib
view m4/rmdir-errno.m4 @ 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
# serial 10 # Copyright (C) 2000-2001, 2005-2006, 2009-2013 Free Software Foundation, Inc. # This file is free software; the Free Software Foundation # gives unlimited permission to copy and/or distribute it, # with or without modifications, as long as this notice is preserved. # When rmdir fails because the specified directory is not empty, it sets # errno to some value, usually ENOTEMPTY. However, on some AIX systems, # ENOTEMPTY is mistakenly defined to be EEXIST. To work around this, and # in general, to avoid depending on the use of any particular symbol, this # test runs a test to determine the actual numeric value. AC_DEFUN([gl_FUNC_RMDIR_NOTEMPTY], [dnl AC_CHECK_HEADERS_ONCE([unistd.h]) AC_CACHE_CHECK([for rmdir-not-empty errno value], gl_cv_func_rmdir_errno_not_empty, [ # Arrange for deletion of the temporary directory this test creates. ac_clean_files="$ac_clean_files confdir2" mkdir confdir2; : > confdir2/file AC_RUN_IFELSE([AC_LANG_SOURCE([[ #include <stdio.h> #include <errno.h> #ifdef HAVE_UNISTD_H # include <unistd.h> #endif int main () { FILE *s; int val; rmdir ("confdir2"); val = errno; s = fopen ("confdir2/errno", "w"); fprintf (s, "%d\n", val); return 0; } ]])], [gl_cv_func_rmdir_errno_not_empty=`cat confdir2/errno`], [gl_cv_func_rmdir_errno_not_empty='configure error in rmdir-errno.m4'], [gl_cv_func_rmdir_errno_not_empty=ENOTEMPTY] ) ] ) AC_DEFINE_UNQUOTED([RMDIR_ERRNO_NOT_EMPTY], $gl_cv_func_rmdir_errno_not_empty, [the value to which errno is set when rmdir fails on a nonempty directory]) ])