Mercurial > gnulib
view m4/ldexpf.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
# ldexpf.m4 serial 2 dnl Copyright (C) 2011-2013 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, dnl with or without modifications, as long as this notice is preserved. AC_DEFUN([gl_FUNC_LDEXPF], [ AC_REQUIRE([gl_MATH_H_DEFAULTS]) AC_REQUIRE([gl_FUNC_LDEXP]) dnl Persuade glibc <math.h> to declare ldexpf(). AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) dnl Test whether ldexpf() exists. We cannot assume that ldexpf(), if it dnl exists, is defined in the same library as ldexp(). This is not the case dnl on FreeBSD, NetBSD, OpenBSD. gl_MATHFUNC([ldexpf], [float], [(float, int)]) if test $gl_cv_func_ldexpf_no_libm = no \ && test $gl_cv_func_ldexpf_in_libm = no; then HAVE_LDEXPF=0 LDEXPF_LIBM="$LDEXP_LIBM" fi AC_SUBST([LDEXPF_LIBM]) ])