Mercurial > gnulib
view m4/vsnprintf.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 |
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# vsnprintf.m4 serial 6 dnl Copyright (C) 2002-2004, 2007-2013 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. dnl Libintl 0.17 will replace vsnprintf only if it does not support %1$s, dnl but defers to any gnulib vsnprintf replacements. Therefore, gnulib dnl must guarantee that the decision for replacing vsnprintf is a superset dnl of the reasons checked by libintl. AC_DEFUN([gl_FUNC_VSNPRINTF], [ AC_REQUIRE([gl_STDIO_H_DEFAULTS]) gl_cv_func_vsnprintf_usable=no AC_CHECK_FUNCS([vsnprintf]) if test $ac_cv_func_vsnprintf = yes; then gl_SNPRINTF_SIZE1 case "$gl_cv_func_snprintf_size1" in *yes) gl_SNPRINTF_RETVAL_C99 case "$gl_cv_func_snprintf_retval_c99" in *yes) gl_PRINTF_POSITIONS case "$gl_cv_func_printf_positions" in *yes) gl_cv_func_vsnprintf_usable=yes ;; esac ;; esac ;; esac fi if test $gl_cv_func_vsnprintf_usable = no; then gl_REPLACE_VSNPRINTF fi AC_CHECK_DECLS_ONCE([vsnprintf]) if test $ac_cv_have_decl_vsnprintf = no; then HAVE_DECL_VSNPRINTF=0 fi ]) AC_DEFUN([gl_REPLACE_VSNPRINTF], [ AC_REQUIRE([gl_STDIO_H_DEFAULTS]) AC_LIBOBJ([vsnprintf]) if test $ac_cv_func_vsnprintf = yes; then REPLACE_VSNPRINTF=1 fi gl_PREREQ_VSNPRINTF ]) # Prerequisites of lib/vsnprintf.c. AC_DEFUN([gl_PREREQ_VSNPRINTF], [:])