Mercurial > gnulib
view m4/ttyname_r.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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# ttyname_r.m4 serial 9 dnl Copyright (C) 2010-2013 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_TTYNAME_R], [ AC_REQUIRE([gl_UNISTD_H_DEFAULTS]) dnl Persuade Solaris <unistd.h> to provide the POSIX compliant declaration of dnl ttyname_r(). AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) AC_CHECK_DECLS_ONCE([ttyname_r]) if test $ac_cv_have_decl_ttyname_r = no; then HAVE_DECL_TTYNAME_R=0 fi AC_CHECK_FUNCS([ttyname_r]) if test $ac_cv_func_ttyname_r = no; then HAVE_TTYNAME_R=0 else HAVE_TTYNAME_R=1 dnl On Mac OS X 10.4 (and Solaris 10 without gl_USE_SYSTEM_EXTENSIONS) dnl the return type is 'char *', not 'int'. AC_CACHE_CHECK([whether ttyname_r is compatible with its POSIX signature], [gl_cv_func_ttyname_r_posix], [AC_COMPILE_IFELSE( [AC_LANG_PROGRAM( [[#include <stddef.h> #include <unistd.h>]], [[*ttyname_r (0, NULL, 0);]]) ], [gl_cv_func_ttyname_r_posix=no], [gl_cv_func_ttyname_r_posix=yes]) ]) if test $gl_cv_func_ttyname_r_posix = no; then REPLACE_TTYNAME_R=1 else AC_DEFINE([HAVE_POSIXDECL_TTYNAME_R], [1], [Define if the ttyname_r function has a POSIX compliant declaration.]) dnl On Solaris 10, both ttyname_r functions (the one with the non-POSIX dnl declaration and the one with the POSIX declaration) refuse to do dnl anything when the output buffer is less than 128 bytes large. dnl On OSF/1 5.1, ttyname_r ignores the buffer size and assumes the dnl buffer is large enough. AC_REQUIRE([AC_CANONICAL_HOST]) AC_CACHE_CHECK([whether ttyname_r works with small buffers], [gl_cv_func_ttyname_r_works], [ dnl Initial guess, used when cross-compiling or when /dev/tty cannot dnl be opened. changequote(,)dnl case "$host_os" in # Guess no on Solaris. solaris*) gl_cv_func_ttyname_r_works="guessing no" ;; # Guess no on OSF/1. osf*) gl_cv_func_ttyname_r_works="guessing no" ;; # Guess yes otherwise. *) gl_cv_func_ttyname_r_works="guessing yes" ;; esac changequote([,])dnl AC_RUN_IFELSE( [AC_LANG_SOURCE([[ #include <fcntl.h> #include <unistd.h> int main (void) { int result = 0; int fd; char buf[31]; /* use any size < 128 here */ fd = open ("/dev/tty", O_RDONLY); if (fd < 0) result |= 16; else if (ttyname_r (fd, buf, sizeof (buf)) != 0) result |= 17; else if (ttyname_r (fd, buf, 1) == 0) result |= 18; return result; }]])], [gl_cv_func_ttyname_r_works=yes], [case $? in 17 | 18) gl_cv_func_ttyname_r_works=no ;; esac], [:]) ]) case "$gl_cv_func_ttyname_r_works" in *yes) ;; *) REPLACE_TTYNAME_R=1 ;; esac fi fi ]) # Prerequisites of lib/ttyname_r.c. AC_DEFUN([gl_PREREQ_TTYNAME_R], [ AC_CHECK_FUNCS([ttyname]) ])