Mercurial > gnulib
view lib/timespec-add.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 | 32c233e31143 |
children | 344018b6e5d7 |
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/* Add two struct timespec values. Copyright (C) 2011-2013 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/>. */ /* Written by Paul Eggert. */ /* Return the sum of two timespec values A and B. On overflow, return an extremal value. This assumes 0 <= tv_nsec < TIMESPEC_RESOLUTION. */ #include <config.h> #include "timespec.h" #include "intprops.h" struct timespec timespec_add (struct timespec a, struct timespec b) { time_t rs = a.tv_sec; time_t bs = b.tv_sec; int ns = a.tv_nsec + b.tv_nsec; int nsd = ns - TIMESPEC_RESOLUTION; int rns = ns; if (0 <= nsd) { rns = nsd; if (rs == TYPE_MAXIMUM (time_t)) { if (0 <= bs) goto high_overflow; bs++; } else rs++; } if (INT_ADD_OVERFLOW (rs, bs)) { if (rs < 0) { rs = TYPE_MINIMUM (time_t); rns = 0; } else { high_overflow: rs = TYPE_MAXIMUM (time_t); rns = TIMESPEC_RESOLUTION - 1; } } else rs += bs; return make_timespec (rs, rns); }