Mercurial > gnulib
view lib/crc.h @ 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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/* crc.h -- cyclic redundancy checks Copyright (C) 2005, 2009-2013 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 Simon Josefsson. */ #ifndef CRC_H # define CRC_H 1 #include <stddef.h> #include <stdint.h> /* Compute CRC-32 value of LEN bytes long BUF, and return it. */ extern uint32_t crc32 (const char *buf, size_t len); /* Incrementally update CRC-32 value CRC using LEN bytes long BUF. In the first call, use 0 as the value for CRC. Return the updated CRC-32 value. */ extern uint32_t crc32_update (uint32_t crc, const char *buf, size_t len); /* Compute modified-CRC-32 value of LEN bytes long BUF, and return it. The "modification" is to avoid the initial and final XOR operation. Due to historic implementation errors, this variant is sometimes used (i.e., in RFC 3961). */ extern uint32_t crc32_no_xor (const char *buf, size_t len); /* Incrementally update modified-CRC-32 value CRC using LEN bytes long BUF. In the first call, use 0 as the value for CRC. Return the updated modified-CRC-32 value. The "modification" is to avoid the initial and final XOR operation. Due to historic implementation errors, this variant is sometimes used (i.e., in RFC 3961). */ extern uint32_t crc32_update_no_xor (uint32_t crc, const char *buf, size_t len); #endif /* CRC_H */