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List: kde-commits
Subject: branches/KDE/4.4/kdelibs/kjs
From: Germain Garand <germain () ebooksfrance ! org>
Date: 2010-02-22 21:09:28
Message-ID: 1266872968.155699.11265.nullmailer () svn ! kde ! org
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SVN commit 1094496 by ggarand:
automatically merged revision 1094436:
let's grab more stack room if the operating system agrees.
this will let really ill-designed regexps match +/-32Kb in the worst case
(recursion at each char).
Regular expressions unable to perform their function in such conditions
deserve to die a preposterous death.
M +33 -4 regexp.cpp
M +3 -0 regexp.h
--- branches/KDE/4.4/kdelibs/kjs/regexp.cpp #1094495:1094496
@@ -31,8 +31,19 @@
#include <stdlib.h>
#include <string.h>
#include <wtf/Vector.h>
+
+#if defined _WIN32 || defined _WIN64
+#undef HAVE_SYS_TIME_H
+#endif
+#if HAVE(SYS_TIME_H)
+#include <sys/time.h>
+#include <sys/resource.h>
+#endif
+
using WTF::Vector;
+static const rlim_t sWantedStackSizeLimit = 32*1024*1024;
+
// GCC cstring uses these automatically, but not all implementations do.
using std::strlen;
using std::strcpy;
@@ -244,6 +255,10 @@
}
}
+bool RegExp::tryGrowingMaxStackSize = true;
+bool RegExp::didIncreaseMaxStackSize = false;
+int RegExp::availableStackSize = 8*1024*1024;
+
RegExp::RegExp(const UString &p, char flags)
: _pat(p), _flags(flags), _valid(true), _numSubPatterns(0), _buffer(0), _originalPos(0)
{
@@ -489,15 +504,29 @@
pcre_config(PCRE_CONFIG_STACKRECURSE, (void*)&stackGlutton);
pcre_extra limits;
if (stackGlutton) {
+#if HAVE(SYS_TIME_H)
+ if (tryGrowingMaxStackSize) {
+ rlimit l;
+ getrlimit(RLIMIT_STACK, &l);
+ availableStackSize = l.rlim_cur;
+ if (l.rlim_cur < sWantedStackSizeLimit &&
+ (l.rlim_max > l.rlim_cur || l.rlim_max == RLIM_INFINITY)) {
+ l.rlim_cur = (l.rlim_max == RLIM_INFINITY) ?
+ sWantedStackSizeLimit : std::min(l.rlim_max, sWantedStackSizeLimit);
+ if ((didIncreaseMaxStackSize = !setrlimit( RLIMIT_STACK, &l)))
+ availableStackSize = l.rlim_cur;
+ }
+ tryGrowingMaxStackSize = false;
+ }
+#endif
+
limits.flags = PCRE_EXTRA_MATCH_LIMIT_RECURSION;
// libPCRE docs claim that it munches about 500 bytes per recursion.
// The crash in #160792 actually showed pcre 7.4 using about 1300 bytes
// (and I've measured 800 in an another instance)
- // So the usual 8MiB rlimit on Linux produces about 6452 frames.
- // We go somewhat conservative, and use about 2/3rds of that, for 4300
+ // We go somewhat conservative, and use about 3/4ths of that,
// especially since we're not exactly light on the stack, either
- // ### TODO: get some build system help to use getrlimit.
- limits.match_limit_recursion = 4300;
+ limits.match_limit_recursion = (availableStackSize/1300)*3/4;
}
const int numMatches = pcre_exec(_regex, stackGlutton ? &limits : 0, _buffer, _bufferSize, startPos, \
baseFlags, offsetVector, offsetVectorSize);
--- branches/KDE/4.4/kdelibs/kjs/regexp.h #1094495:1094496
@@ -58,6 +58,9 @@
void prepareMatch(const UString &s);
void doneMatch();
+ static bool tryGrowingMaxStackSize;
+ static bool didIncreaseMaxStackSize;
+ static int availableStackSize;
private:
#ifdef HAVE_PCREPOSIX
pcre *_regex;
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