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336e0c87fa
The linked list of stack marks may cause problems if the allocation stack is used between an exception and a higher-level popstackmark(), as it may then touch a stack mark that is local to a function which has returned. Also, the adjustment compares to a pointer passed to realloc(), which is undefined behaviour. Instead of adjusting stack marks when reallocating stack blocks, ensure that such an adjustment is never necessary by fixing a small piece of memory in place at a stack mark. This also simplifies the code. To avoid the problems reported in bin/175922, it remains necessary to call setstackmark() after popstackmark() if the stack mark remains in use.
86 lines
3.3 KiB
C
86 lines
3.3 KiB
C
/*-
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* Copyright (c) 1991, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Kenneth Almquist.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)memalloc.h 8.2 (Berkeley) 5/4/95
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* $FreeBSD$
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*/
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#include <string.h>
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struct stackmark {
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struct stack_block *stackp;
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char *stacknxt;
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int stacknleft;
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};
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extern char *stacknxt;
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extern int stacknleft;
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extern char *sstrend;
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pointer ckmalloc(size_t);
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pointer ckrealloc(pointer, int);
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void ckfree(pointer);
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char *savestr(const char *);
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pointer stalloc(int);
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void stunalloc(pointer);
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void setstackmark(struct stackmark *);
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void popstackmark(struct stackmark *);
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char *growstackstr(void);
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char *makestrspace(int, char *);
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char *stputbin(const char *data, size_t len, char *p);
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char *stputs(const char *data, char *p);
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#define stackblock() stacknxt
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#define stackblocksize() stacknleft
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#define grabstackblock(n) stalloc(n)
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#define STARTSTACKSTR(p) p = stackblock()
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#define STPUTC(c, p) do { if (p == sstrend) p = growstackstr(); *p++ = (c); } while(0)
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#define CHECKSTRSPACE(n, p) { if ((size_t)(sstrend - p) < n) p = makestrspace(n, p); }
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#define USTPUTC(c, p) (*p++ = (c))
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/*
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* STACKSTRNUL's use is where we want to be able to turn a stack
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* (non-sentinel, character counting string) into a C string,
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* and later pretend the NUL is not there.
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* Note: Because of STACKSTRNUL's semantics, STACKSTRNUL cannot be used
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* on a stack that will grabstackstr()ed.
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*/
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#define STACKSTRNUL(p) (p == sstrend ? (p = growstackstr(), *p = '\0') : (*p = '\0'))
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#define STUNPUTC(p) (--p)
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#define STTOPC(p) p[-1]
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#define STADJUST(amount, p) (p += (amount))
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#define grabstackstr(p) stalloc((char *)p - stackblock())
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#define ungrabstackstr(s, p) stunalloc((s))
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#define STPUTBIN(s, len, p) p = stputbin((s), (len), p)
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#define STPUTS(s, p) p = stputs((s), p)
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