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faaad6e75d
We should explicitly check if we can hold the sync point, otherwise we may wrap the array index and reach incorrect value (if we're lucky). So instead we make the index "almost" unlmited. Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
134 lines
3.8 KiB
C
134 lines
3.8 KiB
C
/* ----------------------------------------------------------------------- *
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*
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* Copyright 1996-2009 The NASM Authors - All Rights Reserved
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* See the file AUTHORS included with the NASM distribution for
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* the specific copyright holders.
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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
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* conditions are met:
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*
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* * 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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* * Redistributions in binary form must reproduce the above
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* copyright notice, this list of conditions and the following
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* disclaimer in the documentation and/or other materials provided
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* with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
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* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
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* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
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* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
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* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* ----------------------------------------------------------------------- */
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/*
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* sync.c the Netwide Disassembler synchronisation processing module
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*/
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#include "compiler.h"
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#include <stdio.h>
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#include <stdlib.h>
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#include <limits.h>
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#include <inttypes.h>
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#include "nasmlib.h"
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#include "sync.h"
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#define SYNC_MAX_SHIFT 31
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#define SYNC_MAX_SIZE (1U << SYNC_MAX_SHIFT)
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/* initial # of sync points (*must* be power of two)*/
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#define SYNC_INITIAL_CHUNK (1U << 12)
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/*
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* This lot manages the current set of sync points by means of a
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* heap (priority queue) structure.
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*/
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static struct Sync {
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uint32_t pos;
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uint32_t length;
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} *synx;
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static uint32_t max_synx, nsynx;
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static inline void swap_sync(uint32_t dst, uint32_t src)
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{
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struct Sync t = synx[dst];
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synx[dst] = synx[src];
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synx[src] = t;
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}
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void init_sync(void)
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{
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max_synx = SYNC_INITIAL_CHUNK;
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synx = nasm_malloc((max_synx + 1) * sizeof(*synx));
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nsynx = 0;
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}
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void add_sync(uint32_t pos, uint32_t length)
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{
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uint32_t i;
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if (nsynx >= max_synx) {
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if (max_synx >= SYNC_MAX_SIZE) /* too many sync points! */
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return;
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max_synx = (max_synx << 1);
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synx = nasm_realloc(synx, (max_synx + 1) * sizeof(*synx));
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}
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nsynx++;
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synx[nsynx].pos = pos;
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synx[nsynx].length = length;
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for (i = nsynx; i > 1; i /= 2) {
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if (synx[i / 2].pos > synx[i].pos)
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swap_sync(i / 2, i);
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}
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}
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uint32_t next_sync(uint32_t position, uint32_t *length)
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{
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while (nsynx > 0 && synx[1].pos + synx[1].length <= position) {
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uint32_t i, j;
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swap_sync(nsynx, 1);
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nsynx--;
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i = 1;
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while (i * 2 <= nsynx) {
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j = i * 2;
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if (synx[j].pos < synx[i].pos &&
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(j + 1 > nsynx || synx[j + 1].pos > synx[j].pos)) {
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swap_sync(j, i);
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i = j;
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} else if (j + 1 <= nsynx && synx[j + 1].pos < synx[i].pos) {
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swap_sync(j + 1, i);
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i = j + 1;
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} else
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break;
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}
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}
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if (nsynx > 0) {
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if (length)
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*length = synx[1].length;
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return synx[1].pos;
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} else {
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if (length)
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*length = 0L;
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return 0;
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}
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}
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