/* This program is free software; you can redistribute it and/or modify it
* under the terms of the license (GNU LGPL) which comes with this package. */
+#include <stdbool.h>
+
#include "mc_private.h"
#include "mc_mmu.h"
+#include "mc_page_store.h"
mc_mem_region_t mc_get_snapshot_region(void* addr, mc_snapshot_t snapshot)
{
return NULL;
}
-void* mc_translate_address_region(uintptr_t addr, mc_mem_region_t region)
-{
- xbt_assert(mc_region_contain(region, (void*) addr), "Trying to read out of the region boundary.");
-
- if (!region) {
- return (void *) addr;
- }
-
- // Flat snapshot:
- else if (region->data) {
- uintptr_t offset = addr - (uintptr_t) region->start_addr;
- return (void *) ((uintptr_t) region->data + offset);
- }
-
- // Per-page snapshot:
- else if (region->page_numbers) {
- size_t pageno = mc_page_number(region->start_addr, (void*) addr);
- size_t snapshot_pageno = region->page_numbers[pageno];
- const void* snapshot_page = mc_page_store_get_page(mc_model_checker->pages, snapshot_pageno);
- return (char*) snapshot_page + mc_page_offset((void*) addr);
- }
-
- else {
- xbt_die("No data for this memory region");
- }
-}
-
-void* mc_translate_address(uintptr_t addr, mc_snapshot_t snapshot)
-{
-
- // If not in a process state/clone:
- if (!snapshot) {
- return (uintptr_t *) addr;
- }
-
- mc_mem_region_t region = mc_get_snapshot_region((void*) addr, snapshot);
- return mc_translate_address_region(addr, region);
-}
-
/** @brief Read memory from a snapshot region broken across fragmented pages
*
* @param addr Process (non-snapshot) address of the data
* @param size Size of the data to read in bytes
* @return Pointer where the data is located (target buffer of original location)
*/
-static void* mc_snapshot_read_fragmented(void* addr, mc_mem_region_t region, void* target, size_t size)
+void* mc_snapshot_read_fragmented(void* addr, mc_mem_region_t region, void* target, size_t size)
{
void* end = (char*) addr + size - 1;
size_t page_end = mc_page_number(NULL, end);
return target;
}
-/** @brief Read memory from a snapshot region
- *
- * @param addr Process (non-snapshot) address of the data
- * @param region Snapshot memory region where the data is located
- * @param target Buffer to store the value
- * @param size Size of the data to read in bytes
- * @return Pointer where the data is located (target buffer of original location)
- */
-void* mc_snapshot_read_region(void* addr, mc_mem_region_t region, void* target, size_t size)
-{
- uintptr_t offset = (uintptr_t) addr - (uintptr_t) region->start_addr;
-
- xbt_assert(addr >= region->start_addr && (char*) addr+size < (char*)region->start_addr+region->size,
- "Trying to read out of the region boundary.");
-
- // Linear memory region:
- if (region->data) {
- return (void*) ((uintptr_t) region->data + offset);
- }
-
- // Fragmented memory region:
- else if (region->page_numbers) {
- void* end = (char*) addr + size - 1;
- if( mc_same_page(addr, end) ) {
- // The memory is contained in a single page:
- return mc_translate_address_region((uintptr_t) addr, region);
- } else {
- // The memory spans several pages:
- return mc_snapshot_read_fragmented(addr, region, target, size);
- }
- }
-
- else {
- xbt_die("No data available for this region");
- }
-}
-
/** @brief Read memory from a snapshot
*
* @param addr Process (non-snapshot) address of the data
void* addr1, mc_mem_region_t region1,
void* addr2, mc_mem_region_t region2, size_t size)
{
- // TODO, optimize this, avoid alloca
- void* buffer1 = mc_snapshot_read_region(addr1, region1, alloca(size), size);
- void* buffer2 = mc_snapshot_read_region(addr2, region2, alloca(size), size);
+ // Using alloca() for large allocations may trigger stack overflow:
+ // use malloc if the buffer is too big.
+
+ bool stack_alloc = size < 64;
+ void* buffer = stack_alloc ? alloca(2*size) : malloc(2*size);
+ void* buffer1 = mc_snapshot_read_region(addr1, region1, buffer, size);
+ void* buffer2 = mc_snapshot_read_region(addr2, region2, (char*) buffer + size, size);
+ int res;
if (buffer1 == buffer2) {
- return 0;
+ res = 0;
+ } else {
+ res = memcmp(buffer1, buffer2, size);
+ }
+ if (!stack_alloc) {
+ free(buffer);
}
- return memcmp(buffer1, buffer2, size);
+ return res;
}
/** Compare memory between snapshots
void* addr1, mc_snapshot_t snapshot1,
void* addr2, mc_snapshot_t snapshot2, size_t size)
{
- // TODO, optimize this, avoid alloca
- void* buffer1 = mc_snapshot_read(addr1, snapshot1, alloca(size), size);
- void* buffer2 = mc_snapshot_read(addr2, snapshot2, alloca(size), size);
- if (buffer1 == buffer2) {
- return 0;
- }
- return memcmp(buffer1, buffer2, size);
+ mc_mem_region_t region1 = mc_get_snapshot_region(addr1, snapshot1);
+ mc_mem_region_t region2 = mc_get_snapshot_region(addr2, snapshot2);
+ return mc_snapshot_region_memcp(addr1, region1, addr2, region2, size);
}
