1 /* Copyright (c) 2014. The SimGrid Team.
2 * All rights reserved. */
4 /* This program is free software; you can redistribute it and/or modify it
5 * under the terms of the license (GNU LGPL) which comes with this package. */
7 #include "mc_private.h"
10 mc_mem_region_t mc_get_snapshot_region(void* addr, mc_snapshot_t snapshot)
12 for (size_t i = 0; i != NB_REGIONS; ++i) {
13 mc_mem_region_t region = snapshot->regions[i];
14 void* start = region->start_addr;
15 void* end = (char*) start + region->size;
17 if (addr >= start && addr < end) {
25 void* mc_translate_address_region(uintptr_t addr, mc_mem_region_t region)
32 else if (region->data) {
33 uintptr_t offset = addr - (uintptr_t) region->start_addr;
34 return (void *) ((uintptr_t) region->data + offset);
38 else if (region->page_numbers) {
39 size_t pageno = mc_page_number(region->start_addr, (void*) addr);
40 size_t snapshot_pageno = region->page_numbers[pageno];
41 const void* snapshot_page = mc_page_store_get_page(mc_model_checker->pages, snapshot_pageno);
42 return (char*) snapshot_page + mc_page_offset((void*) addr);
46 xbt_die("No data for this memory region");
50 void* mc_translate_address(uintptr_t addr, mc_snapshot_t snapshot)
53 // If not in a process state/clone:
55 return (uintptr_t *) addr;
58 mc_mem_region_t region = mc_get_snapshot_region((void*) addr, snapshot);
59 return mc_translate_address_region(addr, region);
62 /** @brief Read memory from a snapshot region broken across fragmented pages
64 * @param addr Process (non-snapshot) address of the data
65 * @param region Snapshot memory region where the data is located
66 * @param target Buffer to store the value
67 * @param size Size of the data to read in bytes
68 * @return Pointer where the data is located (target buffer of original location)
70 static void* mc_snapshot_read_fragmented(void* addr, mc_mem_region_t region, void* target, size_t size)
72 void* end = (char*) addr + size - 1;
73 size_t page_end = mc_page_number(NULL, end);
76 while (mc_page_number(NULL, addr) != page_end) {
77 void* snapshot_addr = mc_translate_address_region((uintptr_t) addr, region);
78 void* next_page = mc_page_from_number(NULL, mc_page_number(NULL, addr) + 1);
79 size_t readable = (char*) next_page - (char*) addr;
80 memcpy(target, snapshot_addr, readable);
81 target = (char*) target + readable;
86 void* snapshot_addr = mc_translate_address_region((uintptr_t)addr, region);
87 memcpy(target, snapshot_addr, size);
92 /** @brief Read memory from a snapshot region
94 * @param addr Process (non-snapshot) address of the data
95 * @param region Snapshot memory region where the data is located
96 * @param target Buffer to store the value
97 * @param size Size of the data to read in bytes
98 * @return Pointer where the data is located (target buffer of original location)
100 void* mc_snapshot_read_region(void* addr, mc_mem_region_t region, void* target, size_t size)
102 uintptr_t offset = (uintptr_t) addr - (uintptr_t) region->start_addr;
104 if (addr < region->start_addr || (char*) addr+size >= (char*)region->start_addr+region->size) {
105 xbt_die("Trying to read out of the region boundary.");
108 // Linear memory region:
110 return (void*) ((uintptr_t) region->data + offset);
113 // Fragmented memory region:
114 else if (region->page_numbers) {
115 void* end = (char*) addr + size - 1;
116 if( mc_same_page(addr, end) ) {
117 // The memory is contained in a single page:
118 return mc_translate_address_region((uintptr_t) addr, region);
120 // The memory spans several pages:
121 return mc_snapshot_read_fragmented(addr, region, target, size);
126 xbt_die("No data available for this region");
130 /** @brief Read memory from a snapshot
132 * @param addr Process (non-snapshot) address of the data
133 * @param snapshot Snapshot (or NULL is no snapshot)
134 * @param target Buffer to store the value
135 * @param size Size of the data to read in bytes
136 * @return Pointer where the data is located (target buffer of original location)
138 void* mc_snapshot_read(void* addr, mc_snapshot_t snapshot, void* target, size_t size)
141 mc_mem_region_t region = mc_get_snapshot_region(addr, snapshot);
142 return mc_snapshot_read_region(addr, region, target, size);
148 int mc_snapshot_memcp(
149 void* addr1, mc_snapshot_t snapshot1,
150 void* addr2, mc_snapshot_t snapshot2, size_t size)
152 void* buffer1 = mc_snapshot_read(addr1, snapshot1, alloca(size), size);
153 void* buffer2 = mc_snapshot_read(addr2, snapshot2, alloca(size), size);
154 if (buffer1 == buffer2) {
157 return memcmp(buffer1, buffer2, size);