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. */
9 #include "mc_private.h"
11 #include "mc_page_store.h"
13 mc_mem_region_t mc_get_snapshot_region(void* addr, mc_snapshot_t snapshot)
15 for (size_t i = 0; i != NB_REGIONS; ++i) {
16 mc_mem_region_t region = snapshot->regions[i];
17 void* start = region->start_addr;
18 void* end = (char*) start + region->size;
20 if (addr >= start && addr < end) {
28 void* mc_translate_address_region(uintptr_t addr, mc_mem_region_t region)
30 xbt_assert(mc_region_contain(region, (void*) addr), "Trying to read out of the region boundary.");
37 else if (region->data) {
38 uintptr_t offset = addr - (uintptr_t) region->start_addr;
39 return (void *) ((uintptr_t) region->data + offset);
43 else if (region->page_numbers) {
44 size_t pageno = mc_page_number(region->start_addr, (void*) addr);
45 size_t snapshot_pageno = region->page_numbers[pageno];
46 const void* snapshot_page = mc_page_store_get_page(mc_model_checker->pages, snapshot_pageno);
47 return (char*) snapshot_page + mc_page_offset((void*) addr);
51 xbt_die("No data for this memory region");
55 void* mc_translate_address(uintptr_t addr, mc_snapshot_t snapshot)
58 // If not in a process state/clone:
60 return (uintptr_t *) addr;
63 mc_mem_region_t region = mc_get_snapshot_region((void*) addr, snapshot);
64 return mc_translate_address_region(addr, region);
67 /** @brief Read memory from a snapshot region broken across fragmented pages
69 * @param addr Process (non-snapshot) address of the data
70 * @param region Snapshot memory region where the data is located
71 * @param target Buffer to store the value
72 * @param size Size of the data to read in bytes
73 * @return Pointer where the data is located (target buffer of original location)
75 static void* mc_snapshot_read_fragmented(void* addr, mc_mem_region_t region, void* target, size_t size)
77 void* end = (char*) addr + size - 1;
78 size_t page_end = mc_page_number(NULL, end);
82 while (mc_page_number(NULL, addr) != page_end) {
83 void* snapshot_addr = mc_translate_address_region((uintptr_t) addr, region);
84 void* next_page = mc_page_from_number(NULL, mc_page_number(NULL, addr) + 1);
85 size_t readable = (char*) next_page - (char*) addr;
86 memcpy(dest, snapshot_addr, readable);
87 addr = (char*) addr + readable;
88 dest = (char*) dest + readable;
93 void* snapshot_addr = mc_translate_address_region((uintptr_t)addr, region);
94 memcpy(dest, snapshot_addr, size);
99 /** @brief Read memory from a snapshot region
101 * @param addr Process (non-snapshot) address of the data
102 * @param region Snapshot memory region where the data is located
103 * @param target Buffer to store the value
104 * @param size Size of the data to read in bytes
105 * @return Pointer where the data is located (target buffer of original location)
107 void* mc_snapshot_read_region(void* addr, mc_mem_region_t region, void* target, size_t size)
109 uintptr_t offset = (uintptr_t) addr - (uintptr_t) region->start_addr;
111 xbt_assert(addr >= region->start_addr && (char*) addr+size < (char*)region->start_addr+region->size,
112 "Trying to read out of the region boundary.");
114 // Linear memory region:
116 return (void*) ((uintptr_t) region->data + offset);
119 // Fragmented memory region:
120 else if (region->page_numbers) {
121 void* end = (char*) addr + size - 1;
122 if( mc_same_page(addr, end) ) {
123 // The memory is contained in a single page:
124 return mc_translate_address_region((uintptr_t) addr, region);
126 // The memory spans several pages:
127 return mc_snapshot_read_fragmented(addr, region, target, size);
132 xbt_die("No data available for this region");
136 /** @brief Read memory from a snapshot
138 * @param addr Process (non-snapshot) address of the data
139 * @param snapshot Snapshot (or NULL is no snapshot)
140 * @param target Buffer to store the value
141 * @param size Size of the data to read in bytes
142 * @return Pointer where the data is located (target buffer of original location)
144 void* mc_snapshot_read(void* addr, mc_snapshot_t snapshot, void* target, size_t size)
147 mc_mem_region_t region = mc_get_snapshot_region(addr, snapshot);
148 return mc_snapshot_read_region(addr, region, target, size);
154 /** Compare memory between snapshots (with known regions)
156 * @param addr1 Address in the first snapshot
157 * @param snapshot2 Region of the address in the first snapshot
158 * @param addr2 Address in the second snapshot
159 * @param snapshot2 Region of the address in the second snapshot
160 * @return same as memcmp
162 int mc_snapshot_region_memcp(
163 void* addr1, mc_mem_region_t region1,
164 void* addr2, mc_mem_region_t region2, size_t size)
166 // Using alloca() for large allocations may trigger stack overflow:
167 // use malloc if the buffer is too big.
169 bool stack_alloc = size < 64;
170 void* buffer = stack_alloc ? alloca(2*size) : malloc(2*size);
171 void* buffer1 = mc_snapshot_read_region(addr1, region1, buffer, size);
172 void* buffer2 = mc_snapshot_read_region(addr2, region2, (char*) buffer + size, size);
174 if (buffer1 == buffer2) {
177 res = memcmp(buffer1, buffer2, size);
185 /** Compare memory between snapshots
187 * @param addr1 Address in the first snapshot
188 * @param snapshot1 First snapshot
189 * @param addr2 Address in the second snapshot
190 * @param snapshot2 Second snapshot
191 * @return same as memcmp
193 int mc_snapshot_memcp(
194 void* addr1, mc_snapshot_t snapshot1,
195 void* addr2, mc_snapshot_t snapshot2, size_t size)
197 mc_mem_region_t region1 = mc_get_snapshot_region(addr1, snapshot1);
198 mc_mem_region_t region2 = mc_get_snapshot_region(addr2, snapshot2);
199 return mc_snapshot_region_memcp(addr1, region1, addr2, region2, size);