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 /** @brief Read memory from a snapshot region broken across fragmented pages
30 * @param addr Process (non-snapshot) address of the data
31 * @param region Snapshot memory region where the data is located
32 * @param target Buffer to store the value
33 * @param size Size of the data to read in bytes
34 * @return Pointer where the data is located (target buffer of original location)
36 void* mc_snapshot_read_fragmented(void* addr, mc_mem_region_t region, void* target, size_t size)
38 void* end = (char*) addr + size - 1;
39 size_t page_end = mc_page_number(NULL, end);
43 while (mc_page_number(NULL, addr) != page_end) {
44 void* snapshot_addr = mc_translate_address_region((uintptr_t) addr, region);
45 void* next_page = mc_page_from_number(NULL, mc_page_number(NULL, addr) + 1);
46 size_t readable = (char*) next_page - (char*) addr;
47 memcpy(dest, snapshot_addr, readable);
48 addr = (char*) addr + readable;
49 dest = (char*) dest + readable;
54 void* snapshot_addr = mc_translate_address_region((uintptr_t)addr, region);
55 memcpy(dest, snapshot_addr, size);
60 /** @brief Read memory from a snapshot
62 * @param addr Process (non-snapshot) address of the data
63 * @param snapshot Snapshot (or NULL is no snapshot)
64 * @param target Buffer to store the value
65 * @param size Size of the data to read in bytes
66 * @return Pointer where the data is located (target buffer of original location)
68 void* mc_snapshot_read(void* addr, mc_snapshot_t snapshot, void* target, size_t size)
71 mc_mem_region_t region = mc_get_snapshot_region(addr, snapshot);
72 return mc_snapshot_read_region(addr, region, target, size);
78 /** Compare memory between snapshots (with known regions)
80 * @param addr1 Address in the first snapshot
81 * @param snapshot2 Region of the address in the first snapshot
82 * @param addr2 Address in the second snapshot
83 * @param snapshot2 Region of the address in the second snapshot
84 * @return same as memcmp
86 int mc_snapshot_region_memcp(
87 void* addr1, mc_mem_region_t region1,
88 void* addr2, mc_mem_region_t region2, size_t size)
90 // Using alloca() for large allocations may trigger stack overflow:
91 // use malloc if the buffer is too big.
93 bool stack_alloc = size < 64;
94 void* buffer = stack_alloc ? alloca(2*size) : malloc(2*size);
95 void* buffer1 = mc_snapshot_read_region(addr1, region1, buffer, size);
96 void* buffer2 = mc_snapshot_read_region(addr2, region2, (char*) buffer + size, size);
98 if (buffer1 == buffer2) {
101 res = memcmp(buffer1, buffer2, size);
109 /** Compare memory between snapshots
111 * @param addr1 Address in the first snapshot
112 * @param snapshot1 First snapshot
113 * @param addr2 Address in the second snapshot
114 * @param snapshot2 Second snapshot
115 * @return same as memcmp
117 int mc_snapshot_memcp(
118 void* addr1, mc_snapshot_t snapshot1,
119 void* addr2, mc_snapshot_t snapshot2, size_t size)
121 mc_mem_region_t region1 = mc_get_snapshot_region(addr1, snapshot1);
122 mc_mem_region_t region2 = mc_get_snapshot_region(addr2, snapshot2);
123 return mc_snapshot_region_memcp(addr1, region1, addr2, region2, size);