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92a42be0 SL |
1 | // Regression test for |
2 | // https://code.google.com/p/chromium/issues/detail?id=446692 | |
3 | // where asan consumed too much RAM due to transparent hugetables. | |
4 | // | |
5 | // RUN: %clangxx_asan -g %s -o %t | |
6 | // RUN: %env_asan_opts=no_huge_pages_for_shadow=1 %run %t 2>&1 | FileCheck %s | |
7 | // RUN: %run %t 2>&1 | FileCheck %s | |
8 | // | |
9 | // Would be great to run the test with no_huge_pages_for_shadow=0, but | |
10 | // the result will depend on the OS version and settings... | |
11 | // | |
5bcae85e | 12 | // REQUIRES: x86_64-target-arch |
92a42be0 SL |
13 | // |
14 | // WARNING: this test is very subtle and may nto work on some systems. | |
15 | // If this is the case we'll need to futher improve it or disable it. | |
16 | #include <assert.h> | |
17 | #include <stdio.h> | |
18 | #include <stdlib.h> | |
19 | #include <string.h> | |
20 | #include <sys/mman.h> | |
21 | #include <sys/types.h> | |
22 | #include <sys/stat.h> | |
23 | #include <fcntl.h> | |
24 | #include <unistd.h> | |
25 | #include <errno.h> | |
26 | #include <sanitizer/asan_interface.h> | |
27 | ||
28 | char FileContents[1 << 16]; | |
29 | ||
30 | void FileToString(const char *path) { | |
31 | FileContents[0] = 0; | |
32 | int fd = open(path, 0); | |
33 | if (fd < 0) return; | |
34 | char *p = FileContents; | |
35 | ssize_t size = sizeof(FileContents) - 1; | |
36 | ssize_t res = 0; | |
37 | do { | |
38 | ssize_t got = read (fd, p, size); | |
39 | if (got == 0) | |
40 | break; | |
41 | else if (got > 0) | |
42 | { | |
43 | p += got; | |
44 | res += got; | |
45 | size -= got; | |
46 | } | |
47 | else if (errno != EINTR) | |
48 | break; | |
49 | } while (size > 0 && res < sizeof(FileContents)); | |
50 | if (res >= 0) | |
51 | FileContents[res] = 0; | |
52 | } | |
53 | ||
54 | long ReadShadowRss() { | |
55 | const char *path = "/proc/self/smaps"; | |
56 | FileToString(path); | |
57 | char *s = strstr(FileContents, "2008fff7000-10007fff8000"); | |
58 | if (!s) return 0; | |
59 | ||
60 | s = strstr(s, "Rss:"); | |
61 | if (!s) return 0; | |
62 | s = s + 4; | |
63 | return atol(s); | |
64 | } | |
65 | ||
66 | const int kAllocSize = 1 << 28; // 256Mb | |
67 | const int kTwoMb = 1 << 21; | |
68 | const int kAsanShadowGranularity = 8; | |
69 | ||
70 | char *x; | |
71 | ||
72 | __attribute__((no_sanitize_address)) void TouchNoAsan(size_t i) { x[i] = 0; } | |
73 | ||
74 | int main() { | |
75 | long rss[5]; | |
76 | rss[0] = ReadShadowRss(); | |
77 | // use mmap directly to avoid asan touching the shadow. | |
78 | x = (char *)mmap(0, kAllocSize, PROT_READ | PROT_WRITE, | |
79 | MAP_PRIVATE | MAP_ANON, 0, 0); | |
80 | fprintf(stderr, "X: %p-%p\n", x, x + kAllocSize); | |
81 | rss[1] = ReadShadowRss(); | |
82 | ||
83 | // Touch the allocated region, but not the shadow. | |
84 | for (size_t i = 0; i < kAllocSize; i += kTwoMb * kAsanShadowGranularity) | |
85 | TouchNoAsan(i); | |
86 | rss[2] = ReadShadowRss(); | |
87 | ||
88 | // Touch the shadow just a bit, in 2Mb*Granularity steps. | |
89 | for (size_t i = 0; i < kAllocSize; i += kTwoMb * kAsanShadowGranularity) | |
90 | __asan_poison_memory_region(x + i, kAsanShadowGranularity); | |
91 | rss[3] = ReadShadowRss(); | |
92 | ||
93 | // Touch all the shadow. | |
94 | __asan_poison_memory_region(x, kAllocSize); | |
95 | rss[4] = ReadShadowRss(); | |
96 | ||
97 | // Print the differences. | |
98 | for (int i = 0; i < 4; i++) { | |
99 | assert(rss[i] > 0); | |
100 | assert(rss[i+1] >= rss[i]); | |
101 | long diff = rss[i+1] / rss[i]; | |
102 | fprintf(stderr, "RSS CHANGE IS %d => %d: %s (%ld vs %ld)\n", i, i + 1, | |
103 | diff < 10 ? "SMALL" : "LARGE", rss[i], rss[i + 1]); | |
104 | } | |
105 | } | |
106 | // CHECK: RSS CHANGE IS 2 => 3: SMALL | |
107 | // CHECK: RSS CHANGE IS 3 => 4: LARGE |