Pirama Arumuga Nainar | 7c91505 | 2015-04-08 08:58:29 -0700 | [diff] [blame] | 1 | // RUN: %clang_dfsan %s -o %t && %run %t | FileCheck %s |
| 2 | // RUN: %clang_dfsan -mllvm -dfsan-args-abi %s -o %t && %run %t | FileCheck %s |
Stephen Hines | 2d1fdb2 | 2014-05-28 23:58:16 -0700 | [diff] [blame] | 3 | |
| 4 | // Tests that the custom implementation of write() does writes with or without |
| 5 | // a callback set using dfsan_set_write_callback(). |
| 6 | |
| 7 | #include <sanitizer/dfsan_interface.h> |
| 8 | |
| 9 | #include <assert.h> |
| 10 | #include <fcntl.h> |
| 11 | #include <stdio.h> |
| 12 | #include <string.h> |
| 13 | #include <unistd.h> |
| 14 | |
| 15 | // Check write callback arguments by having the callback store them in |
| 16 | // the following variables: |
| 17 | static int last_callback_arg_fd; |
| 18 | static const void *last_callback_arg_buf; |
| 19 | static size_t last_callback_arg_count; |
| 20 | |
| 21 | // Allow tests to check the number of callbacks made by incrementing |
| 22 | // this count. When callbacks are verified, the count is reset. |
| 23 | static int count_unverified_callbacks = 0; |
| 24 | |
| 25 | // This callbact will be installed using dfsan_set_write_callback() |
| 26 | // in tests below. |
| 27 | static void write_callback(int fd, const void *buf, size_t count) { |
| 28 | // Do not do anything in this function that might call write(). |
| 29 | count_unverified_callbacks++; |
| 30 | |
| 31 | last_callback_arg_fd = fd; |
| 32 | last_callback_arg_buf = buf; |
| 33 | last_callback_arg_count = count; |
| 34 | } |
| 35 | |
| 36 | static void write_string_to_stdout(char *string) { |
| 37 | char *cur = string; |
| 38 | int bytes_left = strlen(string); |
| 39 | while (bytes_left > 0) { |
| 40 | int res = write(fileno(stdout), cur, bytes_left); |
| 41 | assert (res >= 0); |
| 42 | cur += res; |
| 43 | bytes_left -= res; |
| 44 | } |
| 45 | } |
| 46 | |
| 47 | static void test_can_write_without_callback() { |
| 48 | dfsan_set_write_callback(NULL); |
| 49 | count_unverified_callbacks = 0; |
| 50 | |
| 51 | char aString[] = "Test that writes work without callback.\n"; |
| 52 | // CHECK: Test that writes work without callback. |
| 53 | write_string_to_stdout(aString); |
| 54 | |
| 55 | assert(count_unverified_callbacks == 0); |
| 56 | } |
| 57 | |
| 58 | static void test_can_write_with_callback() { |
| 59 | dfsan_set_write_callback(write_callback); |
| 60 | |
| 61 | count_unverified_callbacks = 0; |
| 62 | |
| 63 | char stringWithCallback[] = "Test that writes work with callback.\n"; |
| 64 | // CHECK: Test that writes work with callback. |
| 65 | write_string_to_stdout(stringWithCallback); |
| 66 | |
| 67 | // Data was written, so at least one call to write() was made. |
| 68 | // Because a write may not process all the bytes it is passed, there |
| 69 | // may have been several calls to write(). |
| 70 | assert(count_unverified_callbacks > 0); |
| 71 | count_unverified_callbacks = 0; |
| 72 | |
| 73 | dfsan_set_write_callback(NULL); |
| 74 | |
| 75 | char stringWithoutCallback[] = "Writes work after the callback is removed.\n"; |
| 76 | // CHECK: Writes work after the callback is removed. |
| 77 | write_string_to_stdout(stringWithoutCallback); |
| 78 | assert(count_unverified_callbacks == 0); |
| 79 | } |
| 80 | |
| 81 | static void test_failing_write_runs_callback() { |
| 82 | // Open /dev/null in read-only mode. Calling write() on fd will fail. |
| 83 | int fd = open("/dev/null", O_RDONLY); |
| 84 | assert(fd != -1); |
| 85 | |
| 86 | // Install a callback. |
| 87 | dfsan_set_write_callback(write_callback); |
| 88 | |
| 89 | // Write to the read-only file handle. The write will fail, but the callback |
| 90 | // should still be invoked. |
| 91 | char aString[] = "This text will fail to be written.\n"; |
| 92 | int len = strlen(aString); |
| 93 | int write_result = write(fd, aString, len); |
| 94 | assert(write_result == -1); |
| 95 | |
| 96 | assert(count_unverified_callbacks == 1); |
| 97 | count_unverified_callbacks = 0; |
| 98 | |
| 99 | assert(fd == last_callback_arg_fd); |
| 100 | assert(aString == last_callback_arg_buf); |
| 101 | assert(len == last_callback_arg_count); |
| 102 | |
| 103 | close(fd); |
| 104 | } |
| 105 | |
| 106 | int main(int argc, char* argv[]) { |
| 107 | test_can_write_without_callback(); |
| 108 | test_can_write_with_callback(); |
| 109 | test_failing_write_runs_callback(); |
| 110 | } |