Commit | Line | Data |
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591ee332 | 1 | /* |
9d16b343 | 2 | * Copyright (C) 2017 Francis Deslauriers <francis.deslauriers@efficios.com> |
591ee332 | 3 | * |
9d16b343 | 4 | * SPDX-License-Identifier: LGPL-2.1-only |
591ee332 | 5 | * |
591ee332 FD |
6 | */ |
7 | ||
8 | #include <fcntl.h> | |
9 | #include <signal.h> | |
10 | #include <stdbool.h> | |
11 | #include <stdio.h> | |
12 | #include <stdlib.h> | |
13 | #include <string.h> | |
14 | #include <sys/syscall.h> | |
15 | #include <sys/types.h> | |
16 | #include <unistd.h> | |
17 | ||
18 | #include "utils.h" | |
19 | ||
20 | /** | |
21 | * The process waits for the creation of a file passed as argument from an | |
22 | * external processes to execute a syscall and exiting. This is useful for tests | |
23 | * in combinaison with LTTng's PID tracker feature where we can trace the kernel | |
24 | * events generated by our test process only. | |
25 | */ | |
26 | ||
51c2fb6c FD |
27 | #if defined(__clang__) |
28 | #define nooptimization __attribute__((noinline)) __attribute__((optnone)) | |
29 | #else | |
30 | #define nooptimization __attribute__((noinline)) __attribute__((optimize(0))) | |
31 | #endif | |
32 | ||
591ee332 FD |
33 | volatile int val = 0; |
34 | ||
701a99d1 | 35 | long nooptimization my_gettid(void); |
51c2fb6c | 36 | long nooptimization |
591ee332 FD |
37 | my_gettid(void) |
38 | { | |
39 | long ret; | |
40 | #ifdef __x86_64 | |
41 | asm volatile | |
42 | ( | |
43 | "syscall" | |
44 | : "=a" (ret) | |
45 | : "0"(__NR_gettid) | |
46 | : "cc", "rcx", "r11", "memory" | |
47 | ); | |
48 | #elif __i386 | |
49 | asm volatile | |
50 | ( | |
51 | "int $0x80" | |
52 | : "=a" (ret) | |
53 | : "0"(__NR_gettid) | |
54 | : "cc", "edi", "esi", "memory" | |
55 | ); | |
56 | #else | |
57 | #error "Userspace callstack test not supported for this architecture." | |
58 | #endif | |
59 | return ret; | |
60 | } | |
61 | ||
701a99d1 | 62 | int nooptimization fct_c(void); |
51c2fb6c | 63 | int nooptimization |
591ee332 FD |
64 | fct_c(void) |
65 | { | |
66 | return my_gettid(); | |
67 | } | |
68 | ||
701a99d1 | 69 | int nooptimization fct_b(void); |
51c2fb6c | 70 | int nooptimization |
591ee332 FD |
71 | fct_b(void) |
72 | { | |
73 | val += fct_c(); | |
74 | return val; | |
75 | } | |
76 | ||
701a99d1 | 77 | int nooptimization fct_a(void); |
51c2fb6c | 78 | int nooptimization |
591ee332 FD |
79 | fct_a(void) |
80 | { | |
81 | val += fct_b(); | |
82 | return val; | |
83 | } | |
84 | ||
85 | int main(int argc, char **argv) | |
86 | { | |
87 | int ret = 0; | |
88 | char *start_file; | |
89 | ||
90 | if (argc != 2) { | |
91 | fprintf(stderr, "Error: Missing argument\n"); | |
92 | fprintf(stderr, "USAGE: %s PATH_WAIT_FILE\n", argv[0]); | |
93 | ret = -1; | |
94 | goto error; | |
95 | } | |
96 | ||
97 | start_file = argv[1]; | |
98 | ||
99 | /* | |
100 | * Wait for the start_file to be created by an external process | |
101 | * (typically the test script) before executing the syscall | |
102 | */ | |
103 | ret = wait_on_file(start_file); | |
104 | if (ret != 0) { | |
105 | goto error; | |
106 | } | |
107 | ||
108 | /* Start the callchain to the syscall */ | |
109 | ret = fct_a(); | |
110 | ||
111 | /* Return success */ | |
112 | if (ret >= 0) { | |
113 | ret = 0; | |
114 | } | |
115 | ||
116 | error: | |
117 | return ret; | |
118 | } |