tests: add declarations for functions in gen-syscall-events-callstack.c
[lttng-tools.git] / tests / utils / testapp / gen-syscall-events-callstack / gen-syscall-events-callstack.c
1 /*
2 * Copyright (C) - 2017 Francis Deslauriers <francis.deslauriers@efficios.com>
3 *
4 * This library is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU Lesser General Public License as published by the
6 * Free Software Foundation; version 2.1 of the License.
7 *
8 * This library is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
11 * for more details.
12 *
13 * You should have received a copy of the GNU Lesser General Public License
14 * along with this library; if not, write to the Free Software Foundation,
15 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
16 */
17
18 #include <fcntl.h>
19 #include <signal.h>
20 #include <stdbool.h>
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <string.h>
24 #include <sys/syscall.h>
25 #include <sys/types.h>
26 #include <unistd.h>
27
28 #include "utils.h"
29
30 /**
31 * The process waits for the creation of a file passed as argument from an
32 * external processes to execute a syscall and exiting. This is useful for tests
33 * in combinaison with LTTng's PID tracker feature where we can trace the kernel
34 * events generated by our test process only.
35 */
36
37 #if defined(__clang__)
38 #define nooptimization __attribute__((noinline)) __attribute__((optnone))
39 #else
40 #define nooptimization __attribute__((noinline)) __attribute__((optimize(0)))
41 #endif
42
43 volatile int val = 0;
44
45 long nooptimization my_gettid(void);
46 long nooptimization
47 my_gettid(void)
48 {
49 long ret;
50 #ifdef __x86_64
51 asm volatile
52 (
53 "syscall"
54 : "=a" (ret)
55 : "0"(__NR_gettid)
56 : "cc", "rcx", "r11", "memory"
57 );
58 #elif __i386
59 asm volatile
60 (
61 "int $0x80"
62 : "=a" (ret)
63 : "0"(__NR_gettid)
64 : "cc", "edi", "esi", "memory"
65 );
66 #else
67 #error "Userspace callstack test not supported for this architecture."
68 #endif
69 return ret;
70 }
71
72 int nooptimization fct_c(void);
73 int nooptimization
74 fct_c(void)
75 {
76 return my_gettid();
77 }
78
79 int nooptimization fct_b(void);
80 int nooptimization
81 fct_b(void)
82 {
83 val += fct_c();
84 return val;
85 }
86
87 int nooptimization fct_a(void);
88 int nooptimization
89 fct_a(void)
90 {
91 val += fct_b();
92 return val;
93 }
94
95 int main(int argc, char **argv)
96 {
97 int ret = 0;
98 char *start_file;
99
100 if (argc != 2) {
101 fprintf(stderr, "Error: Missing argument\n");
102 fprintf(stderr, "USAGE: %s PATH_WAIT_FILE\n", argv[0]);
103 ret = -1;
104 goto error;
105 }
106
107 start_file = argv[1];
108
109 /*
110 * Wait for the start_file to be created by an external process
111 * (typically the test script) before executing the syscall
112 */
113 ret = wait_on_file(start_file);
114 if (ret != 0) {
115 goto error;
116 }
117
118 /* Start the callchain to the syscall */
119 ret = fct_a();
120
121 /* Return success */
122 if (ret >= 0) {
123 ret = 0;
124 }
125
126 error:
127 return ret;
128 }
This page took 0.045203 seconds and 4 git commands to generate.