1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Copyright 2014, Michael Ellerman, IBM Corp. |
4 | */ |
5 | |
6 | #define _GNU_SOURCE /* For CPU_ZERO etc. */ |
7 | |
8 | #include <errno.h> |
9 | #include <sched.h> |
10 | #include <setjmp.h> |
11 | #include <stdlib.h> |
12 | #include <sys/wait.h> |
13 | |
14 | #include "utils.h" |
15 | #include "lib.h" |
16 | |
17 | #define PARENT_TOKEN 0xAA |
18 | #define CHILD_TOKEN 0x55 |
19 | |
20 | int sync_with_child(union pipe read_pipe, union pipe write_pipe) |
21 | { |
22 | char c = PARENT_TOKEN; |
23 | |
24 | FAIL_IF(write(write_pipe.write_fd, &c, 1) != 1); |
25 | FAIL_IF(read(read_pipe.read_fd, &c, 1) != 1); |
26 | if (c != CHILD_TOKEN) /* sometimes expected */ |
27 | return 1; |
28 | |
29 | return 0; |
30 | } |
31 | |
32 | int wait_for_parent(union pipe read_pipe) |
33 | { |
34 | char c; |
35 | |
36 | FAIL_IF(read(read_pipe.read_fd, &c, 1) != 1); |
37 | FAIL_IF(c != PARENT_TOKEN); |
38 | |
39 | return 0; |
40 | } |
41 | |
42 | int notify_parent(union pipe write_pipe) |
43 | { |
44 | char c = CHILD_TOKEN; |
45 | |
46 | FAIL_IF(write(write_pipe.write_fd, &c, 1) != 1); |
47 | |
48 | return 0; |
49 | } |
50 | |
51 | int notify_parent_of_error(union pipe write_pipe) |
52 | { |
53 | char c = ~CHILD_TOKEN; |
54 | |
55 | FAIL_IF(write(write_pipe.write_fd, &c, 1) != 1); |
56 | |
57 | return 0; |
58 | } |
59 | |
60 | int wait_for_child(pid_t child_pid) |
61 | { |
62 | int rc; |
63 | |
64 | if (waitpid(child_pid, &rc, 0) == -1) { |
65 | perror("waitpid" ); |
66 | return 1; |
67 | } |
68 | |
69 | if (WIFEXITED(rc)) |
70 | rc = WEXITSTATUS(rc); |
71 | else |
72 | rc = 1; /* Signal or other */ |
73 | |
74 | return rc; |
75 | } |
76 | |
77 | int kill_child_and_wait(pid_t child_pid) |
78 | { |
79 | kill(child_pid, SIGTERM); |
80 | |
81 | return wait_for_child(child_pid); |
82 | } |
83 | |
84 | static int eat_cpu_child(union pipe read_pipe, union pipe write_pipe) |
85 | { |
86 | volatile int i = 0; |
87 | |
88 | /* |
89 | * We are just here to eat cpu and die. So make sure we can be killed, |
90 | * and also don't do any custom SIGTERM handling. |
91 | */ |
92 | signal(SIGTERM, SIG_DFL); |
93 | |
94 | notify_parent(write_pipe); |
95 | wait_for_parent(read_pipe); |
96 | |
97 | /* Soak up cpu forever */ |
98 | while (1) i++; |
99 | |
100 | return 0; |
101 | } |
102 | |
103 | pid_t eat_cpu(int (test_function)(void)) |
104 | { |
105 | union pipe read_pipe, write_pipe; |
106 | int rc; |
107 | pid_t pid; |
108 | |
109 | FAIL_IF(bind_to_cpu(BIND_CPU_ANY) < 0); |
110 | |
111 | if (pipe(read_pipe.fds) == -1) |
112 | return -1; |
113 | |
114 | if (pipe(write_pipe.fds) == -1) |
115 | return -1; |
116 | |
117 | pid = fork(); |
118 | if (pid == 0) |
119 | exit(eat_cpu_child(read_pipe: write_pipe, write_pipe: read_pipe)); |
120 | |
121 | if (sync_with_child(read_pipe, write_pipe)) { |
122 | rc = -1; |
123 | goto out; |
124 | } |
125 | |
126 | printf("main test running as pid %d\n" , getpid()); |
127 | |
128 | rc = test_function(); |
129 | out: |
130 | kill(pid, SIGKILL); |
131 | |
132 | return rc; |
133 | } |
134 | |
135 | struct addr_range libc, vdso; |
136 | |
137 | int parse_proc_maps(void) |
138 | { |
139 | unsigned long start, end; |
140 | char execute, name[128]; |
141 | FILE *f; |
142 | int rc; |
143 | |
144 | f = fopen("/proc/self/maps" , "r" ); |
145 | if (!f) { |
146 | perror("fopen" ); |
147 | return -1; |
148 | } |
149 | |
150 | do { |
151 | /* This skips line with no executable which is what we want */ |
152 | rc = fscanf(f, "%lx-%lx %*c%*c%c%*c %*x %*d:%*d %*d %127s\n" , |
153 | &start, &end, &execute, name); |
154 | if (rc <= 0) |
155 | break; |
156 | |
157 | if (execute != 'x') |
158 | continue; |
159 | |
160 | if (strstr(name, "libc" )) { |
161 | libc.first = start; |
162 | libc.last = end - 1; |
163 | } else if (strstr(name, "[vdso]" )) { |
164 | vdso.first = start; |
165 | vdso.last = end - 1; |
166 | } |
167 | } while(1); |
168 | |
169 | fclose(f); |
170 | |
171 | return 0; |
172 | } |
173 | |
174 | #define PARANOID_PATH "/proc/sys/kernel/perf_event_paranoid" |
175 | |
176 | bool require_paranoia_below(int level) |
177 | { |
178 | int err; |
179 | long current; |
180 | |
181 | err = read_long(PARANOID_PATH, ¤t, 10); |
182 | if (err) { |
183 | printf("Couldn't parse " PARANOID_PATH "?\n" ); |
184 | return false; |
185 | } |
186 | |
187 | return current < level; |
188 | } |
189 | |