1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * tools/testing/selftests/kvm/lib/assert.c
4 *
5 * Copyright (C) 2018, Google LLC.
6 */
7 #include "test_util.h"
8
9 #include <execinfo.h>
10 #include <sys/syscall.h>
11
12 #include "kselftest.h"
13
14 /* Dumps the current stack trace to stderr. */
15 static void __attribute__((noinline)) test_dump_stack(void);
16 static void test_dump_stack(void)
17 {
18 /*
19 * Build and run this command:
20 *
21 * addr2line -s -e /proc/$PPID/exe -fpai {backtrace addresses} | \
22 * cat -n 1>&2
23 *
24 * Note that the spacing is different and there's no newline.
25 */
26 size_t i;
27 size_t n = 20;
28 void *stack[n];
29 const char *addr2line = "addr2line -s -e /proc/$PPID/exe -fpai";
30 const char *pipeline = "|cat -n 1>&2";
31 char cmd[strlen(addr2line) + strlen(pipeline) +
32 /* N bytes per addr * 2 digits per byte + 1 space per addr: */
33 n * (((sizeof(void *)) * 2) + 1) +
34 /* Null terminator: */
35 1];
36 char *c = cmd;
37
38 n = backtrace(stack, n);
39 /*
40 * Skip the first 2 frames, which should be test_dump_stack() and
41 * test_assert(); both of which are declared noinline. Bail if the
42 * resulting stack trace would be empty. Otherwise, addr2line will block
43 * waiting for addresses to be passed in via stdin.
44 */
45 if (n <= 2) {
46 fputs(" (stack trace empty)\n", stderr);
47 return;
48 }
49
50 c += sprintf(c, "%s", addr2line);
51 for (i = 2; i < n; i++)
52 c += sprintf(c, " %lx", ((unsigned long) stack[i]) - 1);
53
54 c += sprintf(c, "%s", pipeline);
55 #pragma GCC diagnostic push
56 #pragma GCC diagnostic ignored "-Wunused-result"
57 system(cmd);
58 #pragma GCC diagnostic pop
59 }
60
61 static pid_t _gettid(void)
62 {
63 return syscall(SYS_gettid);
64 }
65
66 void __attribute__((noinline))
67 test_assert(bool exp, const char *exp_str,
68 const char *file, unsigned int line, const char *fmt, ...)
69 {
70 va_list ap;
71
72 if (!(exp)) {
73 va_start(ap, fmt);
74
75 fprintf(stderr, "==== Test Assertion Failure ====\n"
76 " %s:%u: %s\n"
77 " pid=%d tid=%d errno=%d - %s\n",
78 file, line, exp_str, getpid(), _gettid(),
79 errno, strerror(errno));
80 test_dump_stack();
81 if (fmt) {
82 fputs(" ", stderr);
83 vfprintf(stderr, fmt, ap);
84 fputs("\n", stderr);
85 }
86 va_end(ap);
87
88 if (errno == EACCES) {
89 print_skip("Access denied - Exiting");
90 exit(KSFT_SKIP);
91 }
92 exit(254);
93 }
94
95 return;
96 }
97
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.