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
8 #define _GNU_SOURCE /* for getline(3) and strchrnul(3)*/
9
10 #include "test_util.h"
11
12 #include <execinfo.h>
13 #include <sys/syscall.h>
14
15 #include "kselftest.h"
16
17 /* Dumps the current stack trace to stderr. */
18 static void __attribute__((noinline)) test_dump_stack(void);
test_dump_stack(void)19 static void test_dump_stack(void)
20 {
21 /*
22 * Build and run this command:
23 *
24 * addr2line -s -e /proc/$PPID/exe -fpai {backtrace addresses} | \
25 * grep -v test_dump_stack | cat -n 1>&2
26 *
27 * Note that the spacing is different and there's no newline.
28 */
29 size_t i;
30 size_t n = 20;
31 void *stack[n];
32 const char *addr2line = "addr2line -s -e /proc/$PPID/exe -fpai";
33 const char *pipeline = "|cat -n 1>&2";
34 char cmd[strlen(addr2line) + strlen(pipeline) +
35 /* N bytes per addr * 2 digits per byte + 1 space per addr: */
36 n * (((sizeof(void *)) * 2) + 1) +
37 /* Null terminator: */
38 1];
39 char *c;
40
41 n = backtrace(stack, n);
42 c = &cmd[0];
43 c += sprintf(c, "%s", addr2line);
44 /*
45 * Skip the first 3 frames: backtrace, test_dump_stack, and
46 * test_assert. We hope that backtrace isn't inlined and the other two
47 * we've declared noinline.
48 */
49 for (i = 2; i < n; i++)
50 c += sprintf(c, " %lx", ((unsigned long) stack[i]) - 1);
51 c += sprintf(c, "%s", pipeline);
52 #pragma GCC diagnostic push
53 #pragma GCC diagnostic ignored "-Wunused-result"
54 system(cmd);
55 #pragma GCC diagnostic pop
56 }
57
_gettid(void)58 static pid_t _gettid(void)
59 {
60 return syscall(SYS_gettid);
61 }
62
63 void __attribute__((noinline))
test_assert(bool exp,const char * exp_str,const char * file,unsigned int line,const char * fmt,...)64 test_assert(bool exp, const char *exp_str,
65 const char *file, unsigned int line, const char *fmt, ...)
66 {
67 va_list ap;
68
69 if (!(exp)) {
70 va_start(ap, fmt);
71
72 fprintf(stderr, "==== Test Assertion Failure ====\n"
73 " %s:%u: %s\n"
74 " pid=%d tid=%d - %s\n",
75 file, line, exp_str, getpid(), _gettid(),
76 strerror(errno));
77 test_dump_stack();
78 if (fmt) {
79 fputs(" ", stderr);
80 vfprintf(stderr, fmt, ap);
81 fputs("\n", stderr);
82 }
83 va_end(ap);
84
85 if (errno == EACCES)
86 ksft_exit_skip("Access denied - Exiting.\n");
87 exit(254);
88 }
89
90 return;
91 }
92