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); 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 58 static pid_t _gettid(void) 59 { 60 return syscall(SYS_gettid); 61 } 62 63 void __attribute__((noinline)) 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 errno=%d - %s\n", 75 file, line, exp_str, getpid(), _gettid(), 76 errno, 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 print_skip("Access denied - Exiting"); 87 exit(KSFT_SKIP); 88 } 89 exit(254); 90 } 91 92 return; 93 } 94