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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * tools/testing/selftests/kvm/lib/assert.c4 *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. */15static void __attribute__((noinline)) test_dump_stack(void);16static void test_dump_stack(void)17{18 /*19 * Build and run this command:20 *21 * addr2line -s -e /proc/$PPID/exe -fpai {backtrace addresses} | \22 * cat -n 1>&223 *24 * Note that the spacing is different and there's no newline.25 */26 size_t i;27 size_t n = 20;28 void *stack[n];29 const char *addr2line = "addr2line -s -e /proc/$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() and41 * test_assert(); both of which are declared noinline. Bail if the42 * resulting stack trace would be empty. Otherwise, addr2line will block43 * 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 push56#pragma GCC diagnostic ignored "-Wunused-result"57 system(cmd);58#pragma GCC diagnostic pop59}60 61static pid_t _gettid(void)62{63 return syscall(SYS_gettid);64}65 66void __attribute__((noinline))67test_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