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// SPDX-License-Identifier: GPL-2.0-only
/*
* tools/testing/selftests/kvm/lib/assert.c
*
* Copyright (C) 2018, Google LLC.
*/
#define _GNU_SOURCE /* for getline(3) and strchrnul(3)*/
#include "test_util.h"
#include <execinfo.h>
#include <sys/syscall.h>
#include "kselftest.h"
/* Dumps the current stack trace to stderr. */
static void __attribute__((noinline)) test_dump_stack(void);
static void test_dump_stack(void)
{
/*
* Build and run this command:
*
* addr2line -s -e /proc/$PPID/exe -fpai {backtrace addresses} | \
* cat -n 1>&2
*
* Note that the spacing is different and there's no newline.
*/
size_t i;
size_t n = 20;
void *stack[n];
const char *addr2line = "addr2line -s -e /proc/$PPID/exe -fpai";
const char *pipeline = "|cat -n 1>&2";
char cmd[strlen(addr2line) + strlen(pipeline) +
/* N bytes per addr * 2 digits per byte + 1 space per addr: */
n * (((sizeof(void *)) * 2) + 1) +
/* Null terminator: */
1];
char *c = cmd;
n = backtrace(stack, n);
/*
* Skip the first 2 frames, which should be test_dump_stack() and
* test_assert(); both of which are declared noinline. Bail if the
* resulting stack trace would be empty. Otherwise, addr2line will block
* waiting for addresses to be passed in via stdin.
*/
if (n <= 2) {
fputs(" (stack trace empty)\n", stderr);
return;
}
c += sprintf(c, "%s", addr2line);
for (i = 2; i < n; i++)
c += sprintf(c, " %lx", ((unsigned long) stack[i]) - 1);
c += sprintf(c, "%s", pipeline);
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-result"
system(cmd);
#pragma GCC diagnostic pop
}
static pid_t _gettid(void)
{
return syscall(SYS_gettid);
}
void __attribute__((noinline))
test_assert(bool exp, const char *exp_str,
const char *file, unsigned int line, const char *fmt, ...)
{
va_list ap;
if (!(exp)) {
va_start(ap, fmt);
fprintf(stderr, "==== Test Assertion Failure ====\n"
" %s:%u: %s\n"
" pid=%d tid=%d errno=%d - %s\n",
file, line, exp_str, getpid(), _gettid(),
errno, strerror(errno));
test_dump_stack();
if (fmt) {
fputs(" ", stderr);
vfprintf(stderr, fmt, ap);
fputs("\n", stderr);
}
va_end(ap);
if (errno == EACCES) {
print_skip("Access denied - Exiting");
exit(KSFT_SKIP);
}
exit(254);
}
return;
}
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