// SPDX-License-Identifier: GPL-2.0-only
/*
 * tools/testing/selftests/kvm/lib/assert.c
 *
 * Copyright (C) 2018, Google LLC.
 */
#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;
}