/*
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 */

/*
 * Copyright 2023 Oxide Computer Company
 */

/*
 * This test exercises the swapcontext_extd(3C) functionality and verifies that
 * we can swap contexts that have both extended and non-extended ucontext_t's
 * and that we can get at that state in both cases. This test relies on extended
 * states as we try to validate and ensure that they exist.
 */

#include <err.h>
#include <stdlib.h>
#include <ucontext.h>
#include <limits.h>
#include <errno.h>

#include "xsave_util.h"

static xsu_fpu_t mk_fpu, orig_fpu, found;
static ucontext_t *mk_ctx, *orig_ctx;
static volatile int estatus = EXIT_SUCCESS;

static void
mkctx_target(uint32_t hwsup, uint32_t *testp)
{
        xsu_getfpu(&found, hwsup);
        if (!xsu_same(&mk_fpu, &found, hwsup)) {
                estatus = EXIT_FAILURE;
                warnx("TEST FAILED: initial swap had bad FPU");
        } else {
                (void) printf("TEST PASSED: initial swap had correct FPU\n");
        }

        (void) swapcontext_extd(mk_ctx, 0, orig_ctx);
        err(EXIT_FAILURE, "swapcontext_extd() back failed");
}

static void
mkctx_failure(void)
{
        errx(EXIT_FAILURE, "swapcontext_extd() called failure func");
}

int
main(void)
{
        uint32_t hwsup = xsu_hwsupport();
        uint32_t start = arc4random();

        xsu_fill(&mk_fpu, hwsup, start);
        xsu_fill(&orig_fpu, hwsup, start + INT_MAX);

        mk_ctx = ucontext_alloc(0);
        if (mk_ctx == NULL)
                err(EXIT_FAILURE, "failed to allocate extended ucontext_t");
        orig_ctx = ucontext_alloc(0);
        if (orig_ctx == NULL)
                err(EXIT_FAILURE, "failed to allocate extended ucontext_t");

        /*
         * Set the FPU and snag our initial context. We'll use makecontext to
         * call this and then change our FPU, swap and start checking and then
         * swap back.
         */
        xsu_setfpu(&mk_fpu, hwsup);
        if (getcontext_extd(mk_ctx, 0) != 0) {
                errx(EXIT_FAILURE, "failed to get initial extended context for "
                    "makecontext");
        }

        xsu_ustack_alloc(mk_ctx);
        makecontext(mk_ctx, mkctx_target, 2, hwsup, &hwsup);
        xsu_setfpu(&orig_fpu, hwsup);
        if (swapcontext_extd(orig_ctx, 0, mk_ctx) != 0) {
                err(EXIT_FAILURE, "failed to swap contexts");
        }
        xsu_getfpu(&found, hwsup);
        if (!xsu_same(&orig_fpu, &found, hwsup)) {
                estatus = EXIT_FAILURE;
                warnx("TEST FAILED: swap back did not have the right FPU");
        } else {
                (void) printf("TEST PASSED: swap back had the correct FPU\n");
        }

        xsu_ustack_alloc(mk_ctx);
        makecontext(mk_ctx, mkctx_failure, 0);
        if (swapcontext_extd(orig_ctx, 23, mk_ctx) != -1) {
                errx(EXIT_FAILURE, "somehow got back from error test "
                    "swapcontext_extd() with bad func");
        }
        if (errno != EINVAL) {
                estatus = EXIT_FAILURE;
                warnx("TEST FAILED: swapcontext_extd() with bad flags had "
                    "errno %d expected EINVAL", errno);
        } else {
                (void) printf("TEST PASSED: swapcontext_extd() with bad flags "
                    "has correct errno (EINVAL)\n");
        }

        return (estatus);
}