/*
 * 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 verifies the following:
 *
 *   o xregs and fpregs report the same content for the xmm registers at least.
 *   o A write to xregs is reflected in reads of fpregs.
 *   o A write to the fpregs is reflected in reads of xregs and doesn't
 *     clobber additional state in xregs.
 *   o A thread in our victim process sees the final state here and can print
 *     that out.
 *   o As a side effect it makes sure that libproc isn't incorrectly caching
 *     register info on handles.
 *
 * We use the xsu_dump process of the same bitness as us.
 */

#include <err.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>

#include "xsave_util.h"

static xsu_fpu_t fpu;

int
main(int argc, char *argv[])
{
        uint32_t seed, hwsup;
        unsigned long ul;
        char *eptr;
        prxregset_t *prx, *cmp_prx;
        size_t prx_len, cmp_prx_len;
        xsu_proc_t xp;
        fpregset_t fpr;

        if (argc != 5) {
                errx(EXIT_FAILURE, "missing args: <prog> <output file> "
                    "<seed> <func>");
        }

        errno = 0;
        ul = strtoul(argv[3], &eptr, 0);
        if (errno != 0 || *eptr != '\0') {
                errx(EXIT_FAILURE, "seed value is bad: %s", argv[3]);
        }

#if defined(_LP64)
        if (ul > UINT32_MAX) {
                errx(EXIT_FAILURE, "seed %s outside of [0, UINT32_MAX]",
                    argv[3]);
        }
#endif

        seed = (uint32_t)ul;
        hwsup = xsu_hwsupport();
        xsu_fill(&fpu, hwsup, seed);
        xsu_fpu_to_xregs(&fpu, hwsup, &prx, &prx_len);

        (void) memset(&xp, 0, sizeof (xsu_proc_t));
        xp.xp_prog = argv[1];
        xp.xp_arg = argv[2];
        xp.xp_object = "a.out";
        xp.xp_symname = argv[4];
        xsu_proc_bkpt(&xp);

        /*
         * First get the xregs into a reasonable place.
         */
        if (Plwp_setxregs(xp.xp_proc, 1, prx, prx_len) != 0) {
                err(EXIT_FAILURE, "failed to set target's xregs");
        }

        /*
         * Now that we have that, let's go and get the fpregs. Because of
         * differences between the 32-bit representation and the xsave state in
         * the xregs, we stick to different checking in an ILP32 vs. LP64 pieces
         * of this.
         */
        if (Plwp_getfpregs(xp.xp_proc, 1, &fpr) != 0) {
                err(EXIT_FAILURE, "failed to get the fp registers");
        }

        if (!xsu_fpregs_cmp(&fpr, prx)) {
                errx(EXIT_FAILURE, "fpregs do not reflect xsave changes!");
        }
        (void) printf("TEST PASSED: fpregs read respects xregs write\n");

        /*
         * Override the xmm registers with the known variant of the seed and set
         * that. Update the xregs data so we can later compare them usefully.
         */
        xsu_fpregset_xmm_set(&fpr, seed + INT32_MAX);
        xsu_xregs_xmm_set(prx, seed + INT32_MAX);
        if (Plwp_setfpregs(xp.xp_proc, 1, &fpr) != 0) {
                err(EXIT_FAILURE, "failed to set fpregs");
        }

        if (Plwp_getxregs(xp.xp_proc, 1, &cmp_prx, &cmp_prx_len) != 0) {
                err(EXIT_FAILURE, "failed to get comparison xregs");
        }

        if (!xsu_fpregs_cmp(&fpr, cmp_prx)) {
                errx(EXIT_FAILURE, "fpregs do not reflect xsave changes!");
        }
        (void) printf("TEST PASSED: xregs read respects fpregs write\n");

        if (!xsu_xregs_comp_equal(prx, cmp_prx, PRX_INFO_YMM)) {
                errx(EXIT_FAILURE, "%%ymm state changed across fpregs write");
        }
        (void) printf("TEST PASSED: fpregs did not change other xregs "
            "components\n");

        xsu_proc_finish(&xp);

        return (EXIT_SUCCESS);
}