// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2021 ARM Limited
 *
 * Attempt to change the streaming SVE vector length in a signal
 * handler, this is not supported and is expected to segfault.
 */

#include <kselftest.h>
#include <signal.h>
#include <ucontext.h>
#include <sys/prctl.h>

#include "test_signals_utils.h"
#include "sve_helpers.h"
#include "testcases.h"

struct fake_sigframe sf;

static bool sme_get_vls(struct tdescr *td)
{
        int res = sve_fill_vls(VLS_USE_SME, 2);

        if (!res)
                return true;

        if (res == KSFT_SKIP)
                td->result = KSFT_SKIP;

        return false;
}

static int fake_sigreturn_ssve_change_vl(struct tdescr *td,
                                         siginfo_t *si, ucontext_t *uc)
{
        size_t resv_sz, offset;
        struct _aarch64_ctx *head = GET_SF_RESV_HEAD(sf);
        struct za_context *za;

        /* Get a signal context with a SME ZA frame in it */
        if (!get_current_context(td, &sf.uc, sizeof(sf.uc)))
                return 1;

        resv_sz = GET_SF_RESV_SIZE(sf);
        head = get_header(head, ZA_MAGIC, resv_sz, &offset);
        if (!head) {
                fprintf(stderr, "No ZA context\n");
                return 1;
        }

        if (head->size != sizeof(struct za_context)) {
                fprintf(stderr, "Register data present, aborting\n");
                return 1;
        }

        za = (struct za_context *)head;

        /* No changes are supported; init left us at minimum VL so go to max */
        fprintf(stderr, "Attempting to change VL from %d to %d\n",
                za->vl, vls[0]);
        za->vl = vls[0];

        fake_sigreturn(&sf, sizeof(sf), 0);

        return 1;
}

struct tdescr tde = {
        .name = "FAKE_SIGRETURN_SSVE_CHANGE",
        .descr = "Attempt to change Streaming SVE VL",
        .feats_required = FEAT_SME,
        .sig_ok = SIGSEGV,
        .timeout = 3,
        .init = sme_get_vls,
        .run = fake_sigreturn_ssve_change_vl,
};