// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2023 ARM Limited
 */

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

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

static union {
        ucontext_t uc;
        char buf[1024 * 64];
} context;

static int gcs_regs(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
{
        size_t offset;
        struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context);
        struct gcs_context *gcs;
        unsigned long expected, gcspr;
        uint64_t *u64_val;
        int ret;

        ret = prctl(PR_GET_SHADOW_STACK_STATUS, &expected, 0, 0, 0);
        if (ret != 0) {
                fprintf(stderr, "Unable to query GCS status\n");
                return 1;
        }

        /* We expect a cap to be added to the GCS in the signal frame */
        gcspr = get_gcspr_el0();
        gcspr -= 8;
        fprintf(stderr, "Expecting GCSPR_EL0 %lx\n", gcspr);

        if (!get_current_context(td, &context.uc, sizeof(context))) {
                fprintf(stderr, "Failed getting context\n");
                return 1;
        }

        /* Ensure that the signal restore token was consumed */
        u64_val = (uint64_t *)get_gcspr_el0() + 1;
        if (*u64_val) {
                fprintf(stderr, "GCS value at %p is %lx not 0\n",
                        u64_val, *u64_val);
                return 1;
        }

        fprintf(stderr, "Got context\n");

        head = get_header(head, GCS_MAGIC, GET_BUF_RESV_SIZE(context),
                          &offset);
        if (!head) {
                fprintf(stderr, "No GCS context\n");
                return 1;
        }

        gcs = (struct gcs_context *)head;

        /* Basic size validation is done in get_current_context() */

        if (gcs->features_enabled != expected) {
                fprintf(stderr, "Features enabled %llx but expected %lx\n",
                        gcs->features_enabled, expected);
                return 1;
        }

        if (gcs->gcspr != gcspr) {
                fprintf(stderr, "Got GCSPR %llx but expected %lx\n",
                        gcs->gcspr, gcspr);
                return 1;
        }

        fprintf(stderr, "GCS context validated\n");
        td->pass = 1;

        return 0;
}

struct tdescr tde = {
        .name = "GCS basics",
        .descr = "Validate a GCS signal context",
        .feats_required = FEAT_GCS,
        .timeout = 3,
        .run = gcs_regs,
};