// 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 <signal.h>
#include <ucontext.h>
#include <sys/prctl.h>
#include "test_signals_utils.h"
#include "testcases.h"
struct fake_sigframe sf;
static unsigned int vls[SVE_VQ_MAX];
unsigned int nvls = 0;
static bool sme_get_vls(struct tdescr *td)
{
int vq, vl;
/*
* Enumerate up to SVE_VQ_MAX vector lengths
*/
for (vq = SVE_VQ_MAX; vq > 0; --vq) {
vl = prctl(PR_SVE_SET_VL, vq * 16);
if (vl == -1)
return false;
vl &= PR_SME_VL_LEN_MASK;
/* Skip missing VLs */
vq = sve_vq_from_vl(vl);
vls[nvls++] = vl;
}
/* We need at least two VLs */
if (nvls < 2) {
fprintf(stderr, "Only %d VL supported\n", nvls);
return false;
}
return true;
}
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 sve_context *sve;
/* 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, SVE_MAGIC, resv_sz, &offset);
if (!head) {
fprintf(stderr, "No SVE context\n");
return 1;
}
if (head->size != sizeof(struct sve_context)) {
fprintf(stderr, "Register data present, aborting\n");
return 1;
}
sve = (struct sve_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",
sve->vl, vls[0]);
sve->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,
};