signal/testcases/za_regs.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * Copyright (C) 2021 ARM Limited
0004  *
0005  * Verify that the ZA register context in signal frames is set up as
0006  * expected.
0007  */
0008
0009 #include <signal.h>
0010 #include <ucontext.h>
0011 #include <sys/prctl.h>
0012
0013 #include "test_signals_utils.h"
0014 #include "testcases.h"
0015
0016 struct fake_sigframe sf;
0017 static unsigned int vls[SVE_VQ_MAX];
0018 unsigned int nvls = 0;
0019
0020 static bool sme_get_vls(struct tdescr *td)
0021 {
0022     int vq, vl;
0023
0024     /*
0025      * Enumerate up to SVE_VQ_MAX vector lengths
0026      */
0027     for (vq = SVE_VQ_MAX; vq > 0; --vq) {
0028         vl = prctl(PR_SVE_SET_VL, vq * 16);
0029         if (vl == -1)
0030             return false;
0031
0032         vl &= PR_SME_VL_LEN_MASK;
0033
0034         /* Skip missing VLs */
0035         vq = sve_vq_from_vl(vl);
0036
0037         vls[nvls++] = vl;
0038     }
0039
0040     /* We need at least one VL */
0041     if (nvls < 1) {
0042         fprintf(stderr, "Only %d VL supported\n", nvls);
0043         return false;
0044     }
0045
0046     return true;
0047 }
0048
0049 static void setup_za_regs(void)
0050 {
0051     /* smstart za; real data is TODO */
0052     asm volatile(".inst 0xd503457f" : : : );
0053 }
0054
0055 static int do_one_sme_vl(struct tdescr *td, siginfo_t *si, ucontext_t *uc,
0056              unsigned int vl)
0057 {
0058     size_t resv_sz, offset;
0059     struct _aarch64_ctx *head = GET_SF_RESV_HEAD(sf);
0060     struct za_context *za;
0061
0062     fprintf(stderr, "Testing VL %d\n", vl);
0063
0064     if (prctl(PR_SME_SET_VL, vl) != vl) {
0065         fprintf(stderr, "Failed to set VL\n");
0066         return 1;
0067     }
0068
0069     /*
0070      * Get a signal context which should have a SVE frame and registers
0071      * in it.
0072      */
0073     setup_za_regs();
0074     if (!get_current_context(td, &sf.uc))
0075         return 1;
0076
0077     resv_sz = GET_SF_RESV_SIZE(sf);
0078     head = get_header(head, ZA_MAGIC, resv_sz, &offset);
0079     if (!head) {
0080         fprintf(stderr, "No ZA context\n");
0081         return 1;
0082     }
0083
0084     za = (struct za_context *)head;
0085     if (za->vl != vl) {
0086         fprintf(stderr, "Got VL %d, expected %d\n", za->vl, vl);
0087         return 1;
0088     }
0089
0090     /* The actual size validation is done in get_current_context() */
0091     fprintf(stderr, "Got expected size %u and VL %d\n",
0092         head->size, za->vl);
0093
0094     return 0;
0095 }
0096
0097 static int sme_regs(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
0098 {
0099     int i;
0100
0101     for (i = 0; i < nvls; i++) {
0102         /*
0103          * TODO: the signal test helpers can't currently cope
0104          * with signal frames bigger than struct sigcontext,
0105          * skip VLs that will trigger that.
0106          */
0107         if (vls[i] > 32) {
0108             printf("Skipping VL %u due to stack size\n", vls[i]);
0109             continue;
0110         }
0111
0112         if (do_one_sme_vl(td, si, uc, vls[i]))
0113             return 1;
0114     }
0115
0116     td->pass = 1;
0117
0118     return 0;
0119 }
0120
0121 struct tdescr tde = {
0122     .name = "ZA register",
0123     .descr = "Check that we get the right ZA registers reported",
0124     .feats_required = FEAT_SME,
0125     .timeout = 3,
0126     .init = sme_get_vls,
0127     .run = sme_regs,
0128 };