1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2022 ARM Limited
4 *
5 * Verify that the TPIDR2 register context in signal frames is set up as
6 * expected.
7 */
8
9#include <signal.h>
10#include <ucontext.h>
11#include <sys/auxv.h>
12#include <sys/prctl.h>
13#include <unistd.h>
14#include <asm/sigcontext.h>
15
16#include "test_signals_utils.h"
17#include "testcases.h"
18
19static union {
20	ucontext_t uc;
21	char buf[1024 * 128];
22} context;
23
24#define SYS_TPIDR2 "S3_3_C13_C0_5"
25
26static uint64_t get_tpidr2(void)
27{
28	uint64_t val;
29
30	asm volatile (
31		"mrs	%0, " SYS_TPIDR2 "\n"
32		: "=r"(val)
33		:
34		: "cc");
35
36	return val;
37}
38
39int tpidr2_present(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
40{
41	struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context);
42	struct tpidr2_context *tpidr2_ctx;
43	size_t offset;
44	bool in_sigframe;
45	bool have_sme;
46	__u64 orig_tpidr2;
47
48	have_sme = getauxval(AT_HWCAP2) & HWCAP2_SME;
49	if (have_sme)
50		orig_tpidr2 = get_tpidr2();
51
52	if (!get_current_context(td, &context.uc, sizeof(context)))
53		return 1;
54
55	tpidr2_ctx = (struct tpidr2_context *)
56		get_header(head, TPIDR2_MAGIC, td->live_sz, &offset);
57
58	in_sigframe = tpidr2_ctx != NULL;
59
60	fprintf(stderr, "TPIDR2 sigframe %s on system %s SME\n",
61		in_sigframe ? "present" : "absent",
62		have_sme ? "with" : "without");
63
64	td->pass = (in_sigframe == have_sme);
65
66	/*
67	 * Check that the value we read back was the one present at
68	 * the time that the signal was triggered.  TPIDR2 is owned by
69	 * libc so we can't safely choose the value and it is possible
70	 * that we may need to revisit this in future if something
71	 * starts deciding to set a new TPIDR2 between us reading and
72	 * the signal.
73	 */
74	if (have_sme && tpidr2_ctx) {
75		if (tpidr2_ctx->tpidr2 != orig_tpidr2) {
76			fprintf(stderr, "TPIDR2 in frame is %llx, was %llx\n",
77				tpidr2_ctx->tpidr2, orig_tpidr2);
78			td->pass = false;
79		}
80	}
81
82	return 0;
83}
84
85struct tdescr tde = {
86	.name = "TPIDR2",
87	.descr = "Validate that TPIDR2 is present as expected",
88	.timeout = 3,
89	.run = tpidr2_present,
90};
91