poe_siginfo.c

 1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * Copyright (C) 2023 Arm Limited
 4 *
 5 * Verify that the POR_EL0 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_POR_EL0 "S3_3_C10_C2_4"
25
26static uint64_t get_por_el0(void)
27{
28	uint64_t val;
29
30	asm volatile(
31		"mrs	%0, " SYS_POR_EL0 "\n"
32		: "=r"(val)
33		:
34		: );
35
36	return val;
37}
38
39int poe_present(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
40{
41	struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context);
42	struct poe_context *poe_ctx;
43	size_t offset;
44	bool in_sigframe;
45	bool have_poe;
46	__u64 orig_poe;
47
48	have_poe = getauxval(AT_HWCAP2) & HWCAP2_POE;
49	if (have_poe)
50		orig_poe = get_por_el0();
51
52	if (!get_current_context(td, &context.uc, sizeof(context)))
53		return 1;
54
55	poe_ctx = (struct poe_context *)
56		get_header(head, POE_MAGIC, td->live_sz, &offset);
57
58	in_sigframe = poe_ctx != NULL;
59
60	fprintf(stderr, "POR_EL0 sigframe %s on system %s POE\n",
61		in_sigframe ? "present" : "absent",
62		have_poe ? "with" : "without");
63
64	td->pass = (in_sigframe == have_poe);
65
66	/*
67	 * Check that the value we read back was the one present at
68	 * the time that the signal was triggered.
69	 */
70	if (have_poe && poe_ctx) {
71		if (poe_ctx->por_el0 != orig_poe) {
72			fprintf(stderr, "POR_EL0 in frame is %llx, was %llx\n",
73				poe_ctx->por_el0, orig_poe);
74			td->pass = false;
75		}
76	}
77
78	return 0;
79}
80
81struct tdescr tde = {
82	.name = "POR_EL0",
83	.descr = "Validate that POR_EL0 is present as expected",
84	.timeout = 3,
85	.run = poe_present,
86};