xref: /linux/tools/testing/selftests/arm64/signal/testcases/poe_siginfo.c (revision 55d0969c451159cff86949b38c39171cab962069)
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 
19 static union {
20 	ucontext_t uc;
21 	char buf[1024 * 128];
22 } context;
23 
24 #define SYS_POR_EL0 "S3_3_C10_C2_4"
25 
26 static 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 
39 int 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 
81 struct tdescr tde = {
82 	.name = "POR_EL0",
83 	.descr = "Validate that POR_EL0 is present as expected",
84 	.timeout = 3,
85 	.run = poe_present,
86 };
87