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};
87

source code of linux/tools/testing/selftests/arm64/signal/testcases/poe_siginfo.c