xref: /linux/tools/testing/selftests/arm64/signal/testcases/fpmr_siginfo.c (revision 4b660dbd9ee2059850fd30e0df420ca7a38a1856)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2023 ARM Limited
4  *
5  * Verify that the FPMR 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_FPMR "S3_3_C4_C4_2"
25 
26 static uint64_t get_fpmr(void)
27 {
28 	uint64_t val;
29 
30 	asm volatile (
31 		"mrs	%0, " SYS_FPMR "\n"
32 		: "=r"(val)
33 		:
34 		: "cc");
35 
36 	return val;
37 }
38 
39 int fpmr_present(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
40 {
41 	struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context);
42 	struct fpmr_context *fpmr_ctx;
43 	size_t offset;
44 	bool in_sigframe;
45 	bool have_fpmr;
46 	__u64 orig_fpmr;
47 
48 	have_fpmr = getauxval(AT_HWCAP2) & HWCAP2_FPMR;
49 	if (have_fpmr)
50 		orig_fpmr = get_fpmr();
51 
52 	if (!get_current_context(td, &context.uc, sizeof(context)))
53 		return 1;
54 
55 	fpmr_ctx = (struct fpmr_context *)
56 		get_header(head, FPMR_MAGIC, td->live_sz, &offset);
57 
58 	in_sigframe = fpmr_ctx != NULL;
59 
60 	fprintf(stderr, "FPMR sigframe %s on system %s FPMR\n",
61 		in_sigframe ? "present" : "absent",
62 		have_fpmr ? "with" : "without");
63 
64 	td->pass = (in_sigframe == have_fpmr);
65 
66 	if (have_fpmr && fpmr_ctx) {
67 		if (fpmr_ctx->fpmr != orig_fpmr) {
68 			fprintf(stderr, "FPMR in frame is %llx, was %llx\n",
69 				fpmr_ctx->fpmr, orig_fpmr);
70 			td->pass = false;
71 		}
72 	}
73 
74 	return 0;
75 }
76 
77 struct tdescr tde = {
78 	.name = "FPMR",
79 	.descr = "Validate that FPMR is present as expected",
80 	.timeout = 3,
81 	.run = fpmr_present,
82 };
83