xref: /linux/tools/testing/selftests/arm64/signal/testcases/tpidr2_restore.c (revision cdd5b5a9761fd66d17586e4f4ba6588c70e640ea)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2023 ARM Limited
4  *
5  * Verify that the TPIDR2 register context in signal frames is restored.
6  */
7 
8 #include <signal.h>
9 #include <ucontext.h>
10 #include <sys/auxv.h>
11 #include <sys/prctl.h>
12 #include <unistd.h>
13 #include <asm/sigcontext.h>
14 
15 #include "test_signals_utils.h"
16 #include "testcases.h"
17 
18 #define SYS_TPIDR2 "S3_3_C13_C0_5"
19 
get_tpidr2(void)20 static uint64_t get_tpidr2(void)
21 {
22 	uint64_t val;
23 
24 	asm volatile (
25 		"mrs	%0, " SYS_TPIDR2 "\n"
26 		: "=r"(val)
27 		:
28 		: "cc");
29 
30 	return val;
31 }
32 
set_tpidr2(uint64_t val)33 static void set_tpidr2(uint64_t val)
34 {
35 	asm volatile (
36 		"msr	" SYS_TPIDR2 ", %0\n"
37 		:
38 		: "r"(val)
39 		: "cc");
40 }
41 
42 
43 static uint64_t initial_tpidr2;
44 
save_tpidr2(struct tdescr * td)45 static bool save_tpidr2(struct tdescr *td)
46 {
47 	initial_tpidr2 = get_tpidr2();
48 	fprintf(stderr, "Initial TPIDR2: %lx\n", initial_tpidr2);
49 
50 	return true;
51 }
52 
modify_tpidr2(struct tdescr * td,siginfo_t * si,ucontext_t * uc)53 static int modify_tpidr2(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
54 {
55 	uint64_t my_tpidr2 = get_tpidr2();
56 
57 	my_tpidr2++;
58 	fprintf(stderr, "Setting TPIDR2 to %lx\n", my_tpidr2);
59 	set_tpidr2(my_tpidr2);
60 
61 	return 0;
62 }
63 
check_tpidr2(struct tdescr * td)64 static void check_tpidr2(struct tdescr *td)
65 {
66 	uint64_t tpidr2 = get_tpidr2();
67 
68 	td->pass = tpidr2 == initial_tpidr2;
69 
70 	if (td->pass)
71 		fprintf(stderr, "TPIDR2 restored\n");
72 	else
73 		fprintf(stderr, "TPIDR2 was %lx but is now %lx\n",
74 			initial_tpidr2, tpidr2);
75 }
76 
77 struct tdescr tde = {
78 	.name = "TPIDR2 restore",
79 	.descr = "Validate that TPIDR2 is restored from the sigframe",
80 	.feats_required = FEAT_SME,
81 	.timeout = 3,
82 	.sig_trig = SIGUSR1,
83 	.init = save_tpidr2,
84 	.run = modify_tpidr2,
85 	.check_result = check_tpidr2,
86 };
87