1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Ptrace test for TAR, PPR, DSCR registers
4  *
5  * Copyright (C) 2015 Anshuman Khandual, IBM Corporation.
6  */
7 #include "ptrace.h"
8 #include "ptrace-tar.h"
9 
10 /* Tracer and Tracee Shared Data */
11 int shm_id;
12 int *cptr;
13 int *pptr;
14 
15 void tar(void)
16 {
17 	unsigned long reg[3];
18 	int ret;
19 
20 	cptr = (int *)shmat(shm_id, NULL, 0);
21 	printf("%-30s TAR: %u PPR: %lx DSCR: %u\n",
22 			user_write, TAR_1, PPR_1, DSCR_1);
23 
24 	mtspr(SPRN_TAR, TAR_1);
25 	mtspr(SPRN_PPR, PPR_1);
26 	mtspr(SPRN_DSCR, DSCR_1);
27 
28 	cptr[2] = 1;
29 
30 	/* Wait on parent */
31 	while (!cptr[0])
32 		asm volatile("" : : : "memory");
33 
34 	reg[0] = mfspr(SPRN_TAR);
35 	reg[1] = mfspr(SPRN_PPR);
36 	reg[2] = mfspr(SPRN_DSCR);
37 
38 	printf("%-30s TAR: %lu PPR: %lx DSCR: %lu\n",
39 			user_read, reg[0], reg[1], reg[2]);
40 
41 	/* Unblock the parent now */
42 	cptr[1] = 1;
43 	shmdt((int *)cptr);
44 
45 	ret = validate_tar_registers(reg, TAR_2, PPR_2, DSCR_2);
46 	if (ret)
47 		exit(1);
48 	exit(0);
49 }
50 
51 int trace_tar(pid_t child)
52 {
53 	unsigned long reg[3];
54 
55 	FAIL_IF(start_trace(child));
56 	FAIL_IF(show_tar_registers(child, reg));
57 	printf("%-30s TAR: %lu PPR: %lx DSCR: %lu\n",
58 			ptrace_read_running, reg[0], reg[1], reg[2]);
59 
60 	FAIL_IF(validate_tar_registers(reg, TAR_1, PPR_1, DSCR_1));
61 	FAIL_IF(stop_trace(child));
62 	return TEST_PASS;
63 }
64 
65 int trace_tar_write(pid_t child)
66 {
67 	FAIL_IF(start_trace(child));
68 	FAIL_IF(write_tar_registers(child, TAR_2, PPR_2, DSCR_2));
69 	printf("%-30s TAR: %u PPR: %lx DSCR: %u\n",
70 			ptrace_write_running, TAR_2, PPR_2, DSCR_2);
71 
72 	FAIL_IF(stop_trace(child));
73 	return TEST_PASS;
74 }
75 
76 int ptrace_tar(void)
77 {
78 	pid_t pid;
79 	int ret, status;
80 
81 	// TAR was added in v2.07
82 	SKIP_IF_MSG(!have_hwcap2(PPC_FEATURE2_ARCH_2_07), "TAR requires ISA 2.07 compatible hardware");
83 
84 	shm_id = shmget(IPC_PRIVATE, sizeof(int) * 3, 0777|IPC_CREAT);
85 	pid = fork();
86 	if (pid < 0) {
87 		perror("fork() failed");
88 		return TEST_FAIL;
89 	}
90 
91 	if (pid == 0)
92 		tar();
93 
94 	if (pid) {
95 		pptr = (int *)shmat(shm_id, NULL, 0);
96 		pptr[0] = 0;
97 		pptr[1] = 0;
98 
99 		while (!pptr[2])
100 			asm volatile("" : : : "memory");
101 		ret = trace_tar(pid);
102 		if (ret)
103 			return ret;
104 
105 		ret = trace_tar_write(pid);
106 		if (ret)
107 			return ret;
108 
109 		/* Unblock the child now */
110 		pptr[0] = 1;
111 
112 		/* Wait on child */
113 		while (!pptr[1])
114 			asm volatile("" : : : "memory");
115 
116 		shmdt((int *)pptr);
117 
118 		ret = wait(&status);
119 		shmctl(shm_id, IPC_RMID, NULL);
120 		if (ret != pid) {
121 			printf("Child's exit status not captured\n");
122 			return TEST_PASS;
123 		}
124 
125 		return (WIFEXITED(status) && WEXITSTATUS(status)) ? TEST_FAIL :
126 			TEST_PASS;
127 	}
128 	return TEST_PASS;
129 }
130 
131 int main(int argc, char *argv[])
132 {
133 	return test_harness(ptrace_tar, "ptrace_tar");
134 }
135