1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Ptrace test for GPR/FPR registers
4  *
5  * Copyright (C) 2015 Anshuman Khandual, IBM Corporation.
6  */
7 #include "ptrace.h"
8 #include "ptrace-gpr.h"
9 #include "reg.h"
10 #include <time.h>
11 
12 /* Tracer and Tracee Shared Data */
13 int shm_id;
14 int *cptr, *pptr;
15 
16 extern void gpr_child_loop(int *read_flag, int *write_flag,
17 			   unsigned long *gpr_buf, double *fpr_buf);
18 
19 unsigned long child_gpr_val, parent_gpr_val;
20 double child_fpr_val, parent_fpr_val;
21 
child(void)22 static int child(void)
23 {
24 	unsigned long gpr_buf[32];
25 	double fpr_buf[32];
26 	int i;
27 
28 	cptr = (int *)shmat(shm_id, NULL, 0);
29 	memset(gpr_buf, 0, sizeof(gpr_buf));
30 	memset(fpr_buf, 0, sizeof(fpr_buf));
31 
32 	for (i = 0; i < 32; i++) {
33 		gpr_buf[i] = child_gpr_val;
34 		fpr_buf[i] = child_fpr_val;
35 	}
36 
37 	gpr_child_loop(&cptr[0], &cptr[1], gpr_buf, fpr_buf);
38 
39 	shmdt((void *)cptr);
40 
41 	FAIL_IF(validate_gpr(gpr_buf, parent_gpr_val));
42 	FAIL_IF(validate_fpr_double(fpr_buf, parent_fpr_val));
43 
44 	return 0;
45 }
46 
trace_gpr(pid_t child)47 int trace_gpr(pid_t child)
48 {
49 	__u64 tmp, fpr[32], *peeked_fprs;
50 	unsigned long gpr[18];
51 
52 	FAIL_IF(start_trace(child));
53 
54 	// Check child GPRs match what we expect using GETREGS
55 	FAIL_IF(show_gpr(child, gpr));
56 	FAIL_IF(validate_gpr(gpr, child_gpr_val));
57 
58 	// Check child FPRs match what we expect using GETFPREGS
59 	FAIL_IF(show_fpr(child, fpr));
60 	memcpy(&tmp, &child_fpr_val, sizeof(tmp));
61 	FAIL_IF(validate_fpr(fpr, tmp));
62 
63 	// Check child FPRs match what we expect using PEEKUSR
64 	peeked_fprs = peek_fprs(child);
65 	FAIL_IF(!peeked_fprs);
66 	FAIL_IF(validate_fpr(peeked_fprs, tmp));
67 	free(peeked_fprs);
68 
69 	// Write child GPRs using SETREGS
70 	FAIL_IF(write_gpr(child, parent_gpr_val));
71 
72 	// Write child FPRs using SETFPREGS
73 	memcpy(&tmp, &parent_fpr_val, sizeof(tmp));
74 	FAIL_IF(write_fpr(child, tmp));
75 
76 	// Check child FPRs match what we just set, using PEEKUSR
77 	peeked_fprs = peek_fprs(child);
78 	FAIL_IF(!peeked_fprs);
79 	FAIL_IF(validate_fpr(peeked_fprs, tmp));
80 
81 	// Write child FPRs using POKEUSR
82 	FAIL_IF(poke_fprs(child, (unsigned long *)peeked_fprs));
83 
84 	// Child will check its FPRs match before exiting
85 	FAIL_IF(stop_trace(child));
86 
87 	return TEST_PASS;
88 }
89 
90 #ifndef __LONG_WIDTH__
91 #define __LONG_WIDTH__ (sizeof(long) * 8)
92 #endif
93 
rand_reg(void)94 static uint64_t rand_reg(void)
95 {
96 	uint64_t result;
97 	long r;
98 
99 	r = random();
100 
101 	// Small values are typical
102 	result = r & 0xffff;
103 	if (r & 0x10000)
104 		return result;
105 
106 	// Pointers tend to have high bits set
107 	result |= random() << (__LONG_WIDTH__ - 31);
108 	if (r & 0x100000)
109 		return result;
110 
111 	// And sometimes we want a full 64-bit value
112 	result ^= random() << 16;
113 
114 	return result;
115 }
116 
ptrace_gpr(void)117 int ptrace_gpr(void)
118 {
119 	unsigned long seed;
120 	int ret, status;
121 	pid_t pid;
122 
123 	seed = getpid() ^ time(NULL);
124 	printf("srand(%lu)\n", seed);
125 	srand(seed);
126 
127 	child_gpr_val = rand_reg();
128 	child_fpr_val = rand_reg();
129 	parent_gpr_val = rand_reg();
130 	parent_fpr_val = rand_reg();
131 
132 	shm_id = shmget(IPC_PRIVATE, sizeof(int) * 2, 0777|IPC_CREAT);
133 	pid = fork();
134 	if (pid < 0) {
135 		perror("fork() failed");
136 		return TEST_FAIL;
137 	}
138 	if (pid == 0)
139 		exit(child());
140 
141 	if (pid) {
142 		pptr = (int *)shmat(shm_id, NULL, 0);
143 		while (!pptr[1])
144 			asm volatile("" : : : "memory");
145 
146 		ret = trace_gpr(pid);
147 		if (ret) {
148 			kill(pid, SIGTERM);
149 			shmdt((void *)pptr);
150 			shmctl(shm_id, IPC_RMID, NULL);
151 			return TEST_FAIL;
152 		}
153 
154 		pptr[0] = 1;
155 		shmdt((void *)pptr);
156 
157 		ret = wait(&status);
158 		shmctl(shm_id, IPC_RMID, NULL);
159 		if (ret != pid) {
160 			printf("Child's exit status not captured\n");
161 			return TEST_FAIL;
162 		}
163 
164 		return (WIFEXITED(status) && WEXITSTATUS(status)) ? TEST_FAIL :
165 			TEST_PASS;
166 	}
167 
168 	return TEST_PASS;
169 }
170 
main(int argc,char * argv[])171 int main(int argc, char *argv[])
172 {
173 	return test_harness(ptrace_gpr, "ptrace_gpr");
174 }
175