1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Ptrace test for TAR, PPR, DSCR registers in the TM Suspend context
4  *
5  * Copyright (C) 2015 Anshuman Khandual, IBM Corporation.
6  */
7 #include "ptrace.h"
8 #include "tm.h"
9 #include "ptrace-tar.h"
10 
11 int shm_id;
12 int *cptr, *pptr;
13 
14 __attribute__((used)) void wait_parent(void)
15 {
16 	cptr[2] = 1;
17 	while (!cptr[1])
18 		asm volatile("" : : : "memory");
19 }
20 
21 void tm_spd_tar(void)
22 {
23 	unsigned long result, texasr;
24 	unsigned long regs[3];
25 	int ret;
26 
27 	cptr = (int *)shmat(shm_id, NULL, 0);
28 
29 trans:
30 	cptr[2] = 0;
31 	asm __volatile__(
32 		"li	4, %[tar_1];"
33 		"mtspr %[sprn_tar],  4;"	/* TAR_1 */
34 		"li	4, %[dscr_1];"
35 		"mtspr %[sprn_dscr], 4;"	/* DSCR_1 */
36 		"or     31,31,31;"		/* PPR_1*/
37 
38 		"1: ;"
39 		"tbegin.;"
40 		"beq 2f;"
41 
42 		"li	4, %[tar_2];"
43 		"mtspr %[sprn_tar],  4;"	/* TAR_2 */
44 		"li	4, %[dscr_2];"
45 		"mtspr %[sprn_dscr], 4;"	/* DSCR_2 */
46 		"or     1,1,1;"			/* PPR_2 */
47 
48 		"tsuspend.;"
49 		"li	4, %[tar_3];"
50 		"mtspr %[sprn_tar],  4;"	/* TAR_3 */
51 		"li	4, %[dscr_3];"
52 		"mtspr %[sprn_dscr], 4;"	/* DSCR_3 */
53 		"or     6,6,6;"			/* PPR_3 */
54 		"bl wait_parent;"
55 		"tresume.;"
56 
57 		"tend.;"
58 		"li 0, 0;"
59 		"ori %[res], 0, 0;"
60 		"b 3f;"
61 
62 		/* Transaction abort handler */
63 		"2: ;"
64 		"li 0, 1;"
65 		"ori %[res], 0, 0;"
66 		"mfspr %[texasr], %[sprn_texasr];"
67 
68 		"3: ;"
69 
70 		: [res] "=r" (result), [texasr] "=r" (texasr)
71 		: [sprn_dscr]"i"(SPRN_DSCR),
72 		[sprn_tar]"i"(SPRN_TAR), [sprn_ppr]"i"(SPRN_PPR),
73 		[sprn_texasr]"i"(SPRN_TEXASR), [tar_1]"i"(TAR_1),
74 		[dscr_1]"i"(DSCR_1), [tar_2]"i"(TAR_2), [dscr_2]"i"(DSCR_2),
75 		[tar_3]"i"(TAR_3), [dscr_3]"i"(DSCR_3)
76 		: "memory", "r0", "r3", "r4", "r5", "r6", "lr"
77 		);
78 
79 	/* TM failed, analyse */
80 	if (result) {
81 		if (!cptr[0])
82 			goto trans;
83 
84 		regs[0] = mfspr(SPRN_TAR);
85 		regs[1] = mfspr(SPRN_PPR);
86 		regs[2] = mfspr(SPRN_DSCR);
87 
88 		shmdt(&cptr);
89 		printf("%-30s TAR: %lu PPR: %lx DSCR: %lu\n",
90 				user_read, regs[0], regs[1], regs[2]);
91 
92 		ret = validate_tar_registers(regs, TAR_4, PPR_4, DSCR_4);
93 		if (ret)
94 			exit(1);
95 		exit(0);
96 	}
97 	shmdt(&cptr);
98 	exit(1);
99 }
100 
101 int trace_tm_spd_tar(pid_t child)
102 {
103 	unsigned long regs[3];
104 
105 	FAIL_IF(start_trace(child));
106 	FAIL_IF(show_tar_registers(child, regs));
107 	printf("%-30s TAR: %lu PPR: %lx DSCR: %lu\n",
108 			ptrace_read_running, regs[0], regs[1], regs[2]);
109 
110 	FAIL_IF(validate_tar_registers(regs, TAR_3, PPR_3, DSCR_3));
111 	FAIL_IF(show_tm_checkpointed_state(child, regs));
112 	printf("%-30s TAR: %lu PPR: %lx DSCR: %lu\n",
113 			ptrace_read_ckpt, regs[0], regs[1], regs[2]);
114 
115 	FAIL_IF(validate_tar_registers(regs, TAR_1, PPR_1, DSCR_1));
116 	FAIL_IF(write_ckpt_tar_registers(child, TAR_4, PPR_4, DSCR_4));
117 	printf("%-30s TAR: %u PPR: %lx DSCR: %u\n",
118 			ptrace_write_ckpt, TAR_4, PPR_4, DSCR_4);
119 
120 	pptr[0] = 1;
121 	pptr[1] = 1;
122 	FAIL_IF(stop_trace(child));
123 	return TEST_PASS;
124 }
125 
126 int ptrace_tm_spd_tar(void)
127 {
128 	pid_t pid;
129 	int ret, status;
130 
131 	SKIP_IF_MSG(!have_htm(), "Don't have transactional memory");
132 	SKIP_IF_MSG(htm_is_synthetic(), "Transactional memory is synthetic");
133 	shm_id = shmget(IPC_PRIVATE, sizeof(int) * 3, 0777|IPC_CREAT);
134 	pid = fork();
135 	if (pid == 0)
136 		tm_spd_tar();
137 
138 	pptr = (int *)shmat(shm_id, NULL, 0);
139 	pptr[0] = 0;
140 	pptr[1] = 0;
141 
142 	if (pid) {
143 		while (!pptr[2])
144 			asm volatile("" : : : "memory");
145 		ret = trace_tm_spd_tar(pid);
146 		if (ret) {
147 			kill(pid, SIGTERM);
148 			shmdt(&pptr);
149 			shmctl(shm_id, IPC_RMID, NULL);
150 			return TEST_FAIL;
151 		}
152 
153 		shmdt(&pptr);
154 
155 		ret = wait(&status);
156 		shmctl(shm_id, IPC_RMID, NULL);
157 		if (ret != pid) {
158 			printf("Child's exit status not captured\n");
159 			return TEST_FAIL;
160 		}
161 
162 		return (WIFEXITED(status) && WEXITSTATUS(status)) ? TEST_FAIL :
163 			TEST_PASS;
164 	}
165 	return TEST_PASS;
166 }
167 
168 int main(int argc, char *argv[])
169 {
170 	return test_harness(ptrace_tm_spd_tar, "ptrace_tm_spd_tar");
171 }
172