1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Ptrace test for TAR, PPR, DSCR registers in the TM 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 unsigned long *cptr, *pptr;
13 
14 
15 void tm_tar(void)
16 {
17 	unsigned long result, texasr;
18 	unsigned long regs[3];
19 	int ret;
20 
21 	cptr = (unsigned long *)shmat(shm_id, NULL, 0);
22 
23 trans:
24 	cptr[1] = 0;
25 	asm __volatile__(
26 		"li	4, %[tar_1];"
27 		"mtspr %[sprn_tar],  4;"	/* TAR_1 */
28 		"li	4, %[dscr_1];"
29 		"mtspr %[sprn_dscr], 4;"	/* DSCR_1 */
30 		"or     31,31,31;"		/* PPR_1*/
31 
32 		"1: ;"
33 		"tbegin.;"
34 		"beq 2f;"
35 
36 		"li	4, %[tar_2];"
37 		"mtspr %[sprn_tar],  4;"	/* TAR_2 */
38 		"li	4, %[dscr_2];"
39 		"mtspr %[sprn_dscr], 4;"	/* DSCR_2 */
40 		"or     1,1,1;"			/* PPR_2 */
41 		"tsuspend.;"
42 		"li 0, 1;"
43 		"stw 0, 0(%[cptr1]);"
44 		"tresume.;"
45 		"b .;"
46 
47 		"tend.;"
48 		"li 0, 0;"
49 		"ori %[res], 0, 0;"
50 		"b 3f;"
51 
52 		/* Transaction abort handler */
53 		"2: ;"
54 		"li 0, 1;"
55 		"ori %[res], 0, 0;"
56 		"mfspr %[texasr], %[sprn_texasr];"
57 
58 		"3: ;"
59 
60 		: [res] "=r" (result), [texasr] "=r" (texasr)
61 		: [sprn_dscr]"i"(SPRN_DSCR), [sprn_tar]"i"(SPRN_TAR),
62 		[sprn_ppr]"i"(SPRN_PPR), [sprn_texasr]"i"(SPRN_TEXASR),
63 		[tar_1]"i"(TAR_1), [dscr_1]"i"(DSCR_1), [tar_2]"i"(TAR_2),
64 		[dscr_2]"i"(DSCR_2), [cptr1] "b" (&cptr[1])
65 		: "memory", "r0", "r3", "r4", "r5", "r6"
66 		);
67 
68 	/* TM failed, analyse */
69 	if (result) {
70 		if (!cptr[0])
71 			goto trans;
72 
73 		regs[0] = mfspr(SPRN_TAR);
74 		regs[1] = mfspr(SPRN_PPR);
75 		regs[2] = mfspr(SPRN_DSCR);
76 
77 		shmdt(&cptr);
78 		printf("%-30s TAR: %lu PPR: %lx DSCR: %lu\n",
79 				user_read, regs[0], regs[1], regs[2]);
80 
81 		ret = validate_tar_registers(regs, TAR_4, PPR_4, DSCR_4);
82 		if (ret)
83 			exit(1);
84 		exit(0);
85 	}
86 	shmdt(&cptr);
87 	exit(1);
88 }
89 
90 int trace_tm_tar(pid_t child)
91 {
92 	unsigned long regs[3];
93 
94 	FAIL_IF(start_trace(child));
95 	FAIL_IF(show_tar_registers(child, regs));
96 	printf("%-30s TAR: %lu PPR: %lx DSCR: %lu\n",
97 			ptrace_read_running, regs[0], regs[1], regs[2]);
98 
99 	FAIL_IF(validate_tar_registers(regs, TAR_2, PPR_2, DSCR_2));
100 	FAIL_IF(show_tm_checkpointed_state(child, regs));
101 	printf("%-30s TAR: %lu PPR: %lx DSCR: %lu\n",
102 			ptrace_read_ckpt, regs[0], regs[1], regs[2]);
103 
104 	FAIL_IF(validate_tar_registers(regs, TAR_1, PPR_1, DSCR_1));
105 	FAIL_IF(write_ckpt_tar_registers(child, TAR_4, PPR_4, DSCR_4));
106 	printf("%-30s TAR: %u PPR: %lx DSCR: %u\n",
107 			ptrace_write_ckpt, TAR_4, PPR_4, DSCR_4);
108 
109 	pptr[0] = 1;
110 	FAIL_IF(stop_trace(child));
111 	return TEST_PASS;
112 }
113 
114 int ptrace_tm_tar(void)
115 {
116 	pid_t pid;
117 	int ret, status;
118 
119 	SKIP_IF_MSG(!have_htm(), "Don't have transactional memory");
120 	SKIP_IF_MSG(htm_is_synthetic(), "Transactional memory is synthetic");
121 	shm_id = shmget(IPC_PRIVATE, sizeof(int) * 2, 0777|IPC_CREAT);
122 	pid = fork();
123 	if (pid == 0)
124 		tm_tar();
125 
126 	pptr = (unsigned long *)shmat(shm_id, NULL, 0);
127 	pptr[0] = 0;
128 
129 	if (pid) {
130 		while (!pptr[1])
131 			asm volatile("" : : : "memory");
132 		ret = trace_tm_tar(pid);
133 		if (ret) {
134 			kill(pid, SIGTERM);
135 			shmdt(&pptr);
136 			shmctl(shm_id, IPC_RMID, NULL);
137 			return TEST_FAIL;
138 		}
139 		shmdt(&pptr);
140 
141 		ret = wait(&status);
142 		shmctl(shm_id, IPC_RMID, NULL);
143 		if (ret != pid) {
144 			printf("Child's exit status not captured\n");
145 			return TEST_FAIL;
146 		}
147 
148 		return (WIFEXITED(status) && WEXITSTATUS(status)) ? TEST_FAIL :
149 			TEST_PASS;
150 	}
151 	return TEST_PASS;
152 }
153 
154 int main(int argc, char *argv[])
155 {
156 	return test_harness(ptrace_tm_tar, "ptrace_tm_tar");
157 }
158