1 /*
2  * Ptrace test TM SPR registers
3  *
4  * Copyright (C) 2015 Anshuman Khandual, IBM Corporation.
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version
9  * 2 of the License, or (at your option) any later version.
10  */
11 #include "ptrace.h"
12 #include "tm.h"
13 
14 /* Tracee and tracer shared data */
15 struct shared {
16 	int flag;
17 	struct tm_spr_regs regs;
18 };
19 unsigned long tfhar;
20 
21 int shm_id;
22 struct shared *cptr, *pptr;
23 
24 int shm_id1;
25 int *cptr1, *pptr1;
26 
27 #define TM_KVM_SCHED   0xe0000001ac000001
28 int validate_tm_spr(struct tm_spr_regs *regs)
29 {
30 	FAIL_IF(regs->tm_tfhar != tfhar);
31 	FAIL_IF((regs->tm_texasr == TM_KVM_SCHED) && (regs->tm_tfiar != 0));
32 
33 	return TEST_PASS;
34 }
35 
36 void tm_spr(void)
37 {
38 	unsigned long result, texasr;
39 	int ret;
40 
41 	cptr = (struct shared *)shmat(shm_id, NULL, 0);
42 	cptr1 = (int *)shmat(shm_id1, NULL, 0);
43 
44 trans:
45 	cptr1[0] = 0;
46 	asm __volatile__(
47 		"1: ;"
48 		/* TM failover handler should follow "tbegin.;" */
49 		"mflr 31;"
50 		"bl 4f;"	/* $ = TFHAR - 12 */
51 		"4: ;"
52 		"mflr %[tfhar];"
53 		"mtlr 31;"
54 
55 		"tbegin.;"
56 		"beq 2f;"
57 
58 		"tsuspend.;"
59 		"li 8, 1;"
60 		"sth 8, 0(%[cptr1]);"
61 		"tresume.;"
62 		"b .;"
63 
64 		"tend.;"
65 		"li 0, 0;"
66 		"ori %[res], 0, 0;"
67 		"b 3f;"
68 
69 		"2: ;"
70 
71 		"li 0, 1;"
72 		"ori %[res], 0, 0;"
73 		"mfspr %[texasr], %[sprn_texasr];"
74 
75 		"3: ;"
76 		: [tfhar] "=r" (tfhar), [res] "=r" (result),
77 		[texasr] "=r" (texasr), [cptr1] "=r" (cptr1)
78 		: [sprn_texasr] "i"  (SPRN_TEXASR)
79 		: "memory", "r0", "r8", "r31"
80 		);
81 
82 	/* There are 2 32bit instructions before tbegin. */
83 	tfhar += 12;
84 
85 	if (result) {
86 		if (!cptr->flag)
87 			goto trans;
88 
89 		ret = validate_tm_spr((struct tm_spr_regs *)&cptr->regs);
90 		shmdt((void *)cptr);
91 		shmdt((void *)cptr1);
92 		if (ret)
93 			exit(1);
94 		exit(0);
95 	}
96 	shmdt((void *)cptr);
97 	shmdt((void *)cptr1);
98 	exit(1);
99 }
100 
101 int trace_tm_spr(pid_t child)
102 {
103 	FAIL_IF(start_trace(child));
104 	FAIL_IF(show_tm_spr(child, (struct tm_spr_regs *)&pptr->regs));
105 
106 	printf("TFHAR: %lx TEXASR: %lx TFIAR: %lx\n", pptr->regs.tm_tfhar,
107 				pptr->regs.tm_texasr, pptr->regs.tm_tfiar);
108 
109 	pptr->flag = 1;
110 	FAIL_IF(stop_trace(child));
111 
112 	return TEST_PASS;
113 }
114 
115 int ptrace_tm_spr(void)
116 {
117 	pid_t pid;
118 	int ret, status;
119 
120 	SKIP_IF(!have_htm());
121 	shm_id = shmget(IPC_PRIVATE, sizeof(struct shared), 0777|IPC_CREAT);
122 	shm_id1 = shmget(IPC_PRIVATE, sizeof(int), 0777|IPC_CREAT);
123 	pid = fork();
124 	if (pid < 0) {
125 		perror("fork() failed");
126 		return TEST_FAIL;
127 	}
128 
129 	if (pid == 0)
130 		tm_spr();
131 
132 	if (pid) {
133 		pptr = (struct shared *)shmat(shm_id, NULL, 0);
134 		pptr1 = (int *)shmat(shm_id1, NULL, 0);
135 
136 		while (!pptr1[0])
137 			asm volatile("" : : : "memory");
138 		ret = trace_tm_spr(pid);
139 		if (ret) {
140 			kill(pid, SIGKILL);
141 			shmdt((void *)pptr);
142 			shmdt((void *)pptr1);
143 			shmctl(shm_id, IPC_RMID, NULL);
144 			shmctl(shm_id1, IPC_RMID, NULL);
145 			return TEST_FAIL;
146 		}
147 
148 		shmdt((void *)pptr);
149 		shmdt((void *)pptr1);
150 		ret = wait(&status);
151 		shmctl(shm_id, IPC_RMID, NULL);
152 		shmctl(shm_id1, IPC_RMID, NULL);
153 		if (ret != pid) {
154 			printf("Child's exit status not captured\n");
155 			return TEST_FAIL;
156 		}
157 
158 		return (WIFEXITED(status) && WEXITSTATUS(status)) ? TEST_FAIL :
159 			TEST_PASS;
160 	}
161 	return TEST_PASS;
162 }
163 
164 int main(int argc, char *argv[])
165 {
166 	return test_harness(ptrace_tm_spr, "ptrace_tm_spr");
167 }
168