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      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