linux_kernel/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spd-tar.c

/*
 * Ptrace test for TAR, PPR, DSCR registers in the TM Suspend context
 *
 * Copyright (C) 2015 Anshuman Khandual, IBM Corporation.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */
#include "ptrace.h"
#include "tm.h"
#include "ptrace-tar.h"

int shm_id;
int *cptr, *pptr;

__attribute__((used)) void wait_parent(void)
{
	cptr[2] = 1;
	while (!cptr[1])
		asm volatile("" : : : "memory");
}

void tm_spd_tar(void)
{
	unsigned long result, texasr;
	unsigned long regs[3];
	int ret;

	cptr = (int *)shmat(shm_id, NULL, 0);

trans:
	cptr[2] = 0;
	asm __volatile__(
		"li	4, %[tar_1];"
		"mtspr %[sprn_tar],  4;"	/* TAR_1 */
		"li	4, %[dscr_1];"
		"mtspr %[sprn_dscr], 4;"	/* DSCR_1 */
		"or     31,31,31;"		/* PPR_1*/

		"1: ;"
		"tbegin.;"
		"beq 2f;"

		"li	4, %[tar_2];"
		"mtspr %[sprn_tar],  4;"	/* TAR_2 */
		"li	4, %[dscr_2];"
		"mtspr %[sprn_dscr], 4;"	/* DSCR_2 */
		"or     1,1,1;"			/* PPR_2 */

		"tsuspend.;"
		"li	4, %[tar_3];"
		"mtspr %[sprn_tar],  4;"	/* TAR_3 */
		"li	4, %[dscr_3];"
		"mtspr %[sprn_dscr], 4;"	/* DSCR_3 */
		"or     6,6,6;"			/* PPR_3 */
		"bl wait_parent;"
		"tresume.;"

		"tend.;"
		"li 0, 0;"
		"ori %[res], 0, 0;"
		"b 3f;"

		/* Transaction abort handler */
		"2: ;"
		"li 0, 1;"
		"ori %[res], 0, 0;"
		"mfspr %[texasr], %[sprn_texasr];"

		"3: ;"

		: [res] "=r" (result), [texasr] "=r" (texasr)
		: [val] "r" (cptr[1]), [sprn_dscr]"i"(SPRN_DSCR),
		[sprn_tar]"i"(SPRN_TAR), [sprn_ppr]"i"(SPRN_PPR),
		[sprn_texasr]"i"(SPRN_TEXASR), [tar_1]"i"(TAR_1),
		[dscr_1]"i"(DSCR_1), [tar_2]"i"(TAR_2), [dscr_2]"i"(DSCR_2),
		[tar_3]"i"(TAR_3), [dscr_3]"i"(DSCR_3)
		: "memory", "r0", "r1", "r3", "r4", "r5", "r6"
		);

	/* TM failed, analyse */
	if (result) {
		if (!cptr[0])
			goto trans;

		regs[0] = mfspr(SPRN_TAR);
		regs[1] = mfspr(SPRN_PPR);
		regs[2] = mfspr(SPRN_DSCR);

		shmdt(&cptr);
		printf("%-30s TAR: %lu PPR: %lx DSCR: %lu\n",
				user_read, regs[0], regs[1], regs[2]);

		ret = validate_tar_registers(regs, TAR_4, PPR_4, DSCR_4);
		if (ret)
			exit(1);
		exit(0);
	}
	shmdt(&cptr);
	exit(1);
}

int trace_tm_spd_tar(pid_t child)
{
	unsigned long regs[3];

	FAIL_IF(start_trace(child));
	FAIL_IF(show_tar_registers(child, regs));
	printf("%-30s TAR: %lu PPR: %lx DSCR: %lu\n",
			ptrace_read_running, regs[0], regs[1], regs[2]);

	FAIL_IF(validate_tar_registers(regs, TAR_3, PPR_3, DSCR_3));
	FAIL_IF(show_tm_checkpointed_state(child, regs));
	printf("%-30s TAR: %lu PPR: %lx DSCR: %lu\n",
			ptrace_read_ckpt, regs[0], regs[1], regs[2]);

	FAIL_IF(validate_tar_registers(regs, TAR_1, PPR_1, DSCR_1));
	FAIL_IF(write_ckpt_tar_registers(child, TAR_4, PPR_4, DSCR_4));
	printf("%-30s TAR: %u PPR: %lx DSCR: %u\n",
			ptrace_write_ckpt, TAR_4, PPR_4, DSCR_4);

	pptr[0] = 1;
	pptr[1] = 1;
	FAIL_IF(stop_trace(child));
	return TEST_PASS;
}

int ptrace_tm_spd_tar(void)
{
	pid_t pid;
	int ret, status;

	SKIP_IF(!have_htm());
	shm_id = shmget(IPC_PRIVATE, sizeof(int) * 3, 0777|IPC_CREAT);
	pid = fork();
	if (pid == 0)
		tm_spd_tar();

	pptr = (int *)shmat(shm_id, NULL, 0);
	pptr[0] = 0;
	pptr[1] = 0;

	if (pid) {
		while (!pptr[2])
			asm volatile("" : : : "memory");
		ret = trace_tm_spd_tar(pid);
		if (ret) {
			kill(pid, SIGTERM);
			shmdt(&pptr);
			shmctl(shm_id, IPC_RMID, NULL);
			return TEST_FAIL;
		}

		shmdt(&pptr);

		ret = wait(&status);
		shmctl(shm_id, IPC_RMID, NULL);
		if (ret != pid) {
			printf("Child's exit status not captured\n");
			return TEST_FAIL;
		}

		return (WIFEXITED(status) && WEXITSTATUS(status)) ? TEST_FAIL :
			TEST_PASS;
	}
	return TEST_PASS;
}

int main(int argc, char *argv[])
{
	return test_harness(ptrace_tm_spd_tar, "ptrace_tm_spd_tar");
}