selftests/powerpc: Add ptrace tests for TAR, PPR, DSCR registers

This patch adds ptrace interface test for TAR, PPR, DSCR
registers. This also adds ptrace interface based helper
functions related to TAR, PPR, DSCR register access.
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

tools/testing/selftests/powerpc/ptrace/.gitignore

 ptrace-gpr
 ptrace-tm-gpr
 ptrace-tm-spd-gpr
+ptrace-tar
\ No newline at end of file

tools/testing/selftests/powerpc/ptrace/Makefile

-TEST_PROGS := ptrace-gpr ptrace-tm-gpr ptrace-tm-spd-gpr
+TEST_PROGS := ptrace-gpr ptrace-tm-gpr ptrace-tm-spd-gpr \
+              ptrace-tar
 
 include ../../lib.mk
 

tools/testing/selftests/powerpc/ptrace/ptrace-tar.c

+/*
+ * Ptrace test for TAR, PPR, DSCR registers
+ *
+ * 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 "ptrace-tar.h"
+
+/* Tracer and Tracee Shared Data */
+int shm_id;
+int *cptr;
+int *pptr;
+
+void tar(void)
+{
+	unsigned long reg[3];
+	int ret;
+
+	cptr = (int *)shmat(shm_id, NULL, 0);
+	printf("%-30s TAR: %u PPR: %lx DSCR: %u\n",
+			user_write, TAR_1, PPR_1, DSCR_1);
+
+	mtspr(SPRN_TAR, TAR_1);
+	mtspr(SPRN_PPR, PPR_1);
+	mtspr(SPRN_DSCR, DSCR_1);
+
+	cptr[2] = 1;
+
+	/* Wait on parent */
+	while (!cptr[0])
+		asm volatile("" : : : "memory");
+
+	reg[0] = mfspr(SPRN_TAR);
+	reg[1] = mfspr(SPRN_PPR);
+	reg[2] = mfspr(SPRN_DSCR);
+
+	printf("%-30s TAR: %lu PPR: %lx DSCR: %lu\n",
+			user_read, reg[0], reg[1], reg[2]);
+
+	/* Unblock the parent now */
+	cptr[1] = 1;
+	shmdt((int *)cptr);
+
+	ret = validate_tar_registers(reg, TAR_2, PPR_2, DSCR_2);
+	if (ret)
+		exit(1);
+	exit(0);
+}
+
+int trace_tar(pid_t child)
+{
+	unsigned long reg[3];
+
+	FAIL_IF(start_trace(child));
+	FAIL_IF(show_tar_registers(child, reg));
+	printf("%-30s TAR: %lu PPR: %lx DSCR: %lu\n",
+			ptrace_read_running, reg[0], reg[1], reg[2]);
+
+	FAIL_IF(validate_tar_registers(reg, TAR_1, PPR_1, DSCR_1));
+	FAIL_IF(stop_trace(child));
+	return TEST_PASS;
+}
+
+int trace_tar_write(pid_t child)
+{
+	FAIL_IF(start_trace(child));
+	FAIL_IF(write_tar_registers(child, TAR_2, PPR_2, DSCR_2));
+	printf("%-30s TAR: %u PPR: %lx DSCR: %u\n",
+			ptrace_write_running, TAR_2, PPR_2, DSCR_2);
+
+	FAIL_IF(stop_trace(child));
+	return TEST_PASS;
+}
+
+int ptrace_tar(void)
+{
+	pid_t pid;
+	int ret, status;
+
+	shm_id = shmget(IPC_PRIVATE, sizeof(int) * 3, 0777|IPC_CREAT);
+	pid = fork();
+	if (pid < 0) {
+		perror("fork() failed");
+		return TEST_FAIL;
+	}
+
+	if (pid == 0)
+		tar();
+
+	if (pid) {
+		pptr = (int *)shmat(shm_id, NULL, 0);
+		pptr[0] = 0;
+		pptr[1] = 0;
+
+		while (!pptr[2])
+			asm volatile("" : : : "memory");
+		ret = trace_tar(pid);
+		if (ret)
+			return ret;
+
+		ret = trace_tar_write(pid);
+		if (ret)
+			return ret;
+
+		/* Unblock the child now */
+		pptr[0] = 1;
+
+		/* Wait on child */
+		while (!pptr[1])
+			asm volatile("" : : : "memory");
+
+		shmdt((int *)pptr);
+
+		ret = wait(&status);
+		shmctl(shm_id, IPC_RMID, NULL);
+		if (ret != pid) {
+			printf("Child's exit status not captured\n");
+			return TEST_PASS;
+		}
+
+		return (WIFEXITED(status) && WEXITSTATUS(status)) ? TEST_FAIL :
+			TEST_PASS;
+	}
+	return TEST_PASS;
+}
+
+int main(int argc, char *argv[])
+{
+	return test_harness(ptrace_tar, "ptrace_tar");
+}

tools/testing/selftests/powerpc/ptrace/ptrace-tar.h

+/*
+ * 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.
+ */
+#define TAR_1   10
+#define TAR_2   20
+#define TAR_3   30
+#define TAR_4   40
+#define TAR_5   50
+
+#define DSCR_1  100
+#define DSCR_2  200
+#define DSCR_3  300
+#define DSCR_4  400
+#define DSCR_5  500
+
+#define PPR_1   0x4000000000000         /* or 31,31,31*/
+#define PPR_2   0x8000000000000         /* or 1,1,1 */
+#define PPR_3   0xc000000000000         /* or 6,6,6 */
+#define PPR_4   0x10000000000000        /* or 2,2,2 */
+
+char *user_read = "[User Read (Running)]";
+char *user_write = "[User Write (Running)]";
+char *ptrace_read_running = "[Ptrace Read (Running)]";
+char *ptrace_write_running = "[Ptrace Write (Running)]";
+char *ptrace_read_ckpt = "[Ptrace Read (Checkpointed)]";
+char *ptrace_write_ckpt = "[Ptrace Write (Checkpointed)]";
+
+int validate_tar_registers(unsigned long *reg, unsigned long tar,
+				unsigned long ppr, unsigned long dscr)
+{
+	int match = 1;
+
+	if (reg[0] != tar)
+		match = 0;
+
+	if (reg[1] != ppr)
+		match = 0;
+
+	if (reg[2] != dscr)
+		match = 0;
+
+	if (!match)
+		return TEST_FAIL;
+	return TEST_PASS;
+}

tools/testing/selftests/powerpc/ptrace/ptrace.h

@@ -97,6 +97,187 @@ int cont_trace(pid_t child)
 	return TEST_PASS;
 }
 
+/* TAR, PPR, DSCR */
+int show_tar_registers(pid_t child, unsigned long *out)
+{
+	struct iovec iov;
+	unsigned long *reg;
+	int ret;
+
+	reg = malloc(sizeof(unsigned long));
+	if (!reg) {
+		perror("malloc() failed");
+		return TEST_FAIL;
+	}
+	iov.iov_base = (u64 *) reg;
+	iov.iov_len = sizeof(unsigned long);
+
+	ret = ptrace(PTRACE_GETREGSET, child, NT_PPC_TAR, &iov);
+	if (ret) {
+		perror("ptrace(PTRACE_GETREGSET) failed");
+		goto fail;
+	}
+	if (out)
+		out[0] = *reg;
+
+	ret = ptrace(PTRACE_GETREGSET, child, NT_PPC_PPR, &iov);
+	if (ret) {
+		perror("ptrace(PTRACE_GETREGSET) failed");
+		goto fail;
+	}
+	if (out)
+		out[1] = *reg;
+
+	ret = ptrace(PTRACE_GETREGSET, child, NT_PPC_DSCR, &iov);
+	if (ret) {
+		perror("ptrace(PTRACE_GETREGSET) failed");
+		goto fail;
+	}
+	if (out)
+		out[2] = *reg;
+
+	free(reg);
+	return TEST_PASS;
+fail:
+	free(reg);
+	return TEST_FAIL;
+}
+
+int write_tar_registers(pid_t child, unsigned long tar,
+		unsigned long ppr, unsigned long dscr)
+{
+	struct iovec iov;
+	unsigned long *reg;
+	int ret;
+
+	reg = malloc(sizeof(unsigned long));
+	if (!reg) {
+		perror("malloc() failed");
+		return TEST_FAIL;
+	}
+
+	iov.iov_base = (u64 *) reg;
+	iov.iov_len = sizeof(unsigned long);
+
+	*reg = tar;
+	ret = ptrace(PTRACE_SETREGSET, child, NT_PPC_TAR, &iov);
+	if (ret) {
+		perror("ptrace(PTRACE_SETREGSET) failed");
+		goto fail;
+	}
+
+	*reg = ppr;
+	ret = ptrace(PTRACE_SETREGSET, child, NT_PPC_PPR, &iov);
+	if (ret) {
+		perror("ptrace(PTRACE_SETREGSET) failed");
+		goto fail;
+	}
+
+	*reg = dscr;
+	ret = ptrace(PTRACE_SETREGSET, child, NT_PPC_DSCR, &iov);
+	if (ret) {
+		perror("ptrace(PTRACE_SETREGSET) failed");
+		goto fail;
+	}
+
+	free(reg);
+	return TEST_PASS;
+fail:
+	free(reg);
+	return TEST_FAIL;
+}
+
+int show_tm_checkpointed_state(pid_t child, unsigned long *out)
+{
+	struct iovec iov;
+	unsigned long *reg;
+	int ret;
+
+	reg = malloc(sizeof(unsigned long));
+	if (!reg) {
+		perror("malloc() failed");
+		return TEST_FAIL;
+	}
+
+	iov.iov_base = (u64 *) reg;
+	iov.iov_len = sizeof(unsigned long);
+
+	ret = ptrace(PTRACE_GETREGSET, child, NT_PPC_TM_CTAR, &iov);
+	if (ret) {
+		perror("ptrace(PTRACE_GETREGSET) failed");
+		goto fail;
+	}
+	if (out)
+		out[0] = *reg;
+
+	ret = ptrace(PTRACE_GETREGSET, child, NT_PPC_TM_CPPR, &iov);
+	if (ret) {
+		perror("ptrace(PTRACE_GETREGSET) failed");
+		goto fail;
+	}
+	if (out)
+		out[1] = *reg;
+
+	ret = ptrace(PTRACE_GETREGSET, child, NT_PPC_TM_CDSCR, &iov);
+	if (ret) {
+		perror("ptrace(PTRACE_GETREGSET) failed");
+		goto fail;
+	}
+	if (out)
+		out[2] = *reg;
+
+	free(reg);
+	return TEST_PASS;
+
+fail:
+	free(reg);
+	return TEST_FAIL;
+}
+
+int write_ckpt_tar_registers(pid_t child, unsigned long tar,
+		unsigned long ppr, unsigned long dscr)
+{
+	struct iovec iov;
+	unsigned long *reg;
+	int ret;
+
+	reg = malloc(sizeof(unsigned long));
+	if (!reg) {
+		perror("malloc() failed");
+		return TEST_FAIL;
+	}
+
+	iov.iov_base = (u64 *) reg;
+	iov.iov_len = sizeof(unsigned long);
+
+	*reg = tar;
+	ret = ptrace(PTRACE_SETREGSET, child, NT_PPC_TM_CTAR, &iov);
+	if (ret) {
+		perror("ptrace(PTRACE_GETREGSET) failed");
+		goto fail;
+	}
+
+	*reg = ppr;
+	ret = ptrace(PTRACE_SETREGSET, child, NT_PPC_TM_CPPR, &iov);
+	if (ret) {
+		perror("ptrace(PTRACE_GETREGSET) failed");
+		goto fail;
+	}
+
+	*reg = dscr;
+	ret = ptrace(PTRACE_SETREGSET, child, NT_PPC_TM_CDSCR, &iov);
+	if (ret) {
+		perror("ptrace(PTRACE_GETREGSET) failed");
+		goto fail;
+	}
+
+	free(reg);
+	return TEST_PASS;
+fail:
+	free(reg);
+	return TEST_FAIL;
+}
+
 /* FPR */
 int show_fpr(pid_t child, unsigned long *fpr)
 {