Subject: Re: [PATCH v14 07/15] selftests/powerpc: Add ptrace tests for TAR, PPR, DSCR registers

From: Cyril Bur <[email-masked]>
Date: Wed, 14 Sep 2016 14:53:31 +1000

On Mon, 2016-09-12 at 15:33 +0800, [email-masked] wrote:
> From: Anshuman Khandual <[email-masked]>
> 
> 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 <[email-masked]>
> Signed-off-by: Simon Guo <[email-masked]>
> ---
>  tools/testing/selftests/powerpc/ptrace/Makefile    |   3 +-
>  .../testing/selftests/powerpc/ptrace/ptrace-tar.c  | 159
> ++++++++++++++++++
>  .../testing/selftests/powerpc/ptrace/ptrace-tar.h  |  50 ++++++
>  tools/testing/selftests/powerpc/ptrace/ptrace.h    | 181
> +++++++++++++++++++++
>  4 files changed, 392 insertions(+), 1 deletion(-)
>  create mode 100644 tools/testing/selftests/powerpc/ptrace/ptrace-
> tar.c
>  create mode 100644 tools/testing/selftests/powerpc/ptrace/ptrace-
> tar.h
> 

[snip]

> +
> +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];
> +	int ret;
> +
> +	ret = start_trace(child);
> +	if (ret)
> +		return TEST_FAIL;
> +
> +	ret = show_tar_registers(child, reg);
> +	if (ret)
> +		return TEST_FAIL;
> +
> +	printf("%-30s TAR: %lu PPR: %lx DSCR: %lu\n",
> +			ptrace_read_running, reg[0], reg[1],
> reg[2]);
> +
> +	ret = validate_tar_registers(reg, TAR_1, PPR_1, DSCR_1);
> +	if (ret)
> +		return TEST_FAIL;
> +
> +	ret = stop_trace(child);
> +	if (ret)
> +		return TEST_FAIL;
> +
> +	return TEST_PASS;
> +}
> +
> +int trace_tar_write(pid_t child)
> +{
> +	int ret;
> +
> +	ret = start_trace(child);
> +	if (ret)
> +		return TEST_FAIL;
> +
> +	ret = write_tar_registers(child, TAR_2, PPR_2, DSCR_2);
> +	if (ret)
> +		return TEST_FAIL;
> +
> +	printf("%-30s TAR: %u PPR: %lx DSCR: %u\n",
> +			ptrace_write_running, TAR_2, PPR_2, DSCR_2);
> +
> +	ret = stop_trace(child);
> +	if (ret)
> +		return TEST_FAIL;
> +
> +	return TEST_PASS;
> +}

More comments about calling TEST_FAIL(x)

> +
> +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) {
> 

[snip]