Re: [PATCH] selftests: arm64: Fix redundancy of a testcase

On Wed, Jun 05, 2024 at 05:24:48PM +0530, Dev Jain wrote:

Currently, we are writing the same value as we read, into the TLS register; hence, we cannot confirm updation of the register, making the testcase "verify_tpidr_one" redundant. Fix this; while at it, do a style change.

Please don't combine unrelated changes into a single patch.

/* ...write a new value.. */ write_iov.iov_len = sizeof(uint64_t);

• write_val[0] = read_val[0]++;

• write_val[0] = read_val[0] + 1; ret = ptrace(PTRACE_SETREGSET, child, NT_ARM_TLS, &write_iov); ksft_test_result(ret == 0, "write_tpidr_one\n");

This is a good fix:

Reviewed-by: Mark Brown broonie@kernel.org

@@ -108,7 +108,7 @@ static void test_tpidr(pid_t child) /* Writing only TPIDR... */ write_iov.iov_len = sizeof(uint64_t); memcpy(write_val, read_val, sizeof(read_val));

• write_val[0] += 1;
  

• ++write_val[0];
  

I'm less convinced that this is a good style change.