Re: [PATCH] selftests: mm: Make map_fixed_noreplace test names stable

[Ryan Roberts]

On 05/06/2024 23:36, Mark Brown wrote:
> KTAP parsers interpret the output of ksft_test_result_*() as being the
> name of the test.  The map_fixed_noreplace test uses a dynamically
> allocated base address for the mmap()s that it tests and currently
> includes this in the test names that it logs so the test names that are
> logged are not stable between runs.  It also uses multiples of PAGE_SIZE
> which mean that runs for kernels with different PAGE_SIZE configurations
> can't be directly compared.  Both these factors cause issues for CI
> systems when interpreting and displaying results.
> 
> Fix this by replacing the current test names with fixed strings
> describing the intent of the mappings that are logged, the existing
> messages with the actual addresses and sizes are retained as diagnostic
> prints to aid in debugging.
> 
> Fixes: 4838cf70e539 ("selftests/mm: map_fixed_noreplace: conform test to TAP format output")
> Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>

Reviewed-by: Ryan Roberts <ryan.roberts@xxxxxxx>

> ---
>  tools/testing/selftests/mm/map_fixed_noreplace.c | 24 ++++++++++++++++--------
>  1 file changed, 16 insertions(+), 8 deletions(-)
> 
> diff --git a/tools/testing/selftests/mm/map_fixed_noreplace.c b/tools/testing/selftests/mm/map_fixed_noreplace.c
> index b74813fdc951..d53de2486080 100644
> --- a/tools/testing/selftests/mm/map_fixed_noreplace.c
> +++ b/tools/testing/selftests/mm/map_fixed_noreplace.c
> @@ -67,7 +67,8 @@ int main(void)
>  		dump_maps();
>  		ksft_exit_fail_msg("Error: munmap failed!?\n");
>  	}
> -	ksft_test_result_pass("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p);
> +	ksft_print_msg("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p);
> +	ksft_test_result_pass("mmap() 5*PAGE_SIZE at base\n");
>  
>  	addr = base_addr + page_size;
>  	size = 3 * page_size;
> @@ -76,7 +77,8 @@ int main(void)
>  		dump_maps();
>  		ksft_exit_fail_msg("Error: first mmap() failed unexpectedly\n");
>  	}
> -	ksft_test_result_pass("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p);
> +	ksft_print_msg("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p);
> +	ksft_test_result_pass("mmap() 3*PAGE_SIZE at base+PAGE_SIZE\n");
>  
>  	/*
>  	 * Exact same mapping again:
> @@ -93,7 +95,8 @@ int main(void)
>  		dump_maps();
>  		ksft_exit_fail_msg("Error:1: mmap() succeeded when it shouldn't have\n");
>  	}
> -	ksft_test_result_pass("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p);
> +	ksft_print_msg("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p);
> +	ksft_test_result_pass("mmap() 5*PAGE_SIZE at base\n");
>  
>  	/*
>  	 * Second mapping contained within first:
> @@ -111,7 +114,8 @@ int main(void)
>  		dump_maps();
>  		ksft_exit_fail_msg("Error:2: mmap() succeeded when it shouldn't have\n");
>  	}
> -	ksft_test_result_pass("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p);
> +	ksft_print_msg("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p);
> +	ksft_test_result_pass("mmap() 2*PAGE_SIZE at base+PAGE_SIZE\n");
>  
>  	/*
>  	 * Overlap end of existing mapping:
> @@ -128,7 +132,8 @@ int main(void)
>  		dump_maps();
>  		ksft_exit_fail_msg("Error:3: mmap() succeeded when it shouldn't have\n");
>  	}
> -	ksft_test_result_pass("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p);
> +	ksft_print_msg("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p);
> +	ksft_test_result_pass("mmap() 2*PAGE_SIZE  at base+(3*PAGE_SIZE)\n");
>  
>  	/*
>  	 * Overlap start of existing mapping:
> @@ -145,7 +150,8 @@ int main(void)
>  		dump_maps();
>  		ksft_exit_fail_msg("Error:4: mmap() succeeded when it shouldn't have\n");
>  	}
> -	ksft_test_result_pass("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p);
> +	ksft_print_msg("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p);
> +	ksft_test_result_pass("mmap() 2*PAGE_SIZE bytes at base\n");
>  
>  	/*
>  	 * Adjacent to start of existing mapping:
> @@ -162,7 +168,8 @@ int main(void)
>  		dump_maps();
>  		ksft_exit_fail_msg("Error:5: mmap() failed when it shouldn't have\n");
>  	}
> -	ksft_test_result_pass("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p);
> +	ksft_print_msg("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p);
> +	ksft_test_result_pass("mmap() PAGE_SIZE at base\n");
>  
>  	/*
>  	 * Adjacent to end of existing mapping:
> @@ -179,7 +186,8 @@ int main(void)
>  		dump_maps();
>  		ksft_exit_fail_msg("Error:6: mmap() failed when it shouldn't have\n");
>  	}
> -	ksft_test_result_pass("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p);
> +	ksft_print_msg("mmap() @ 0x%lx-0x%lx p=%p result=%m\n", addr, addr + size, p);
> +	ksft_test_result_pass("mmap() PAGE_SIZE at base+(4*PAGE_SIZE)\n");
>  
>  	addr = base_addr;
>  	size = 5 * page_size;
> 
> ---
> base-commit: c3f38fa61af77b49866b006939479069cd451173
> change-id: 20240605-kselftest-mm-fixed-noreplace-44e7e55c861a
> 
> Best regards,