Re: [PATCH] [gdb/testsuite] Fix gdb.base/gdb-index-err.exp for root user

[Lancelot SIX <lsix@lancelotsix.com>]

Hi Tom,

On Fri, Dec 29, 2023 at 07:35:43AM +0100, Tom de Vries wrote:
> When running test-case gdb.base/gdb-index-err.exp in a container as root user,
> I run into:
> ...
> FAIL: gdb.base/gdb-index-err.exp: flag=: \
>   try to write index to a non-writable directory
> FAIL: gdb.base/gdb-index-err.exp: flag=-dwarf-5: \
>   try to write index to a non-writable directory
> ...
> 
> The test-case creates a directory without write permissions:
> ...
> $ ls -ald private
> dr-xr-xr-x 2 root root 4096 Dec 29 06:26 private/
> ...
> but apparently the root user is still able to write in it.
> 
> Fix this by making the test unsupported for the root user.
> 
> Tested on x86_64-linux.
> 
> PR testsuite/31197
> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31197
> ---
>  gdb/testsuite/gdb.base/gdb-index-err.exp | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/gdb/testsuite/gdb.base/gdb-index-err.exp b/gdb/testsuite/gdb.base/gdb-index-err.exp
> index 31f133efbcd..cefd708f5ab 100644
> --- a/gdb/testsuite/gdb.base/gdb-index-err.exp
> +++ b/gdb/testsuite/gdb.base/gdb-index-err.exp
> @@ -62,9 +62,15 @@ remote_exec host "chmod u-w,g-w ${non_writable_dir}"
>  
>  # Try to write the index into a non-writable directory.
>  foreach_with_prefix flag { "" "-dwarf-5" } {
> +    set test "try to write index to a non-writable directory"
> +    if { [root_user] } {
> +	unsupported $test
> +	continue
> +    }
> +
>      gdb_test "save gdb-index ${flag} ${non_writable_dir}" \
>  	"Error while writing index for `[string_to_regexp $binfile]': couldn't open `[string_to_regexp $non_writable_dir]/${gdb_test_file_name}.*': Permission denied\\." \
> -	"try to write index to a non-writable directory"
> +	$test
>  }
>  
>  # Create copies of the executable, we will add an index section to
> 
> base-commit: a6d0019eb7fcd634e12b7bcc535d5181c47fc82a
> -- 
> 2.35.3
> 

This looks reasonable to me.  Thanks for doing this.

I had a look around because the other places which use root_user
generate XFAILs and not UNSUPPORTED as you do here.  I however don’t
think that gdb.base/fileio.exp could use UNSUPPORTED, and it is better
suited for the case you are addressing here, so that LGTM.

Best,
Lancelot.

Reviewed-By: Lancelot SIX <lancelot.six@amd.com>