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

[Tom de Vries <tdevries@suse.de>]

On 12/30/23 16:47, Lancelot SIX wrote:
> 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.
> 

Thanks for the review, pushed.

[ FWIW, I've looked at the case of gdb.base/fileio.exp, and I suspect it 
also should use unsupported.  The xfail tag is supposed to tag known 
incorrect behaviour of the environment (say, a compiler bug in 
generating debug info), and I don't see any there. ]

Thanks,
- Tom

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