Interesting error emitted by gparted

[Cameron Simpson]

On 23Oct2015 14:25, jd1008 <jd1008 at gmail.com> wrote:
>On 10/21/2015 07:48 PM, jd1008 wrote:
>>On 10/21/2015 07:35 PM, Cameron Simpson wrote:
>>>Hmm. It looks like this message comes from a subcommand that gparted 
>>>invokes, or a subprocess before executing the subcommand.
>>>
>>>See here:
>>>
>>> access("/bin/systemctl", R_OK)          = 0
>>> rt_sigprocmask(SIG_BLOCK, [INT CHLD], [], 8) = 0
>>> rt_sigprocmask(SIG_BLOCK, [CHLD], [INT CHLD], 8) = 0
>>> rt_sigprocmask(SIG_SETMASK, [INT CHLD], NULL, 8) = 0
>>> clone(child_stack=0, 
>>>flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, 
>>>child_tidptr=0x7ff209b239d0) = 12884
>>> rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
>>> rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0
>>> rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
>>> rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0
>>> rt_sigaction(SIGINT, {0x559e190c9290, [], SA_RESTORER, 
>>>0x7ff209192a50}, {SIG_DFL, [], SA_RESTORER, 0x7ff209192a50}, 8) = 
>>>0
>>> wait4(-1, Failed to execute operation: Access denied
>>> [{WIFEXITED(s) && WEXITSTATUS(s) == 1}], 0, NULL) = 12884
>>>
>>>That "Failed to execute operation: Access denied" is not an error 
>>>from a system call in the main process; instead if is embedded in 
>>>the stderr output. The sequence above suggests that gparted is 
>>>about to invoke the systemctl command, and perhaps that issues the 
>>>error, or gparted issues the error in the cloned subprocess.
>>>
>>>Please rerun strace with the "-f" option to follow forked 
>>>processes. That should reveal more detail.
>>>
>>OK.
>>Here is the output (much larger though):
>>https://fs10n4.sendspace.com/dl/3c9a124ef8adc2f92e3986ddd6f6f015/56283fe3277f93ee/oiuyue/strace_-f_gparted.out.bz2
>>
>>I hope you can correlate it somehow to source code.
>>I used to use source code debuggers which made my life a lot eazier.
>>
>Well...
>What did the strace output tell ya :) ???

Surprisingly little. I'll have to find some time to examine it at greater 
length.

Cheers,
Cameron Simpson <cs at zip.com.au>