[systemd-devel] [PATCH] vconsole-setup: check error of child process

[Lucas De Marchi]

On Wed, Mar 11, 2015 at 12:55 PM, David Herrmann <dh.herrmann at gmail.com> wrote:
> Hi
>
> On Tue, Mar 10, 2015 at 8:56 PM,  <lucas.de.marchi at gmail.com> wrote:
>> From: Lucas De Marchi <lucas.demarchi at intel.com>
>>
>> If we don't check the error of the child process, systemd-vconsole-setup
>> would exit with 0 even if it could not really setup the console.
>>
>> For a simple test, move loadkeys elsewhere and execute
>> systemd-vconsole-setup:
>>
>>         [root at localhost ~]# strace -f -e execve /usr/lib/systemd/systemd-vconsole-setup
>>         execve("/usr/lib/systemd/systemd-vconsole-setup", ["/usr/lib/systemd/systemd-vconsol"...], [/* 15 vars */]) = 0
>>         Process 171 attached
>>         [pid   171] execve("/usr/bin/loadkeys", ["/usr/bin/loadkeys", "-q", "-C", "/dev/tty0", "br-abnt2"], [/* 15 vars */]) = -1 ENOENT (No such file or directory)
>>         [pid   171] +++ exited with 1 +++
>>         --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=171, si_uid=0, si_status=1, si_utime=0, si_stime=0} ---
>>         +++ exited with 0 +++
>>
>> Now systemd-vconsole-setup exits with EXIT_FAILURE if the child failed
>> for whatever reason.
>> ---
>>  src/vconsole/vconsole-setup.c | 17 ++++++++++++-----
>>  1 file changed, 12 insertions(+), 5 deletions(-)
>>
>> diff --git a/src/vconsole/vconsole-setup.c b/src/vconsole/vconsole-setup.c
>> index bf681d9..601ca4a 100644
>> --- a/src/vconsole/vconsole-setup.c
>> +++ b/src/vconsole/vconsole-setup.c
>> @@ -304,8 +304,12 @@ int main(int argc, char **argv) {
>>                  return EXIT_FAILURE;
>>          }
>>
>> -        if (font_pid > 0)
>> -                wait_for_terminate_and_warn(KBD_SETFONT, font_pid, true);
>> +        if (font_pid > 0) {
>> +                r = wait_for_terminate_and_warn(KBD_SETFONT, font_pid, true);
>> +                if (r != 0)
>> +                        return EXIT_FAILURE;
>> +        }
>> +
>
> Looks mostly good. However, I'd prefer if we continue on "r > 0" but
> remember the error for later. This way, we still try loading the right
> keymap even though the font might have failed.

Is there any reason to continue on r > 0 but not on r < 0? I'm ok with
changing the current behavior, but just like to know which one is
better.


-- 
Lucas De Marchi