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

[David Herrmann]

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.

Thanks
David

>
>          r = keymap_load(vc, vc_keymap, vc_keymap_toggle, utf8, &keymap_pid);
>          if (r < 0) {
> @@ -313,10 +317,13 @@ int main(int argc, char **argv) {
>                  return EXIT_FAILURE;
>          }
>
> -        if (keymap_pid > 0)
> -                wait_for_terminate_and_warn(KBD_LOADKEYS, keymap_pid, true);
> +        if (keymap_pid > 0) {
> +                r = wait_for_terminate_and_warn(KBD_LOADKEYS, keymap_pid, true);
> +                if (r != 0)
> +                        return EXIT_FAILURE;
> +        }
>
> -        /* Only copy the font when we started setfont successfully */
> +        /* Only copy the font when we executed setfont successfully */
>          if (font_copy && font_pid > 0)
>                  font_copy_to_all_vcs(fd);
>
> --
> 2.3.2
>
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