We need to include <sys/mkdev.h> on Solaris.
Reported-by: Richard Palo <richard@netbsd.org>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89763
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Adam Sampson spotted that
"It's possible (but not very sensible) to exec a program with an empty
argument list, so argv[0] is not necessarily a valid pointer. For
example:
$ cat exec0.c
int main(int argc, char *argv[]) {
char *empty[1] = { NULL };
execvp(argv[1], empty);
perror("execvp");
return 1;
}
$ ./exec0 /usr/libexec/xf86-video-intel-backlight-helper
Usage: (null) <iface>
"
He sensibly suggested that we hardcode the program name to avoid the
NULL dereference. Being the paranoid type, we should also be careful not
to write to any file descriptors outside of our control (i.e. stderr),
so disable the messages unless we are debugging.
Reported-by: Adam Sampson
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
- don't allow '/' in the interface name to avoid escaping the /sys
hierarchy
- check snprintf() return value for overflow.
Problems reported by Adam Sampson. Thanks.
Signed-off-by: Matthieu Herrb <matthieu@herrb.eu>
Reviewed-by: Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Since the helper is a standalone app, the usual xserver rules of not using
stdio because of signal handling don't apply.
And since the helper does run with elevated rights, it is important to keep
the code KISS so that it can be audited easily.
This commit replaces the hard to read "raw" read loop with a much simpler
loop using fgets, improving readability of the code.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Once the xserver stops running as root on kms capabable systems, we will need
some other way to access the backlight.
The approach taken in this patch moves most of the heavy lifting to a
helper that runs with root privileges and pipes our requested brightness
into the sysfs backlight interface. Where required, we use pkexec to
launch the helper with the elevated privilege.
v2: Amalgamate much more of the duplicate code.
Keep the daemon and pipe alive for the lifetime of the backlight interface.
Provide an alternative for systems without PolicyKit.
Signed-off-by: Hans de Goede <hdegoede@redhat.com> [v1]
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Chris Wilson
Matthieu Herrb
Hans de Goede