Hi,
the recent discussion on procfs and driverfs caused me to look at the
existing uses with respect to races against disconnect.
I think I found something in stv680, the second driver I looked at.
from usb_stv680_remove_disconnected:
#if defined(CONFIG_PROC_FS) && defined(CONFIG_VIDEO_PROC_FS)
destroy_proc_stv680_cam (stv680);
#endif
/* Free the memory */
kfree (stv680);
now destroy_proc_stv680_cam:
sprintf (name, "video%d", stv680->vdev.minor);
remove_proc_entry (name, stv680_proc_entry);
stv680->proc_entry = NULL;
So this is safe if, and only if, remove_proc_entry waits
for current readers to finish before it returns.
As far as I can tell, this is not the case.
So reading from the proc file while the camera is disconnected is
potentially deadly. I see no easy fix.
Comments?
Regards
Oliver
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