Christoph Lameter <cl@xxxxxxxxx> writes: > On Thu, 19 Jan 2012, Eric W. Biederman wrote: > >> On the flip side removing from sysfs with locks held must be done >> carefully, and as a default I would recommend not to hold locks over >> removing things from sysfs. As removal blocks waiting for all of the >> callers into sysfs those sysfs attributes to complete. >> >> It looks like you are ok on the removal because none of the sysfs >> attributes appear to take the slub_lock, just /proc/slabinfo. But >> it does look like playing with fire. > > Ok then I guess my last patch is needed to make sysfs operations safe. > > It may be good to audit the kernel for locks being held while calling > sysfs functions. Isnt there a lockdep check that ensures that no locks are > held? I don't see a no locks are held check but call_usermodehelper in the blocking case could certainly use one. For the sysfs remove case lockdep should work. Eric -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>