Vineeth Vijayan 38a2ba82e2 s390/cio: dont call css_wait_for_slow_path() inside a lock ... commit c749d8c018daf5fba6dfac7b6c5c78b27efd7d65 upstream. Currently css_wait_for_slow_path() gets called inside the chp->lock. The path-verification-loop of slowpath inside this lock could lead to deadlock as reported by the lockdep validator. The ccw_device_get_chp_desc() during the instance of a device-set-online would try to acquire the same 'chp->lock' to read the chp->desc. The instance of this function can get called from multiple scenario, like probing or setting-device online manually. This could, in some corner-cases lead to the deadlock. lockdep validator reported this as, CPU0 CPU1 ---- ---- lock(&chp->lock); lock(kn->active#43); lock(&chp->lock); lock((wq_completion)cio); The chp->lock was introduced to serialize the access of struct channel_path. This lock is not needed for the css_wait_for_slow_path() function, so invoke the slow-path function outside this lock. Fixes: b730f3a933 ("[S390] cio: add lock to struct channel_path") Cc: <stable@vger.kernel.org> Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com> Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2021-07-14 16:55:43 +02:00
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cio	s390/cio: dont call css_wait_for_slow_path() inside a lock	2021-07-14 16:55:43 +02:00
crypto	s390/ap: Fix hanging ioctl caused by wrong msg counter	2021-06-23 14:42:51 +02:00
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