From: Andrew Donnellan Date: Thu, 1 Dec 2016 00:23:05 +0000 (+1100) Subject: powerpc/eeh: Fix deadlock when PE frozen state can't be cleared X-Git-Tag: v4.8.15~33 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=84b36287c72d3c4be42efb23928a1645aa74cc5f;p=thirdparty%2Fkernel%2Fstable.git powerpc/eeh: Fix deadlock when PE frozen state can't be cleared commit 409bf7f8a02ef88db5a0f2cdcf9489914f4b8508 upstream. In eeh_reset_device(), we take the pci_rescan_remove_lock immediately after after we call eeh_reset_pe() to reset the PCI controller. We then call eeh_clear_pe_frozen_state(), which can return an error. In this case, we bail out of eeh_reset_device() without calling pci_unlock_rescan_remove(). Add a call to pci_unlock_rescan_remove() in the eeh_clear_pe_frozen_state() error path so that we don't cause a deadlock later on. Reported-by: Pradipta Ghosh Fixes: 78954700631f ("powerpc/eeh: Avoid I/O access during PE reset") Signed-off-by: Andrew Donnellan Acked-by: Russell Currey Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c index 29aa8d1ce273c..248f28bc4641b 100644 --- a/arch/powerpc/kernel/eeh_driver.c +++ b/arch/powerpc/kernel/eeh_driver.c @@ -671,8 +671,10 @@ static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus, /* Clear frozen state */ rc = eeh_clear_pe_frozen_state(pe, false); - if (rc) + if (rc) { + pci_unlock_rescan_remove(); return rc; + } /* Give the system 5 seconds to finish running the user-space * hotplug shutdown scripts, e.g. ifdown for ethernet. Yes,