From 409bf7f8a02ef88db5a0f2cdcf9489914f4b8508 Mon Sep 17 00:00:00 2001 From: Andrew Donnellan Date: Thu, 1 Dec 2016 11:23:05 +1100 Subject: [PATCH] powerpc/eeh: Fix deadlock when PE frozen state can't be cleared 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") Cc: stable@vger.kernel.org # v3.16+ Signed-off-by: Andrew Donnellan Acked-by: Russell Currey Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/eeh_driver.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c index a62be72..5c31369 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, -- 2.7.4