From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Joseph Bao <joseph.bao@intel.com>,
Lukas Wunner <lukas@wunner.de>,
Bjorn Helgaas <bhelgaas@google.com>,
Stuart Hayes <stuart.w.hayes@gmail.com>
Subject: [PATCH 5.15 01/32] PCI: pciehp: Fix infinite loop in IRQ handler upon power fault
Date: Fri, 4 Feb 2022 10:22:11 +0100 [thread overview]
Message-ID: <20220204091915.298182626@linuxfoundation.org> (raw)
In-Reply-To: <20220204091915.247906930@linuxfoundation.org>
From: Lukas Wunner <lukas@wunner.de>
commit 23584c1ed3e15a6f4bfab8dc5a88d94ab929ee12 upstream.
The Power Fault Detected bit in the Slot Status register differs from
all other hotplug events in that it is sticky: It can only be cleared
after turning off slot power. Per PCIe r5.0, sec. 6.7.1.8:
If a power controller detects a main power fault on the hot-plug slot,
it must automatically set its internal main power fault latch [...].
The main power fault latch is cleared when software turns off power to
the hot-plug slot.
The stickiness used to cause interrupt storms and infinite loops which
were fixed in 2009 by commits 5651c48cfafe ("PCI pciehp: fix power fault
interrupt storm problem") and 99f0169c17f3 ("PCI: pciehp: enable
software notification on empty slots").
Unfortunately in 2020 the infinite loop issue was inadvertently
reintroduced by commit 8edf5332c393 ("PCI: pciehp: Fix MSI interrupt
race"): The hardirq handler pciehp_isr() clears the PFD bit until
pciehp's power_fault_detected flag is set. That happens in the IRQ
thread pciehp_ist(), which never learns of the event because the hardirq
handler is stuck in an infinite loop. Fix by setting the
power_fault_detected flag already in the hardirq handler.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=214989
Link: https://lore.kernel.org/linux-pci/DM8PR11MB5702255A6A92F735D90A4446868B9@DM8PR11MB5702.namprd11.prod.outlook.com
Fixes: 8edf5332c393 ("PCI: pciehp: Fix MSI interrupt race")
Link: https://lore.kernel.org/r/66eaeef31d4997ceea357ad93259f290ededecfd.1637187226.git.lukas@wunner.de
Reported-by: Joseph Bao <joseph.bao@intel.com>
Tested-by: Joseph Bao <joseph.bao@intel.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org # v4.19+
Cc: Stuart Hayes <stuart.w.hayes@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/pci/hotplug/pciehp_hpc.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -642,6 +642,8 @@ read_status:
*/
if (ctrl->power_fault_detected)
status &= ~PCI_EXP_SLTSTA_PFD;
+ else if (status & PCI_EXP_SLTSTA_PFD)
+ ctrl->power_fault_detected = true;
events |= status;
if (!events) {
@@ -651,7 +653,7 @@ read_status:
}
if (status) {
- pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, events);
+ pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, status);
/*
* In MSI mode, all event bits must be zero before the port
@@ -725,8 +727,7 @@ static irqreturn_t pciehp_ist(int irq, v
}
/* Check Power Fault Detected */
- if ((events & PCI_EXP_SLTSTA_PFD) && !ctrl->power_fault_detected) {
- ctrl->power_fault_detected = 1;
+ if (events & PCI_EXP_SLTSTA_PFD) {
ctrl_err(ctrl, "Slot(%s): Power fault\n", slot_name(ctrl));
pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
PCI_EXP_SLTCTL_ATTN_IND_ON);
next prev parent reply other threads:[~2022-02-04 9:23 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-04 9:22 [PATCH 5.15 00/32] 5.15.20-rc1 review Greg Kroah-Hartman
2022-02-04 9:22 ` Greg Kroah-Hartman [this message]
2022-02-04 9:22 ` [PATCH 5.15 02/32] selftests: mptcp: fix ipv6 routing setup Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 03/32] net: ipa: use a bitmap for endpoint replenish_enabled Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 04/32] net: ipa: prevent concurrent replenish Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 05/32] drm/vc4: hdmi: Make sure the device is powered with CEC Greg Kroah-Hartman
2022-02-05 17:12 ` Guenter Roeck
2022-02-05 17:56 ` Greg Kroah-Hartman
2022-02-05 18:41 ` Guenter Roeck
2022-02-06 12:09 ` Greg Kroah-Hartman
2022-02-06 17:32 ` Guenter Roeck
2022-02-04 9:22 ` [PATCH 5.15 06/32] cgroup-v1: Require capabilities to set release_agent Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 07/32] Revert "mm/gup: small refactoring: simplify try_grab_page()" Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 08/32] ovl: dont fail copy up if no fileattr support on upper Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 09/32] lockd: fix server crash on reboot of client holding lock Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 10/32] lockd: fix failure to cleanup client locks Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 11/32] net/mlx5e: IPsec: Fix tunnel mode crypto offload for non TCP/UDP traffic Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 12/32] net/mlx5: Bridge, take rtnl lock in init error handler Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 13/32] net/mlx5: Bridge, ensure dev_name is null-terminated Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 14/32] net/mlx5e: Fix handling of wrong devices during bond netevent Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 15/32] net/mlx5: Use del_timer_sync in fw reset flow of halting poll Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 16/32] net/mlx5e: Fix module EEPROM query Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 17/32] net/mlx5: Fix offloading with ESWITCH_IPV4_TTL_MODIFY_ENABLE Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 18/32] net/mlx5e: Dont treat small ceil values as unlimited in HTB offload Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 19/32] net/mlx5: Bridge, Fix devlink deadlock on net namespace deletion Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 20/32] net/mlx5: E-Switch, Fix uninitialized variable modact Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 21/32] ipheth: fix EOVERFLOW in ipheth_rcvbulk_callback Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 22/32] i40e: Fix reset bw limit when DCB enabled with 1 TC Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 23/32] i40e: Fix reset path while removing the driver Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 24/32] net: amd-xgbe: ensure to reset the tx_timer_active flag Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 25/32] net: amd-xgbe: Fix skb data length underflow Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 26/32] fanotify: Fix stale file descriptor in copy_event_to_user() Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 27/32] net: sched: fix use-after-free in tc_new_tfilter() Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 28/32] rtnetlink: make sure to refresh master_dev/m_ops in __rtnl_newlink() Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 29/32] cpuset: Fix the bug that subpart_cpus updated wrongly in update_cpumask() Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 30/32] e1000e: Handshake with CSME starts from ADL platforms Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 31/32] af_packet: fix data-race in packet_setsockopt / packet_setsockopt Greg Kroah-Hartman
2022-02-04 9:22 ` [PATCH 5.15 32/32] tcp: add missing tcp_skb_can_collapse() test in tcp_shift_skb_data() Greg Kroah-Hartman
2022-02-04 12:21 ` [PATCH 5.15 00/32] 5.15.20-rc1 review Bagas Sanjaya
2022-02-04 15:20 ` Jon Hunter
2022-02-04 17:48 ` Florian Fainelli
2022-02-04 20:31 ` Shuah Khan
2022-02-04 21:08 ` Guenter Roeck
2022-02-04 22:42 ` Ron Economos
2022-02-04 23:04 ` Justin Forbes
2022-02-05 0:18 ` Fox Chen
2022-02-05 5:07 ` Slade Watkins
2022-02-05 6:51 ` Naresh Kamboju
2022-02-05 14:32 ` Sudip Mukherjee
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