This is a note to let you know that I've just added the patch titled
cxgb4: fix BUG() on interrupt deallocating path of ULD
to the 4.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
cxgb4-fix-bug-on-interrupt-deallocating-path-of-uld.patch
and it can be found in the queue-4.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Mon Jul 17 18:46:41 CEST 2017
From: "Guilherme G. Piccoli" <gpiccoli@xxxxxxxxxxxxxxxxxx>
Date: Mon, 10 Jul 2017 10:55:46 -0300
Subject: cxgb4: fix BUG() on interrupt deallocating path of ULD
From: "Guilherme G. Piccoli" <gpiccoli@xxxxxxxxxxxxxxxxxx>
[ Upstream commit 6a146f3a5894b751cef16feb3d7903e45e3c445c ]
Since the introduction of ULD (Upper-Layer Drivers), the MSI-X
deallocating path changed in cxgb4: the driver frees the interrupts
of ULD when unregistering it or on shutdown PCI handler.
Problem is that if a MSI-X is not freed before deallocated in the PCI
layer, it will trigger a BUG() due to still "alive" interrupt being
tentatively quiesced.
The below trace was observed when doing a simple unbind of Chelsio's
adapter PCI function, like:
"echo 001e:80:00.4 > /sys/bus/pci/drivers/cxgb4/unbind"
Trace:
kernel BUG at drivers/pci/msi.c:352!
Oops: Exception in kernel mode, sig: 5 [#1]
...
NIP [c0000000005a5e60] free_msi_irqs+0xa0/0x250
LR [c0000000005a5e50] free_msi_irqs+0x90/0x250
Call Trace:
[c0000000005a5e50] free_msi_irqs+0x90/0x250 (unreliable)
[c0000000005a72c4] pci_disable_msix+0x124/0x180
[d000000011e06708] disable_msi+0x88/0xb0 [cxgb4]
[d000000011e06948] free_some_resources+0xa8/0x160 [cxgb4]
[d000000011e06d60] remove_one+0x170/0x3c0 [cxgb4]
[c00000000058a910] pci_device_remove+0x70/0x110
[c00000000064ef04] device_release_driver_internal+0x1f4/0x2c0
...
This patch fixes the issue by refactoring the shutdown path of ULD on
cxgb4 driver, by properly freeing and disabling interrupts on PCI
remove handler too.
Fixes: 0fbc81b3ad51 ("Allocate resources dynamically for all cxgb4 ULD's")
Reported-by: Harsha Thyagaraja <hathyaga@xxxxxxxxxx>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@xxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c | 16 ++++++---
drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.c | 42 ++++++++++++++----------
2 files changed, 36 insertions(+), 22 deletions(-)
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
@@ -2055,12 +2055,12 @@ static void detach_ulds(struct adapter *
mutex_lock(&uld_mutex);
list_del(&adap->list_node);
+
for (i = 0; i < CXGB4_ULD_MAX; i++)
- if (adap->uld && adap->uld[i].handle) {
+ if (adap->uld && adap->uld[i].handle)
adap->uld[i].state_change(adap->uld[i].handle,
CXGB4_STATE_DETACH);
- adap->uld[i].handle = NULL;
- }
+
if (netevent_registered && list_empty(&adapter_list)) {
unregister_netevent_notifier(&cxgb4_netevent_nb);
netevent_registered = false;
@@ -5086,8 +5086,10 @@ static void remove_one(struct pci_dev *p
*/
destroy_workqueue(adapter->workq);
- if (is_uld(adapter))
+ if (is_uld(adapter)) {
detach_ulds(adapter);
+ t4_uld_clean_up(adapter);
+ }
disable_interrupts(adapter);
@@ -5164,7 +5166,11 @@ static void shutdown_one(struct pci_dev
if (adapter->port[i]->reg_state == NETREG_REGISTERED)
cxgb_close(adapter->port[i]);
- t4_uld_clean_up(adapter);
+ if (is_uld(adapter)) {
+ detach_ulds(adapter);
+ t4_uld_clean_up(adapter);
+ }
+
disable_interrupts(adapter);
disable_msi(adapter);
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.c
@@ -589,22 +589,37 @@ void t4_uld_mem_free(struct adapter *ada
kfree(adap->uld);
}
+/* This function should be called with uld_mutex taken. */
+static void cxgb4_shutdown_uld_adapter(struct adapter *adap, enum cxgb4_uld type)
+{
+ if (adap->uld[type].handle) {
+ adap->uld[type].handle = NULL;
+ adap->uld[type].add = NULL;
+ release_sge_txq_uld(adap, type);
+
+ if (adap->flags & FULL_INIT_DONE)
+ quiesce_rx_uld(adap, type);
+
+ if (adap->flags & USING_MSIX)
+ free_msix_queue_irqs_uld(adap, type);
+
+ free_sge_queues_uld(adap, type);
+ free_queues_uld(adap, type);
+ }
+}
+
void t4_uld_clean_up(struct adapter *adap)
{
unsigned int i;
- if (!adap->uld)
- return;
+ mutex_lock(&uld_mutex);
for (i = 0; i < CXGB4_ULD_MAX; i++) {
if (!adap->uld[i].handle)
continue;
- if (adap->flags & FULL_INIT_DONE)
- quiesce_rx_uld(adap, i);
- if (adap->flags & USING_MSIX)
- free_msix_queue_irqs_uld(adap, i);
- free_sge_queues_uld(adap, i);
- free_queues_uld(adap, i);
+
+ cxgb4_shutdown_uld_adapter(adap, i);
}
+ mutex_unlock(&uld_mutex);
}
static void uld_init(struct adapter *adap, struct cxgb4_lld_info *lld)
@@ -782,15 +797,8 @@ int cxgb4_unregister_uld(enum cxgb4_uld
continue;
if (type == CXGB4_ULD_ISCSIT && is_t4(adap->params.chip))
continue;
- adap->uld[type].handle = NULL;
- adap->uld[type].add = NULL;
- release_sge_txq_uld(adap, type);
- if (adap->flags & FULL_INIT_DONE)
- quiesce_rx_uld(adap, type);
- if (adap->flags & USING_MSIX)
- free_msix_queue_irqs_uld(adap, type);
- free_sge_queues_uld(adap, type);
- free_queues_uld(adap, type);
+
+ cxgb4_shutdown_uld_adapter(adap, type);
}
mutex_unlock(&uld_mutex);
Patches currently in stable-queue which might be from gpiccoli@xxxxxxxxxxxxxxxxxx are
queue-4.12/cxgb4-fix-bug-on-interrupt-deallocating-path-of-uld.patch