setpci reset on nytro warpdrive card along with sysfs access and
cli ioctl access resulted in kernel oops
1. pci_access_mutex lock added to provide synchronization between IOCTL,
sysfs, PCI resource handling path
2. gioc_lock spinlock to protect list operations over multiple
controllers
This patch is ported from below mpt2sas driver patch,
'commit 6229b414b3adb3aac0b54e67d72d6462fc230c0d
("mpt2sas: setpci reset kernel oops fix")
Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@xxxxxxxxxxxxx>
---
drivers/scsi/mpt3sas/mpt3sas_base.c | 6 ++++++
drivers/scsi/mpt3sas/mpt3sas_base.h | 20 ++++++++++++++++-
drivers/scsi/mpt3sas/mpt3sas_ctl.c | 42 +++++++++++++++++++++++++++++-------
drivers/scsi/mpt3sas/mpt3sas_scsih.c | 12 +++++++++++
4 files changed, 71 insertions(+), 9 deletions(-)
diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
index bec3163..f5d589e 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -108,9 +108,12 @@ _scsih_set_fwfault_debug(const char *val, struct kernel_param *kp)
if (ret)
return ret;
+ /* global ioc spinlock to protect controller list on list operations */
pr_info("setting fwfault_debug(%d)\n", mpt3sas_fwfault_debug);
+ spin_lock(&gioc_lock);
list_for_each_entry(ioc, &mpt3sas_ioc_list, list)
ioc->fwfault_debug = mpt3sas_fwfault_debug;
+ spin_unlock(&gioc_lock);
return 0;
}
module_param_call(mpt3sas_fwfault_debug, _scsih_set_fwfault_debug,
@@ -5136,6 +5139,8 @@ mpt3sas_base_free_resources(struct MPT3SAS_ADAPTER *ioc)
dexitprintk(ioc, pr_info(MPT3SAS_FMT "%s\n", ioc->name,
__func__));
+ /* synchronizing freeing resource with pci_access_mutex lock */
+ mutex_lock(&ioc->pci_access_mutex);
if (ioc->chip_phys && ioc->chip) {
_base_mask_interrupts(ioc);
ioc->shost_recovery = 1;
@@ -5144,6 +5149,7 @@ mpt3sas_base_free_resources(struct MPT3SAS_ADAPTER *ioc)
}
mpt3sas_base_unmap_resources(ioc);
+ mutex_unlock(&ioc->pci_access_mutex);
return;
}
diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.h b/drivers/scsi/mpt3sas/mpt3sas_base.h
index c92be3c..6d64fa8 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.h
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.h
@@ -916,7 +916,13 @@ typedef void (*MPT3SAS_FLUSH_RUNNING_CMDS)(struct MPT3SAS_ADAPTER *ioc);
* @replyPostRegisterIndex: index of next position in Reply Desc Post Queue
* @delayed_tr_list: target reset link list
* @delayed_tr_volume_list: volume target reset link list
- * @@temp_sensors_count: flag to carry the number of temperature sensors
+ * @temp_sensors_count: flag to carry the number of temperature sensors
+ * @pci_access_mutex: Mutex to synchronize ioctl,sysfs show path and
+ * pci resource handling. PCI resource freeing will lead to free
+ * vital hardware/memory resource, which might be in use by cli/sysfs
+ * path functions resulting in Null pointer reference followed by kernel
+ * crash. To avoid the above race condition we use mutex syncrhonization
+ * which ensures the syncrhonization between cli/sysfs_show path.
*/
struct MPT3SAS_ADAPTER {
struct list_head list;
@@ -1131,6 +1137,7 @@ struct MPT3SAS_ADAPTER {
struct list_head delayed_tr_list;
struct list_head delayed_tr_volume_list;
u8 temp_sensors_count;
+ struct mutex pci_access_mutex;
/* diag buffer support */
u8 *diag_buffer[MPI2_DIAG_BUF_TYPE_COUNT];
@@ -1161,6 +1168,17 @@ typedef u8 (*MPT_CALLBACK)(struct MPT3SAS_ADAPTER *ioc, u16 smid, u8 msix_index,
/* base shared API */
extern struct list_head mpt3sas_ioc_list;
extern char driver_name[MPT_NAME_LENGTH];
+/* spinlock on list operations over IOCs
+ * Case: when multiple warpdrive cards(IOCs) are in use
+ * Each IOC will added to the ioc list structure on initialization.
+ * Watchdog threads run at regular intervals to check IOC for any
+ * fault conditions which will trigger the dead_ioc thread to
+ * deallocate pci resource, resulting deleting the IOC netry from list,
+ * this deletion need to protected by spinlock to enusre that
+ * ioc removal is syncrhonized, if not synchronized it might lead to
+ * list_del corruption as the ioc list is traversed in cli path.
+ */
+extern spinlock_t gioc_lock;
void mpt3sas_base_start_watchdog(struct MPT3SAS_ADAPTER *ioc);
void mpt3sas_base_stop_watchdog(struct MPT3SAS_ADAPTER *ioc);
diff --git a/drivers/scsi/mpt3sas/mpt3sas_ctl.c b/drivers/scsi/mpt3sas/mpt3sas_ctl.c
index 1c62db8..f257c96 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_ctl.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_ctl.c
@@ -416,13 +416,16 @@ static int
_ctl_verify_adapter(int ioc_number, struct MPT3SAS_ADAPTER **iocpp)
{
struct MPT3SAS_ADAPTER *ioc;
-
+ /* global ioc lock to protect controller on list operations */
+ spin_lock(&gioc_lock);
list_for_each_entry(ioc, &mpt3sas_ioc_list, list) {
if (ioc->id != ioc_number)
continue;
+ spin_unlock(&gioc_lock);
*iocpp = ioc;
return ioc_number;
}
+ spin_unlock(&gioc_lock);
*iocpp = NULL;
return -1;
}
@@ -511,10 +514,15 @@ ctl_poll(struct file *filep, poll_table *wait)
poll_wait(filep, &ctl_poll_wait, wait);
+ /* global ioc lock to protect controller on list operations */
+ spin_lock(&gioc_lock);
list_for_each_entry(ioc, &mpt3sas_ioc_list, list) {
- if (ioc->aen_event_read_flag)
+ if (ioc->aen_event_read_flag) {
+ spin_unlock(&gioc_lock);
return POLLIN | POLLRDNORM;
+ }
}
+ spin_unlock(&gioc_lock);
return 0;
}
@@ -2211,16 +2219,25 @@ _ctl_ioctl_main(struct file *file, unsigned int cmd, void __user *arg,
if (_ctl_verify_adapter(ioctl_header.ioc_number, &ioc) == -1 || !ioc)
return -ENODEV;
+ /* pci_access_mutex lock acquired by ioctl path */
+ mutex_lock(&ioc->pci_access_mutex);
+
if (ioc->shost_recovery || ioc->pci_error_recovery ||
- ioc->is_driver_loading)
- return -EAGAIN;
+ ioc->is_driver_loading || ioc->remove_host) {
+ ret = -EAGAIN;
+ goto out_unlock_pciaccess;
+ }
state = (file->f_flags & O_NONBLOCK) ? NON_BLOCKING : BLOCKING;
if (state == NON_BLOCKING) {
- if (!mutex_trylock(&ioc->ctl_cmds.mutex))
- return -EAGAIN;
- } else if (mutex_lock_interruptible(&ioc->ctl_cmds.mutex))
- return -ERESTARTSYS;
+ if (!mutex_trylock(&ioc->ctl_cmds.mutex)) {
+ ret = -EAGAIN;
+ goto out_unlock_pciaccess;
+ }
+ } else if (mutex_lock_interruptible(&ioc->ctl_cmds.mutex)) {
+ ret = -ERESTARTSYS;
+ goto out_unlock_pciaccess;
+ }
switch (cmd) {
@@ -2301,6 +2318,8 @@ _ctl_ioctl_main(struct file *file, unsigned int cmd, void __user *arg,
}
mutex_unlock(&ioc->ctl_cmds.mutex);
+out_unlock_pciaccess:
+ mutex_unlock(&ioc->pci_access_mutex);
return ret;
}
@@ -2748,6 +2767,12 @@ _ctl_BRM_status_show(struct device *cdev, struct device_attribute *attr,
" warpdrive\n", ioc->name, __func__);
goto out;
}
+ /* pci_access_mutex lock acquired by sysfs show path */
+ mutex_lock(&ioc->pci_access_mutex);
+ if (ioc->pci_error_recovery || ioc->remove_host) {
+ mutex_unlock(&ioc->pci_access_mutex);
+ return 0;
+ }
/* allocate upto GPIOVal 36 entries */
sz = offsetof(Mpi2IOUnitPage3_t, GPIOVal) + (sizeof(u16) * 36);
@@ -2786,6 +2811,7 @@ _ctl_BRM_status_show(struct device *cdev, struct device_attribute *attr,
out:
kfree(io_unit_pg3);
+ mutex_unlock(&ioc->pci_access_mutex);
return rc;
}
static DEVICE_ATTR(BRM_status, S_IRUGO, _ctl_BRM_status_show, NULL);
diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
index 436e65e..d0ab002 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
@@ -90,6 +90,8 @@ _scsih_setup_direct_io(struct MPT3SAS_ADAPTER *ioc, struct scsi_cmnd *scmd,
/* global parameters */
LIST_HEAD(mpt3sas_ioc_list);
char driver_name[MPT_NAME_LENGTH];
+/* global ioc lock for list operations */
+DEFINE_SPINLOCK(gioc_lock);
/* local parameters */
static u8 scsi_io_cb_idx = -1;
@@ -294,8 +296,10 @@ _scsih_set_debug_level(const char *val, struct kernel_param *kp)
return ret;
pr_info("setting logging_level(0x%08x)\n", logging_level);
+ spin_lock(&gioc_lock);
list_for_each_entry(ioc, &mpt3sas_ioc_list, list)
ioc->logging_level = logging_level;
+ spin_unlock(&gioc_lock);
return 0;
}
module_param_call(logging_level, _scsih_set_debug_level, param_get_int,
@@ -7997,7 +8001,9 @@ void scsih_remove(struct pci_dev *pdev)
sas_remove_host(shost);
scsi_remove_host(shost);
mpt3sas_base_detach(ioc);
+ spin_lock(&gioc_lock);
list_del(&ioc->list);
+ spin_unlock(&gioc_lock);
scsi_host_put(shost);
}
@@ -8384,7 +8390,9 @@ scsih_probe(struct pci_dev *pdev, struct Scsi_Host *shost)
ioc = shost_priv(shost);
memset(ioc, 0, sizeof(struct MPT3SAS_ADAPTER));
INIT_LIST_HEAD(&ioc->list);
+ spin_lock(&gioc_lock);
list_add_tail(&ioc->list, &mpt3sas_ioc_list);
+ spin_unlock(&gioc_lock);
ioc->shost = shost;
ioc->id = mpt_ids++;
ioc->pdev = pdev;
@@ -8403,6 +8411,8 @@ scsih_probe(struct pci_dev *pdev, struct Scsi_Host *shost)
ioc->schedule_dead_ioc_flush_running_cmds = &_scsih_flush_running_cmds;
/* misc semaphores and spin locks */
mutex_init(&ioc->reset_in_progress_mutex);
+ /* initializing pci_access_mutex lock */
+ mutex_init(&ioc->pci_access_mutex);
spin_lock_init(&ioc->ioc_reset_in_progress_lock);
spin_lock_init(&ioc->scsi_lookup_lock);
spin_lock_init(&ioc->sas_device_lock);
@@ -8510,7 +8520,9 @@ out_add_shost_fail:
out_attach_fail:
destroy_workqueue(ioc->firmware_event_thread);
out_thread_fail:
+ spin_lock(&gioc_lock);
list_del(&ioc->list);
+ spin_unlock(&gioc_lock);
scsi_host_put(shost);
return rv;
}
--
2.0.2
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