[Intel-wired-lan] [PATCH iwl-next v4 0/3] ice: split ice_aq_wait_for_event() func into two

[Intel-wired-lan] [PATCH iwl-next v4 0/3] ice: split ice_aq_wait_for_event() func into two

[Przemek Kitszel]

Mitigate race between registering on wait list and receiving
AQ Response from FW.

The first patch fixes bound check to be more inclusive;
the second one refactors code to make the third one smaller,
which is an actual fix for the race.

Thanks Simon Horman for pushing into split, it's easier to follow now.

v4: remove excessive newlines, thanks Tony for catching this up
v3: split into 3 commits

Przemek Kitszel (3):
  ice: ice_aq_check_events: fix off-by-one check when filling buffer
  ice: embed &ice_rq_event_info event into struct ice_aq_task
  ice: split ice_aq_wait_for_event() func into two

 drivers/net/ethernet/intel/ice/ice.h          | 21 +++-
 .../net/ethernet/intel/ice/ice_fw_update.c    | 45 +++++----
 drivers/net/ethernet/intel/ice/ice_main.c     | 99 ++++++++++---------
 3 files changed, 93 insertions(+), 72 deletions(-)


base-commit: b91d6ff19e94ec46cf6473e7d50ec11615e9ede6
-- 
2.40.1

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[Intel-wired-lan] [PATCH iwl-next v4 1/3] ice: ice_aq_check_events: fix off-by-one check when filling buffer

[Przemek Kitszel]

Allow task's event buffer to be filled also in the case that it's size
is exactly the size of the message.

Fixes: d69ea414c9b4 ("ice: implement device flash update via devlink")
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_main.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index a73895483e6c..279e7f790312 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -1357,23 +1357,24 @@ int ice_aq_wait_for_event(struct ice_pf *pf, u16 opcode, unsigned long timeout,
 static void ice_aq_check_events(struct ice_pf *pf, u16 opcode,
 				struct ice_rq_event_info *event)
 {
+	struct ice_rq_event_info *task_ev;
 	struct ice_aq_task *task;
 	bool found = false;
 
 	spin_lock_bh(&pf->aq_wait_lock);
 	hlist_for_each_entry(task, &pf->aq_wait_list, entry) {
 		if (task->state || task->opcode != opcode)
 			continue;
 
-		memcpy(&task->event->desc, &event->desc, sizeof(event->desc));
-		task->event->msg_len = event->msg_len;
+		task_ev = task->event;
+		memcpy(&task_ev->desc, &event->desc, sizeof(event->desc));
+		task_ev->msg_len = event->msg_len;
 
 		/* Only copy the data buffer if a destination was set */
-		if (task->event->msg_buf &&
-		    task->event->buf_len > event->buf_len) {
-			memcpy(task->event->msg_buf, event->msg_buf,
+		if (task_ev->msg_buf && task_ev->buf_len >= event->buf_len) {
+			memcpy(task_ev->msg_buf, event->msg_buf,
 			       event->buf_len);
-			task->event->buf_len = event->buf_len;
+			task_ev->buf_len = event->buf_len;
 		}
 
 		task->state = ICE_AQ_TASK_COMPLETE;
-- 
2.40.1

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Re: [Intel-wired-lan] [PATCH iwl-next v4 1/3] ice: ice_aq_check_events: fix off-by-one check when filling buffer

[Pucha, HimasekharX Reddy]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of Przemek Kitszel
> Sent: Wednesday, August 9, 2023 3:24 AM
> To: intel-wired-lan@lists.osuosl.org
> Cc: netdev@vger.kernel.org; Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Simon Horman <horms@kernel.org>; Kitszel, Przemyslaw <przemyslaw.kitszel@intel.com>
> Subject: [Intel-wired-lan] [PATCH iwl-next v4 1/3] ice: ice_aq_check_events: fix off-by-one check when filling buffer
>
> Allow task's event buffer to be filled also in the case that it's size is exactly the size of the message.
>
> Fixes: d69ea414c9b4 ("ice: implement device flash update via devlink")
> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
> Signed-off-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
> ---
>  drivers/net/ethernet/intel/ice/ice_main.c | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
>

Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)


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[Intel-wired-lan] [PATCH iwl-next v4 2/3] ice: embed &ice_rq_event_info event into struct ice_aq_task

[Przemek Kitszel]

Expose struct ice_aq_task to callers,
what takes burden of memory ownership out from AQ-wait family of functions,
and reduces need for heap-based allocations.

Embed struct ice_rq_event_info event into struct ice_aq_task
(instead of it being a ptr). to remove some more code from the callers.

Subsequent commit will improve more based on this one.

Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>

---
add/remove: 0/0 grow/shrink: 3/1 up/down: 266/-68 (198)
---
 drivers/net/ethernet/intel/ice/ice.h          | 18 +++++++-
 .../net/ethernet/intel/ice/ice_fw_update.c    | 42 +++++++++----------
 drivers/net/ethernet/intel/ice/ice_main.c     | 29 ++-----------
 3 files changed, 40 insertions(+), 49 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice.h b/drivers/net/ethernet/intel/ice/ice.h
index 34be1cb1e28f..bcd56ba908a7 100644
--- a/drivers/net/ethernet/intel/ice/ice.h
+++ b/drivers/net/ethernet/intel/ice/ice.h
@@ -931,8 +931,22 @@ void ice_fdir_release_flows(struct ice_hw *hw);
 void ice_fdir_replay_flows(struct ice_hw *hw);
 void ice_fdir_replay_fltrs(struct ice_pf *pf);
 int ice_fdir_create_dflt_rules(struct ice_pf *pf);
-int ice_aq_wait_for_event(struct ice_pf *pf, u16 opcode, unsigned long timeout,
-			  struct ice_rq_event_info *event);
+
+enum ice_aq_task_state {
+	ICE_AQ_TASK_WAITING,
+	ICE_AQ_TASK_COMPLETE,
+	ICE_AQ_TASK_CANCELED,
+};
+
+struct ice_aq_task {
+	struct hlist_node entry;
+	struct ice_rq_event_info event;
+	enum ice_aq_task_state state;
+	u16 opcode;
+};
+
+int ice_aq_wait_for_event(struct ice_pf *pf, struct ice_aq_task *task,
+			  u16 opcode, unsigned long timeout);
 int ice_open(struct net_device *netdev);
 int ice_open_internal(struct net_device *netdev);
 int ice_stop(struct net_device *netdev);
diff --git a/drivers/net/ethernet/intel/ice/ice_fw_update.c b/drivers/net/ethernet/intel/ice/ice_fw_update.c
index 3dc5662d62a6..819b70823e9c 100644
--- a/drivers/net/ethernet/intel/ice/ice_fw_update.c
+++ b/drivers/net/ethernet/intel/ice/ice_fw_update.c
@@ -293,13 +293,12 @@ ice_write_one_nvm_block(struct ice_pf *pf, u16 module, u32 offset,
 {
 	u16 completion_module, completion_retval;
 	struct device *dev = ice_pf_to_dev(pf);
-	struct ice_rq_event_info event;
+	struct ice_aq_task task = {};
 	struct ice_hw *hw = &pf->hw;
+	struct ice_aq_desc *desc;
 	u32 completion_offset;
 	int err;
 
-	memset(&event, 0, sizeof(event));
-
 	dev_dbg(dev, "Writing block of %u bytes for module 0x%02x at offset %u\n",
 		block_size, module, offset);
 
@@ -319,19 +318,20 @@ ice_write_one_nvm_block(struct ice_pf *pf, u16 module, u32 offset,
 	 * is conservative and is intended to prevent failure to update when
 	 * firmware is slow to respond.
 	 */
-	err = ice_aq_wait_for_event(pf, ice_aqc_opc_nvm_write, 15 * HZ, &event);
+	err = ice_aq_wait_for_event(pf, &task, ice_aqc_opc_nvm_write, 15 * HZ);
 	if (err) {
 		dev_err(dev, "Timed out while trying to flash module 0x%02x with block of size %u at offset %u, err %d\n",
 			module, block_size, offset, err);
 		NL_SET_ERR_MSG_MOD(extack, "Timed out waiting for firmware");
 		return -EIO;
 	}
 
-	completion_module = le16_to_cpu(event.desc.params.nvm.module_typeid);
-	completion_retval = le16_to_cpu(event.desc.retval);
+	desc = &task.event.desc;
+	completion_module = le16_to_cpu(desc->params.nvm.module_typeid);
+	completion_retval = le16_to_cpu(desc->retval);
 
-	completion_offset = le16_to_cpu(event.desc.params.nvm.offset_low);
-	completion_offset |= event.desc.params.nvm.offset_high << 16;
+	completion_offset = le16_to_cpu(desc->params.nvm.offset_low);
+	completion_offset |= desc->params.nvm.offset_high << 16;
 
 	if (completion_module != module) {
 		dev_err(dev, "Unexpected module_typeid in write completion: got 0x%x, expected 0x%x\n",
@@ -363,8 +363,8 @@ ice_write_one_nvm_block(struct ice_pf *pf, u16 module, u32 offset,
 	 */
 	if (reset_level && last_cmd && module == ICE_SR_1ST_NVM_BANK_PTR) {
 		if (hw->dev_caps.common_cap.pcie_reset_avoidance) {
-			*reset_level = (event.desc.params.nvm.cmd_flags &
-					ICE_AQC_NVM_RESET_LVL_M);
+			*reset_level = desc->params.nvm.cmd_flags &
+				       ICE_AQC_NVM_RESET_LVL_M;
 			dev_dbg(dev, "Firmware reported required reset level as %u\n",
 				*reset_level);
 		} else {
@@ -479,15 +479,14 @@ ice_erase_nvm_module(struct ice_pf *pf, u16 module, const char *component,
 {
 	u16 completion_module, completion_retval;
 	struct device *dev = ice_pf_to_dev(pf);
-	struct ice_rq_event_info event;
+	struct ice_aq_task task = {};
 	struct ice_hw *hw = &pf->hw;
+	struct ice_aq_desc *desc;
 	struct devlink *devlink;
 	int err;
 
 	dev_dbg(dev, "Beginning erase of flash component '%s', module 0x%02x\n", component, module);
 
-	memset(&event, 0, sizeof(event));
-
 	devlink = priv_to_devlink(pf);
 
 	devlink_flash_update_timeout_notify(devlink, "Erasing", component, ICE_FW_ERASE_TIMEOUT);
@@ -502,16 +501,17 @@ ice_erase_nvm_module(struct ice_pf *pf, u16 module, const char *component,
 		goto out_notify_devlink;
 	}
 
-	err = ice_aq_wait_for_event(pf, ice_aqc_opc_nvm_erase, ICE_FW_ERASE_TIMEOUT * HZ, &event);
+	err = ice_aq_wait_for_event(pf, &task, ice_aqc_opc_nvm_erase, ICE_FW_ERASE_TIMEOUT * HZ);
 	if (err) {
 		dev_err(dev, "Timed out waiting for firmware to respond with erase completion for %s (module 0x%02x), err %d\n",
 			component, module, err);
 		NL_SET_ERR_MSG_MOD(extack, "Timed out waiting for firmware");
 		goto out_notify_devlink;
 	}
 
-	completion_module = le16_to_cpu(event.desc.params.nvm.module_typeid);
-	completion_retval = le16_to_cpu(event.desc.retval);
+	desc = &task.event.desc;
+	completion_module = le16_to_cpu(desc->params.nvm.module_typeid);
+	completion_retval = le16_to_cpu(desc->retval);
 
 	if (completion_module != module) {
 		dev_err(dev, "Unexpected module_typeid in erase completion for %s: got 0x%x, expected 0x%x\n",
@@ -560,14 +560,12 @@ ice_switch_flash_banks(struct ice_pf *pf, u8 activate_flags,
 		       u8 *emp_reset_available, struct netlink_ext_ack *extack)
 {
 	struct device *dev = ice_pf_to_dev(pf);
-	struct ice_rq_event_info event;
+	struct ice_aq_task task = {};
 	struct ice_hw *hw = &pf->hw;
 	u16 completion_retval;
 	u8 response_flags;
 	int err;
 
-	memset(&event, 0, sizeof(event));
-
 	err = ice_nvm_write_activate(hw, activate_flags, &response_flags);
 	if (err) {
 		dev_err(dev, "Failed to switch active flash banks, err %d aq_err %s\n",
@@ -592,16 +590,16 @@ ice_switch_flash_banks(struct ice_pf *pf, u8 activate_flags,
 		}
 	}
 
-	err = ice_aq_wait_for_event(pf, ice_aqc_opc_nvm_write_activate, 30 * HZ,
-				    &event);
+	err = ice_aq_wait_for_event(pf, &task, ice_aqc_opc_nvm_write_activate,
+				    30 * HZ);
 	if (err) {
 		dev_err(dev, "Timed out waiting for firmware to switch active flash banks, err %d\n",
 			err);
 		NL_SET_ERR_MSG_MOD(extack, "Timed out waiting for firmware");
 		return err;
 	}
 
-	completion_retval = le16_to_cpu(event.desc.retval);
+	completion_retval = le16_to_cpu(task.event.desc.retval);
 	if (completion_retval) {
 		dev_err(dev, "Firmware failed to switch active flash banks aq_err %s\n",
 			ice_aq_str((enum ice_aq_err)completion_retval));
diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index 279e7f790312..190be3d7cc6b 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -1250,26 +1250,12 @@ ice_handle_link_event(struct ice_pf *pf, struct ice_rq_event_info *event)
 	return status;
 }
 
-enum ice_aq_task_state {
-	ICE_AQ_TASK_WAITING = 0,
-	ICE_AQ_TASK_COMPLETE,
-	ICE_AQ_TASK_CANCELED,
-};
-
-struct ice_aq_task {
-	struct hlist_node entry;
-
-	u16 opcode;
-	struct ice_rq_event_info *event;
-	enum ice_aq_task_state state;
-};
-
 /**
  * ice_aq_wait_for_event - Wait for an AdminQ event from firmware
  * @pf: pointer to the PF private structure
+ * @task: ptr to task structure
  * @opcode: the opcode to wait for
  * @timeout: how long to wait, in jiffies
- * @event: storage for the event info
  *
  * Waits for a specific AdminQ completion event on the ARQ for a given PF. The
  * current thread will be put to sleep until the specified event occurs or
@@ -1281,22 +1267,16 @@ struct ice_aq_task {
  *
  * Returns: zero on success, or a negative error code on failure.
  */
-int ice_aq_wait_for_event(struct ice_pf *pf, u16 opcode, unsigned long timeout,
-			  struct ice_rq_event_info *event)
+int ice_aq_wait_for_event(struct ice_pf *pf, struct ice_aq_task *task,
+			  u16 opcode, unsigned long timeout)
 {
 	struct device *dev = ice_pf_to_dev(pf);
-	struct ice_aq_task *task;
 	unsigned long start;
 	long ret;
 	int err;
 
-	task = kzalloc(sizeof(*task), GFP_KERNEL);
-	if (!task)
-		return -ENOMEM;
-
 	INIT_HLIST_NODE(&task->entry);
 	task->opcode = opcode;
-	task->event = event;
 	task->state = ICE_AQ_TASK_WAITING;
 
 	spin_lock_bh(&pf->aq_wait_lock);
@@ -1331,7 +1311,6 @@ int ice_aq_wait_for_event(struct ice_pf *pf, u16 opcode, unsigned long timeout,
 	spin_lock_bh(&pf->aq_wait_lock);
 	hlist_del(&task->entry);
 	spin_unlock_bh(&pf->aq_wait_lock);
-	kfree(task);
 
 	return err;
 }
@@ -1366,7 +1345,7 @@ static void ice_aq_check_events(struct ice_pf *pf, u16 opcode,
 		if (task->state || task->opcode != opcode)
 			continue;
 
-		task_ev = task->event;
+		task_ev = &task->event;
 		memcpy(&task_ev->desc, &event->desc, sizeof(event->desc));
 		task_ev->msg_len = event->msg_len;
 
-- 
2.40.1

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Re: [Intel-wired-lan] [PATCH iwl-next v4 2/3] ice: embed &ice_rq_event_info event into struct ice_aq_task

[Pucha, HimasekharX Reddy]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of Przemek Kitszel
> Sent: Wednesday, August 9, 2023 3:24 AM
> To: intel-wired-lan@lists.osuosl.org
> Cc: netdev@vger.kernel.org; Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Simon Horman <horms@kernel.org>; Kitszel, Przemyslaw <przemyslaw.kitszel@intel.com>
> Subject: [Intel-wired-lan] [PATCH iwl-next v4 2/3] ice: embed &ice_rq_event_info event into struct ice_aq_task
>
> Expose struct ice_aq_task to callers,
> what takes burden of memory ownership out from AQ-wait family of functions, and reduces need for heap-based allocations.
>
> Embed struct ice_rq_event_info event into struct ice_aq_task (instead of it being a ptr). to remove some more code from the callers.
>
> Subsequent commit will improve more based on this one.
>
> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
> Signed-off-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
>
> ---
> add/remove: 0/0 grow/shrink: 3/1 up/down: 266/-68 (198)
> ---
>  drivers/net/ethernet/intel/ice/ice.h          | 18 +++++++-
>  .../net/ethernet/intel/ice/ice_fw_update.c    | 42 +++++++++----------
>  drivers/net/ethernet/intel/ice/ice_main.c     | 29 ++-----------
>  3 files changed, 40 insertions(+), 49 deletions(-)
>

Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)

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[Intel-wired-lan] [PATCH iwl-next v4 3/3] ice: split ice_aq_wait_for_event() func into two

[Przemek Kitszel]

Mitigate race between registering on wait list and receiving
AQ Response from FW.

ice_aq_prep_for_event() should be called before sending AQ command,
ice_aq_wait_for_event() should be called after sending AQ command,
to wait for AQ Response.

Please note, that this was found by reading the code,
an actual race has not yet materialized.

Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>

---
add/remove: 2/0 grow/shrink: 1/3 up/down: 131/-61 (70)
---
 drivers/net/ethernet/intel/ice/ice.h          |  5 +-
 .../net/ethernet/intel/ice/ice_fw_update.c    | 13 ++--
 drivers/net/ethernet/intel/ice/ice_main.c     | 67 ++++++++++++-------
 3 files changed, 57 insertions(+), 28 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice.h b/drivers/net/ethernet/intel/ice/ice.h
index bcd56ba908a7..3ac645afbc8d 100644
--- a/drivers/net/ethernet/intel/ice/ice.h
+++ b/drivers/net/ethernet/intel/ice/ice.h
@@ -933,6 +933,7 @@ void ice_fdir_replay_fltrs(struct ice_pf *pf);
 int ice_fdir_create_dflt_rules(struct ice_pf *pf);
 
 enum ice_aq_task_state {
+	ICE_AQ_TASK_NOT_PREPARED,
 	ICE_AQ_TASK_WAITING,
 	ICE_AQ_TASK_COMPLETE,
 	ICE_AQ_TASK_CANCELED,
@@ -945,8 +946,10 @@ struct ice_aq_task {
 	u16 opcode;
 };
 
+void ice_aq_prep_for_event(struct ice_pf *pf, struct ice_aq_task *task,
+			   u16 opcode);
 int ice_aq_wait_for_event(struct ice_pf *pf, struct ice_aq_task *task,
-			  u16 opcode, unsigned long timeout);
+			  unsigned long timeout);
 int ice_open(struct net_device *netdev);
 int ice_open_internal(struct net_device *netdev);
 int ice_stop(struct net_device *netdev);
diff --git a/drivers/net/ethernet/intel/ice/ice_fw_update.c b/drivers/net/ethernet/intel/ice/ice_fw_update.c
index 819b70823e9c..319a2d6fe26c 100644
--- a/drivers/net/ethernet/intel/ice/ice_fw_update.c
+++ b/drivers/net/ethernet/intel/ice/ice_fw_update.c
@@ -302,6 +302,8 @@ ice_write_one_nvm_block(struct ice_pf *pf, u16 module, u32 offset,
 	dev_dbg(dev, "Writing block of %u bytes for module 0x%02x at offset %u\n",
 		block_size, module, offset);
 
+	ice_aq_prep_for_event(pf, &task, ice_aqc_opc_nvm_write);
+
 	err = ice_aq_update_nvm(hw, module, offset, block_size, block,
 				last_cmd, 0, NULL);
 	if (err) {
@@ -318,7 +320,7 @@ ice_write_one_nvm_block(struct ice_pf *pf, u16 module, u32 offset,
 	 * is conservative and is intended to prevent failure to update when
 	 * firmware is slow to respond.
 	 */
-	err = ice_aq_wait_for_event(pf, &task, ice_aqc_opc_nvm_write, 15 * HZ);
+	err = ice_aq_wait_for_event(pf, &task, 15 * HZ);
 	if (err) {
 		dev_err(dev, "Timed out while trying to flash module 0x%02x with block of size %u at offset %u, err %d\n",
 			module, block_size, offset, err);
@@ -491,6 +493,8 @@ ice_erase_nvm_module(struct ice_pf *pf, u16 module, const char *component,
 
 	devlink_flash_update_timeout_notify(devlink, "Erasing", component, ICE_FW_ERASE_TIMEOUT);
 
+	ice_aq_prep_for_event(pf, &task, ice_aqc_opc_nvm_erase);
+
 	err = ice_aq_erase_nvm(hw, module, NULL);
 	if (err) {
 		dev_err(dev, "Failed to erase %s (module 0x%02x), err %d aq_err %s\n",
@@ -501,7 +505,7 @@ ice_erase_nvm_module(struct ice_pf *pf, u16 module, const char *component,
 		goto out_notify_devlink;
 	}
 
-	err = ice_aq_wait_for_event(pf, &task, ice_aqc_opc_nvm_erase, ICE_FW_ERASE_TIMEOUT * HZ);
+	err = ice_aq_wait_for_event(pf, &task, ICE_FW_ERASE_TIMEOUT * HZ);
 	if (err) {
 		dev_err(dev, "Timed out waiting for firmware to respond with erase completion for %s (module 0x%02x), err %d\n",
 			component, module, err);
@@ -566,6 +570,8 @@ ice_switch_flash_banks(struct ice_pf *pf, u8 activate_flags,
 	u8 response_flags;
 	int err;
 
+	ice_aq_prep_for_event(pf, &task, ice_aqc_opc_nvm_write_activate);
+
 	err = ice_nvm_write_activate(hw, activate_flags, &response_flags);
 	if (err) {
 		dev_err(dev, "Failed to switch active flash banks, err %d aq_err %s\n",
@@ -590,8 +596,7 @@ ice_switch_flash_banks(struct ice_pf *pf, u8 activate_flags,
 		}
 	}
 
-	err = ice_aq_wait_for_event(pf, &task, ice_aqc_opc_nvm_write_activate,
-				    30 * HZ);
+	err = ice_aq_wait_for_event(pf, &task, 30 * HZ);
 	if (err) {
 		dev_err(dev, "Timed out waiting for firmware to switch active flash banks, err %d\n",
 			err);
diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index 190be3d7cc6b..0baa44fa2baa 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -1251,43 +1251,62 @@ ice_handle_link_event(struct ice_pf *pf, struct ice_rq_event_info *event)
 }
 
 /**
- * ice_aq_wait_for_event - Wait for an AdminQ event from firmware
+ * ice_aq_prep_for_event - Prepare to wait for an AdminQ event from firmware
  * @pf: pointer to the PF private structure
- * @task: ptr to task structure
+ * @task: intermediate helper storage and identifier for waiting
  * @opcode: the opcode to wait for
- * @timeout: how long to wait, in jiffies
  *
- * Waits for a specific AdminQ completion event on the ARQ for a given PF. The
- * current thread will be put to sleep until the specified event occurs or
- * until the given timeout is reached.
+ * Prepares to wait for a specific AdminQ completion event on the ARQ for
+ * a given PF. Actual wait would be done by a call to ice_aq_wait_for_event().
  *
- * To obtain only the descriptor contents, pass an event without an allocated
- * msg_buf. If the complete data buffer is desired, allocate the
- * event->msg_buf with enough space ahead of time.
+ * Calls are separated to allow caller registering for event before sending
+ * the command, which mitigates a race between registering and FW responding.
  *
- * Returns: zero on success, or a negative error code on failure.
+ * To obtain only the descriptor contents, pass an task->event with null
+ * msg_buf. If the complete data buffer is desired, allocate the
+ * task->event.msg_buf with enough space ahead of time.
  */
-int ice_aq_wait_for_event(struct ice_pf *pf, struct ice_aq_task *task,
-			  u16 opcode, unsigned long timeout)
+void ice_aq_prep_for_event(struct ice_pf *pf, struct ice_aq_task *task,
+			   u16 opcode)
 {
-	struct device *dev = ice_pf_to_dev(pf);
-	unsigned long start;
-	long ret;
-	int err;
-
 	INIT_HLIST_NODE(&task->entry);
 	task->opcode = opcode;
 	task->state = ICE_AQ_TASK_WAITING;
 
 	spin_lock_bh(&pf->aq_wait_lock);
 	hlist_add_head(&task->entry, &pf->aq_wait_list);
 	spin_unlock_bh(&pf->aq_wait_lock);
+}
 
-	start = jiffies;
+/**
+ * ice_aq_wait_for_event - Wait for an AdminQ event from firmware
+ * @pf: pointer to the PF private structure
+ * @task: ptr prepared by ice_aq_prep_for_event()
+ * @timeout: how long to wait, in jiffies
+ *
+ * Waits for a specific AdminQ completion event on the ARQ for a given PF. The
+ * current thread will be put to sleep until the specified event occurs or
+ * until the given timeout is reached.
+ *
+ * Returns: zero on success, or a negative error code on failure.
+ */
+int ice_aq_wait_for_event(struct ice_pf *pf, struct ice_aq_task *task,
+			  unsigned long timeout)
+{
+	enum ice_aq_task_state *state = &task->state;
+	struct device *dev = ice_pf_to_dev(pf);
+	unsigned long start = jiffies;
+	long ret;
+	int err;
 
-	ret = wait_event_interruptible_timeout(pf->aq_wait_queue, task->state,
+	ret = wait_event_interruptible_timeout(pf->aq_wait_queue,
+					       *state != ICE_AQ_TASK_WAITING,
 					       timeout);
-	switch (task->state) {
+	switch (*state) {
+	case ICE_AQ_TASK_NOT_PREPARED:
+		WARN(1, "call to %s without ice_aq_prep_for_event()", __func__);
+		err = -EINVAL;
+		break;
 	case ICE_AQ_TASK_WAITING:
 		err = ret < 0 ? ret : -ETIMEDOUT;
 		break;
@@ -1298,15 +1317,15 @@ int ice_aq_wait_for_event(struct ice_pf *pf, struct ice_aq_task *task,
 		err = ret < 0 ? ret : 0;
 		break;
 	default:
-		WARN(1, "Unexpected AdminQ wait task state %u", task->state);
+		WARN(1, "Unexpected AdminQ wait task state %u", *state);
 		err = -EINVAL;
 		break;
 	}
 
 	dev_dbg(dev, "Waited %u msecs (max %u msecs) for firmware response to op 0x%04x\n",
 		jiffies_to_msecs(jiffies - start),
 		jiffies_to_msecs(timeout),
-		opcode);
+		task->opcode);
 
 	spin_lock_bh(&pf->aq_wait_lock);
 	hlist_del(&task->entry);
@@ -1342,7 +1361,9 @@ static void ice_aq_check_events(struct ice_pf *pf, u16 opcode,
 
 	spin_lock_bh(&pf->aq_wait_lock);
 	hlist_for_each_entry(task, &pf->aq_wait_list, entry) {
-		if (task->state || task->opcode != opcode)
+		if (task->state != ICE_AQ_TASK_WAITING)
+			continue;
+		if (task->opcode != opcode)
 			continue;
 
 		task_ev = &task->event;
-- 
2.40.1

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Re: [Intel-wired-lan] [PATCH iwl-next v4 3/3] ice: split ice_aq_wait_for_event() func into two

[Pucha, HimasekharX Reddy]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of Przemek Kitszel
> Sent: Wednesday, August 9, 2023 3:24 AM
> To: intel-wired-lan@lists.osuosl.org
> Cc: netdev@vger.kernel.org; Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Simon Horman <horms@kernel.org>; Kitszel, Przemyslaw <przemyslaw.kitszel@intel.com>
> Subject: [Intel-wired-lan] [PATCH iwl-next v4 3/3] ice: split ice_aq_wait_for_event() func into two
>
> Mitigate race between registering on wait list and receiving AQ Response from FW.
>
> ice_aq_prep_for_event() should be called before sending AQ command,
> ice_aq_wait_for_event() should be called after sending AQ command, to wait for AQ Response.
>
> Please note, that this was found by reading the code, an actual race has not yet materialized.
>
> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
> Signed-off-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
>
> ---
> add/remove: 2/0 grow/shrink: 1/3 up/down: 131/-61 (70)
> ---
>  drivers/net/ethernet/intel/ice/ice.h          |  5 +-
>  .../net/ethernet/intel/ice/ice_fw_update.c    | 13 ++--
>  drivers/net/ethernet/intel/ice/ice_main.c     | 67 ++++++++++++-------
>  3 files changed, 57 insertions(+), 28 deletions(-)
>

Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)

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Re: [Intel-wired-lan] [PATCH iwl-next v4 0/3] ice: split ice_aq_wait_for_event() func into two

[Simon Horman]

On Tue, Aug 08, 2023 at 05:54:14PM -0400, Przemek Kitszel wrote:
> Mitigate race between registering on wait list and receiving
> AQ Response from FW.
> 
> The first patch fixes bound check to be more inclusive;
> the second one refactors code to make the third one smaller,
> which is an actual fix for the race.
> 
> Thanks Simon Horman for pushing into split, it's easier to follow now.
> 
> v4: remove excessive newlines, thanks Tony for catching this up
> v3: split into 3 commits
> 
> Przemek Kitszel (3):
>   ice: ice_aq_check_events: fix off-by-one check when filling buffer
>   ice: embed &ice_rq_event_info event into struct ice_aq_task
>   ice: split ice_aq_wait_for_event() func into two

Thanks for the split :)

Reviewed-by: Simon Horman <horms@kernel.org>
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