qcacmn: Protect pktlog under mutex to avoid possible race conditions

Protect pktlog funcitonality under given mutex to avoid possible
race condition between pktlog_release/pktlog_open and pktlogmod_exit.
Also call pktlogmod_exit before calling wdi_event_detach to avoid
accessing freed memory in pktlog release.

Change-Id: I5ca4b304d0f4dc1af289daa167958d5b773d9a6e
CRs-Fixed: 2578623

utils/pktlog/include/pktlog_ac.h

@@ -132,6 +132,9 @@ void pktlog_callback(void *pdev, enum WDI_EVENT event, void *log_data,
 void pktlog_init(struct hif_opaque_softc *scn);
 int pktlog_enable(struct hif_opaque_softc *scn, int32_t log_state,
 		 bool, uint8_t, uint32_t);
+int __pktlog_enable(struct hif_opaque_softc *scn, int32_t log_state,
+		    bool ini_triggered, uint8_t user_triggered,
+		    uint32_t is_iwpriv_command);
 int pktlog_setsize(struct hif_opaque_softc *scn, int32_t log_state);
 int pktlog_clearbuff(struct hif_opaque_softc *scn, bool clear_buff);
 int pktlog_disable(struct hif_opaque_softc *scn);
@@ -171,6 +174,14 @@ static inline int pktlog_enable(struct hif_opaque_softc *scn, int32_t log_state,
 	return 0;
 }
 
+static inline
+int __pktlog_enable(struct hif_opaque_softc *scn, int32_t log_state,
+		    bool ini_triggered, uint8_t user_triggered,
+		    uint32_t is_iwpriv_command)
+{
+	return 0;
+}
+
 static inline int pktlog_setsize(struct hif_opaque_softc *scn,
 				 int32_t log_state)
 {

utils/pktlog/linux_ac.c

@@ -506,6 +506,12 @@ static void pktlog_detach(struct hif_opaque_softc *scn)
 	}
 
 	pl_info = pl_dev->pl_info;
+	if (!pl_info) {
+		qdf_print("%s: Invalid pktlog handle", __func__);
+		ASSERT(0);
+		return;
+	}
+	mutex_lock(&pl_info->pktlog_mutex);
 	remove_proc_entry(WLANDEV_BASENAME, g_pktlog_pde);
 	pktlog_sysctl_unregister(pl_dev);
 
@@ -516,6 +522,7 @@ static void pktlog_detach(struct hif_opaque_softc *scn)
 		pl_dev->tgt_pktlog_alloced = false;
 	}
 	qdf_spin_unlock_bh(&pl_info->log_lock);
+	mutex_unlock(&pl_info->pktlog_mutex);
 	pktlog_cleanup(pl_info);
 
 	if (pl_dev) {
@@ -529,25 +536,12 @@ static int __pktlog_open(struct inode *i, struct file *f)
 	struct hif_opaque_softc *scn;
 	struct pktlog_dev_t *pl_dev;
 	struct ath_pktlog_info *pl_info;
+	struct ath_pktlog_info_lnx *pl_info_lnx;
 	int ret = 0;
 
 	PKTLOG_MOD_INC_USE_COUNT;
-	pl_info = PDE_DATA(f->f_path.dentry->d_inode);
-	if (!pl_info) {
-		qdf_nofl_err("%s: pl_info NULL", __func__);
-		return -EINVAL;
-	}
-
-	if (pl_info->curr_pkt_state != PKTLOG_OPR_NOT_IN_PROGRESS) {
-		qdf_nofl_info("%s: plinfo state (%d) != PKTLOG_OPR_NOT_IN_PROGRESS",
-			      __func__, pl_info->curr_pkt_state);
-		return -EBUSY;
-	}
-
-	pl_info->curr_pkt_state = PKTLOG_OPR_IN_PROGRESS_READ_START;
 	scn = cds_get_context(QDF_MODULE_ID_HIF);
 	if (!scn) {
-		pl_info->curr_pkt_state = PKTLOG_OPR_NOT_IN_PROGRESS;
 		qdf_print("%s: Invalid scn context", __func__);
 		ASSERT(0);
 		return -EINVAL;
@@ -556,12 +550,38 @@ static int __pktlog_open(struct inode *i, struct file *f)
 	pl_dev = get_pktlog_handle();
 
 	if (!pl_dev) {
-		pl_info->curr_pkt_state = PKTLOG_OPR_NOT_IN_PROGRESS;
 		qdf_print("%s: Invalid pktlog handle", __func__);
 		ASSERT(0);
 		return -ENODEV;
 	}
 
+	pl_info = pl_dev->pl_info;
+
+	if (!pl_info) {
+		qdf_nofl_err("%s: pl_info NULL", __func__);
+		return -EINVAL;
+	}
+
+	mutex_lock(&pl_info->pktlog_mutex);
+	pl_info_lnx = (pl_dev) ? PL_INFO_LNX(pl_dev->pl_info) :
+		PL_INFO_LNX(g_pktlog_info);
+
+	if (!pl_info_lnx->sysctl_header) {
+		mutex_unlock(&pl_info->pktlog_mutex);
+		qdf_print("%s: pktlog sysctl is unergistered.", __func__);
+		ASSERT(0);
+		return -EINVAL;
+	}
+
+	if (pl_info->curr_pkt_state != PKTLOG_OPR_NOT_IN_PROGRESS) {
+		mutex_unlock(&pl_info->pktlog_mutex);
+		qdf_print("%s: plinfo state (%d) != PKTLOG_OPR_NOT_IN_PROGRESS",
+			  __func__, pl_info->curr_pkt_state);
+		return -EBUSY;
+	}
+
+	pl_info->curr_pkt_state = PKTLOG_OPR_IN_PROGRESS_READ_START;
+
 	pl_info->init_saved_state = pl_info->log_state;
 	if (!pl_info->log_state) {
 		/* Pktlog is already disabled.
@@ -569,6 +589,7 @@ static int __pktlog_open(struct inode *i, struct file *f)
 		 */
 		pl_info->curr_pkt_state =
 			PKTLOG_OPR_IN_PROGRESS_READ_START_PKTLOG_DISABLED;
+		mutex_unlock(&pl_info->pktlog_mutex);
 		return ret;
 	}
 	/* Disbable the pktlog internally. */
@@ -576,6 +597,7 @@ static int __pktlog_open(struct inode *i, struct file *f)
 	pl_info->log_state = 0;
 	pl_info->curr_pkt_state =
 			PKTLOG_OPR_IN_PROGRESS_READ_START_PKTLOG_DISABLED;
+	mutex_unlock(&pl_info->pktlog_mutex);
 	return ret;
 }
 
@@ -600,17 +622,12 @@ static int __pktlog_release(struct inode *i, struct file *f)
 	struct hif_opaque_softc *scn;
 	struct pktlog_dev_t *pl_dev;
 	struct ath_pktlog_info *pl_info;
+	struct ath_pktlog_info_lnx *pl_info_lnx;
 	int ret = 0;
 
 	PKTLOG_MOD_DEC_USE_COUNT;
-
-	pl_info = PDE_DATA(f->f_path.dentry->d_inode);
-	if (!pl_info)
-		return -EINVAL;
-
 	scn = cds_get_context(QDF_MODULE_ID_HIF);
 	if (!scn) {
-		pl_info->curr_pkt_state = PKTLOG_OPR_NOT_IN_PROGRESS;
 		qdf_print("%s: Invalid scn context", __func__);
 		ASSERT(0);
 		return -EINVAL;
@@ -619,12 +636,30 @@ static int __pktlog_release(struct inode *i, struct file *f)
 	pl_dev = get_pktlog_handle();
 
 	if (!pl_dev) {
-		pl_info->curr_pkt_state = PKTLOG_OPR_NOT_IN_PROGRESS;
 		qdf_print("%s: Invalid pktlog handle", __func__);
 		ASSERT(0);
 		return -ENODEV;
 	}
 
+	pl_info = pl_dev->pl_info;
+
+	if (!pl_info) {
+		qdf_print("%s: Invalid pktlog info", __func__);
+		ASSERT(0);
+		return -EINVAL;
+	}
+
+	mutex_lock(&pl_info->pktlog_mutex);
+	pl_info_lnx = (pl_dev) ? PL_INFO_LNX(pl_dev->pl_info) :
+		PL_INFO_LNX(g_pktlog_info);
+
+	if (!pl_info_lnx->sysctl_header) {
+		pl_info->curr_pkt_state = PKTLOG_OPR_NOT_IN_PROGRESS;
+		mutex_unlock(&pl_info->pktlog_mutex);
+		qdf_print("%s: pktlog sysctl is unergistered.", __func__);
+		ASSERT(0);
+		return -EINVAL;
+	}
 	pl_info->curr_pkt_state = PKTLOG_OPR_IN_PROGRESS_READ_COMPLETE;
 	/*clear pktlog buffer.*/
 	pktlog_clearbuff(scn, true);
@@ -632,15 +667,16 @@ static int __pktlog_release(struct inode *i, struct file *f)
 	pl_info->init_saved_state = 0;
 
 	/*Enable pktlog again*/
-	ret = pl_dev->pl_funcs->pktlog_enable(
+	ret = __pktlog_enable(
 			(struct hif_opaque_softc *)scn, pl_info->log_state,
 			cds_is_packet_log_enabled(), 0, 1);
 
-	if (ret != 0)
-		qdf_nofl_warn("%s: pktlog cannot be enabled. ret value %d",
-			      __func__, ret);
-
 	pl_info->curr_pkt_state = PKTLOG_OPR_NOT_IN_PROGRESS;
+	mutex_unlock(&pl_info->pktlog_mutex);
+	if (ret != 0)
+		qdf_print("%s: pktlog cannot be enabled. ret value %d",
+			  __func__, ret);
+
 	return ret;
 }
 

utils/pktlog/pktlog_ac.c

@@ -625,9 +625,9 @@ void pktlog_init(struct hif_opaque_softc *scn)
 	pktlog_callback_registration(pl_dev->callback_type);
 }
 
-static int __pktlog_enable(struct hif_opaque_softc *scn, int32_t log_state,
+int __pktlog_enable(struct hif_opaque_softc *scn, int32_t log_state,
-		 bool ini_triggered, uint8_t user_triggered,
+		    bool ini_triggered, uint8_t user_triggered,
-		 uint32_t is_iwpriv_command)
+		    uint32_t is_iwpriv_command)
 {
 	struct pktlog_dev_t *pl_dev;
 	struct ath_pktlog_info *pl_info;