Merge "soc: qcom: hab: hold the message when the read buffer is smaller"

4 files changed, 57 insertions, 51 deletions

diff --git a/drivers/soc/qcom/hab/hab.c b/drivers/soc/qcom/hab/hab.c
index 3294fc34bdf8..37afe025a97a 100644
--- a/drivers/soc/qcom/hab/hab.c
+++ b/drivers/soc/qcom/hab/hab.c
@@ -356,18 +356,21 @@ err:
 	return ret;
 }
 
-struct hab_message *hab_vchan_recv(struct uhab_context *ctx,
+int hab_vchan_recv(struct uhab_context *ctx,
+				struct hab_message **message,
 				int vcid,
+				int *rsize,
 				unsigned int flags)
 {
 	struct virtual_channel *vchan;
-	struct hab_message *message;
 	int ret = 0;
 	int nonblocking_flag = flags & HABMM_SOCKET_RECV_FLAGS_NON_BLOCKING;
 
 	vchan = hab_get_vchan_fromvcid(vcid, ctx);
-	if (!vchan)
-		return ERR_PTR(-ENODEV);
+	if (!vchan) {
+		pr_err("vcid %X, vchan %p ctx %p\n", vcid, vchan, ctx);
+		return -ENODEV;
+	}
 
 	if (nonblocking_flag) {
 		/*
@@ -378,18 +381,18 @@ struct hab_message *hab_vchan_recv(struct uhab_context *ctx,
 		physical_channel_rx_dispatch((unsigned long) vchan->pchan);
 	}
 
-	message = hab_msg_dequeue(vchan, flags);
-	if (!message) {
+	ret = hab_msg_dequeue(vchan, message, rsize, flags);
+	if (!(*message)) {
 		if (nonblocking_flag)
 			ret = -EAGAIN;
 		else if (vchan->otherend_closed)
 			ret = -ENODEV;
-		else
-			ret = -EPIPE;
+		else if (ret == -ERESTARTSYS)
+			ret = -EINTR;
 	}
 
 	hab_vchan_put(vchan);
-	return ret ? ERR_PTR(ret) : message;
+	return ret;
 }
 
 bool hab_is_loopback(void)
@@ -843,29 +846,22 @@ static long hab_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
 			break;
 		}
 
-		msg = hab_vchan_recv(ctx, recv_param->vcid, recv_param->flags);
-
-		if (IS_ERR(msg)) {
-			recv_param->sizebytes = 0;
-			ret = PTR_ERR(msg);
-			break;
-		}
+		ret = hab_vchan_recv(ctx, &msg, recv_param->vcid,
+				&recv_param->sizebytes, recv_param->flags);
 
-		if (recv_param->sizebytes < msg->sizebytes) {
-			recv_param->sizebytes = 0;
-			ret = -EINVAL;
-		} else if (copy_to_user((void __user *)recv_param->data,
+		if (ret == 0 && msg) {
+			if (copy_to_user((void __user *)recv_param->data,
 					msg->data,
 					msg->sizebytes)) {
-			pr_err("copy_to_user failed: vc=%x size=%d\n",
-				recv_param->vcid, (int)msg->sizebytes);
-			recv_param->sizebytes = 0;
-			ret = -EFAULT;
-		} else {
-			recv_param->sizebytes = msg->sizebytes;
+				pr_err("copy_to_user failed: vc=%x size=%d\n",
+				   recv_param->vcid, (int)msg->sizebytes);
+				recv_param->sizebytes = 0;
+				ret = -EFAULT;
+			}
 		}
 
-		hab_msg_free(msg);
+		if (msg)
+			hab_msg_free(msg);
 		break;
 	case IOCTL_HAB_VC_EXPORT:
 		ret = hab_mem_export(ctx, (struct hab_export *)data, 0);
diff --git a/drivers/soc/qcom/hab/hab.h b/drivers/soc/qcom/hab/hab.h
index ffb0637055d4..2a07da728e00 100644
--- a/drivers/soc/qcom/hab/hab.h
+++ b/drivers/soc/qcom/hab/hab.h
@@ -373,9 +373,11 @@ long hab_vchan_send(struct uhab_context *ctx,
 		size_t sizebytes,
 		void *data,
 		unsigned int flags);
-struct hab_message *hab_vchan_recv(struct uhab_context *ctx,
-				int vcid,
-				unsigned int flags);
+int hab_vchan_recv(struct uhab_context *ctx,
+		struct hab_message **msg,
+		int vcid,
+		int *rsize,
+		unsigned int flags);
 void hab_vchan_stop(struct virtual_channel *vchan);
 void hab_vchans_stop(struct physical_channel *pchan);
 void hab_vchan_stop_notify(struct virtual_channel *vchan);
@@ -422,8 +424,8 @@ int habmem_imp_hyp_mmap(struct file *flip, struct vm_area_struct *vma);
 
 
 void hab_msg_free(struct hab_message *message);
-struct hab_message *hab_msg_dequeue(struct virtual_channel *vchan,
-		unsigned int flags);
+int hab_msg_dequeue(struct virtual_channel *vchan,
+		struct hab_message **msg, int *rsize, unsigned int flags);
 
 void hab_msg_recv(struct physical_channel *pchan,
 		struct hab_header *header);
diff --git a/drivers/soc/qcom/hab/hab_msg.c b/drivers/soc/qcom/hab/hab_msg.c
index d5c625e8c1c9..d904cdee838c 100644
--- a/drivers/soc/qcom/hab/hab_msg.c
+++ b/drivers/soc/qcom/hab/hab_msg.c
@@ -42,8 +42,9 @@ void hab_msg_free(struct hab_message *message)
 	kfree(message);
 }
 
-struct hab_message *
-hab_msg_dequeue(struct virtual_channel *vchan, unsigned int flags)
+int
+hab_msg_dequeue(struct virtual_channel *vchan, struct hab_message **msg,
+		int *rsize, unsigned int flags)
 {
 	struct hab_message *message = NULL;
 	int ret = 0;
@@ -64,15 +65,30 @@ hab_msg_dequeue(struct virtual_channel *vchan, unsigned int flags)
 	}
 
 	/* return all the received messages before the remote close */
-	if (!ret && !hab_rx_queue_empty(vchan)) {
+	if ((!ret || (ret == -ERESTARTSYS)) && !hab_rx_queue_empty(vchan)) {
 		spin_lock_bh(&vchan->rx_lock);
 		message = list_first_entry(&vchan->rx_list,
 				struct hab_message, node);
-		list_del(&message->node);
+		if (message) {
+			if (*rsize >= message->sizebytes) {
+				/* msg can be safely retrieved in full */
+				list_del(&message->node);
+				ret = 0;
+				*rsize = message->sizebytes;
+			} else {
+				pr_err("rcv buffer too small %d < %zd\n",
+					   *rsize, message->sizebytes);
+				*rsize = 0;
+				message = NULL;
+				ret = -EINVAL;
+			}
+		}
 		spin_unlock_bh(&vchan->rx_lock);
-	}
+	} else
+		*rsize = 0;
 
-	return message;
+	*msg = message;
+	return ret;
 }
 
 static void hab_msg_queue(struct virtual_channel *vchan,
diff --git a/drivers/soc/qcom/hab/khab.c b/drivers/soc/qcom/hab/khab.c
index 3fdd11f7daf7..ba77e5e9cca2 100644
--- a/drivers/soc/qcom/hab/khab.c
+++ b/drivers/soc/qcom/hab/khab.c
@@ -51,22 +51,14 @@ int32_t habmm_socket_recv(int32_t handle, void *dst_buff, uint32_t *size_bytes,
 	if (!size_bytes || !dst_buff)
 		return -EINVAL;
 
-	msg = hab_vchan_recv(hab_driver.kctx, handle, flags);
+	ret = hab_vchan_recv(hab_driver.kctx, &msg, handle, size_bytes, flags);
 
-	if (IS_ERR(msg)) {
-		*size_bytes = 0;
-		return PTR_ERR(msg);
-	}
-
-	if (*size_bytes < msg->sizebytes) {
-		*size_bytes = 0;
-		ret = -EINVAL;
-	} else {
+	if (ret == 0 && msg)
 		memcpy(dst_buff, msg->data, msg->sizebytes);
-		*size_bytes = msg->sizebytes;
-	}
 
-	hab_msg_free(msg);
+	if (msg)
+		hab_msg_free(msg);
+
 	return ret;
 }
 EXPORT_SYMBOL(habmm_socket_recv);