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[PATCH v2 0/8] NFC: fix device allocation and nfcmrvl crashes

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  [PATCH v2 0/8] NFC: fix device allocation and nfcmrvl crashes Johan Hovold <johan@kernel.org> - 2017-03-30 12:30 +0200
    [PATCH v2 1/8] NFC: fix broken device allocation Johan Hovold <johan@kernel.org> - 2017-03-30 12:30 +0200
    [PATCH v2 2/8] NFC: nfcmrvl_uart: add missing tty-device sanity check Johan Hovold <johan@kernel.org> - 2017-03-30 12:30 +0200
    [PATCH v2 4/8] NFC: nfcmrvl: use nfc-device for firmware download Johan Hovold <johan@kernel.org> - 2017-03-30 12:30 +0200
    [PATCH v2 7/8] NFC: nfcmrvl_usb: use interface as phy device Johan Hovold <johan@kernel.org> - 2017-03-30 12:30 +0200
    [PATCH v2 5/8] NFC: nfcmrvl: fix firmware-management initialisation Johan Hovold <johan@kernel.org> - 2017-03-30 12:30 +0200

#1612899 — [PATCH v2 0/8] NFC: fix device allocation and nfcmrvl crashes

This started out with the observation that the nfcmrvl_uart driver
unconditionally dereferenced the tty class device despite the fact that
not every tty has an associated struct device (Unix98 ptys). Some
further changes were needed in the common nfcmrvl code to fully address
this, some of which also incidentally fixed a few related bugs (e.g.
resource leaks in error paths).

While fixing this I stumbled over a regression in NFC core that lead to
broken registration error paths and misnamed workqueues.

Note that this has only been tested by configuring the n_hci line
discipline for different ttys without any actual NFC hardware connected.

Johan


Changes in v2
 - fix typo in commit message (1/8)
 - release reset gpio in error paths (3/8)
 - fix description of patch impact (3/8)
 - allow gpio 0 to be used for reset signalling (8/8, new)


Johan Hovold (8):
  NFC: fix broken device allocation
  NFC: nfcmrvl_uart: add missing tty-device sanity check
  NFC: nfcmrvl: do not use device-managed resources
  NFC: nfcmrvl: use nfc-device for firmware download
  NFC: nfcmrvl: fix firmware-management initialisation
  NFC: nfcmrvl_uart: fix device-node leak during probe
  NFC: nfcmrvl_usb: use interface as phy device
  NFC: nfcmrvl: allow gpio 0 for reset signalling

 drivers/nfc/nfcmrvl/fw_dnld.c         |  7 ++++--
 drivers/nfc/nfcmrvl/main.c            | 40 +++++++++++++++++++----------------
 drivers/nfc/nfcmrvl/uart.c            | 11 ++++++----
 drivers/nfc/nfcmrvl/usb.c             |  4 +---
 include/linux/platform_data/nfcmrvl.h |  2 +-
 net/nfc/core.c                        | 31 +++++++++++++++------------
 net/nfc/nci/core.c                    |  3 +--
 7 files changed, 55 insertions(+), 43 deletions(-)

-- 
2.12.2

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#1612900 — [PATCH v2 1/8] NFC: fix broken device allocation

Commit 7eda8b8e9677 ("NFC: Use IDR library to assing NFC devices IDs")
moved device-id allocation and struct-device initialisation from
nfc_allocate_device() to nfc_register_device().

This broke just about every nfc-device-registration error path, which
continue to call nfc_free_device() that tries to put the device
reference of the now uninitialised (but zeroed) struct device:

kobject: '(null)' (ce316420): is not initialized, yet kobject_put() is being called.

The late struct-device initialisation also meant that various work
queues whose names are derived from the nfc device name were also
misnamed:

  421 root         0 SW<  [(null)_nci_cmd_]
  422 root         0 SW<  [(null)_nci_rx_w]
  423 root         0 SW<  [(null)_nci_tx_w]

Move the id-allocation and struct-device initialisation back to
nfc_allocate_device() and fix up the single call site which did not use
nfc_free_device() in its error path.

Fixes: 7eda8b8e9677 ("NFC: Use IDR library to assing NFC devices IDs")
Cc: stable <stable@vger.kernel.org>     # 3.8
Cc: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 net/nfc/core.c     | 31 ++++++++++++++++++-------------
 net/nfc/nci/core.c |  3 +--
 2 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/net/nfc/core.c b/net/nfc/core.c
index 122bb81da918..5cf33df888c3 100644
--- a/net/nfc/core.c
+++ b/net/nfc/core.c
@@ -982,6 +982,8 @@ static void nfc_release(struct device *d)
 			kfree(se);
 	}
 
+	ida_simple_remove(&nfc_index_ida, dev->idx);
+
 	kfree(dev);
 }
 
@@ -1056,6 +1058,7 @@ struct nfc_dev *nfc_allocate_device(struct nfc_ops *ops,
 				    int tx_headroom, int tx_tailroom)
 {
 	struct nfc_dev *dev;
+	int rc;
 
 	if (!ops->start_poll || !ops->stop_poll || !ops->activate_target ||
 	    !ops->deactivate_target || !ops->im_transceive)
@@ -1068,6 +1071,15 @@ struct nfc_dev *nfc_allocate_device(struct nfc_ops *ops,
 	if (!dev)
 		return NULL;
 
+	rc = ida_simple_get(&nfc_index_ida, 0, 0, GFP_KERNEL);
+	if (rc < 0)
+		goto err_free_dev;
+	dev->idx = rc;
+
+	dev->dev.class = &nfc_class;
+	dev_set_name(&dev->dev, "nfc%d", dev->idx);
+	device_initialize(&dev->dev);
+
 	dev->ops = ops;
 	dev->supported_protocols = supported_protocols;
 	dev->tx_headroom = tx_headroom;
@@ -1090,6 +1102,11 @@ struct nfc_dev *nfc_allocate_device(struct nfc_ops *ops,
 	}
 
 	return dev;
+
+err_free_dev:
+	kfree(dev);
+
+	return ERR_PTR(rc);
 }
 EXPORT_SYMBOL(nfc_allocate_device);
 
@@ -1104,14 +1121,6 @@ int nfc_register_device(struct nfc_dev *dev)
 
 	pr_debug("dev_name=%s\n", dev_name(&dev->dev));
 
-	dev->idx = ida_simple_get(&nfc_index_ida, 0, 0, GFP_KERNEL);
-	if (dev->idx < 0)
-		return dev->idx;
-
-	dev->dev.class = &nfc_class;
-	dev_set_name(&dev->dev, "nfc%d", dev->idx);
-	device_initialize(&dev->dev);
-
 	mutex_lock(&nfc_devlist_mutex);
 	nfc_devlist_generation++;
 	rc = device_add(&dev->dev);
@@ -1149,12 +1158,10 @@ EXPORT_SYMBOL(nfc_register_device);
  */
 void nfc_unregister_device(struct nfc_dev *dev)
 {
-	int rc, id;
+	int rc;
 
 	pr_debug("dev_name=%s\n", dev_name(&dev->dev));
 
-	id = dev->idx;
-
 	if (dev->rfkill) {
 		rfkill_unregister(dev->rfkill);
 		rfkill_destroy(dev->rfkill);
@@ -1179,8 +1186,6 @@ void nfc_unregister_device(struct nfc_dev *dev)
 	nfc_devlist_generation++;
 	device_del(&dev->dev);
 	mutex_unlock(&nfc_devlist_mutex);
-
-	ida_simple_remove(&nfc_index_ida, id);
 }
 EXPORT_SYMBOL(nfc_unregister_device);
 
diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
index 61fff422424f..85a3d9ed4c29 100644
--- a/net/nfc/nci/core.c
+++ b/net/nfc/nci/core.c
@@ -1173,8 +1173,7 @@ struct nci_dev *nci_allocate_device(struct nci_ops *ops,
 	return ndev;
 
 free_nfc:
-	kfree(ndev->nfc_dev);
-
+	nfc_free_device(ndev->nfc_dev);
 free_nci:
 	kfree(ndev);
 	return NULL;
-- 
2.12.2

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#1612901 — [PATCH v2 2/8] NFC: nfcmrvl_uart: add missing tty-device sanity check

Make sure to check the tty-device pointer before trying to access the
parent device to avoid dereferencing a NULL-pointer when the tty is one
end of a Unix98 pty.

Fixes: e097dc624f78 ("NFC: nfcmrvl: add UART driver")
Cc: stable <stable@vger.kernel.org>     # 4.2
Cc: Vincent Cuissard <cuissard@marvell.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/nfc/nfcmrvl/uart.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/nfc/nfcmrvl/uart.c b/drivers/nfc/nfcmrvl/uart.c
index 83a99e38e7bd..6c0c301611c4 100644
--- a/drivers/nfc/nfcmrvl/uart.c
+++ b/drivers/nfc/nfcmrvl/uart.c
@@ -109,6 +109,7 @@ static int nfcmrvl_nci_uart_open(struct nci_uart *nu)
 	struct nfcmrvl_private *priv;
 	struct nfcmrvl_platform_data *pdata = NULL;
 	struct nfcmrvl_platform_data config;
+	struct device *dev = nu->tty->dev;
 
 	/*
 	 * Platform data cannot be used here since usually it is already used
@@ -116,9 +117,8 @@ static int nfcmrvl_nci_uart_open(struct nci_uart *nu)
 	 * and check if DT entries were added.
 	 */
 
-	if (nu->tty->dev->parent && nu->tty->dev->parent->of_node)
-		if (nfcmrvl_uart_parse_dt(nu->tty->dev->parent->of_node,
-					  &config) == 0)
+	if (dev && dev->parent && dev->parent->of_node)
+		if (nfcmrvl_uart_parse_dt(dev->parent->of_node, &config) == 0)
 			pdata = &config;
 
 	if (!pdata) {
@@ -131,7 +131,7 @@ static int nfcmrvl_nci_uart_open(struct nci_uart *nu)
 	}
 
 	priv = nfcmrvl_nci_register_dev(NFCMRVL_PHY_UART, nu, &uart_ops,
-					nu->tty->dev, pdata);
+					dev, pdata);
 	if (IS_ERR(priv))
 		return PTR_ERR(priv);
 
-- 
2.12.2

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#1612902 — [PATCH v2 4/8] NFC: nfcmrvl: use nfc-device for firmware download

Use the nfc- rather than phy-device in firmware-management code that
needs a valid struct device.

This specifically fixes a NULL-pointer dereference in
nfcmrvl_fw_dnld_init() during registration when the underlying tty is
one end of a Unix98 pty.

Note that the driver still uses the phy device for any debugging, which
is fine for now.

Fixes: 3194c6870158 ("NFC: nfcmrvl: add firmware download support")
Cc: stable <stable@vger.kernel.org>     # 4.4
Cc: Vincent Cuissard <cuissard@marvell.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/nfc/nfcmrvl/fw_dnld.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/nfc/nfcmrvl/fw_dnld.c b/drivers/nfc/nfcmrvl/fw_dnld.c
index f8dcdf4b24f6..af62c4c854f3 100644
--- a/drivers/nfc/nfcmrvl/fw_dnld.c
+++ b/drivers/nfc/nfcmrvl/fw_dnld.c
@@ -459,7 +459,7 @@ int	nfcmrvl_fw_dnld_init(struct nfcmrvl_private *priv)
 
 	INIT_WORK(&priv->fw_dnld.rx_work, fw_dnld_rx_work);
 	snprintf(name, sizeof(name), "%s_nfcmrvl_fw_dnld_rx_wq",
-		 dev_name(priv->dev));
+		 dev_name(&priv->ndev->nfc_dev->dev));
 	priv->fw_dnld.rx_wq = create_singlethread_workqueue(name);
 	if (!priv->fw_dnld.rx_wq)
 		return -ENOMEM;
@@ -496,6 +496,7 @@ int nfcmrvl_fw_dnld_start(struct nci_dev *ndev, const char *firmware_name)
 {
 	struct nfcmrvl_private *priv = nci_get_drvdata(ndev);
 	struct nfcmrvl_fw_dnld *fw_dnld = &priv->fw_dnld;
+	int res;
 
 	if (!priv->support_fw_dnld)
 		return -ENOTSUPP;
@@ -511,7 +512,9 @@ int nfcmrvl_fw_dnld_start(struct nci_dev *ndev, const char *firmware_name)
 	 */
 
 	/* Retrieve FW binary */
-	if (request_firmware(&fw_dnld->fw, firmware_name, priv->dev) < 0) {
+	res = request_firmware(&fw_dnld->fw, firmware_name,
+			       &ndev->nfc_dev->dev);
+	if (res < 0) {
 		nfc_err(priv->dev, "failed to retrieve FW %s", firmware_name);
 		return -ENOENT;
 	}
-- 
2.12.2

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#1612904 — [PATCH v2 7/8] NFC: nfcmrvl_usb: use interface as phy device

Use the USB-interface rather than parent USB-device device, which is
what this driver binds to, when registering the nci device.

Note that using the right device is important when dealing with device-
managed resources as the interface can be unbound independently of the
parent device.

Also note that private device pointer had already been set by
nfcmrvl_nci_register_dev() so the redundant assignment can therefore be
removed.

Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/nfc/nfcmrvl/usb.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/nfc/nfcmrvl/usb.c b/drivers/nfc/nfcmrvl/usb.c
index 585a0f20835b..728b3321842d 100644
--- a/drivers/nfc/nfcmrvl/usb.c
+++ b/drivers/nfc/nfcmrvl/usb.c
@@ -341,15 +341,13 @@ static int nfcmrvl_probe(struct usb_interface *intf,
 	init_usb_anchor(&drv_data->deferred);
 
 	priv = nfcmrvl_nci_register_dev(NFCMRVL_PHY_USB, drv_data, &usb_ops,
-					&drv_data->udev->dev, &config);
+					&intf->dev, &config);
 	if (IS_ERR(priv))
 		return PTR_ERR(priv);
 
 	drv_data->priv = priv;
 	drv_data->priv->support_fw_dnld = false;
 
-	priv->dev = &drv_data->udev->dev;
-
 	usb_set_intfdata(intf, drv_data);
 
 	return 0;
-- 
2.12.2

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#1612905 — [PATCH v2 5/8] NFC: nfcmrvl: fix firmware-management initialisation

The nci-device was never deregistered in the event that
fw-initialisation failed.

Fix this by moving the firmware initialisation before device
registration since the firmware work queue should be available before
registering.

Note that this depends on a recent fix that moved device-name
initialisation back to to nci_allocate_device() as the
firmware-workqueue name is now derived from the nfc-device name.

Fixes: 3194c6870158 ("NFC: nfcmrvl: add firmware download support")
Cc: stable <stable@vger.kernel.org>     # 4.4
Cc: Vincent Cuissard <cuissard@marvell.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/nfc/nfcmrvl/main.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/nfc/nfcmrvl/main.c b/drivers/nfc/nfcmrvl/main.c
index 3e3fc9588f10..a446590a71ca 100644
--- a/drivers/nfc/nfcmrvl/main.c
+++ b/drivers/nfc/nfcmrvl/main.c
@@ -158,26 +158,28 @@ struct nfcmrvl_private *nfcmrvl_nci_register_dev(enum nfcmrvl_phy phy,
 		goto error_free_gpio;
 	}
 
+	rc = nfcmrvl_fw_dnld_init(priv);
+	if (rc) {
+		nfc_err(dev, "failed to initialize FW download %d\n", rc);
+		goto error_free_dev;
+	}
+
 	nci_set_drvdata(priv->ndev, priv);
 
 	rc = nci_register_device(priv->ndev);
 	if (rc) {
 		nfc_err(dev, "nci_register_device failed %d\n", rc);
-		goto error_free_dev;
+		goto error_fw_dnld_deinit;
 	}
 
 	/* Ensure that controller is powered off */
 	nfcmrvl_chip_halt(priv);
 
-	rc = nfcmrvl_fw_dnld_init(priv);
-	if (rc) {
-		nfc_err(dev, "failed to initialize FW download %d\n", rc);
-		goto error_free_dev;
-	}
-
 	nfc_info(dev, "registered with nci successfully\n");
 	return priv;
 
+error_fw_dnld_deinit:
+	nfcmrvl_fw_dnld_deinit(priv);
 error_free_dev:
 	nci_free_device(priv->ndev);
 error_free_gpio:
-- 
2.12.2

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