[PATCH AUTOSEL 5.10 03/39] spi: Fix spi device unregister flow

[PATCH AUTOSEL 5.10 03/39] spi: Fix spi device unregister flow

[Sasha Levin]

From: Saravana Kannan <saravanak@google.com>

[ Upstream commit c7299fea67696db5bd09d924d1f1080d894f92ef ]

When an SPI device is unregistered, the spi->controller->cleanup() is
called in the device's release callback. That's wrong for a couple of
reasons:

1. spi_dev_put() can be called before spi_add_device() is called. And
   it's spi_add_device() that calls spi_setup(). This will cause clean()
   to get called without the spi device ever being setup.

2. There's no guarantee that the controller's driver would be present by
   the time the spi device's release function gets called.

3. It also causes "sleeping in atomic context" stack dump[1] when device
   link deletion code does a put_device() on the spi device.

Fix these issues by simply moving the cleanup from the device release
callback to the actual spi_unregister_device() function.

[1] - https://lore.kernel.org/lkml/CAHp75Vc=FCGcUyS0v6fnxme2YJ+qD+Y-hQDQLa2JhWNON9VmsQ@mail.gmail.com/

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20210426235638.1285530-1-saravanak@google.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/spi/spi.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 419de3d40481..72143bc13078 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -47,10 +47,6 @@ static void spidev_release(struct device *dev)
 {
 	struct spi_device	*spi = to_spi_device(dev);
 
-	/* spi controllers may cleanup for released devices */
-	if (spi->controller->cleanup)
-		spi->controller->cleanup(spi);
-
 	spi_controller_put(spi->controller);
 	kfree(spi->driver_override);
 	kfree(spi);
@@ -550,6 +546,12 @@ static int spi_dev_check(struct device *dev, void *data)
 	return 0;
 }
 
+static void spi_cleanup(struct spi_device *spi)
+{
+	if (spi->controller->cleanup)
+		spi->controller->cleanup(spi);
+}
+
 /**
  * spi_add_device - Add spi_device allocated with spi_alloc_device
  * @spi: spi_device to register
@@ -614,11 +616,13 @@ int spi_add_device(struct spi_device *spi)
 
 	/* Device may be bound to an active driver when this returns */
 	status = device_add(&spi->dev);
-	if (status < 0)
+	if (status < 0) {
 		dev_err(dev, "can't add %s, status %d\n",
 				dev_name(&spi->dev), status);
-	else
+		spi_cleanup(spi);
+	} else {
 		dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
+	}
 
 done:
 	mutex_unlock(&spi_add_lock);
@@ -705,6 +709,8 @@ void spi_unregister_device(struct spi_device *spi)
 	if (!spi)
 		return;
 
+	spi_cleanup(spi);
+
 	if (spi->dev.of_node) {
 		of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
 		of_node_put(spi->dev.of_node);
-- 
2.30.2

[PATCH AUTOSEL 5.10 04/39] spi: spi-zynq-qspi: Fix stack violation bug

[Sasha Levin]

From: Karen Dombroski <karen.dombroski@marsbioimaging.com>

[ Upstream commit 6d5ff8e632a4f2389c331e5554cd1c2a9a28c7aa ]

When the number of bytes for the op is greater than one, the read could
run off the end of the function stack and cause a crash.

This patch restores the behaviour of safely reading out of the original
opcode location.

Signed-off-by: Karen Dombroski <karen.dombroski@marsbioimaging.com>
Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@xilinx.com>
Link: https://lore.kernel.org/r/20210429053802.17650-3-amit.kumar-mahapatra@xilinx.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/spi/spi-zynq-qspi.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/spi-zynq-qspi.c b/drivers/spi/spi-zynq-qspi.c
index 5d8a5ee62fa2..2765289028fa 100644
--- a/drivers/spi/spi-zynq-qspi.c
+++ b/drivers/spi/spi-zynq-qspi.c
@@ -528,18 +528,17 @@ static int zynq_qspi_exec_mem_op(struct spi_mem *mem,
 	struct zynq_qspi *xqspi = spi_controller_get_devdata(mem->spi->master);
 	int err = 0, i;
 	u8 *tmpbuf;
-	u8 opcode = op->cmd.opcode;
 
 	dev_dbg(xqspi->dev, "cmd:%#x mode:%d.%d.%d.%d\n",
-		opcode, op->cmd.buswidth, op->addr.buswidth,
+		op->cmd.opcode, op->cmd.buswidth, op->addr.buswidth,
 		op->dummy.buswidth, op->data.buswidth);
 
 	zynq_qspi_chipselect(mem->spi, true);
 	zynq_qspi_config_op(xqspi, mem->spi);
 
-	if (op->cmd.nbytes) {
+	if (op->cmd.opcode) {
 		reinit_completion(&xqspi->data_completion);
-		xqspi->txbuf = &opcode;
+		xqspi->txbuf = (u8 *)&op->cmd.opcode;
 		xqspi->rxbuf = NULL;
 		xqspi->tx_bytes = op->cmd.nbytes;
 		xqspi->rx_bytes = op->cmd.nbytes;
-- 
2.30.2

[PATCH AUTOSEL 5.10 14/39] spi: sprd: Add missing MODULE_DEVICE_TABLE

[Sasha Levin]

From: Chunyan Zhang <chunyan.zhang@unisoc.com>

[ Upstream commit 7907cad7d07e0055789ec0c534452f19dfe1fc80 ]

MODULE_DEVICE_TABLE is used to extract the device information out of the
driver and builds a table when being compiled. If using this macro,
kernel can find the driver if available when the device is plugged in,
and then loads that driver and initializes the device.

Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
Link: https://lore.kernel.org/r/20210512093534.243040-1-zhang.lyra@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/spi/spi-sprd.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/spi/spi-sprd.c b/drivers/spi/spi-sprd.c
index b41a75749b49..28e70db9bbba 100644
--- a/drivers/spi/spi-sprd.c
+++ b/drivers/spi/spi-sprd.c
@@ -1068,6 +1068,7 @@ static const struct of_device_id sprd_spi_of_match[] = {
 	{ .compatible = "sprd,sc9860-spi", },
 	{ /* sentinel */ }
 };
+MODULE_DEVICE_TABLE(of, sprd_spi_of_match);
 
 static struct platform_driver sprd_spi_driver = {
 	.driver = {
-- 
2.30.2