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Commit 05dfa5c9 authored by David Mosberger-Tang's avatar David Mosberger-Tang Committed by Greg Kroah-Hartman
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usb: host: max3421-hcd: fix "spi_rd8" uses dynamic stack allocation warning 



kmalloc the SPI rx and tx data buffers.  This appears to be the only
portable way to guarantee that the buffers are DMA-safe (e.g., in
separate DMA cache-lines).  This patch makes the spi_rdX()/spi_wrX()
non-reentrant, but that's OK because calls to them are guaranteed to
be serialized by the per-HCD SPI-thread.

Reported-by: default avatarkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: default avatarDavid Mosberger <davidm@egauge.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 00c5aa17

drivers/usb/host/max3421-hcd.c

+60 −34
Original line number Diff line number Diff line
@@ -102,6 +102,10 @@ enum scheduling_pass { 
	SCHED_PASS_DONE

};



struct max3421_dma_buf {

	u8 data[2];

};



struct max3421_hcd {

	spinlock_t lock;
@@ -123,6 +127,12 @@ struct max3421_hcd { 
	 */

	u8 rev;				/* chip revision */

	u16 frame_number;

	/*

	 * kmalloc'd buffers guaranteed to be in separate (DMA)

	 * cache-lines:

	 */

	struct max3421_dma_buf *tx;

	struct max3421_dma_buf *rx;

	/*

	 * URB we're currently processing.  Must not be reset to NULL

	 * unless MAX3421E chip is idle:
@@ -332,51 +342,47 @@ max3421_to_hcd(struct max3421_hcd *max3421_hcd) 
static u8

spi_rd8(struct usb_hcd *hcd, unsigned int reg)

{

	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);

	struct spi_device *spi = to_spi_device(hcd->self.controller);

	struct spi_transfer transfer;

	u8 tx_data[1];

	/*

	 * RX data must be in its own cache-line so it stays flushed

	 * from the cache until the transfer is complete.  Otherwise,

	 * we get stale data from the cache.

	 */

	u8 rx_data[SMP_CACHE_BYTES] ____cacheline_aligned;

	struct spi_message msg;



	memset(&transfer, 0, sizeof(transfer));



	spi_message_init(&msg);



	tx_data[0] = (field(reg, MAX3421_SPI_REG_SHIFT) |

	max3421_hcd->tx->data[0] =

		(field(reg, MAX3421_SPI_REG_SHIFT) |

		 field(MAX3421_SPI_DIR_RD, MAX3421_SPI_DIR_SHIFT));



	transfer.tx_buf = tx_data;

	transfer.rx_buf = rx_data;

	transfer.tx_buf = max3421_hcd->tx->data;

	transfer.rx_buf = max3421_hcd->rx->data;

	transfer.len = 2;



	spi_message_add_tail(&transfer, &msg);

	spi_sync(spi, &msg);



	return rx_data[1];

	return max3421_hcd->rx->data[1];

}



static void

spi_wr8(struct usb_hcd *hcd, unsigned int reg, u8 val)

{

	struct spi_device *spi = to_spi_device(hcd->self.controller);

	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);

	struct spi_transfer transfer;

	struct spi_message msg;

	u8 tx_data[2];



	memset(&transfer, 0, sizeof(transfer));



	spi_message_init(&msg);



	tx_data[0] = (field(reg, MAX3421_SPI_REG_SHIFT) |

	max3421_hcd->tx->data[0] =

		(field(reg, MAX3421_SPI_REG_SHIFT) |

		 field(MAX3421_SPI_DIR_WR, MAX3421_SPI_DIR_SHIFT));

	tx_data[1] = val;

	max3421_hcd->tx->data[1] = val;



	transfer.tx_buf = tx_data;

	transfer.tx_buf = max3421_hcd->tx->data;

	transfer.len = 2;



	spi_message_add_tail(&transfer, &msg);
@@ -387,18 +393,18 @@ static void 
spi_rd_buf(struct usb_hcd *hcd, unsigned int reg, void *buf, size_t len)

{

	struct spi_device *spi = to_spi_device(hcd->self.controller);

	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);

	struct spi_transfer transfer[2];

	struct spi_message msg;

	u8 cmd;



	memset(transfer, 0, sizeof(transfer));



	spi_message_init(&msg);



	cmd = (field(reg, MAX3421_SPI_REG_SHIFT) |

	max3421_hcd->tx->data[0] =

		(field(reg, MAX3421_SPI_REG_SHIFT) |

		 field(MAX3421_SPI_DIR_RD, MAX3421_SPI_DIR_SHIFT));



	transfer[0].tx_buf = &cmd;

	transfer[0].tx_buf = max3421_hcd->tx->data;

	transfer[0].len = 1;



	transfer[1].rx_buf = buf;
@@ -413,18 +419,19 @@ static void 
spi_wr_buf(struct usb_hcd *hcd, unsigned int reg, void *buf, size_t len)

{

	struct spi_device *spi = to_spi_device(hcd->self.controller);

	struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd);

	struct spi_transfer transfer[2];

	struct spi_message msg;

	u8 cmd;



	memset(transfer, 0, sizeof(transfer));



	spi_message_init(&msg);



	cmd = (field(reg, MAX3421_SPI_REG_SHIFT) |

	max3421_hcd->tx->data[0] =

		(field(reg, MAX3421_SPI_REG_SHIFT) |

		 field(MAX3421_SPI_DIR_WR, MAX3421_SPI_DIR_SHIFT));



	transfer[0].tx_buf = &cmd;

	transfer[0].tx_buf = max3421_hcd->tx->data;

	transfer[0].len = 1;



	transfer[1].tx_buf = buf;
@@ -1834,8 +1841,8 @@ static int 
max3421_probe(struct spi_device *spi)

{

	struct max3421_hcd *max3421_hcd;

	struct usb_hcd *hcd;

	int retval;

	struct usb_hcd *hcd = NULL;

	int retval = -ENOMEM;



	if (spi_setup(spi) < 0) {

		dev_err(&spi->dev, "Unable to setup SPI bus");
@@ -1846,7 +1853,7 @@ max3421_probe(struct spi_device *spi) 
			     dev_name(&spi->dev));

	if (!hcd) {

		dev_err(&spi->dev, "failed to create HCD structure\n");

		return -ENOMEM;

		goto error;

	}

	set_bit(HCD_FLAG_POLL_RH, &hcd->flags);

	max3421_hcd = hcd_to_max3421(hcd);
@@ -1854,29 +1861,48 @@ max3421_probe(struct spi_device *spi) 
	max3421_hcd_list = max3421_hcd;

	INIT_LIST_HEAD(&max3421_hcd->ep_list);



	max3421_hcd->tx = kmalloc(sizeof(*max3421_hcd->tx), GFP_KERNEL);

	if (!max3421_hcd->tx) {

		dev_err(&spi->dev, "failed to kmalloc tx buffer\n");

		goto error;

	}

	max3421_hcd->rx = kmalloc(sizeof(*max3421_hcd->rx), GFP_KERNEL);

	if (!max3421_hcd->rx) {

		dev_err(&spi->dev, "failed to kmalloc rx buffer\n");

		goto error;

	}



	max3421_hcd->spi_thread = kthread_run(max3421_spi_thread, hcd,

					      "max3421_spi_thread");

	if (max3421_hcd->spi_thread == ERR_PTR(-ENOMEM)) {

		dev_err(&spi->dev,

			"failed to create SPI thread (out of memory)\n");

		return -ENOMEM;

		goto error;

	}



	retval = usb_add_hcd(hcd, 0, 0);

	if (retval) {

		dev_err(&spi->dev, "failed to add HCD\n");

		usb_put_hcd(hcd);

		return retval;

		goto error;

	}



	retval = request_irq(spi->irq, max3421_irq_handler,

			     IRQF_TRIGGER_LOW, "max3421", hcd);

	if (retval < 0) {

		usb_put_hcd(hcd);

		dev_err(&spi->dev, "failed to request irq %d\n", spi->irq);

		return retval;

		goto error;

	}

	return 0;



error:

	if (hcd) {

		kfree(max3421_hcd->tx);

		kfree(max3421_hcd->rx);

		if (max3421_hcd->spi_thread)

			kthread_stop(max3421_hcd->spi_thread);

		usb_put_hcd(hcd);

	}

	return retval;

}



static int