On Fri, 21 Sep 2018 11:32:53 +0200 Ahmad Fatoum a.fatoum@pengutronix.de wrote:

fsl_qspi_get_seqid() may return -EINVAL, but fsl_qspi_init_ahb_read() doesn't check for error codes with the result that -EINVAL could find itself signalled over the bus.

In conjunction with the LS1046A SoC's A-009283 errata ("Illegal accesses to SPI flash memory can result in a system hang") this illegal access to SPI flash memory results in a system hang if userspace attempts reading later on.

Avoid this by always checking fsl_qspi_get_seqid()'s return value and bail out otherwise.

Cc: stable@vger.kernel.org Signed-off-by: Ahmad Fatoum a.fatoum@pengutronix.de

Added

Fixes: e46ecda764dc ("mtd: spi-nor: Add Freescale QuadSPI driver")

and queued it to spi-nor/next.

Thanks,

Boris

---

drivers/mtd/spi-nor/fsl-quadspi.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c index 7d9620c7ff6c..1bb42e40c38b 100644 --- a/drivers/mtd/spi-nor/fsl-quadspi.c +++ b/drivers/mtd/spi-nor/fsl-quadspi.c @@ -543,6 +543,9 @@ fsl_qspi_runcmd(struct fsl_qspi *q, u8 cmd, unsigned int addr, int len) /* trigger the LUT now */ seqid = fsl_qspi_get_seqid(q, cmd);

• if (seqid < 0)

• return seqid;
  

• qspi_writel(q, (seqid << QUADSPI_IPCR_SEQID_SHIFT) | len, base + QUADSPI_IPCR);

@@ -671,7 +674,7 @@ static void fsl_qspi_set_map_addr(struct fsl_qspi *q)

• causes the controller to clear the buffer, and use the sequence pointed
• by the QUADSPI_BFGENCR[SEQID] to initiate a read from the flash.

*/ -static void fsl_qspi_init_ahb_read(struct fsl_qspi *q) +static int fsl_qspi_init_ahb_read(struct fsl_qspi *q) { void __iomem *base = q->iobase; int seqid; @@ -696,8 +699,12 @@ static void fsl_qspi_init_ahb_read(struct fsl_qspi *q) /* Set the default lut sequence for AHB Read. */ seqid = fsl_qspi_get_seqid(q, q->nor[0].read_opcode);

• if (seqid < 0)

• return seqid;
  

• qspi_writel(q, seqid << QUADSPI_BFGENCR_SEQID_SHIFT, q->iobase + QUADSPI_BFGENCR);
• return 0;

} /* This function was used to prepare and enable QSPI clock */ @@ -805,9 +812,7 @@ static int fsl_qspi_nor_setup_last(struct fsl_qspi *q) fsl_qspi_init_lut(q); /* Init for AHB read */

• fsl_qspi_init_ahb_read(q);
• return 0;

• return fsl_qspi_init_ahb_read(q);

} static const struct of_device_id fsl_qspi_dt_ids[] = {