lkml.org 
[lkml]   [2020]   [Jun]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.14 043/190] spi: dw: fix possible race condition
    Date
    [ Upstream commit 66b19d762378785d1568b5650935205edfeb0503 ]

    It is possible to get an interrupt as soon as it is requested. dw_spi_irq
    does spi_controller_get_devdata(master) and expects it to be different than
    NULL. However, spi_controller_set_devdata() is called after request_irq(),
    resulting in the following crash:

    CPU 0 Unable to handle kernel paging request at virtual address 00000030, epc == 8058e09c, ra == 8018ff90
    [...]
    Call Trace:
    [<8058e09c>] dw_spi_irq+0x8/0x64
    [<8018ff90>] __handle_irq_event_percpu+0x70/0x1d4
    [<80190128>] handle_irq_event_percpu+0x34/0x8c
    [<801901c4>] handle_irq_event+0x44/0x80
    [<801951a8>] handle_level_irq+0xdc/0x194
    [<8018f580>] generic_handle_irq+0x38/0x50
    [<804c6924>] ocelot_irq_handler+0x104/0x1c0

    Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
    Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
    Signed-off-by: Mark Brown <broonie@kernel.org>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    drivers/spi/spi-dw.c | 3 ++-
    1 file changed, 2 insertions(+), 1 deletion(-)

    diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
    index cbdad3c4930f..5c16f7b17029 100644
    --- a/drivers/spi/spi-dw.c
    +++ b/drivers/spi/spi-dw.c
    @@ -499,6 +499,8 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
    dws->dma_addr = (dma_addr_t)(dws->paddr + DW_SPI_DR);
    spin_lock_init(&dws->buf_lock);

    + spi_master_set_devdata(master, dws);
    +
    ret = request_irq(dws->irq, dw_spi_irq, IRQF_SHARED, dev_name(dev),
    master);
    if (ret < 0) {
    @@ -532,7 +534,6 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
    }
    }

    - spi_master_set_devdata(master, dws);
    ret = devm_spi_register_master(dev, master);
    if (ret) {
    dev_err(&master->dev, "problem registering spi master\n");
    --
    2.25.1


    \
     
     \ /
      Last update: 2020-06-19 18:39    [W:4.237 / U:0.088 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site