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    Subject[PATCH AUTOSEL 4.18 55/76] net: cadence: Fix a sleep-in-atomic-context bug in macb_halt_tx()
    Date
    From: Jia-Ju Bai <baijiaju1990@gmail.com>

    [ Upstream commit 16fe10cf92783ed9ceb182d6ea2b8adf5e8ec1b8 ]

    The kernel module may sleep with holding a spinlock.

    The function call paths (from bottom to top) in Linux-4.16 are:

    [FUNC] usleep_range
    drivers/net/ethernet/cadence/macb_main.c, 648:
    usleep_range in macb_halt_tx
    drivers/net/ethernet/cadence/macb_main.c, 730:
    macb_halt_tx in macb_tx_error_task
    drivers/net/ethernet/cadence/macb_main.c, 721:
    _raw_spin_lock_irqsave in macb_tx_error_task

    To fix this bug, usleep_range() is replaced with udelay().

    This bug is found by my static analysis tool DSAC.

    Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>
    Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
    ---
    drivers/net/ethernet/cadence/macb_main.c | 2 +-
    1 file changed, 1 insertion(+), 1 deletion(-)

    diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
    index 515d96e32143..c4d7479938e2 100644
    --- a/drivers/net/ethernet/cadence/macb_main.c
    +++ b/drivers/net/ethernet/cadence/macb_main.c
    @@ -648,7 +648,7 @@ static int macb_halt_tx(struct macb *bp)
    if (!(status & MACB_BIT(TGO)))
    return 0;

    - usleep_range(10, 250);
    + udelay(250);
    } while (time_before(halt_time, timeout));

    return -ETIMEDOUT;
    --
    2.17.1
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