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| author | Jia-Ju Bai <baijiaju1990@gmail.com> | 2018-09-15 11:13:03 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-09-18 13:29:10 +0200 |
| commit | bffa9b1cc64a12f3162f79151dee56199efbc785 (patch) | |
| tree | d7a541b5324a9b1e7d168c8fdf8d6a29a31fcd5f | |
| parent | 2051c6ae928ddbd4d314ba8ea89298d686ad86b7 (diff) | |
| download | linux-stable-bffa9b1cc64a12f3162f79151dee56199efbc785.tar.gz linux-stable-bffa9b1cc64a12f3162f79151dee56199efbc785.tar.bz2 linux-stable-bffa9b1cc64a12f3162f79151dee56199efbc785.zip | |
staging: dgnc: Fix a sleep-in-atomic-context bug in cls_assert_modem_signals()
The driver may sleep with holding a spinlock.
The function call path (from bottom to top) in Linux-4.17 is:
[FUNC] usleep_range
drivers/staging/dgnc/dgnc_cls.c, 391:
usleep_range in cls_assert_modem_signals
drivers/staging/dgnc/dgnc_cls.c, 449:
cls_assert_modem_signals in cls_copy_data_from_queue_to_uart
drivers/staging/dgnc/dgnc_cls.c, 406:
_raw_spin_lock_irqsave in cls_copy_data_from_queue_to_uart
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/staging/dgnc/dgnc_cls.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/staging/dgnc/dgnc_cls.c b/drivers/staging/dgnc/dgnc_cls.c index 7e6cbfe4e4ee..a1e98ee7f9e0 100644 --- a/drivers/staging/dgnc/dgnc_cls.c +++ b/drivers/staging/dgnc/dgnc_cls.c @@ -388,7 +388,7 @@ static void cls_assert_modem_signals(struct channel_t *ch) writeb(out, &ch->ch_cls_uart->mcr); /* Give time for the UART to actually drop the signals */ - usleep_range(10, 20); + udelay(20); } static void cls_copy_data_from_queue_to_uart(struct channel_t *ch) |