Messages in this thread Patch in this message | | | From | Sasha Levin <> | Subject | [PATCH AUTOSEL 4.14 33/66] scsi: atari_scsi: Fix race condition between .queuecommand and EH | Date | Tue, 22 Dec 2020 21:22:19 -0500 |
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From: Finn Thain <fthain@telegraphics.com.au>
[ Upstream commit 03fe6a640a05c5dc04b6bcdddfb981d015e84ed4 ]
It is possible that bus_reset_cleanup() or .eh_abort_handler could be invoked during NCR5380_queuecommand(). If that takes place before the new command is enqueued and after the ST-DMA "lock" has been acquired, the ST-DMA "lock" will be released again. This will result in a lost DMA interrupt and a command timeout. Fix this by excluding EH and interrupt handlers while the new command is enqueued.
Link: https://lore.kernel.org/r/af25163257796b50bb99d4ede4025cea55787b8f.1605847196.git.fthain@telegraphics.com.au Tested-by: Michael Schmitz <schmitzmic@gmail.com> Reviewed-by: Michael Schmitz <schmitzmic@gmail.com> Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/scsi/NCR5380.c | 9 ++++++--- drivers/scsi/atari_scsi.c | 10 +++------- 2 files changed, 9 insertions(+), 10 deletions(-)
diff --git a/drivers/scsi/NCR5380.c b/drivers/scsi/NCR5380.c index 79b0b4eece194..d8268abf5a307 100644 --- a/drivers/scsi/NCR5380.c +++ b/drivers/scsi/NCR5380.c @@ -559,11 +559,14 @@ static int NCR5380_queue_command(struct Scsi_Host *instance, cmd->result = 0; - if (!NCR5380_acquire_dma_irq(instance)) - return SCSI_MLQUEUE_HOST_BUSY; - spin_lock_irqsave(&hostdata->lock, flags); + if (!NCR5380_acquire_dma_irq(instance)) { + spin_unlock_irqrestore(&hostdata->lock, flags); + + return SCSI_MLQUEUE_HOST_BUSY; + } + /* * Insert the cmd into the issue queue. Note that REQUEST SENSE * commands are added to the head of the queue since any command will diff --git a/drivers/scsi/atari_scsi.c b/drivers/scsi/atari_scsi.c index 764c46d7333e6..42f11c8815a7f 100644 --- a/drivers/scsi/atari_scsi.c +++ b/drivers/scsi/atari_scsi.c @@ -376,15 +376,11 @@ static int falcon_get_lock(struct Scsi_Host *instance) if (IS_A_TT()) return 1; - if (stdma_is_locked_by(scsi_falcon_intr) && - instance->hostt->can_queue > 1) + if (stdma_is_locked_by(scsi_falcon_intr)) return 1; - if (in_interrupt()) - return stdma_try_lock(scsi_falcon_intr, instance); - - stdma_lock(scsi_falcon_intr, instance); - return 1; + /* stdma_lock() may sleep which means it can't be used here */ + return stdma_try_lock(scsi_falcon_intr, instance); } #ifndef MODULE -- 2.27.0
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