2017-12-12 13:30:50

by Jia-Ju Bai

Subject: [PATCH] arcmsr: Fix possible sleep-in-atomic bugs in arcmsr_queue_command

From: Jia-Ju Bai <[email protected]>

The driver may sleep under a spinlock, and the function call paths are:
arcmsr_queue_command(acquire the spinlock)
arcmsr_queue_command_lck
arcmsr_handle_virtual_command
arcmsr_iop_message_xfer
arcmsr_iop_parking
arcmsr_stop_adapter_bgrb
arcmsr_hbaA_stop_bgrb
arcmsr_hbaA_wait_msgint_ready
msleep --> may sleep

arcmsr_queue_command(acquire the spinlock)
arcmsr_queue_command_lck
arcmsr_handle_virtual_command
arcmsr_iop_message_xfer
arcmsr_iop_parking
arcmsr_stop_adapter_bgrb
arcmsr_hbaB_stop_bgrb
arcmsr_hbaB_wait_msgint_ready
msleep --> may sleep

arcmsr_queue_command(acquire the spinlock)
arcmsr_queue_command_lck
arcmsr_handle_virtual_command
arcmsr_iop_message_xfer
arcmsr_iop_parking
arcmsr_stop_adapter_bgrb
arcmsr_hbaC_stop_bgrb
arcmsr_hbaC_wait_msgint_ready
msleep --> may sleep

arcmsr_queue_command(acquire the spinlock)
arcmsr_queue_command_lck
arcmsr_handle_virtual_command
arcmsr_iop_message_xfer
arcmsr_iop_parking
arcmsr_stop_adapter_bgrb
arcmsr_hbaD_stop_bgrb
arcmsr_hbaD_wait_msgint_ready
msleep --> may sleep

To fix them, msleep is replaced with mdelay.
These bugs are found by my static analysis tool and my code review.

Signed-off-by: Jia-Ju Bai <[email protected]>
---
drivers/scsi/arcmsr/arcmsr_hba.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/arcmsr/arcmsr_hba.c b/drivers/scsi/arcmsr/arcmsr_hba.c
index af032c4..31d94bd 100644
--- a/drivers/scsi/arcmsr/arcmsr_hba.c
+++ b/drivers/scsi/arcmsr/arcmsr_hba.c
@@ -347,7 +347,7 @@ static uint8_t arcmsr_hbaA_wait_msgint_ready(struct AdapterControlBlock *acb)
&reg->outbound_intstatus);
return true;
}
- msleep(10);
+ mdelay(10);
} /* max 20 seconds */

return false;
@@ -367,7 +367,7 @@ static uint8_t arcmsr_hbaB_wait_msgint_ready(struct AdapterControlBlock *acb)
reg->drv2iop_doorbell);
return true;
}
- msleep(10);
+ mdelay(10);
} /* max 20 seconds */

return false;
@@ -385,7 +385,7 @@ static uint8_t arcmsr_hbaC_wait_msgint_ready(struct AdapterControlBlock *pACB)
&phbcmu->outbound_doorbell_clear); /*clear interrupt*/
return true;
}
- msleep(10);
+ mdelay(10);
} /* max 20 seconds */

return false;
@@ -403,7 +403,7 @@ static bool arcmsr_hbaD_wait_msgint_ready(struct AdapterControlBlock *pACB)
reg->outbound_doorbell);
return true;
}
- msleep(10);
+ mdelay(10);
} /* max 20 seconds */
return false;
}
--
1.7.9.5