[PATCH 2/2] block: DAC960: Replace GFP_ATOMIC with GFP_KERNEL in DAC960_CreateAuxiliaryStructures

From: Jia-Ju Bai
Date: Fri Jan 26 2018 - 05:21:21 EST


After checking all possible call chains to
DAC960_CreateAuxiliaryStructures(),
my tool finds that this function is never called in atomic context,
namely never in an interrupt handler or holding a spinlock.
And DAC960_CreateAuxiliaryStructures() calls
pci_pool_create() and pci_pool_destroy() that can sleep,
so it indicates that DAC960_CreateAuxiliaryStructures() can call
functions which may sleep.
Thus GFP_ATOMIC is not necessary, and it can be replaced with GFP_KERNEL.

This is found by a static analysis tool named DCNS written by myself.

Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
---
drivers/block/DAC960.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/block/DAC960.c b/drivers/block/DAC960.c
index 442e777..39fc016 100644
--- a/drivers/block/DAC960.c
+++ b/drivers/block/DAC960.c
@@ -323,7 +323,7 @@ static bool DAC960_CreateAuxiliaryStructures(DAC960_Controller_T *Controller)
CommandsRemaining = CommandAllocationGroupSize;
CommandGroupByteCount =
CommandsRemaining * CommandAllocationLength;
- AllocationPointer = kzalloc(CommandGroupByteCount, GFP_ATOMIC);
+ AllocationPointer = kzalloc(CommandGroupByteCount, GFP_KERNEL);
if (AllocationPointer == NULL)
return DAC960_Failure(Controller,
"AUXILIARY STRUCTURE CREATION");
@@ -335,13 +335,13 @@ static bool DAC960_CreateAuxiliaryStructures(DAC960_Controller_T *Controller)
Command->Next = Controller->FreeCommands;
Controller->FreeCommands = Command;
Controller->Commands[CommandIdentifier-1] = Command;
- ScatterGatherCPU = pci_pool_alloc(ScatterGatherPool, GFP_ATOMIC,
+ ScatterGatherCPU = pci_pool_alloc(ScatterGatherPool, GFP_KERNEL,
&ScatterGatherDMA);
if (ScatterGatherCPU == NULL)
return DAC960_Failure(Controller, "AUXILIARY STRUCTURE CREATION");

if (RequestSensePool != NULL) {
- RequestSenseCPU = pci_pool_alloc(RequestSensePool, GFP_ATOMIC,
+ RequestSenseCPU = pci_pool_alloc(RequestSensePool, GFP_KERNEL,
&RequestSenseDMA);
if (RequestSenseCPU == NULL) {
pci_pool_free(ScatterGatherPool, ScatterGatherCPU,
--
1.7.9.5