[bug report] [SCSI] mvumi: GFP_KERNEL under spin lock

[bug report] [SCSI] mvumi: GFP_KERNEL under spin lock

[Dan Carpenter]

Hello Jianyun Li,

The patch f0c568a478f0: "[SCSI] mvumi: Add Marvell UMI driver" from 
May 11, 2011, leads to the following warning:
drivers/scsi/mvumi.c:121 mvumi_alloc_mem_resource()
	 error: scheduling with locks held: 'spin_lock:host_lock'

The problem is that we do a couple GPF_KERNEL allocations in
mvumi_alloc_mem_resource() and this static analysis program sees a path
where that function is called with spin_locks held.

mvumi_isr_handler() <- takes a spin lock
-> mvumi_handshake()
   -> mvumi_init_data()
      -> mvumi_alloc_mem_resource() <- GFP_KERNEL

The IRQ handler does print a warning before calling mvumi_handshake()
so it seems like this path doesn't get exercised very much.

regards,
dan carpenter

Re: [bug report] [SCSI] mvumi: GFP_KERNEL under spin lock

[Dan Carpenter]

Whatever happened with this?  You could just change the GFP_KERNEL
to GFP_ATOMIC.

regards,
dan carpenter

On Tue, Aug 14, 2012 at 05:59:27PM +0300, Dan Carpenter wrote:
> Hello Jianyun Li,
> 
> The patch f0c568a478f0: "[SCSI] mvumi: Add Marvell UMI driver" from 
> May 11, 2011, leads to the following warning:
> drivers/scsi/mvumi.c:121 mvumi_alloc_mem_resource()
> 	 error: scheduling with locks held: 'spin_lock:host_lock'
> 
> The problem is that we do a couple GPF_KERNEL allocations in
> mvumi_alloc_mem_resource() and this static analysis program sees a path
> where that function is called with spin_locks held.
> 
> mvumi_isr_handler() <- takes a spin lock
> -> mvumi_handshake()
>    -> mvumi_init_data()
>       -> mvumi_alloc_mem_resource() <- GFP_KERNEL
> 
> The IRQ handler does print a warning before calling mvumi_handshake()
> so it seems like this path doesn't get exercised very much.
> 
> regards,
> dan carpenter
> 
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Re: [bug report] [SCSI] mvumi: GFP_KERNEL under spin lock

[Dan Carpenter]

On Fri, Sep 28, 2012 at 02:30:22PM +0300, Dan Carpenter wrote:
> Whatever happened with this?  You could just change the GFP_KERNEL
> to GFP_ATOMIC.
> 

Ah, that email address is dead is what happened.  I'll send a patch
that changes this to GFP_ATOMIC.

regards,
dan carpenter

[patch] [SCSI] mvumi: use GFP_ATOMIC under spin lock

[Dan Carpenter]

This is called from the interrupt handler and with spin_locks held.  Use
GFP_ATOMIC.  The call tree looks like:
  mvumi_isr_handler() <- takes a spin lock
  -> mvumi_handshake()
     -> mvumi_init_data()
        -> mvumi_alloc_mem_resource() <- GFP_KERNEL

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/scsi/mvumi.c b/drivers/scsi/mvumi.c
index 783edc7..5ad8da4 100644
--- a/drivers/scsi/mvumi.c
+++ b/drivers/scsi/mvumi.c
@@ -118,7 +118,7 @@ static int mvumi_map_pci_addr(struct pci_dev *dev, void **addr_array)
 static struct mvumi_res *mvumi_alloc_mem_resource(struct mvumi_hba *mhba,
 				enum resource_type type, unsigned int size)
 {
-	struct mvumi_res *res = kzalloc(sizeof(*res), GFP_KERNEL);
+	struct mvumi_res *res = kzalloc(sizeof(*res), GFP_ATOMIC);
 
 	if (!res) {
 		dev_err(&mhba->pdev->dev,
@@ -128,7 +128,7 @@ static struct mvumi_res *mvumi_alloc_mem_resource(struct mvumi_hba *mhba,
 
 	switch (type) {
 	case RESOURCE_CACHED_MEMORY:
-		res->virt_addr = kzalloc(size, GFP_KERNEL);
+		res->virt_addr = kzalloc(size, GFP_ATOMIC);
 		if (!res->virt_addr) {
 			dev_err(&mhba->pdev->dev,
 				"unable to allocate memory,size = %d.\n", size);