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[PATCH 2/3] staging/rdma/hfi1: check return value of kcalloc

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  [PATCH 2/3] staging/rdma/hfi1: check return value of kcalloc Nicholas Mc Guire <hofrat@osadl.org> - 2015-12-14 16:00 +0100
    RE: [PATCH 2/3] staging/rdma/hfi1: check return value of kcalloc "Marciniszyn, Mike" <mike.marciniszyn@intel.com> - 2015-12-14 16:30 +0100
      Re: [PATCH 2/3] staging/rdma/hfi1: check return value of kcalloc Nicholas Mc Guire <der.herr@hofr.at> - 2015-12-14 18:40 +0100

#1291239 — [PATCH 2/3] staging/rdma/hfi1: check return value of kcalloc

Add a null check after the kcalloc call as proposed by
Mike Marciniszyn <mike.marciniszyn@intel.com>.

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
---

Patch was compile tested with: x86_64_defconfig
CONFIG_INFINIBAND=m, CONFIG_STAGING=y, CONFIG_STAGING_RDMA=m

Patch is against linux-next (localversion-next is -next-20151214)

 drivers/staging/rdma/hfi1/chip.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/staging/rdma/hfi1/chip.c b/drivers/staging/rdma/hfi1/chip.c
index 31eec8a..52d2bd7 100644
--- a/drivers/staging/rdma/hfi1/chip.c
+++ b/drivers/staging/rdma/hfi1/chip.c
@@ -10129,6 +10129,9 @@ static void init_qos(struct hfi1_devdata *dd, u32 first_ctxt)
 	if (num_vls * qpns_per_vl > dd->chip_rcv_contexts)
 		goto bail;
 	rsmmap = kcalloc(NUM_MAP_REGS, sizeof(u64), GFP_KERNEL);
+	if (!rsmmap)
+		goto bail;
+
 	/* init the local copy of the table */
 	for (i = 0, ctxt = first_ctxt; i < num_vls; i++) {
 		unsigned tctxt;
-- 
1.7.10.4

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#1291273

> @@ -10129,6 +10129,9 @@ static void init_qos(struct hfi1_devdata *dd,
> u32 first_ctxt)
>  	if (num_vls * qpns_per_vl > dd->chip_rcv_contexts)
>  		goto bail;
>  	rsmmap = kcalloc(NUM_MAP_REGS, sizeof(u64), GFP_KERNEL);
> +	if (!rsmmap)
> +		goto bail;
> +

I checked out a linux-next remote at the next-20151214 tag.

The allocation method is clearly kmalloc_array() not kcalloc().

Where are you seeing the kcalloc()?

While it is tempting to allocate and zero, there is a chip rev specific difference.

Mike
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#1291367

On Mon, Dec 14, 2015 at 03:21:24PM +0000, Marciniszyn, Mike wrote:
> > @@ -10129,6 +10129,9 @@ static void init_qos(struct hfi1_devdata *dd,
> > u32 first_ctxt)
> >  	if (num_vls * qpns_per_vl > dd->chip_rcv_contexts)
> >  		goto bail;
> >  	rsmmap = kcalloc(NUM_MAP_REGS, sizeof(u64), GFP_KERNEL);
> > +	if (!rsmmap)
> > +		goto bail;
> > +
> 
> I checked out a linux-next remote at the next-20151214 tag.
> 
> The allocation method is clearly kmalloc_array() not kcalloc().
> 
> Where are you seeing the kcalloc()?
> 
> While it is tempting to allocate and zero, there is a chip rev specific difference.
>
x = kmalloc_array(...)
if(!x)
   ...
memset(x...)

should be equivalent to

kcalloc - include/linux/slab.h

static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
{
        return kmalloc_array(n, size, flags | __GFP_ZERO);
}

if the assumption that this is equvalent is wrong I appologize
the intent was simply API consolidation as the patch description
stated.

thx!
hofrta
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