From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Date: Sat, 12 Jan 2019 05:44:26 +0000 Subject: Re: [PATCH] powerpc/powernv/npu: Allocate enough memory in pnv_try_setup_npu_table_group() Message-Id: <20190112054426.GF1743@kadam> List-Id: References: <20190109102328.GB5476@kadam> <20190112003035.GA10427@350D> In-Reply-To: <20190112003035.GA10427@350D> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Balbir Singh Cc: Alexey Kardashevskiy , Mark Hairgrove , kernel-janitors@vger.kernel.org, Paul Mackerras , Alistair Popple , linuxppc-dev@lists.ozlabs.org On Sat, Jan 12, 2019 at 11:30:35AM +1100, Balbir Singh wrote: > On Wed, Jan 09, 2019 at 01:23:29PM +0300, Dan Carpenter wrote: > > There is a typo so we accidentally allocate enough memory for a pointer > > when we wanted to allocate enough for a struct. > > > > Fixes: 0bd971676e68 ("powerpc/powernv/npu: Add compound IOMMU groups") > > Signed-off-by: Dan Carpenter > > --- > > arch/powerpc/platforms/powernv/npu-dma.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/arch/powerpc/platforms/powernv/npu-dma.c b/arch/powerpc/platforms/powernv/npu-dma.c > > index d7f742ed48ba..3f58c7dbd581 100644 > > --- a/arch/powerpc/platforms/powernv/npu-dma.c > > +++ b/arch/powerpc/platforms/powernv/npu-dma.c > > @@ -564,7 +564,7 @@ struct iommu_table_group *pnv_try_setup_npu_table_group(struct pnv_ioda_pe *pe) > > } > > } else { > > /* Create a group for 1 GPU and attached NPUs for POWER8 */ > > - pe->npucomp = kzalloc(sizeof(pe->npucomp), GFP_KERNEL); > > + pe->npucomp = kzalloc(sizeof(*pe->npucomp), GFP_KERNEL); > > To avoid these in the future, I wonder if instead of sizeof(pe->npucomp), we insist on > sizeof structure > > pe->npucomp = kzalloc(sizeof(struct npucomp), GFP_KERNEL); > The latest kernel fashion is sizeof(*ptr). It can go wrong either way. I don't have strong feelings about it. These sorts of bugs don't last long because they're caught in testing or with static analysis. regards, dan carpenter