Re: [PATCH] crypto: hisilicon - fix strncpy warning with strlcpy

[Zhangfei Gao]

On 2020/6/4 äå11:39, Herbert Xu wrote:
> On Thu, Jun 04, 2020 at 11:32:04AM +0800, Zhangfei Gao wrote:
> > Use strlcpy to fix the warning
> > warning: 'strncpy' specified bound 64 equals destination size
> >           [-Wstringop-truncation]
> >
> > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > Signed-off-by: Zhangfei Gao <zhangfei.gao@xxxxxxxxxx>
> > ---
> >   drivers/crypto/hisilicon/qm.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/crypto/hisilicon/qm.c b/drivers/crypto/hisilicon/qm.c
> > index f795fb5..224f3e2 100644
> > --- a/drivers/crypto/hisilicon/qm.c
> > +++ b/drivers/crypto/hisilicon/qm.c
> > @@ -1574,7 +1574,7 @@ static int qm_alloc_uacce(struct hisi_qm *qm)
> >   		.ops = &uacce_qm_ops,
> >   	};
> >   
> > -	strncpy(interface.name, pdev->driver->name, sizeof(interface.name));
> > +	strlcpy(interface.name, pdev->driver->name, sizeof(interface.name));
> Should this even allow truncation? Perhaps it'd be better to fail
> in case of an overrun?
I think we do not need consider overrun, since it at most copy size-1 
bytes to dest.
From the manual: strlcpy()
 This function is similar to strncpy(), but it copies at 
most size-1 bytes to dest, always adds a terminating null
ÂÂÂÂÂÂ byte,
And simple tested with smaller SIZE of interface.name, only SIZE-1 is 
copied, so it is safe.
-#define UACCE_MAX_NAME_SIZEÂÂÂ 64
+#define UACCE_MAX_NAME_SIZEÂÂÂ 4

Thanks