Re: [PATCH 2/3] lkdtm/perms: Check possible NULL pointer returned by kmalloc(),vmalloc()

[tury]

When there is insufficient memory, the allocation will fail.

the return value is void,so i think it is ok .

should i have changed comment to something like this ?

As the possible alloc failure of the kmalloc() and vmalloc(),
the return pointer could be NULL.therefore it should be better to check it.


在 2022年07月25日 16:42, Greg KH 写道:
> On Mon, Jul 25, 2022 at 04:11:53PM +0800, Ren Yu wrote:
> > As the possible alloc failure of the kmalloc() and vmalloc(),the
> > return pointer could be NULL.therefore it should be better to check it.
> >
> > Signed-off-by: Ren Yu <renyu@xxxxxxxxxxxx>
> > ---
> >   drivers/misc/lkdtm/perms.c | 6 ++++++
> >   1 file changed, 6 insertions(+)
> >
> > diff --git a/drivers/misc/lkdtm/perms.c b/drivers/misc/lkdtm/perms.c
> > index b93404d65650..34b43b9ea1f1 100644
> > --- a/drivers/misc/lkdtm/perms.c
> > +++ b/drivers/misc/lkdtm/perms.c
> > @@ -180,6 +180,9 @@ static void lkdtm_EXEC_STACK(void)
> >   static void lkdtm_EXEC_KMALLOC(void)
> >   {
> >   	u32 *kmalloc_area = kmalloc(EXEC_SIZE, GFP_KERNEL);
> > +	if (!kmalloc_area)
> > +		return;
> > +
> Always run checkpatch on your patches so that grumpy maintainers do not
> have to tell you to run checkpatch on your patches...
>
> Also, shouldn't this return an error?
>
> But most importantly, how can this ever fail?
>
> thanks,
>
> greg k-h