On Sat, Jun 16, 2018 at 12:42:31AM +0300, Yury Norov wrote:
> Hi Andy,
>
> On Fri, Jun 15, 2018 at 04:20:17PM +0300, Andy Shevchenko wrote:
> > Switch to bitmap_zalloc() to show clearly what we are allocating.
> > Besides that it returns pointer of bitmap type instead of opaque void *.
> >
> > Acked-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> > Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> > ---
> > drivers/input/evdev.c | 16 +++++++---------
> > 1 file changed, 7 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
> > index c81c79d01d93..370206f987f9 100644
> > --- a/drivers/input/evdev.c
> > +++ b/drivers/input/evdev.c
> > @@ -481,7 +481,7 @@ static int evdev_release(struct inode *inode, struct file *file)
> > evdev_detach_client(evdev, client);
> >
> > for (i = 0; i < EV_CNT; ++i)
> > - kfree(client->evmasks[i]);
> > + bitmap_free(client->evmasks[i]);
> >
> > kvfree(client);
> >
> > @@ -925,17 +925,15 @@ static int evdev_handle_get_val(struct evdev_client *client,
> > {
> > int ret;
> > unsigned long *mem;
> > - size_t len;
> >
> > - len = BITS_TO_LONGS(maxbit) * sizeof(unsigned long);
> > - mem = kmalloc(len, GFP_KERNEL);
> > + mem = bitmap_alloc(maxbit, GFP_KERNEL);
> > if (!mem)
> > return -ENOMEM;
>
> But in commit message you say you switch to bitmap_zalloc(). IIUC
> bitmap_alloc() is OK here. But could you please update comment to
> avoid confusing.
>
> >
> > spin_lock_irq(&dev->event_lock);
> > spin_lock(&client->buffer_lock);
> >
> > - memcpy(mem, bits, len);
> > + bitmap_copy(mem, bits, maxbit);
> >
> > spin_unlock(&dev->event_lock);
> >
> > @@ -947,7 +945,7 @@ static int evdev_handle_get_val(struct evdev_client *client,
> > if (ret < 0)
> > evdev_queue_syn_dropped(client);
> >
> > - kfree(mem);
> > + bitmap_free(mem);
> >
> > return ret;
> > }
> > @@ -1003,13 +1001,13 @@ static int evdev_set_mask(struct evdev_client *client,
> > if (!cnt)
> > return 0;
> >
> > - mask = kcalloc(sizeof(unsigned long), BITS_TO_LONGS(cnt), GFP_KERNEL);
> > + mask = bitmap_zalloc(cnt, GFP_KERNEL);
> > if (!mask)
> > return -ENOMEM;
> >
> > error = bits_from_user(mask, cnt - 1, codes_size, codes, compat);
>
> If my understanding of bits_from_user() correct, here you can also use
> bitmap_alloc(), true?
bits_from_user() copies as much as user supplied, we want to zero out
the tail to make sure there is no garbage, so we want to use
kcalloc/kzalloc/bitmap_zalloc here.
Thanks.
--
Dmitry
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