lkml.org 
[lkml]   [2020]   [May]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 05/10] comedi: get rid of compat_alloc_user_space() mess in COMEDI_INSN compat
From
Date
On 29/05/2020 01:35, Al Viro wrote:
> From: Al Viro <viro@zeniv.linux.org.uk>
>
> Just take copy_from_user() out of do_insn_ioctl() into the caller and
> have compat_insn() build a native version and pass it to do_insn_ioctl()
> directly.
>
> One difference from the previous commits is that the helper used to
> convert 32bit variant to native has two users - compat_insn() and
> compat_insnlist(). The latter will be converted in next commit;
> for now we simply split the helper in two variants - "userland 32bit
> to kernel native" and "userland 32bit to userland native". The latter
> is renamed old get_compat_insn(); it will be gone in the next commit.
>
> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
> ---
> drivers/staging/comedi/comedi_fops.c | 73 +++++++++++++++++++++++-------------
> 1 file changed, 46 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c
> index d96dc85d8a98..ae0067ab5ead 100644
[snip]
> @@ -2244,10 +2241,13 @@ static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd,
> (struct comedi_insnlist __user *)arg,
> file);
> break;
> - case COMEDI_INSN:
> - rc = do_insn_ioctl(dev, (struct comedi_insn __user *)arg,
> - file);
> + case COMEDI_INSN: {
> + struct comedi_insn insn;
> + if (copy_from_user(&insn, (void __user *)arg, sizeof(insn)))
> + rc = -EFAULT;

Missing an 'else' here:

> + rc = do_insn_ioctl(dev, &insn, file);
> break;
> + }
> case COMEDI_POLL:

--
-=( Ian Abbott <abbotti@mev.co.uk> || Web: www.mev.co.uk )=-
-=( MEV Ltd. is a company registered in England & Wales. )=-
-=( Registered number: 02862268. Registered address: )=-
-=( 15 West Park Road, Bramhall, STOCKPORT, SK7 3JZ, UK. )=-

\
 
 \ /
  Last update: 2020-05-29 12:12    [W:0.098 / U:2.804 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site