lkml.org 
[lkml]   [2020]   [May]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCHES] uaccess comedi compat
From
Date
On 29/05/2020 01:34, Al Viro wrote:
> The way comedi compat ioctls are done is wrong.
> Instead of having ->compat_ioctl() copying the 32bit
> stuff in, then passing the kernel copies to helpers shared
> with native ->ioctl() and doing copyout with conversion if
> needed, it's playing silly buggers with creating a 64bit
> copy on user stack, then calling native ioctl (which copies
> that copy into the kernel), then fetching it from user stack,
> converting to 32bit variant and copying that to user.
> Extra headache for no good reason. And the single
> largest remaining pile of __put_user()/__get_user() this side
> of arch/*. IMO compat_alloc_user_space() should die...
>
> NOTE: this is only compile-tested - I simply don't
> have the hardware in question.
>
> Anyway, the branch lives in #uaccess.comedi, based
> at v5.7-rc1
>
> Al Viro (10):
> comedi: move compat ioctl handling to native fops
> comedi: get rid of indirection via translated_ioctl()
> comedi: get rid of compat_alloc_user_space() mess in COMEDI_CHANINFO compat
> comedi: get rid of compat_alloc_user_space() mess in COMEDI_RANGEINFO compat
> comedi: get rid of compat_alloc_user_space() mess in COMEDI_INSN compat
> comedi: get rid of compat_alloc_user_space() mess in COMEDI_INSNLIST compat
> comedi: lift copy_from_user() into callers of __comedi_get_user_cmd()
> comedi: do_cmdtest_ioctl(): lift copyin/copyout into the caller
> comedi: do_cmd_ioctl(): lift copyin/copyout into the caller
> comedi: get rid of compat_alloc_user_space() mess in COMEDI_CMD{,TEST} compat

There is a bug in patch 05. Patch 10 doesn't seem to have been sent yet
(I didn't receive it and I can't see it in the thread in the LKML
archives). I've signed off on 01-04, 06-09.

These should be Cc'd to Greg KH and to devel@driverdev.osuosl.org.

Cheers,
Ian

--
-=( 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 12:59    [W:0.321 / U:2.924 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site