Re: [PATCH] Fix/add raw1394 CONFIG_COMPAT code

[Stefan Richter <stefanr@s5r6.in-berlin.de>]

Petr Vandrovec wrote:
[...]
> * read() always failed with -EFAULT.  This was happening due to
>   raw1394_compat_read copying data to wrong location - access_ok always
>   failed as 'r' is kernel address, not user.  Whole function just tried to
>   copy data from 'r' to 'r', which is not good.
> 
> * write(fd, buf, 52) from 32bit app was returning 56.  Most of callers did not
>   care, but some (arm registration) did, and anyway it looks bad if request for
>   writing 52 bytes returns 56.  And returning sizeof anything in 'int' is not
>   good as well.  So all functions now return '0' instead of
>   sizeof(struct raw1394_request) on success, and write() itself provides correct
>   return value (it just returns value it was asked to write on success as raw1394
>   does not do any partial writes at all).
> 
> * Related to this was problem that write() could have returned 0 when kernel
>   state would become corrupted and moved to different state than
>   opened/initialized/connected.  Now it returns -EBADFD which seemed appropriate.
> 
> * And add compat_ioctl.  Although all structures are more or less same,
>   raw1394_iso_packets got pointer inside, and raw1394_cycle_timer got unwanted
>   padding in the middle.  I did not add any translation for ioctls passing array
>   of integers around as integers seem to have same size (32 bits) on all 
>   architectures supported by Linux.
[...]

Thanks for these fixes.  They look good at first glance but I will look
at them in more detail during the week (and hope that Dan can have a
look at them too).  I will get back to you once more before I commit
because I would like to split it into three patches (for
raw1394_compat_read, for write, and for compat_ioctl).
-- 
Stefan Richter
-=====-=-=== -=-= --===
http://arcgraph.de/sr/