Re: +drivers-acpi-apei-erst-dbgc-get_useru64-doesnt-work-on-i386.patch added to-mm tree

[Huang Ying]

On Thu, 2010-08-12 at 08:33 +0800, Andrew Morton wrote:
> On Wed, 11 Aug 2010 16:43:10 -0700 Randy Dunlap <randy.dunlap@xxxxxxxxxx> wrote:
> 
> > On Wed, 11 Aug 2010 16:06:24 -0700 akpm@xxxxxxxxxxxxxxxxxxxx wrote:
> > 
> > > 
> > > The patch titled
> > >      drivers/acpi/apei/erst-dbg.c: get_user(u64) doesn't work on i386
> > > has been added to the -mm tree.  Its filename is
> > >      drivers-acpi-apei-erst-dbgc-get_useru64-doesnt-work-on-i386.patch
> > > 
> > > Before you just go and hit "reply", please:
> > >    a) Consider who else should be cc'ed
> > >    b) Prefer to cc a suitable mailing list as well
> > >    c) Ideally: find the original patch on the mailing list and do a
> > >       reply-to-all to that, adding suitable additional cc's
> > > 
> > > *** Remember to use Documentation/SubmitChecklist when testing your code ***
> > > 
> > > See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
> > > out what to do about this
> > > 
> > > The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
> > > 
> > > ------------------------------------------------------
> > > Subject: drivers/acpi/apei/erst-dbg.c: get_user(u64) doesn't work on i386
> > > From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> > > 
> > > Might be an x86 bug?  A get_user() on a u64 on i386 expands to
> > > 
> > > #define __get_user_8(__ret_gu, __val_gu, ptr)				\
> > > 		__get_user_x(X, __ret_gu, __val_gu, ptr)
> > > 
> > > which emits a call to __get_user_X(), which doesn't exist.
> > > 
> > > Kludge around it with copy_from_user().
> > > 
> > 
> > Reported and fixed yesterday.
> 
> Not very well.
> 
> +		rc = copy_from_user(&record_id, (void __user *)arg,
> +				    sizeof(u64));
> 
> better to use sizeof(record_id).

Will fix this with a new version. And the ssize printk format string.

> Where's Len??
>
> Anyway, this should be fixed in x86 core, I suspect.

Yes. I think so too.

Best Regards,
Huang Ying


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