lkml.org 
[lkml]   [2011]   [May]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH v4 1/6] x86-64: Clean up vdso/kernel shared variables
On Mon, May 16, 2011 at 1:23 PM, Borislav Petkov <bp@amd64.org> wrote:
> On Mon, May 16, 2011 at 12:00:58PM -0400, Andy Lutomirski wrote:
>> Variables that are shared between the vdso and the kernel are
>> currently a bit of a mess.  They are each defined with their own
>> magic, they are accessed differently in the kernel, the vsyscall page,
>> and the vdso, and one of them (vsyscall_clock) doesn't even really
>> exist.
>>
>> This changes them all to use a common mechanism.  All of them are
>> delcared in vvar.h with a fixed address (validated by the linker
>> script).  In the kernel (as before), they look like ordinary
>> read-write variables.  In the vsyscall page and the vdso, they are
>> accessed through a new macro VVAR, which gives read-only access.
>>
>> The vdso is now loaded verbatim into memory without any fixups.  As a
>> side bonus, access from the vdso is faster because a level of
>> indirection is removed.
>>
>> While we're at it, pack jiffies and vgetcpu_mode into the same
>> cacheline.
>
> How about
>
> Signed-off-by:...

Signed-off-by: Andy Lutomirski <luto@mit.edu>

If whoever wants to pick up these patches wants it (or if there's a
v5), I'll send a new patch.

>
> or you don't wanna? :)

Nope. I probably just hit the delete button too hard or something.

--Andy
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2011-05-16 19:37    [W:0.045 / U:52.048 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site