lkml.org 
[lkml]   [2018]   [Oct]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [RFC PATCH 1/9] kernel: add support for patchable function pointers
On 5 October 2018 at 15:57, Peter Zijlstra <peterz@infradead.org> wrote:
> On Fri, Oct 05, 2018 at 10:13:25AM +0200, Ard Biesheuvel wrote:
>> Add a function pointer abstraction that can be implemented by the arch
>> in a manner that avoids the downsides of function pointers, i.e., the
>> fact that they are typically located in a writable data section, and
>> their vulnerability to Spectre like defects.
>>
>> The FFP (or fast function pointer) is callable as a function, since
>> the generic incarnation is simply that. However, due to the fact that
>> C does not distinguish between functions and function pointers at the
>> call site, the architecture can instead emit it as a patchable sequence
>> of instructions consisting of ordinary branches.
>
> This is basically a static_key, except for indirection function calls?

Yes, that is why I put you on cc :-)

> So why not call the thing static_func or static_call or something like
> that?

Yep that sounds better.

\
 
 \ /
  Last update: 2018-10-05 16:04    [W:0.118 / U:6.380 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site