lkml.org 
[lkml]   [2019]   [Apr]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC PATCH for 5.2 08/10] rseq/selftests: aarch64 code signature: handle big-endian environment
----- On Apr 24, 2019, at 12:51 PM, Mark Rutland mark.rutland@arm.com wrote:

> On Wed, Apr 24, 2019 at 05:45:38PM +0100, Will Deacon wrote:
>> On Wed, Apr 24, 2019 at 11:25:00AM -0400, Mathieu Desnoyers wrote:
>> > +/*
>> > + * aarch64 -mbig-endian generates mixed endianness code vs data:
>> > + * little-endian code and big-endian data. Ensure the RSEQ_SIG signature
>> > + * matches code endianness.
>> > + */
>> > +#define RSEQ_SIG_CODE 0xd428bc00 /* BRK #0x45E0. */
>> > +
>> > +#ifdef __AARCH64EB__
>> > +#define RSEQ_SIG_DATA 0x00bc28d4 /* BRK #0x45E0. */
>>
>> It would be neater to implement swab32 and use that with RSEQ_SIG_CODE,
>
> If possible, marginally neater than that would be using
> le32_to_cpu(RSEQ_SIG_CODE), without any ifdeffery necessary.
>
> It looks like that's defined in tools/include/linux/kernel.h, but I'm
> not sure if that gets pulled into your include path.

Considering that those RSEQ_SIG* define will end up in public bits/rseq.h
headers within glibc, I'm tempted to keep the amount of dependencies on
external headers to a minimum, if it's OK with you.

Thanks,

Mathieu

--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com

\
 
 \ /
  Last update: 2019-04-24 19:01    [W:0.040 / U:5.944 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site