lkml.org 
[lkml]   [2023]   [Oct]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRE: [PATCH v2 00/11] x86-64: Stack protector and percpu improvements
Date
From: Brian Gerst
> Sent: 26 October 2023 17:01
>
> Currently, x86-64 uses an unusual percpu layout, where the percpu section
> is linked at absolute address 0. The reason behind this is that older GCC
> versions placed the stack protector (if enabled) at a fixed offset from the
> GS segment base. Since the GS segement is also used for percpu variables,
> this forced the current layout.
>
> GCC since version 8.1 supports a configurable location for the stack
> protector value, which allows removal of the restriction on how the percpu
> section is linked. This allows the percpu section to be linked
> normally, like most other architectures. In turn, this allows removal
> of code that was needed to support the zero-based percpu section.

I didn't think the minimum gcc version was anything like 8.1.
I'm using 7.5.0 and I don't think that is the oldest version.

David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)

\
 
 \ /
  Last update: 2023-10-29 22:43    [W:0.240 / U:0.376 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site