lkml.org 
[lkml]   [2020]   [Oct]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH v3 09/10] x86: Convert mmu context ia32_compat into a proper flags field
On Sat, Oct 3, 2020 at 8:26 PM Gabriel Krisman Bertazi
<krisman@collabora.com> wrote:
>
> The ia32_compat attribute is a weird thing. It mirrors TIF_IA32 and
> TIF_X32 and is used only in two very unrelated places: (1) to decide if
> the vsyscall page is accessible (2) for uprobes to find whether the
> patched instruction is 32 or 64 bit. In preparation to remove the TI
> flags, we want new values for ia32_compat, but given its odd semantics,
> I'd rather make it a real flags field that configures these specific
> behaviours. So, set_personality_x64 can ask for the vsyscall page,
> which is not available in x32/ia32 and set_personality_ia32 can
> configure the uprobe code as needed.
>
> uprobe cannot rely on other methods like user_64bit_mode() to decide how
> to patch, so it needs some specific flag like this.

Acked-by: Andy Lutomirski<luto@kernel.org>

There are still issues with vsyscall control, but they were
pre-existing and I'll try to get them fixed up.

--Andy

\
 
 \ /
  Last update: 2020-10-08 02:08    [W:0.083 / U:2.384 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site