07.08.2017 19:20, Andy Lutomirski пишет:
I think
this is the half-step. It clearly shows that you don't want
such state to ever exist, but why not to go a step further
and just make the bases to be reset not only by any
unrelated modify_ldt() call, but always on schedule?
You can state that using
On Mon, Aug 7, 2017 at 10:35 AM, Linus Torvalds
wrote:
> On Mon, Aug 7, 2017 at 9:20 AM, Andy Lutomirski wrote:
>>
>> Windows does something sort of like this (I think), but I don't like
>> this solution. I fully expect that someone will write a program that
>> does:
>>
>> old = rdgsbase();
>> w
On Mon, Aug 7, 2017 at 9:20 AM, Andy Lutomirski wrote:
>
> Windows does something sort of like this (I think), but I don't like
> this solution. I fully expect that someone will write a program that
> does:
>
> old = rdgsbase();
> wrgsbase(new);
> call_very_fast_function();
> wrgsbase(old);
>
> T
I hope this will finally enable thread local support to work in a sane way
in gcc so that we can actually use it in kernel space and get rid of all
the this_cpu_xxx() macros?
And thread local RMVs primitives may actually be provided by gcc and
be usable in user space so that we can write user spac
On Mon, Aug 7, 2017 at 1:06 AM, Stas Sergeev wrote:
> Hello.
>
> 31.07.2017 06:05, Andy Lutomirski пишет:
>>
>> - User code can use the new RD/WR FS/GS BASE instructions.
>> Apparently some users really want this for, umm, userspace threading.
>> Think Java.
>
> I wonder how java avoids the lack
On Jul 31, 2017, at 5:23 PM, Bae, Chang Seok wrote:
>> On an FSGSBASE-enabled system, I think we need to provide deterministic,
>> documented, tested behavior. I can think of three plausible choices:
>> 1a. modify_ldt() immediately updates FSBASE and GSBASE all threads that
>> reference the mo
Hello.
31.07.2017 06:05, Andy Lutomirski пишет:
- User code can use the new RD/WR FS/GS BASE instructions.
Apparently some users really want this for, umm, userspace threading.
Think Java.
I wonder how java avoids the lack of the user-space
continuations support while getting the userspace th
> On an FSGSBASE-enabled system, I think we need to provide deterministic,
> documented, tested behavior. I can think of three plausible choices:
> 1a. modify_ldt() immediately updates FSBASE and GSBASE all threads that
> reference the modified selector.
> 1b. modify_ldt() immediatley updates FS
On Mon, Jul 31, 2017 at 3:55 AM, Kirill A. Shutemov
wrote:
> On Sun, Jul 30, 2017 at 08:05:43PM -0700, Andy Lutomirski wrote:
>> Hi all-
>>
>> Chang wants to get the FSGSBASE patches in. Here's a bit on a brain
>> dump on what I think the relevant considerations are and why I haven't
>> sent out
On Sun, Jul 30, 2017 at 9:38 PM, Linus Torvalds
wrote:
> On Sun, Jul 30, 2017 at 8:05 PM, Andy Lutomirski wrote:
>>
>> This means that, when gdb saves away a regset and reloads it using
>> PTRACE_SETREGS or similar, the effect is to load gs_base and then load
>> gs. If gs != 0, this will blow aw
On Sun, Jul 30, 2017 at 08:05:43PM -0700, Andy Lutomirski wrote:
> Hi all-
>
> Chang wants to get the FSGSBASE patches in. Here's a bit on a brain
> dump on what I think the relevant considerations are and why I haven't
> sent out my patches.
I'm not sure if it would be relevant input for the de
On Sun, Jul 30, 2017 at 8:05 PM, Andy Lutomirski wrote:
>
> This means that, when gdb saves away a regset and reloads it using
> PTRACE_SETREGS or similar, the effect is to load gs_base and then load
> gs. If gs != 0, this will blow away gs_base. Without FSGSBASE, this
> doesn't matter so much.
Hi all-
Chang wants to get the FSGSBASE patches in. Here's a bit on a brain
dump on what I think the relevant considerations are and why I haven't
sent out my patches.
- Background -
Setting CR4.FSGSBASE has two major advantages and one major
disadvantage. The major advantages are:
-
13 matches
Mail list logo
