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Re: [PATCH 5/5 v2 gnumach] x86_64: add 64-bit syscall entry point
From: |
Samuel Thibault |
Subject: |
Re: [PATCH 5/5 v2 gnumach] x86_64: add 64-bit syscall entry point |
Date: |
Thu, 2 Mar 2023 09:05:53 +0100 |
User-agent: |
NeoMutt/20170609 (1.8.3) |
My, should have re-read...
Samuel Thibault, le jeu. 02 mars 2023 09:00:40 +0100, a ecrit:
> I'm not saying it's not a serializing instruction.
>
> I'm saying that the compiler does not have to *care* about the
> instruction being serializing.
>
> But I'm also saying that the very reason why the instruction is
> serialized is also the reason why which should give a memory clobber to
*we
> the compiler.
>
> > The Intel 64 and IA-32 architectures define several serializing
> > instructions. These instructions force the processor to complete all
> > modifications to flags, registers, and memory by previous instructions and
> > to drain all buffered writes to memory before the next instruction is
> > fetched and executed.
>
> Yes, and that is *completely* fine with the compiler not flushing
> variables etc. to buffers before that.
*from register to memory.
> But the very reason why all these flushes are done is that wrmsr can
> have side effect which *requires* that to be done (e.g. structure
> preparation and whatnot), and thus we should *also* tell the compiler to
> do the same.
- [PATCH 5/5 v2 gnumach] x86_64: add 64-bit syscall entry point, Luca Dariz, 2023/03/01
- Re: [PATCH 5/5 v2 gnumach] x86_64: add 64-bit syscall entry point, Samuel Thibault, 2023/03/01
- Re: [PATCH 5/5 v2 gnumach] x86_64: add 64-bit syscall entry point, Luca Dariz, 2023/03/02
- Re: [PATCH 5/5 v2 gnumach] x86_64: add 64-bit syscall entry point, Samuel Thibault, 2023/03/02
- Re: [PATCH 5/5 v2 gnumach] x86_64: add 64-bit syscall entry point,
Samuel Thibault <=
- Re: [PATCH 5/5 v2 gnumach] x86_64: add 64-bit syscall entry point, Luca Dariz, 2023/03/02
- Re: [PATCH 5/5 v2 gnumach] x86_64: add 64-bit syscall entry point, Samuel Thibault, 2023/03/02
- Re: [PATCH 5/5 v2 gnumach] x86_64: add 64-bit syscall entry point, Sergey Bugaev, 2023/03/02
- Re: [PATCH 5/5 v2 gnumach] x86_64: add 64-bit syscall entry point, Luca Dariz, 2023/03/02
- Re: [PATCH 5/5 v2 gnumach] x86_64: add 64-bit syscall entry point, Samuel Thibault, 2023/03/02
[PATCH v3 gnumach] x86_64: add 64-bit syscall entry point, Luca Dariz, 2023/03/08