Messages in this thread | | | Date | Mon, 23 Oct 2023 12:13:25 -0700 | From | Pawan Gupta <> | Subject | Re: [PATCH 2/6] x86/entry_64: Add VERW just before userspace transition |
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On Mon, Oct 23, 2023 at 11:22:11AM -0700, Josh Poimboeuf wrote: > On Fri, Oct 20, 2023 at 01:45:03PM -0700, Pawan Gupta wrote: > > + /* Mitigate CPU data sampling attacks .e.g. MDS */ > > + USER_CLEAR_CPU_BUFFERS > > + > > jmp .Lnative_iret > > > > > > @@ -774,6 +780,9 @@ native_irq_return_ldt: > > */ > > popq %rax /* Restore user RAX */ > > > > + /* Mitigate CPU data sampling attacks .e.g. MDS */ > > + USER_CLEAR_CPU_BUFFERS > > + > > I'm thinking the comments add unnecessary noise here. The macro name is > self-documenting enough. > > The detail about what mitigations are being done can go above the macro > definition itself, which the reader can refer to if they want more > detail about what the macro is doing and why.
Sure, I will move the comments to definition.
> Speaking of the macro name, I think just "CLEAR_CPU_BUFFERS" is > sufficient. The "USER_" prefix makes it harder to read IMO.
Ok, will drop "USER_".
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