Messages in this thread |  | | Subject | Re: [PATCH v2 5/9] x86/desc: add native_[ig]dt_invalidate() to <asm/desc.h> | From | Andy Lutomirski <> | Date | Sat, 15 May 2021 08:29:39 -0700 |
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On 5/14/21 6:43 PM, H. Peter Anvin wrote: > From: "H. Peter Anvin (Intel)" <hpa@zytor.com> > > In some places, we want the native forms of descriptor table > invalidation. Rather than open-coding them, add explicitly native > functions to invalidate the GDT and IDT. > > Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> > --- > arch/x86/include/asm/desc.h | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h > index b8429ae50b71..aa366b2bbc41 100644 > --- a/arch/x86/include/asm/desc.h > +++ b/arch/x86/include/asm/desc.h > @@ -224,6 +224,21 @@ static inline void store_idt(struct desc_ptr *dtr) > asm volatile("sidt %0":"=m" (*dtr)); > } > > +static const struct desc_ptr __invalid_gdt_idt_ptr __maybe_unused = { > + .address = 0, > + .size = 0 > +};
I'm not convinced that putting this in a header is really a great idea. How about:
> + > +static inline void native_gdt_invalidate(void) > +{ const struct desc_ptr ... = ...;
> + native_load_gdt(&__invalid_gdt_idt_ptr); > +}
That should generate two PUSH instructions and may well result in a smaller binary :)
--Andy
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