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Groups > linux.kernel > #1342177
| From | Borislav Petkov <bp@alien8.de> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [tip:efi/core] x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings |
| Date | 2016-02-24 17:30 +0100 |
| Message-ID | <r5Ku7-76F-15@gated-at.bofh.it> (permalink) |
| References | (1 earlier) <r5hir-3dd-29@gated-at.bofh.it> <r5pfX-fN-7@gated-at.bofh.it> <r5vY6-54n-7@gated-at.bofh.it> <r5xGx-6lj-5@gated-at.bofh.it> <r5Ish-5Lf-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Wed, Feb 24, 2016 at 02:10:46PM +0000, Matt Fleming wrote:
> > Normally, the only pages with are _PAGE_GLOBAL are those that are in
> > the normal kernel mappings (swapper_pg_dir and normal mm_struct pgds).
> > By allowing _PAGE_GLOBAL to be set in EFI mappings, you're breaking
> > that convention, which forces you to use extra-expensive
> > __flush_tlb_all calls in efi_call_virt.
Hold on, do you mean the __flush_tlb_all() in the CONFIG_EFI_MIXED code?
That's mixed mode. I think you mean the FLUSH_TLB_ALL in efi_call.
That's EFI on 64-bit but that is mandated by the spec, AFAIR.
So the EFI runtime crap should not change once it is mapped. And those
should be global. It is only natural.
> Nope. The "if (cpa->pgd)" guard ensures that we only call that
> function for the EFI mapping code - no one else sets ->pgd.
But it could - there's no guarantee. kernel_map_pages_in_pgd() is an
exported facility.
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
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[tip:efi/core] x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings tip-bot for Sai Praneeth <tipbot@zytor.com>@zytor.com - 2016-02-23 10:20 +0100
Re: [tip:efi/core] x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings Andy Lutomirski <luto@amacapital.net> - 2016-02-23 18:50 +0100
Re: [tip:efi/core] x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings Linus Torvalds <torvalds@linux-foundation.org> - 2016-02-23 19:10 +0100
Re: [tip:efi/core] x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings Borislav Petkov <bp@alien8.de> - 2016-02-23 19:20 +0100
Re: [tip:efi/core] x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings "H. Peter Anvin" <hpa@zytor.com> - 2016-02-24 03:20 +0100
Re: [tip:efi/core] x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings "H. Peter Anvin" <hpa@zytor.com> - 2016-02-24 03:20 +0100
Re: [tip:efi/core] x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings Ingo Molnar <mingo@kernel.org> - 2016-02-25 10:00 +0100
Re: [tip:efi/core] x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> - 2016-02-24 02:00 +0100
Re: [tip:efi/core] x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings Andy Lutomirski <luto@amacapital.net> - 2016-02-24 03:50 +0100
Re: [tip:efi/core] x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings Matt Fleming <matt@codeblueprint.co.uk> - 2016-02-24 15:20 +0100
Re: [tip:efi/core] x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings Borislav Petkov <bp@alien8.de> - 2016-02-24 17:30 +0100
Re: [tip:efi/core] x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings Andy Lutomirski <luto@amacapital.net> - 2016-02-24 17:40 +0100
Re: [tip:efi/core] x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings Linus Torvalds <torvalds@linux-foundation.org> - 2016-02-24 20:00 +0100
Re: [tip:efi/core] x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings Matt Fleming <matt@codeblueprint.co.uk> - 2016-02-24 20:50 +0100
Re: [tip:efi/core] x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings Andy Lutomirski <luto@amacapital.net> - 2016-02-24 21:00 +0100
Re: [tip:efi/core] x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings Sylvain Chouleur <sylvain.chouleur@gmail.com> - 2016-02-29 12:00 +0100
Re: [tip:efi/core] x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings Matt Fleming <matt@codeblueprint.co.uk> - 2016-03-02 12:30 +0100
Re: [tip:efi/core] x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings Matt Fleming <matt@codeblueprint.co.uk> - 2016-02-24 20:40 +0100
Re: [tip:efi/core] x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings Andy Lutomirski <luto@amacapital.net> - 2016-02-24 21:00 +0100
Re: [tip:efi/core] x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings Ingo Molnar <mingo@kernel.org> - 2016-02-25 10:10 +0100
Re: [tip:efi/core] x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings Matt Fleming <matt@codeblueprint.co.uk> - 2016-02-25 16:30 +0100
Re: [tip:efi/core] x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings Andy Lutomirski <luto@amacapital.net> - 2016-02-24 17:50 +0100
Re: [tip:efi/core] x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings Borislav Petkov <bp@alien8.de> - 2016-02-24 17:50 +0100
Re: [tip:efi/core] x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings Andy Lutomirski <luto@amacapital.net> - 2016-02-24 17:50 +0100
Re: [tip:efi/core] x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings Matt Fleming <matt@codeblueprint.co.uk> - 2016-02-25 17:10 +0100
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