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Groups > linux.kernel > #1538803
| From | Andy Lutomirski <luto@amacapital.net> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [RFC, PATCHv1 24/28] x86/mm: add sync_global_pgds() for configuration with 5-level paging |
| Date | 2016-12-08 19:50 +0100 |
| Message-ID | <sMbVv-188-31@gated-at.bofh.it> (permalink) |
| References | <sM9K2-8la-5@gated-at.bofh.it> <sM9K3-8la-61@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Thu, Dec 8, 2016 at 8:21 AM, Kirill A. Shutemov
<kirill.shutemov@linux.intel.com> wrote:
> This basically restores slightly modified version of original
> sync_global_pgds() which we had before foldedl p4d was introduced.
>
> The only modification is protection against 'address' overflow.
>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> ---
> arch/x86/mm/init_64.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 47 insertions(+)
>
> diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
> index a991f5c4c2c4..d637893ac8c2 100644
> --- a/arch/x86/mm/init_64.c
> +++ b/arch/x86/mm/init_64.c
> @@ -92,6 +92,52 @@ __setup("noexec32=", nonx32_setup);
> * When memory was added/removed make sure all the processes MM have
> * suitable PGD entries in the local PGD level page.
> */
> +#ifdef CONFIG_X86_5LEVEL
> +void sync_global_pgds(unsigned long start, unsigned long end, int removed)
> +{
> + unsigned long address;
> +
> + for (address = start; address <= end && address >= start;
> + address += PGDIR_SIZE) {
> + const pgd_t *pgd_ref = pgd_offset_k(address);
> + struct page *page;
> +
> + /*
> + * When it is called after memory hot remove, pgd_none()
> + * returns true. In this case (removed == 1), we must clear
> + * the PGD entries in the local PGD level page.
> + */
> + if (pgd_none(*pgd_ref) && !removed)
> + continue;
This isn't quite specific to your patch, but can we assert that, if
removed=1, then we're not operating on the vmalloc range? Because if
we do, this will be racy is nasty ways.
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[RFC, PATCHv1 00/28] 5-level paging "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-12-08 17:30 +0100
[RFC, PATCHv1 24/28] x86/mm: add sync_global_pgds() for configuration with 5-level paging "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-12-08 17:30 +0100
Re: [RFC, PATCHv1 24/28] x86/mm: add sync_global_pgds() for configuration with 5-level paging Andy Lutomirski <luto@amacapital.net> - 2016-12-08 19:50 +0100
Re: [RFC, PATCHv1 24/28] x86/mm: add sync_global_pgds() for configuration with 5-level paging "Kirill A. Shutemov" <kirill@shutemov.name> - 2016-12-08 20:40 +0100
[RFC, PATCHv1 19/28] x86/mm: basic defines/helpers for CONFIG_X86_5LEVEL "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-12-08 17:30 +0100
[RFC, PATCHv1 04/28] asm-generic: introduce <asm-generic/pgtable-nop4d.h> "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-12-08 17:30 +0100
[RFC, PATCHv1 17/28] x86/mm: define virtual memory map for 5-level paging "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-12-08 17:30 +0100
Re: [RFC, PATCHv1 17/28] x86/mm: define virtual memory map for 5-level paging Randy Dunlap <rdunlap@infradead.org> - 2016-12-08 20:00 +0100
Re: [RFC, PATCHv1 17/28] x86/mm: define virtual memory map for 5-level paging "Kirill A. Shutemov" <kirill@shutemov.name> - 2016-12-08 20:30 +0100
[RFC, PATCHv1 27/28] x86: enable la57 support "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-12-08 17:30 +0100
[QEMU, PATCH] x86: implement la57 paging mode "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-12-08 17:30 +0100
Re: [Qemu-devel] [QEMU, PATCH] x86: implement la57 paging mode no-reply@patchew.org - 2016-12-08 17:50 +0100
[RFC, PATCHv1 28/28] TESTING-ONLY: bump TASK_SIZE_MAX "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-12-08 17:30 +0100
[RFC, PATCHv1 03/28] arch, mm: convert all architectures to use 5level-fixup.h "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-12-08 17:30 +0100
[RFC, PATCHv1 18/28] x86/paravirt: make paravirt code support 5-level paging "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-12-08 17:30 +0100
[RFC, PATCHv1 07/28] x86: trivial portion of 5-level paging conversion "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-12-08 17:30 +0100
[RFC, PATCHv1 01/28] asm-generic: introduce 5level-fixup.h "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-12-08 17:30 +0100
[RFC, PATCHv1 26/28] x86/mm: add support for 5-level paging for KASLR "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-12-08 17:30 +0100
[RFC, PATCHv1 06/28] x86: basic changes into headers for 5-level paging "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-12-08 17:40 +0100
[RFC, PATCHv1 02/28] asm-generic: introduce __ARCH_USE_5LEVEL_HACK "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-12-08 17:40 +0100
Re: [RFC, PATCHv1 00/28] 5-level paging Linus Torvalds <torvalds@linux-foundation.org> - 2016-12-08 19:20 +0100
Re: [RFC, PATCHv1 00/28] 5-level paging hpa@zytor.com - 2016-12-08 19:30 +0100
Re: [RFC, PATCHv1 00/28] 5-level paging "Kirill A. Shutemov" <kirill@shutemov.name> - 2016-12-08 20:30 +0100
Re: [RFC, PATCHv1 00/28] 5-level paging Ingo Molnar <mingo@kernel.org> - 2016-12-09 06:10 +0100
Re: [RFC, PATCHv1 00/28] 5-level paging Arnd Bergmann <arnd@arndb.de> - 2016-12-09 11:30 +0100
Re: [RFC, PATCHv1 00/28] 5-level paging Catalin Marinas <catalin.marinas@arm.com> - 2016-12-09 12:00 +0100
Re: [RFC, PATCHv1 00/28] 5-level paging "Kirill A. Shutemov" <kirill@shutemov.name> - 2016-12-09 11:40 +0100
Re: [RFC, PATCHv1 00/28] 5-level paging Andi Kleen <ak@linux.intel.com> - 2016-12-09 17:50 +0100
Re: [RFC, PATCHv1 00/28] 5-level paging "Kirill A. Shutemov" <kirill@shutemov.name> - 2016-12-09 18:30 +0100
Re: [RFC, PATCHv1 00/28] 5-level paging Dave Hansen <dave.hansen@intel.com> - 2016-12-09 17:50 +0100
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