145 lines
5.2 KiB
Diff
145 lines
5.2 KiB
Diff
From: Matt Fleming <matt@codeblueprint.co.uk>
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Date: Fri, 27 Nov 2015 21:09:31 +0000
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Subject: [2/5] x86/mm/pat: Ensure cpa->pfn only contains page frame numbers
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Origin: https://git.kernel.org/cgit/linux/kernel/git/mfleming/efi.git/commit?id=edc3b9129cecd0f0857112136f5b8b1bc1d45918
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The x86 pageattr code is confused about the data that is stored
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in cpa->pfn, sometimes it's treated as a page frame number,
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sometimes it's treated as an unshifted physical address, and in
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one place it's treated as a pte.
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The result of this is that the mapping functions do not map the
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intended physical address.
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This isn't a problem in practice because most of the addresses
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we're mapping in the EFI code paths are already mapped in
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'trampoline_pgd' and so the pageattr mapping functions don't
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actually do anything in this case. But when we move to using a
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separate page table for the EFI runtime this will be an issue.
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Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
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Reviewed-by: Borislav Petkov <bp@suse.de>
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Acked-by: Borislav Petkov <bp@suse.de>
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Cc: Andy Lutomirski <luto@amacapital.net>
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Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
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Cc: Borislav Petkov <bp@alien8.de>
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Cc: Brian Gerst <brgerst@gmail.com>
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Cc: Dave Hansen <dave.hansen@intel.com>
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Cc: Denys Vlasenko <dvlasenk@redhat.com>
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Cc: H. Peter Anvin <hpa@zytor.com>
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Cc: Linus Torvalds <torvalds@linux-foundation.org>
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Cc: Peter Zijlstra <peterz@infradead.org>
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Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
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Cc: Thomas Gleixner <tglx@linutronix.de>
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Cc: Toshi Kani <toshi.kani@hp.com>
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Cc: linux-efi@vger.kernel.org
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Link: http://lkml.kernel.org/r/1448658575-17029-3-git-send-email-matt@codeblueprint.co.uk
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Signed-off-by: Ingo Molnar <mingo@kernel.org>
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---
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arch/x86/mm/pageattr.c | 17 ++++++-----------
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arch/x86/platform/efi/efi_64.c | 16 ++++++++++------
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2 files changed, 16 insertions(+), 17 deletions(-)
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diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
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index a3137a4feed1..c70e42014101 100644
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--- a/arch/x86/mm/pageattr.c
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+++ b/arch/x86/mm/pageattr.c
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@@ -905,15 +905,10 @@ static void populate_pte(struct cpa_data *cpa,
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pte = pte_offset_kernel(pmd, start);
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while (num_pages-- && start < end) {
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-
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- /* deal with the NX bit */
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- if (!(pgprot_val(pgprot) & _PAGE_NX))
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- cpa->pfn &= ~_PAGE_NX;
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-
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- set_pte(pte, pfn_pte(cpa->pfn >> PAGE_SHIFT, pgprot));
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+ set_pte(pte, pfn_pte(cpa->pfn, pgprot));
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start += PAGE_SIZE;
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- cpa->pfn += PAGE_SIZE;
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+ cpa->pfn++;
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pte++;
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}
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}
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@@ -969,11 +964,11 @@ static int populate_pmd(struct cpa_data *cpa,
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pmd = pmd_offset(pud, start);
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- set_pmd(pmd, __pmd(cpa->pfn | _PAGE_PSE |
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+ set_pmd(pmd, __pmd(cpa->pfn << PAGE_SHIFT | _PAGE_PSE |
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massage_pgprot(pmd_pgprot)));
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start += PMD_SIZE;
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- cpa->pfn += PMD_SIZE;
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+ cpa->pfn += PMD_SIZE >> PAGE_SHIFT;
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cur_pages += PMD_SIZE >> PAGE_SHIFT;
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}
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@@ -1042,11 +1037,11 @@ static int populate_pud(struct cpa_data *cpa, unsigned long start, pgd_t *pgd,
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* Map everything starting from the Gb boundary, possibly with 1G pages
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*/
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while (end - start >= PUD_SIZE) {
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- set_pud(pud, __pud(cpa->pfn | _PAGE_PSE |
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+ set_pud(pud, __pud(cpa->pfn << PAGE_SHIFT | _PAGE_PSE |
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massage_pgprot(pud_pgprot)));
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start += PUD_SIZE;
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- cpa->pfn += PUD_SIZE;
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+ cpa->pfn += PUD_SIZE >> PAGE_SHIFT;
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cur_pages += PUD_SIZE >> PAGE_SHIFT;
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pud++;
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}
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diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
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index a0ac0f9c307f..5aa186db59e3 100644
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--- a/arch/x86/platform/efi/efi_64.c
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+++ b/arch/x86/platform/efi/efi_64.c
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@@ -143,7 +143,7 @@ void efi_sync_low_kernel_mappings(void)
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int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
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{
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- unsigned long text;
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+ unsigned long pfn, text;
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struct page *page;
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unsigned npages;
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pgd_t *pgd;
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@@ -160,7 +160,8 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
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* and ident-map those pages containing the map before calling
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* phys_efi_set_virtual_address_map().
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*/
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- if (kernel_map_pages_in_pgd(pgd, pa_memmap, pa_memmap, num_pages, _PAGE_NX)) {
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+ pfn = pa_memmap >> PAGE_SHIFT;
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+ if (kernel_map_pages_in_pgd(pgd, pfn, pa_memmap, num_pages, _PAGE_NX)) {
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pr_err("Error ident-mapping new memmap (0x%lx)!\n", pa_memmap);
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return 1;
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}
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@@ -185,8 +186,9 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
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npages = (_end - _text) >> PAGE_SHIFT;
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text = __pa(_text);
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+ pfn = text >> PAGE_SHIFT;
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- if (kernel_map_pages_in_pgd(pgd, text >> PAGE_SHIFT, text, npages, 0)) {
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+ if (kernel_map_pages_in_pgd(pgd, pfn, text, npages, 0)) {
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pr_err("Failed to map kernel text 1:1\n");
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return 1;
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}
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@@ -204,12 +206,14 @@ void __init efi_cleanup_page_tables(unsigned long pa_memmap, unsigned num_pages)
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static void __init __map_region(efi_memory_desc_t *md, u64 va)
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{
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pgd_t *pgd = (pgd_t *)__va(real_mode_header->trampoline_pgd);
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- unsigned long pf = 0;
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+ unsigned long flags = 0;
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+ unsigned long pfn;
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if (!(md->attribute & EFI_MEMORY_WB))
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- pf |= _PAGE_PCD;
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+ flags |= _PAGE_PCD;
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- if (kernel_map_pages_in_pgd(pgd, md->phys_addr, va, md->num_pages, pf))
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+ pfn = md->phys_addr >> PAGE_SHIFT;
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+ if (kernel_map_pages_in_pgd(pgd, pfn, va, md->num_pages, flags))
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pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
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md->phys_addr, va);
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}
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