diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0078-x86-pti-efi-broken-conversion-from-efi-to-kernel-pag.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.9.21/0078-x86-pti-efi-broken-conversion-from-efi-to-kernel-pag.patch | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0078-x86-pti-efi-broken-conversion-from-efi-to-kernel-pag.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0078-x86-pti-efi-broken-conversion-from-efi-to-kernel-pag.patch new file mode 100644 index 00000000..3e743f00 --- /dev/null +++ b/common/recipes-kernel/linux/linux-yocto-4.9.21/0078-x86-pti-efi-broken-conversion-from-efi-to-kernel-pag.patch @@ -0,0 +1,79 @@ +From d0383173a920ac2b316abb04d8a9f2bd9045d598 Mon Sep 17 00:00:00 2001 +From: Pavel Tatashin <pasha.tatashin@oracle.com> +Date: Mon, 15 Jan 2018 11:44:14 -0500 +Subject: [PATCH 078/103] x86/pti/efi: broken conversion from efi to kernel + page table + +The page table order must be increased for EFI table in order to avoid a +bug where NMI tries to change the page table to kernel page table, while +efi page table is active. + +For more disccussion about this bug, see this thread: +http://lkml.iu.edu/hypermail/linux/kernel/1801.1/00951.html + +Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> +Reviewed-by: Steven Sistare <steven.sistare@oracle.com> +Acked-by: Jiri Kosina <jkosina@suse.cz> +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +--- + arch/x86/include/asm/pgalloc.h | 11 +++++++++++ + arch/x86/mm/pgtable.c | 7 ------- + arch/x86/platform/efi/efi_64.c | 2 +- + 3 files changed, 12 insertions(+), 8 deletions(-) + +diff --git a/arch/x86/include/asm/pgalloc.h b/arch/x86/include/asm/pgalloc.h +index b6d4259..1178a51 100644 +--- a/arch/x86/include/asm/pgalloc.h ++++ b/arch/x86/include/asm/pgalloc.h +@@ -27,6 +27,17 @@ static inline void paravirt_release_pud(unsigned long pfn) {} + */ + extern gfp_t __userpte_alloc_gfp; + ++#ifdef CONFIG_PAGE_TABLE_ISOLATION ++/* ++ * Instead of one PGD, we acquire two PGDs. Being order-1, it is ++ * both 8k in size and 8k-aligned. That lets us just flip bit 12 ++ * in a pointer to swap between the two 4k halves. ++ */ ++#define PGD_ALLOCATION_ORDER 1 ++#else ++#define PGD_ALLOCATION_ORDER 0 ++#endif ++ + /* + * Allocate and free page tables. + */ +diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c +index 5aaec8e..209b946 100644 +--- a/arch/x86/mm/pgtable.c ++++ b/arch/x86/mm/pgtable.c +@@ -345,13 +345,6 @@ static inline void _pgd_free(pgd_t *pgd) + } + #else + +-/* +- * Instead of one pgd, Kaiser acquires two pgds. Being order-1, it is +- * both 8k in size and 8k-aligned. That lets us just flip bit 12 +- * in a pointer to swap between the two 4k halves. +- */ +-#define PGD_ALLOCATION_ORDER kaiser_enabled +- + static inline pgd_t *_pgd_alloc(void) + { + return (pgd_t *)__get_free_pages(PGALLOC_GFP, PGD_ALLOCATION_ORDER); +diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c +index 2f25a36..dcb2d9d 100644 +--- a/arch/x86/platform/efi/efi_64.c ++++ b/arch/x86/platform/efi/efi_64.c +@@ -142,7 +142,7 @@ int __init efi_alloc_page_tables(void) + return 0; + + gfp_mask = GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO; +- efi_pgd = (pgd_t *)__get_free_page(gfp_mask); ++ efi_pgd = (pgd_t *)__get_free_pages(gfp_mask, PGD_ALLOCATION_ORDER); + if (!efi_pgd) + return -ENOMEM; + +-- +2.7.4 + |