diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0003-kaiser-allocate-pgd-with-order-0-when-pti-off.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.9.21/0003-kaiser-allocate-pgd-with-order-0-when-pti-off.patch | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0003-kaiser-allocate-pgd-with-order-0-when-pti-off.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0003-kaiser-allocate-pgd-with-order-0-when-pti-off.patch new file mode 100644 index 00000000..df60ee58 --- /dev/null +++ b/common/recipes-kernel/linux/linux-yocto-4.9.21/0003-kaiser-allocate-pgd-with-order-0-when-pti-off.patch @@ -0,0 +1,69 @@ +From cff1c9cfd81b8a7cc350a02d37668b1e3896287e Mon Sep 17 00:00:00 2001 +From: Hugh Dickins <hughd@google.com> +Date: Mon, 29 Jan 2018 18:17:58 -0800 +Subject: [PATCH 03/42] kaiser: allocate pgd with order 0 when pti=off + +The 4.9.77 version of "x86/pti/efi: broken conversion from efi to kernel +page table" looked nicer than the 4.4.112 version, but was suboptimal on +machines booted with "pti=off" (or on AMD machines): it allocated pgd +with an order 1 page whatever the setting of kaiser_enabled. + +Fix that by moving the definition of PGD_ALLOCATION_ORDER from +asm/pgalloc.h to asm/pgtable.h, which already defines kaiser_enabled. + +Fixes: 1b92c48a2eeb ("x86/pti/efi: broken conversion from efi to kernel page table") +Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com> +Cc: Steven Sistare <steven.sistare@oracle.com> +Cc: Jiri Kosina <jkosina@suse.cz> +Signed-off-by: Hugh Dickins <hughd@google.com> +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +--- + arch/x86/include/asm/pgalloc.h | 11 ----------- + arch/x86/include/asm/pgtable.h | 6 ++++++ + 2 files changed, 6 insertions(+), 11 deletions(-) + +diff --git a/arch/x86/include/asm/pgalloc.h b/arch/x86/include/asm/pgalloc.h +index 1178a51..b6d4259 100644 +--- a/arch/x86/include/asm/pgalloc.h ++++ b/arch/x86/include/asm/pgalloc.h +@@ -27,17 +27,6 @@ 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/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h +index 2536f90..5af0401 100644 +--- a/arch/x86/include/asm/pgtable.h ++++ b/arch/x86/include/asm/pgtable.h +@@ -20,9 +20,15 @@ + + #ifdef CONFIG_PAGE_TABLE_ISOLATION + extern int kaiser_enabled; ++/* ++ * 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. ++ */ + #else + #define kaiser_enabled 0 + #endif ++#define PGD_ALLOCATION_ORDER kaiser_enabled + + void ptdump_walk_pgd_level(struct seq_file *m, pgd_t *pgd); + void ptdump_walk_pgd_level_checkwx(void); +-- +2.7.4 + |