4.9-stable review patch. If anyone has any objections, please let me know.
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From: Hugh Dickins hughd@google.com
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(-)
--- a/arch/x86/include/asm/pgalloc.h +++ b/arch/x86/include/asm/pgalloc.h @@ -27,17 +27,6 @@ static inline void paravirt_release_pud( */ 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. */ --- 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);