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| author | Dave Hansen <dave.hansen@intel.com> | 2017-11-06 17:29:52 -0800 |
|---|---|---|
| committer | Dave Hansen <dave.hansen@intel.com> | 2017-11-06 17:29:52 -0800 |
| commit | 66c2620dc495d74ae0456e9f192410a0a89ee432 (patch) | |
| tree | dbea10834af9f34b236caf1c040e643e088f2703 | |
| parent | ef4f9e8cd08df643cedbccf043489edfdf88bf71 (diff) | |
| download | x86-kaiser-66c2620dc495d74ae0456e9f192410a0a89ee432.tar.gz | |
x86, kaiser: make sure static PGDs are 8k in size
From: Dave Hansen <dave.hansen@linux.intel.com>
We have a few PGDs that come out of the kernel binary instead of being
allocated dynamically. Before this patch, they are all 8k-aligned,
but we also need them to be 8k in *size*e
The original KAISER patch did not do this. It probably just lucked out
that it did not trample over data after the last PGD.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Moritz Lipp <moritz.lipp@iaik.tugraz.at>
Cc: Daniel Gruss <daniel.gruss@iaik.tugraz.at>
Cc: Michael Schwarz <michael.schwarz@iaik.tugraz.at>
Cc: Richard Fellner <richard.fellner@student.tugraz.at>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Kees Cook <keescook@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: x86@kernel.org
| -rw-r--r-- | arch/x86/kernel/head_64.S | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 3f13bacd7fe83f..f8c43243666dc1 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -340,11 +340,24 @@ GLOBAL(early_recursion_flag) GLOBAL(name) #ifdef CONFIG_KAISER +/* + * Each PGD needs to be 8k long and 8k aligned. We do not + * ever go out to userspace with these, so we do not + * strictly *need* the second page, but this allows us to + * have a single set_pgd() implementation that does not + * need to worry about whether it has 4k or 8k to work + * with. + * + * This ensures PGDs are 8k long: + */ +#define KAISER_USER_PGD_FILL 512 +/* This ensures they are 8k-aligned: */ #define NEXT_PGD_PAGE(name) \ .balign 2 * PAGE_SIZE; \ GLOBAL(name) #else #define NEXT_PGD_PAGE(name) NEXT_PAGE(name) +#define KAISER_USER_PGD_FILL 0 #endif /* Automate the creation of 1 to 1 mapping pmd entries */ @@ -363,6 +376,7 @@ NEXT_PGD_PAGE(early_top_pgt) #else .quad level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC #endif + .fill KAISER_USER_PGD_FILL,8,0 NEXT_PAGE(early_dynamic_pgts) .fill 512*EARLY_DYNAMIC_PAGE_TABLES,8,0 @@ -372,6 +386,7 @@ NEXT_PAGE(early_dynamic_pgts) #ifndef CONFIG_XEN NEXT_PGD_PAGE(init_top_pgt) .fill 512,8,0 + .fill KAISER_USER_PGD_FILL,8,0 #else NEXT_PGD_PAGE(init_top_pgt) .quad level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC @@ -380,6 +395,7 @@ NEXT_PGD_PAGE(init_top_pgt) .org init_top_pgt + PGD_START_KERNEL*8, 0 /* (2^48-(2*1024*1024*1024))/(2^39) = 511 */ .quad level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC + .fill KAISER_USER_PGD_FILL,8,0 NEXT_PAGE(level3_ident_pgt) .quad level2_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC |