On Sun, 21 Sep, at 05:26:54PM, Mathias Krause wrote:
> In commit 3891a04aafd6 ("x86-64, espfix: Don't leak bits 31:16 of %esp
> returning..") the "ESPFix Area" was added to the page table dump special
> sections. That area, though, has a limited amount of entries printed.
>
> The EFI runtime services are, unfortunately, located in-between the
> espfix area and the high kernel memory mapping. Due to the enforced
> limitation for the espfix area, the EFI mappings won't be printed in the
> page table dump.
>
> To make the ESP runtime service mappings visible again, provide them a
> dedicated entry.
>
> Signed-off-by: Mathias Krause <[email protected]>
> Cc: Matt Fleming <[email protected]>
> Cc: H. Peter Anvin <[email protected]>
> ---
> v2: same as v1
>
> arch/x86/include/asm/pgtable_64_types.h | 2 ++
> arch/x86/mm/dump_pagetables.c | 3 +++
> arch/x86/platform/efi/efi_64.c | 3 +--
> 3 files changed, 6 insertions(+), 2 deletions(-)
Looks OK to me. Borislav?
> diff --git a/arch/x86/include/asm/pgtable_64_types.h
> b/arch/x86/include/asm/pgtable_64_types.h
> index 7166e25ecb57..602b6028c5b6 100644
> --- a/arch/x86/include/asm/pgtable_64_types.h
> +++ b/arch/x86/include/asm/pgtable_64_types.h
> @@ -63,6 +63,8 @@ typedef struct { pteval_t pte; } pte_t;
> #define MODULES_LEN (MODULES_END - MODULES_VADDR)
> #define ESPFIX_PGD_ENTRY _AC(-2, UL)
> #define ESPFIX_BASE_ADDR (ESPFIX_PGD_ENTRY << PGDIR_SHIFT)
> +#define EFI_VA_START ( -4 * (_AC(1, UL) << 30))
> +#define EFI_VA_END (-68 * (_AC(1, UL) << 30))
>
> #define EARLY_DYNAMIC_PAGE_TABLES 64
>
> diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
> index 95a427e57887..1a8053d1012e 100644
> --- a/arch/x86/mm/dump_pagetables.c
> +++ b/arch/x86/mm/dump_pagetables.c
> @@ -76,6 +76,9 @@ static struct addr_marker address_markers[] = {
> # ifdef CONFIG_X86_ESPFIX64
> { ESPFIX_BASE_ADDR, "ESPfix Area", 16 },
> # endif
> +# ifdef CONFIG_EFI
> + { EFI_VA_END, "EFI Runtime Services" },
> +# endif
> { __START_KERNEL_map, "High Kernel Mapping" },
> { MODULES_VADDR, "Modules" },
> { MODULES_END, "End Modules" },
> diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
> index 290d397e1dd9..899c7f17ad85 100644
> --- a/arch/x86/platform/efi/efi_64.c
> +++ b/arch/x86/platform/efi/efi_64.c
> @@ -48,8 +48,7 @@ static unsigned long efi_flags __initdata;
> * We allocate runtime services regions bottom-up, starting from -4G, i.e.
> * 0xffff_ffff_0000_0000 and limit EFI VA mapping space to 64G.
> */
> -static u64 efi_va = -4 * (1UL << 30);
> -#define EFI_VA_END (-68 * (1UL << 30))
> +static u64 efi_va = EFI_VA_START;
>
> /*
> * Scratch space used for switching the pagetable in the EFI stub
> --
> 1.7.10.4
>
> --
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--
Matt Fleming, Intel Open Source Technology Center
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