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| author | Steve Capper <steve.capper@arm.com> | 2018-12-06 23:50:37 +0100 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2018-12-10 19:42:17 +0100 |
| commit | 363524d2b12270d86677e1154ecc1c5061f43219 (patch) | |
| tree | 1b4653ee1c9509e7233e8d3a75a2f8cb8c66f62b /drivers/firmware | |
| parent | mm: mmap: Allow for "high" userspace addresses (diff) | |
| download | linux-363524d2b12270d86677e1154ecc1c5061f43219.tar.xz linux-363524d2b12270d86677e1154ecc1c5061f43219.zip | |
arm64: mm: Introduce DEFAULT_MAP_WINDOW
We wish to introduce a 52-bit virtual address space for userspace but
maintain compatibility with software that assumes the maximum VA space
size is 48 bit.
In order to achieve this, on 52-bit VA systems, we make mmap behave as
if it were running on a 48-bit VA system (unless userspace explicitly
requests a VA where addr[51:48] != 0).
On a system running a 52-bit userspace we need TASK_SIZE to represent
the 52-bit limit as it is used in various places to distinguish between
kernelspace and userspace addresses.
Thus we need a new limit for mmap, stack, ELF loader and EFI (which uses
TTBR0) to represent the non-extended VA space.
This patch introduces DEFAULT_MAP_WINDOW and DEFAULT_MAP_WINDOW_64 and
switches the appropriate logic to use that instead of TASK_SIZE.
Signed-off-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'drivers/firmware')
| -rw-r--r-- | drivers/firmware/efi/arm-runtime.c | 2 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/arm-stub.c | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/drivers/firmware/efi/arm-runtime.c b/drivers/firmware/efi/arm-runtime.c index a00934d263c5..23ea1ed409d1 100644 --- a/drivers/firmware/efi/arm-runtime.c +++ b/drivers/firmware/efi/arm-runtime.c @@ -38,7 +38,7 @@ static struct ptdump_info efi_ptdump_info = { .mm = &efi_mm, .markers = (struct addr_marker[]){ { 0, "UEFI runtime start" }, - { TASK_SIZE_64, "UEFI runtime end" } + { DEFAULT_MAP_WINDOW_64, "UEFI runtime end" } }, .base_addr = 0, }; diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c index 3d36142cf812..6640942a1c0d 100644 --- a/drivers/firmware/efi/libstub/arm-stub.c +++ b/drivers/firmware/efi/libstub/arm-stub.c @@ -33,7 +33,7 @@ #define EFI_RT_VIRTUAL_SIZE SZ_512M #ifdef CONFIG_ARM64 -# define EFI_RT_VIRTUAL_LIMIT TASK_SIZE_64 +# define EFI_RT_VIRTUAL_LIMIT DEFAULT_MAP_WINDOW_64 #else # define EFI_RT_VIRTUAL_LIMIT TASK_SIZE #endif |