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| author | Steve Capper <steve.capper@arm.com> | 2018-01-11 13:11:57 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2018-01-14 21:49:51 +0300 |
| commit | 9dfe4828aa32c49856dffd6cd31297f3466caa0d (patch) | |
| tree | 5e2802e946a4d675f614922dc32580cdc44eced8 /arch/arm64 | |
| parent | 79e9aa59dc29a995921fb01e64cd36b73cf5abe0 (diff) | |
| download | linux-9dfe4828aa32c49856dffd6cd31297f3466caa0d.tar.xz | |
arm64: Re-order reserved_ttbr0 in linker script
Currently one resolves the location of the reserved_ttbr0 for PAN by
taking a positive offset from swapper_pg_dir. In a future patch we wish
to extend the swapper s.t. its size is determined at link time rather
than comile time, rendering SWAPPER_DIR_SIZE unsuitable for such a low
level calculation.
In this patch we re-arrange the order of the linker script s.t. instead
one computes reserved_ttbr0 by subtracting RESERVED_TTBR0_SIZE from
swapper_pg_dir.
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Steve Capper <steve.capper@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/include/asm/asm-uaccess.h | 8 | ||||
| -rw-r--r-- | arch/arm64/include/asm/uaccess.h | 4 | ||||
| -rw-r--r-- | arch/arm64/kernel/vmlinux.lds.S | 5 |
3 files changed, 8 insertions, 9 deletions
diff --git a/arch/arm64/include/asm/asm-uaccess.h b/arch/arm64/include/asm/asm-uaccess.h index f4f234b6155e..8719ce122a38 100644 --- a/arch/arm64/include/asm/asm-uaccess.h +++ b/arch/arm64/include/asm/asm-uaccess.h @@ -13,11 +13,11 @@ */ #ifdef CONFIG_ARM64_SW_TTBR0_PAN .macro __uaccess_ttbr0_disable, tmp1 - mrs \tmp1, ttbr1_el1 // swapper_pg_dir - add \tmp1, \tmp1, #SWAPPER_DIR_SIZE // reserved_ttbr0 at the end of swapper_pg_dir - msr ttbr0_el1, \tmp1 // set reserved TTBR0_EL1 + mrs \tmp1, ttbr1_el1 // swapper_pg_dir + sub \tmp1, \tmp1, #RESERVED_TTBR0_SIZE // reserved_ttbr0 just before swapper_pg_dir + msr ttbr0_el1, \tmp1 // set reserved TTBR0_EL1 isb - sub \tmp1, \tmp1, #SWAPPER_DIR_SIZE + add \tmp1, \tmp1, #RESERVED_TTBR0_SIZE bic \tmp1, \tmp1, #TTBR_ASID_MASK msr ttbr1_el1, \tmp1 // set reserved ASID isb diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index 3821fab01d7d..01ade20d5456 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -108,8 +108,8 @@ static inline void __uaccess_ttbr0_disable(void) unsigned long ttbr; ttbr = read_sysreg(ttbr1_el1); - /* reserved_ttbr0 placed at the end of swapper_pg_dir */ - write_sysreg(ttbr + SWAPPER_DIR_SIZE, ttbr0_el1); + /* reserved_ttbr0 placed before swapper_pg_dir */ + write_sysreg(ttbr - RESERVED_TTBR0_SIZE, ttbr0_el1); isb(); /* Set reserved ASID */ ttbr &= ~TTBR_ASID_MASK; diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S index ddfd3c0942f7..8e567de8f369 100644 --- a/arch/arm64/kernel/vmlinux.lds.S +++ b/arch/arm64/kernel/vmlinux.lds.S @@ -218,13 +218,12 @@ SECTIONS . = ALIGN(PAGE_SIZE); idmap_pg_dir = .; . += IDMAP_DIR_SIZE; - swapper_pg_dir = .; - . += SWAPPER_DIR_SIZE; - #ifdef CONFIG_ARM64_SW_TTBR0_PAN reserved_ttbr0 = .; . += RESERVED_TTBR0_SIZE; #endif + swapper_pg_dir = .; + . += SWAPPER_DIR_SIZE; #ifdef CONFIG_UNMAP_KERNEL_AT_EL0 tramp_pg_dir = .; |