From 0188a894c390e51475274ece76b4d601782d709e Mon Sep 17 00:00:00 2001 From: Joey Gouly Date: Tue, 2 Feb 2021 12:36:58 +0000 Subject: arm64: vmlinux.ld.S: add assertion for tramp_pg_dir offset Add TRAMP_SWAPPER_OFFSET and use that instead of hardcoding the offset between swapper_pg_dir and tramp_pg_dir. Then use TRAMP_SWAPPER_OFFSET to assert that the offset is correct at link time. Signed-off-by: Joey Gouly Reviewed-by: Mark Rutland Tested-by: Mark Rutland Link: https://lore.kernel.org/r/20210202123658.22308-3-joey.gouly@arm.com Signed-off-by: Will Deacon --- arch/arm64/include/asm/memory.h | 6 ++++++ arch/arm64/kernel/entry.S | 4 ++-- arch/arm64/kernel/vmlinux.lds.S | 5 +++++ 3 files changed, 13 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index f6bf8a972a16..6c2674937665 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -165,6 +165,12 @@ */ #define RESERVED_SWAPPER_OFFSET (PAGE_SIZE) +/* + * Open-coded (swapper_pg_dir - tramp_pg_dir) as this cannot be calculated + * until link time. + */ +#define TRAMP_SWAPPER_OFFSET (2 * PAGE_SIZE) + #ifndef __ASSEMBLY__ #include diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index c9bae73f2621..c6aee646eb6b 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -805,7 +805,7 @@ SYM_CODE_END(ret_to_user) // Move from tramp_pg_dir to swapper_pg_dir .macro tramp_map_kernel, tmp mrs \tmp, ttbr1_el1 - add \tmp, \tmp, #(2 * PAGE_SIZE) + add \tmp, \tmp, #TRAMP_SWAPPER_OFFSET bic \tmp, \tmp, #USER_ASID_FLAG msr ttbr1_el1, \tmp #ifdef CONFIG_QCOM_FALKOR_ERRATUM_1003 @@ -825,7 +825,7 @@ alternative_else_nop_endif // Move from swapper_pg_dir to tramp_pg_dir .macro tramp_unmap_kernel, tmp mrs \tmp, ttbr1_el1 - sub \tmp, \tmp, #(2 * PAGE_SIZE) + sub \tmp, \tmp, #TRAMP_SWAPPER_OFFSET orr \tmp, \tmp, #USER_ASID_FLAG msr ttbr1_el1, \tmp /* diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S index a03a5300bce9..68f76a96c60b 100644 --- a/arch/arm64/kernel/vmlinux.lds.S +++ b/arch/arm64/kernel/vmlinux.lds.S @@ -319,3 +319,8 @@ ASSERT(_text == KIMAGE_VADDR, "HEAD is misaligned") ASSERT(swapper_pg_dir - reserved_pg_dir == RESERVED_SWAPPER_OFFSET, "RESERVED_SWAPPER_OFFSET is wrong!") + +#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 +ASSERT(swapper_pg_dir - tramp_pg_dir == TRAMP_SWAPPER_OFFSET, + "TRAMP_SWAPPER_OFFSET is wrong!") +#endif -- cgit v1.2.3