diff options
| author | Joey Gouly <joey.gouly@arm.com> | 2021-02-02 12:36:57 +0000 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2021-02-03 20:43:45 +0000 |
| commit | 00ef543419366e8b742435992d08e0d5a87fd561 (patch) | |
| tree | e41fabcdd9176181f10a0732d290f081f62dcd6d | |
| parent | b9ba680969d1016888fed4e03d8ecb4b97726f34 (diff) | |
arm64: vmlinux.ld.S: add assertion for reserved_pg_dir offset
Add RESERVED_SWAPPER_OFFSET and use that instead of hardcoding
the offset between swapper_pg_dir and reserved_pg_dir.
Then use RESERVED_SWAPPER_OFFSET to assert that the offset is
correct at link time.
Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20210202123658.22308-2-joey.gouly@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
| -rw-r--r-- | arch/arm64/include/asm/asm-uaccess.h | 4 | ||||
| -rw-r--r-- | arch/arm64/include/asm/memory.h | 6 | ||||
| -rw-r--r-- | arch/arm64/include/asm/uaccess.h | 2 | ||||
| -rw-r--r-- | arch/arm64/kernel/vmlinux.lds.S | 3 |
4 files changed, 12 insertions, 3 deletions
diff --git a/arch/arm64/include/asm/asm-uaccess.h b/arch/arm64/include/asm/asm-uaccess.h index 9990059be106..ccedf548dac9 100644 --- a/arch/arm64/include/asm/asm-uaccess.h +++ b/arch/arm64/include/asm/asm-uaccess.h @@ -15,10 +15,10 @@ .macro __uaccess_ttbr0_disable, tmp1 mrs \tmp1, ttbr1_el1 // swapper_pg_dir bic \tmp1, \tmp1, #TTBR_ASID_MASK - sub \tmp1, \tmp1, #PAGE_SIZE // reserved_pg_dir just before swapper_pg_dir + sub \tmp1, \tmp1, #RESERVED_SWAPPER_OFFSET // reserved_pg_dir msr ttbr0_el1, \tmp1 // set reserved TTBR0_EL1 isb - add \tmp1, \tmp1, #PAGE_SIZE + add \tmp1, \tmp1, #RESERVED_SWAPPER_OFFSET msr ttbr1_el1, \tmp1 // set reserved ASID isb .endm diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index 18fce223b67b..f6bf8a972a16 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -159,6 +159,12 @@ #define IOREMAP_MAX_ORDER (PMD_SHIFT) #endif +/* + * Open-coded (swapper_pg_dir - reserved_pg_dir) as this cannot be calculated + * until link time. + */ +#define RESERVED_SWAPPER_OFFSET (PAGE_SIZE) + #ifndef __ASSEMBLY__ #include <linux/bitops.h> diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index f0fe0cc6abe0..0deb88467111 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -87,7 +87,7 @@ static inline void __uaccess_ttbr0_disable(void) ttbr = read_sysreg(ttbr1_el1); ttbr &= ~TTBR_ASID_MASK; /* reserved_pg_dir placed before swapper_pg_dir */ - write_sysreg(ttbr - PAGE_SIZE, ttbr0_el1); + write_sysreg(ttbr - RESERVED_SWAPPER_OFFSET, ttbr0_el1); isb(); /* Set reserved ASID */ write_sysreg(ttbr, ttbr1_el1); diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S index 4c0b0c89ad59..a03a5300bce9 100644 --- a/arch/arm64/kernel/vmlinux.lds.S +++ b/arch/arm64/kernel/vmlinux.lds.S @@ -316,3 +316,6 @@ ASSERT((__entry_tramp_text_end - __entry_tramp_text_start) == PAGE_SIZE, * If padding is applied before .head.text, virt<->phys conversions will fail. */ ASSERT(_text == KIMAGE_VADDR, "HEAD is misaligned") + +ASSERT(swapper_pg_dir - reserved_pg_dir == RESERVED_SWAPPER_OFFSET, + "RESERVED_SWAPPER_OFFSET is wrong!") |