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authorJoey Gouly <joey.gouly@arm.com>2021-02-02 12:36:58 +0000
committerWill Deacon <will@kernel.org>2021-02-03 20:43:45 +0000
commit0188a894c390e51475274ece76b4d601782d709e (patch)
tree79cf592206f63eed00a6b74f88f573ce836cd627 /arch
parent00ef543419366e8b742435992d08e0d5a87fd561 (diff)
downloadlinux-0188a894c390e51475274ece76b4d601782d709e.tar.bz2
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 <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/20210202123658.22308-3-joey.gouly@arm.com Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/include/asm/memory.h6
-rw-r--r--arch/arm64/kernel/entry.S4
-rw-r--r--arch/arm64/kernel/vmlinux.lds.S5
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 <linux/bitops.h>
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