[PATCH 3/4] arm64/mm: make tramp_pg_dir and swapper_pg_dir adjacent

From: Jun Yao
Date: Fri Jun 01 2018 - 04:09:27 EST


To defense KSMA, we need to migrate tramp_pg_dir and swapper_pg_dir
together. Make them adjacent to avoid modifying tramp_(un)map_kernel.

Signed-off-by: Jun Yao <yaojun8558363@xxxxxxxxx>
---
arch/arm64/kernel/entry.S | 4 ++--
arch/arm64/kernel/vmlinux.lds.S | 9 +++++----
2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index ec2ee720e33e..b35425feaf56 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -1004,7 +1004,7 @@ __ni_sys_trace:

.macro tramp_map_kernel, tmp
mrs \tmp, ttbr1_el1
- add \tmp, \tmp, #(PAGE_SIZE + RESERVED_TTBR0_SIZE)
+ add \tmp, \tmp, #(PAGE_SIZE)
bic \tmp, \tmp, #USER_ASID_FLAG
msr ttbr1_el1, \tmp
#ifdef CONFIG_QCOM_FALKOR_ERRATUM_1003
@@ -1023,7 +1023,7 @@ alternative_else_nop_endif

.macro tramp_unmap_kernel, tmp
mrs \tmp, ttbr1_el1
- sub \tmp, \tmp, #(PAGE_SIZE + RESERVED_TTBR0_SIZE)
+ sub \tmp, \tmp, #(PAGE_SIZE)
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 605d1b60469c..3c72e6dec890 100644
--- a/arch/arm64/kernel/vmlinux.lds.S
+++ b/arch/arm64/kernel/vmlinux.lds.S
@@ -219,15 +219,16 @@ SECTIONS
idmap_pg_dir = .;
. += IDMAP_DIR_SIZE;

+#ifdef CONFIG_ARM64_SW_TTBR0_PAN
+ reserved_ttbr0 = .;
+ . += RESERVED_TTBR0_SIZE;
+#endif
+
#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
tramp_pg_dir = .;
. += PAGE_SIZE;
#endif

-#ifdef CONFIG_ARM64_SW_TTBR0_PAN
- reserved_ttbr0 = .;
- . += RESERVED_TTBR0_SIZE;
-#endif
swapper_pg_dir = .;
. += SWAPPER_DIR_SIZE;
swapper_pg_end = .;
--
2.17.0