[PATCH v2 2/8] KVM: arm64: Set up .hyp.rodata ELF section

David Brazdil
2021-01-05T18:06:49Z

We will need to recognize pointers in .rodata specific to hyp, so
establish a .hyp.rodata ELF section. Merge it with the existing
.hyp.data..ro_after_init as they are treated the same at runtime.

Signed-off-by: David Brazdil <dbrazdil@google.com>
---
arch/arm64/include/asm/sections.h | 2 +-
arch/arm64/kernel/vmlinux.lds.S | 7 ++++---
arch/arm64/kvm/arm.c | 7 +++----
arch/arm64/kvm/hyp/nvhe/hyp.lds.S | 4 +++-
4 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/include/asm/sections.h b/arch/arm64/include/asm/sections.h
index 8ff579361731..a6f3557d1ab2 100644
--- a/arch/arm64/include/asm/sections.h
+++ b/arch/arm64/include/asm/sections.h
@@ -11,7 +11,7 @@ extern char __alt_instructions[], __alt_instructions_end[];
extern char __hibernate_exit_text_start[], __hibernate_exit_text_end[];
extern char __hyp_idmap_text_start[], __hyp_idmap_text_end[];
extern char __hyp_text_start[], __hyp_text_end[];
-extern char __hyp_data_ro_after_init_start[], __hyp_data_ro_after_init_end[];
+extern char __hyp_rodata_start[], __hyp_rodata_end[];
extern char __idmap_text_start[], __idmap_text_end[];
extern char __initdata_begin[], __initdata_end[];
extern char __inittext_begin[], __inittext_end[];
diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
index 4c0b0c89ad59..9672b54bba7c 100644
--- a/arch/arm64/kernel/vmlinux.lds.S
+++ b/arch/arm64/kernel/vmlinux.lds.S
@@ -31,10 +31,11 @@ jiffies = jiffies_64;
__stop___kvm_ex_table = .;

#define HYPERVISOR_DATA_SECTIONS \
- HYP_SECTION_NAME(.data..ro_after_init) : { \
- __hyp_data_ro_after_init_start = .; \
+ HYP_SECTION_NAME(.rodata) : { \
+ __hyp_rodata_start = .; \
*(HYP_SECTION_NAME(.data..ro_after_init)) \
- __hyp_data_ro_after_init_end = .; \
+ *(HYP_SECTION_NAME(.rodata)) \
+ __hyp_rodata_end = .; \
}

#define HYPERVISOR_PERCPU_SECTION \
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 04c44853b103..de1af4052780 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1749,11 +1749,10 @@ static int init_hyp_mode(void)
goto out_err;
}

- err = create_hyp_mappings(kvm_ksym_ref(__hyp_data_ro_after_init_start),
- kvm_ksym_ref(__hyp_data_ro_after_init_end),
- PAGE_HYP_RO);
+ err = create_hyp_mappings(kvm_ksym_ref(__hyp_rodata_start),
+ kvm_ksym_ref(__hyp_rodata_end), PAGE_HYP_RO);
if (err) {
- kvm_err("Cannot map .hyp.data..ro_after_init section\n");
+ kvm_err("Cannot map .hyp.rodata section\n");
goto out_err;
}

diff --git a/arch/arm64/kvm/hyp/nvhe/hyp.lds.S b/arch/arm64/kvm/hyp/nvhe/hyp.lds.S
index 70ac48ccede7..cfdc59b4329b 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp.lds.S
+++ b/arch/arm64/kvm/hyp/nvhe/hyp.lds.S
@@ -14,6 +14,9 @@
SECTIONS {
HYP_SECTION(.idmap.text)
HYP_SECTION(.text)
+ HYP_SECTION(.data..ro_after_init)
+ HYP_SECTION(.rodata)
+
/*
* .hyp..data..percpu needs to be page aligned to maintain the same
* alignment for when linking into vmlinux.
@@ -22,5 +25,4 @@ SECTIONS {
HYP_SECTION_NAME(.data..percpu) : {
PERCPU_INPUT(L1_CACHE_BYTES)
}
- HYP_SECTION(.data..ro_after_init)
}
--
2.29.2.729.g45daf8777d-goog