Allow the init of non-zero data in the pKVM hypervisor by adding support
for the .data section.
Signed-off-by: Vincent Donnefort <vdonnef...@google.com>
diff --git a/arch/arm64/include/asm/sections.h
b/arch/arm64/include/asm/sections.h
index 40971ac1303f..51b0d594239e 100644
--- a/arch/arm64/include/asm/sections.h
+++ b/arch/arm64/include/asm/sections.h
@@ -11,6 +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_start[], __hyp_data_end[];
extern char __hyp_rodata_start[], __hyp_rodata_end[];
extern char __hyp_reloc_begin[], __hyp_reloc_end[];
extern char __hyp_bss_start[], __hyp_bss_end[];
diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h
index 5e3c4b58f279..9c5345f1ab66 100644
--- a/arch/arm64/kernel/image-vars.h
+++ b/arch/arm64/kernel/image-vars.h
@@ -131,6 +131,8 @@ KVM_NVHE_ALIAS(__hyp_text_start);
KVM_NVHE_ALIAS(__hyp_text_end);
KVM_NVHE_ALIAS(__hyp_bss_start);
KVM_NVHE_ALIAS(__hyp_bss_end);
+KVM_NVHE_ALIAS(__hyp_data_start);
+KVM_NVHE_ALIAS(__hyp_data_end);
KVM_NVHE_ALIAS(__hyp_rodata_start);
KVM_NVHE_ALIAS(__hyp_rodata_end);
diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
index e73326bd3ff7..7c770053f072 100644
--- a/arch/arm64/kernel/vmlinux.lds.S
+++ b/arch/arm64/kernel/vmlinux.lds.S
@@ -13,7 +13,7 @@
*(__kvm_ex_table) \
__stop___kvm_ex_table = .;
-#define HYPERVISOR_DATA_SECTIONS \
+#define HYPERVISOR_RODATA_SECTIONS \
HYP_SECTION_NAME(.rodata) : { \
. = ALIGN(PAGE_SIZE); \
__hyp_rodata_start = .; \
@@ -23,6 +23,15 @@
__hyp_rodata_end = .; \
}
+#define HYPERVISOR_DATA_SECTION \
+ HYP_SECTION_NAME(.data) : { \
+ . = ALIGN(PAGE_SIZE); \
+ __hyp_data_start = .; \
+ *(HYP_SECTION_NAME(.data)) \
+ . = ALIGN(PAGE_SIZE); \
+ __hyp_data_end = .; \
+ }
+
#define HYPERVISOR_PERCPU_SECTION \
. = ALIGN(PAGE_SIZE); \
HYP_SECTION_NAME(.data..percpu) : { \
@@ -51,7 +60,8 @@
#define SBSS_ALIGN PAGE_SIZE
#else /* CONFIG_KVM */
#define HYPERVISOR_EXTABLE
-#define HYPERVISOR_DATA_SECTIONS
+#define HYPERVISOR_RODATA_SECTIONS
+#define HYPERVISOR_DATA_SECTION
#define HYPERVISOR_PERCPU_SECTION
#define HYPERVISOR_RELOC_SECTION
#define SBSS_ALIGN 0
@@ -190,7 +200,7 @@ SECTIONS
/* everything from this point to __init_begin will be marked RO NX */
RO_DATA(PAGE_SIZE)
- HYPERVISOR_DATA_SECTIONS
+ HYPERVISOR_RODATA_SECTIONS
.got : { *(.got) }
/*
@@ -295,6 +305,8 @@ SECTIONS
_sdata = .;
RW_DATA(L1_CACHE_BYTES, PAGE_SIZE, THREAD_ALIGN)
+ HYPERVISOR_DATA_SECTION
+
/*
* Data written with the MMU off but read with the MMU on requires
* cache lines to be invalidated, discarding up to a Cache Writeback
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 68fec8c95fee..58e8119f66bd 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -2604,6 +2604,13 @@ static int __init init_hyp_mode(void)
goto out_err;
}
+ err = create_hyp_mappings(kvm_ksym_ref(__hyp_data_start),
+ kvm_ksym_ref(__hyp_data_end), PAGE_HYP);
+ if (err) {
+ kvm_err("Cannot map .hyp.data section\n");
+ goto out_err;
+ }
+
err = create_hyp_mappings(kvm_ksym_ref(__hyp_rodata_start),
kvm_ksym_ref(__hyp_rodata_end), PAGE_HYP_RO);
if (err) {
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp.lds.S
b/arch/arm64/kvm/hyp/nvhe/hyp.lds.S
index f4562f417d3f..d724f6d69302 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp.lds.S
+++ b/arch/arm64/kvm/hyp/nvhe/hyp.lds.S
@@ -25,5 +25,7 @@ SECTIONS {
BEGIN_HYP_SECTION(.data..percpu)
PERCPU_INPUT(L1_CACHE_BYTES)
END_HYP_SECTION
+
HYP_SECTION(.bss)
+ HYP_SECTION(.data)
}
diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c
index d62bcb5634a2..46d9bd04348f 100644
--- a/arch/arm64/kvm/hyp/nvhe/setup.c
+++ b/arch/arm64/kvm/hyp/nvhe/setup.c
@@ -119,6 +119,10 @@ static int recreate_hyp_mappings(phys_addr_t phys,
unsigned long size,
if (ret)
return ret;
+ ret = pkvm_create_mappings(__hyp_data_start, __hyp_data_end, PAGE_HYP);
+ if (ret)
+ return ret;
+
ret = pkvm_create_mappings(__hyp_rodata_start, __hyp_rodata_end,
PAGE_HYP_RO);
if (ret)
return ret;
diff --git a/arch/arm64/kvm/pkvm.c b/arch/arm64/kvm/pkvm.c
index 0f89157d31fd..c462140e640a 100644
--- a/arch/arm64/kvm/pkvm.c
+++ b/arch/arm64/kvm/pkvm.c
@@ -262,6 +262,7 @@ static int __init finalize_pkvm(void)
* at, which would end badly once inaccessible.
*/
kmemleak_free_part(__hyp_bss_start, __hyp_bss_end - __hyp_bss_start);
+ kmemleak_free_part(__hyp_data_start, __hyp_data_end - __hyp_data_start);
kmemleak_free_part(__hyp_rodata_start, __hyp_rodata_end -
__hyp_rodata_start);
kmemleak_free_part_phys(hyp_mem_base, hyp_mem_size);
--
2.49.0.967.g6a0df3ecc3-goog
