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authorMarc Zyngier <marc.zyngier@arm.com>2016-06-13 15:00:48 +0100
committerChristoffer Dall <christoffer.dall@linaro.org>2016-06-29 14:01:34 +0200
commit5900270550cbb8a272bfc248b69531cd44dcf0d5 (patch)
tree9683a4f7757d6e45d58302b4d950ac3df703dbad
parent74a6b8885f7026e33f8a4776b7ac17c76b8e5a52 (diff)
downloadop-kernel-dev-5900270550cbb8a272bfc248b69531cd44dcf0d5.zip
op-kernel-dev-5900270550cbb8a272bfc248b69531cd44dcf0d5.tar.gz
arm/arm64: KVM: Map the HYP text as read-only
There should be no reason for mapping the HYP text read/write. As such, let's have a new set of flags (PAGE_HYP_EXEC) that allows execution, but makes the page as read-only, and update the two call sites that deal with mapping code. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
-rw-r--r--arch/arm/include/asm/pgtable.h1
-rw-r--r--arch/arm/kvm/arm.c2
-rw-r--r--arch/arm/kvm/mmu.c6
-rw-r--r--arch/arm64/include/asm/pgtable-prot.h1
4 files changed, 6 insertions, 4 deletions
diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index f332087..7487bf9 100644
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -98,6 +98,7 @@ extern pgprot_t pgprot_s2_device;
#define PAGE_KERNEL _MOD_PROT(pgprot_kernel, L_PTE_XN)
#define PAGE_KERNEL_EXEC pgprot_kernel
#define PAGE_HYP _MOD_PROT(pgprot_kernel, L_PTE_HYP)
+#define PAGE_HYP_EXEC _MOD_PROT(pgprot_kernel, L_PTE_HYP | L_PTE_RDONLY)
#define PAGE_HYP_RO _MOD_PROT(pgprot_kernel, L_PTE_HYP | L_PTE_RDONLY | L_PTE_XN)
#define PAGE_HYP_DEVICE _MOD_PROT(pgprot_hyp_device, L_PTE_HYP)
#define PAGE_S2 _MOD_PROT(pgprot_s2, L_PTE_S2_RDONLY)
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index b308976..c74483f 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -1293,7 +1293,7 @@ static int init_hyp_mode(void)
* Map the Hyp-code called directly from the host
*/
err = create_hyp_mappings(kvm_ksym_ref(__hyp_text_start),
- kvm_ksym_ref(__hyp_text_end), PAGE_HYP);
+ kvm_ksym_ref(__hyp_text_end), PAGE_HYP_EXEC);
if (err) {
kvm_err("Cannot map world-switch code\n");
goto out_err;
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index 49cb5cc..679608f 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -1733,7 +1733,7 @@ int kvm_mmu_init(void)
err = __create_hyp_mappings(boot_hyp_pgd,
hyp_idmap_start, hyp_idmap_end,
__phys_to_pfn(hyp_idmap_start),
- PAGE_HYP);
+ PAGE_HYP_EXEC);
if (err) {
kvm_err("Failed to idmap %lx-%lx\n",
@@ -1756,7 +1756,7 @@ int kvm_mmu_init(void)
err = __create_hyp_mappings(boot_hyp_pgd,
TRAMPOLINE_VA, TRAMPOLINE_VA + PAGE_SIZE,
__phys_to_pfn(hyp_idmap_start),
- PAGE_HYP);
+ PAGE_HYP_EXEC);
if (err) {
kvm_err("Failed to map trampoline @%lx into boot HYP pgd\n",
TRAMPOLINE_VA);
@@ -1767,7 +1767,7 @@ int kvm_mmu_init(void)
err = __create_hyp_mappings(hyp_pgd,
TRAMPOLINE_VA, TRAMPOLINE_VA + PAGE_SIZE,
__phys_to_pfn(hyp_idmap_start),
- PAGE_HYP);
+ PAGE_HYP_EXEC);
if (err) {
kvm_err("Failed to map trampoline @%lx into runtime HYP pgd\n",
TRAMPOLINE_VA);
diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h
index 88db58c..3802048 100644
--- a/arch/arm64/include/asm/pgtable-prot.h
+++ b/arch/arm64/include/asm/pgtable-prot.h
@@ -56,6 +56,7 @@
#define PAGE_KERNEL_EXEC_CONT __pgprot(_PAGE_DEFAULT | PTE_UXN | PTE_DIRTY | PTE_WRITE | PTE_CONT)
#define PAGE_HYP __pgprot(_PAGE_DEFAULT | PTE_HYP)
+#define PAGE_HYP_EXEC __pgprot(_PAGE_DEFAULT | PTE_HYP | PTE_RDONLY)
#define PAGE_HYP_RO __pgprot(_PAGE_DEFAULT | PTE_HYP | PTE_RDONLY | PTE_HYP_XN)
#define PAGE_HYP_DEVICE __pgprot(PROT_DEVICE_nGnRE | PTE_HYP)
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