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authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-10-02 02:24:20 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-10-02 02:24:20 +0200
commit385afbf8c3e8bdf13fc729e8b2c172d1208d97f9 (patch)
tree0d559f1a70a444315a1c9d4c295e1a188b0c4193 /arch
parentMerge tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm... (diff)
parentarm64: KVM: Sanitize PSTATE.M when being set from userspace (diff)
downloadlinux-385afbf8c3e8bdf13fc729e8b2c172d1208d97f9.tar.xz
linux-385afbf8c3e8bdf13fc729e8b2c172d1208d97f9.zip
Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Will writes: "Late arm64 fixes - Fix handling of young contiguous ptes for hugetlb mappings - Fix livelock when taking access faults on contiguous hugetlb mappings - Tighten up register accesses via KVM SET_ONE_REG ioctl()s" * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: KVM: Sanitize PSTATE.M when being set from userspace arm64: KVM: Tighten guest core register access from userspace arm64: hugetlb: Avoid unnecessary clearing in huge_ptep_set_access_flags arm64: hugetlb: Fix handling of young ptes
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/kvm/guest.c55
-rw-r--r--arch/arm64/mm/hugetlbpage.c50
2 files changed, 97 insertions, 8 deletions
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 07256b08226c..a6c9fbaeaefc 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -57,6 +57,45 @@ static u64 core_reg_offset_from_id(u64 id)
return id & ~(KVM_REG_ARCH_MASK | KVM_REG_SIZE_MASK | KVM_REG_ARM_CORE);
}
+static int validate_core_offset(const struct kvm_one_reg *reg)
+{
+ u64 off = core_reg_offset_from_id(reg->id);
+ int size;
+
+ switch (off) {
+ case KVM_REG_ARM_CORE_REG(regs.regs[0]) ...
+ KVM_REG_ARM_CORE_REG(regs.regs[30]):
+ case KVM_REG_ARM_CORE_REG(regs.sp):
+ case KVM_REG_ARM_CORE_REG(regs.pc):
+ case KVM_REG_ARM_CORE_REG(regs.pstate):
+ case KVM_REG_ARM_CORE_REG(sp_el1):
+ case KVM_REG_ARM_CORE_REG(elr_el1):
+ case KVM_REG_ARM_CORE_REG(spsr[0]) ...
+ KVM_REG_ARM_CORE_REG(spsr[KVM_NR_SPSR - 1]):
+ size = sizeof(__u64);
+ break;
+
+ case KVM_REG_ARM_CORE_REG(fp_regs.vregs[0]) ...
+ KVM_REG_ARM_CORE_REG(fp_regs.vregs[31]):
+ size = sizeof(__uint128_t);
+ break;
+
+ case KVM_REG_ARM_CORE_REG(fp_regs.fpsr):
+ case KVM_REG_ARM_CORE_REG(fp_regs.fpcr):
+ size = sizeof(__u32);
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ if (KVM_REG_SIZE(reg->id) == size &&
+ IS_ALIGNED(off, size / sizeof(__u32)))
+ return 0;
+
+ return -EINVAL;
+}
+
static int get_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
/*
@@ -76,6 +115,9 @@ static int get_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
(off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs)
return -ENOENT;
+ if (validate_core_offset(reg))
+ return -EINVAL;
+
if (copy_to_user(uaddr, ((u32 *)regs) + off, KVM_REG_SIZE(reg->id)))
return -EFAULT;
@@ -98,6 +140,9 @@ static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
(off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs)
return -ENOENT;
+ if (validate_core_offset(reg))
+ return -EINVAL;
+
if (KVM_REG_SIZE(reg->id) > sizeof(tmp))
return -EINVAL;
@@ -107,17 +152,25 @@ static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
}
if (off == KVM_REG_ARM_CORE_REG(regs.pstate)) {
- u32 mode = (*(u32 *)valp) & PSR_AA32_MODE_MASK;
+ u64 mode = (*(u64 *)valp) & PSR_AA32_MODE_MASK;
switch (mode) {
case PSR_AA32_MODE_USR:
+ if (!system_supports_32bit_el0())
+ return -EINVAL;
+ break;
case PSR_AA32_MODE_FIQ:
case PSR_AA32_MODE_IRQ:
case PSR_AA32_MODE_SVC:
case PSR_AA32_MODE_ABT:
case PSR_AA32_MODE_UND:
+ if (!vcpu_el1_is_32bit(vcpu))
+ return -EINVAL;
+ break;
case PSR_MODE_EL0t:
case PSR_MODE_EL1t:
case PSR_MODE_EL1h:
+ if (vcpu_el1_is_32bit(vcpu))
+ return -EINVAL;
break;
default:
err = -EINVAL;
diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
index 192b3ba07075..f58ea503ad01 100644
--- a/arch/arm64/mm/hugetlbpage.c
+++ b/arch/arm64/mm/hugetlbpage.c
@@ -117,11 +117,14 @@ static pte_t get_clear_flush(struct mm_struct *mm,
/*
* If HW_AFDBM is enabled, then the HW could turn on
- * the dirty bit for any page in the set, so check
- * them all. All hugetlb entries are already young.
+ * the dirty or accessed bit for any page in the set,
+ * so check them all.
*/
if (pte_dirty(pte))
orig_pte = pte_mkdirty(orig_pte);
+
+ if (pte_young(pte))
+ orig_pte = pte_mkyoung(orig_pte);
}
if (valid) {
@@ -320,11 +323,40 @@ pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
return get_clear_flush(mm, addr, ptep, pgsize, ncontig);
}
+/*
+ * huge_ptep_set_access_flags will update access flags (dirty, accesssed)
+ * and write permission.
+ *
+ * For a contiguous huge pte range we need to check whether or not write
+ * permission has to change only on the first pte in the set. Then for
+ * all the contiguous ptes we need to check whether or not there is a
+ * discrepancy between dirty or young.
+ */
+static int __cont_access_flags_changed(pte_t *ptep, pte_t pte, int ncontig)
+{
+ int i;
+
+ if (pte_write(pte) != pte_write(huge_ptep_get(ptep)))
+ return 1;
+
+ for (i = 0; i < ncontig; i++) {
+ pte_t orig_pte = huge_ptep_get(ptep + i);
+
+ if (pte_dirty(pte) != pte_dirty(orig_pte))
+ return 1;
+
+ if (pte_young(pte) != pte_young(orig_pte))
+ return 1;
+ }
+
+ return 0;
+}
+
int huge_ptep_set_access_flags(struct vm_area_struct *vma,
unsigned long addr, pte_t *ptep,
pte_t pte, int dirty)
{
- int ncontig, i, changed = 0;
+ int ncontig, i;
size_t pgsize = 0;
unsigned long pfn = pte_pfn(pte), dpfn;
pgprot_t hugeprot;
@@ -336,19 +368,23 @@ int huge_ptep_set_access_flags(struct vm_area_struct *vma,
ncontig = find_num_contig(vma->vm_mm, addr, ptep, &pgsize);
dpfn = pgsize >> PAGE_SHIFT;
+ if (!__cont_access_flags_changed(ptep, pte, ncontig))
+ return 0;
+
orig_pte = get_clear_flush(vma->vm_mm, addr, ptep, pgsize, ncontig);
- if (!pte_same(orig_pte, pte))
- changed = 1;
- /* Make sure we don't lose the dirty state */
+ /* Make sure we don't lose the dirty or young state */
if (pte_dirty(orig_pte))
pte = pte_mkdirty(pte);
+ if (pte_young(orig_pte))
+ pte = pte_mkyoung(pte);
+
hugeprot = pte_pgprot(pte);
for (i = 0; i < ncontig; i++, ptep++, addr += pgsize, pfn += dpfn)
set_pte_at(vma->vm_mm, addr, ptep, pfn_pte(pfn, hugeprot));
- return changed;
+ return 1;
}
void huge_ptep_set_wrprotect(struct mm_struct *mm,