| Message ID | 20220706164304.1582687-7-maz@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: arm64: vgic-v3 userspace access consolidation (and other goodies) | expand |
On Wed, Jul 06, 2022 at 05:42:51PM +0100, Marc Zyngier wrote: > These helpers are only used by the invariant stuff now, and while > they pretend to support non-64bit registers, this only serves as > a way to scare the casual reviewer... > > Replace these helpers with our good friends get/put_user(), and > don't look back. > > Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> > --- > arch/arm64/kvm/sys_regs.c | 33 +++++++++------------------------ > 1 file changed, 9 insertions(+), 24 deletions(-) > > diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c > index 1ce439eed3d8..b66be9df7a02 100644 > --- a/arch/arm64/kvm/sys_regs.c > +++ b/arch/arm64/kvm/sys_regs.c > @@ -44,8 +44,6 @@ > * 64bit interface. > */ > > -static int reg_from_user(u64 *val, const void __user *uaddr, u64 id); > -static int reg_to_user(void __user *uaddr, const u64 *val, u64 id); > static u64 sys_reg_to_index(const struct sys_reg_desc *reg); > > static bool read_from_write_only(struct kvm_vcpu *vcpu, > @@ -2661,21 +2659,7 @@ static struct sys_reg_desc invariant_sys_regs[] = { > { SYS_DESC(SYS_CTR_EL0), NULL, get_ctr_el0 }, > }; > > -static int reg_from_user(u64 *val, const void __user *uaddr, u64 id) > -{ > - if (copy_from_user(val, uaddr, KVM_REG_SIZE(id)) != 0) > - return -EFAULT; > - return 0; > -} > - > -static int reg_to_user(void __user *uaddr, const u64 *val, u64 id) > -{ > - if (copy_to_user(uaddr, val, KVM_REG_SIZE(id)) != 0) > - return -EFAULT; > - return 0; > -} > - > -static int get_invariant_sys_reg(u64 id, void __user *uaddr) > +static int get_invariant_sys_reg(u64 id, u64 __user *uaddr) > { > const struct sys_reg_desc *r; > > @@ -2684,23 +2668,24 @@ static int get_invariant_sys_reg(u64 id, void __user *uaddr) > if (!r) > return -ENOENT; > > - return reg_to_user(uaddr, &r->val, id); > + if (put_user(r->val, uaddr)) > + return -EFAULT; > + > + return 0; > } > > -static int set_invariant_sys_reg(u64 id, void __user *uaddr) > +static int set_invariant_sys_reg(u64 id, u64 __user *uaddr) > { > const struct sys_reg_desc *r; > - int err; > - u64 val = 0; /* Make sure high bits are 0 for 32-bit regs */ > + u64 val; > > r = get_reg_by_id(id, invariant_sys_regs, > ARRAY_SIZE(invariant_sys_regs)); > if (!r) > return -ENOENT; > > - err = reg_from_user(&val, uaddr, id); > - if (err) > - return err; > + if (get_user(val, uaddr)) > + return -EFAULT; > > /* This is what we mean by invariant: you can't change it. */ > if (r->val != val) > -- > 2.34.1 >
On Wed, Jul 6, 2022 at 9:43 AM Marc Zyngier <maz@kernel.org> wrote: > > These helpers are only used by the invariant stuff now, and while > they pretend to support non-64bit registers, this only serves as > a way to scare the casual reviewer... > > Replace these helpers with our good friends get/put_user(), and > don't look back. > > Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Reiji Watanabe <reijiw@google.com>
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 1ce439eed3d8..b66be9df7a02 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -44,8 +44,6 @@ * 64bit interface. */ -static int reg_from_user(u64 *val, const void __user *uaddr, u64 id); -static int reg_to_user(void __user *uaddr, const u64 *val, u64 id); static u64 sys_reg_to_index(const struct sys_reg_desc *reg); static bool read_from_write_only(struct kvm_vcpu *vcpu, @@ -2661,21 +2659,7 @@ static struct sys_reg_desc invariant_sys_regs[] = { { SYS_DESC(SYS_CTR_EL0), NULL, get_ctr_el0 }, }; -static int reg_from_user(u64 *val, const void __user *uaddr, u64 id) -{ - if (copy_from_user(val, uaddr, KVM_REG_SIZE(id)) != 0) - return -EFAULT; - return 0; -} - -static int reg_to_user(void __user *uaddr, const u64 *val, u64 id) -{ - if (copy_to_user(uaddr, val, KVM_REG_SIZE(id)) != 0) - return -EFAULT; - return 0; -} - -static int get_invariant_sys_reg(u64 id, void __user *uaddr) +static int get_invariant_sys_reg(u64 id, u64 __user *uaddr) { const struct sys_reg_desc *r; @@ -2684,23 +2668,24 @@ static int get_invariant_sys_reg(u64 id, void __user *uaddr) if (!r) return -ENOENT; - return reg_to_user(uaddr, &r->val, id); + if (put_user(r->val, uaddr)) + return -EFAULT; + + return 0; } -static int set_invariant_sys_reg(u64 id, void __user *uaddr) +static int set_invariant_sys_reg(u64 id, u64 __user *uaddr) { const struct sys_reg_desc *r; - int err; - u64 val = 0; /* Make sure high bits are 0 for 32-bit regs */ + u64 val; r = get_reg_by_id(id, invariant_sys_regs, ARRAY_SIZE(invariant_sys_regs)); if (!r) return -ENOENT; - err = reg_from_user(&val, uaddr, id); - if (err) - return err; + if (get_user(val, uaddr)) + return -EFAULT; /* This is what we mean by invariant: you can't change it. */ if (r->val != val)
These helpers are only used by the invariant stuff now, and while they pretend to support non-64bit registers, this only serves as a way to scare the casual reviewer... Replace these helpers with our good friends get/put_user(), and don't look back. Signed-off-by: Marc Zyngier <maz@kernel.org> --- arch/arm64/kvm/sys_regs.c | 33 +++++++++------------------------ 1 file changed, 9 insertions(+), 24 deletions(-)