[PATCH] powerpc/kvm: Handle the boundary condition correctly

[Alexander Graf]

On 22.08.2013, at 12:37, Aneesh Kumar K.V wrote:

> From: "Aneesh Kumar K.V" <aneesh.kumar at linux.vnet.ibm.com>

Isn't this you?

> 
> We should be able to copy upto count bytes

Why?


Alex

> 
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
> ---
> arch/powerpc/kvm/book3s_64_mmu_hv.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
> index 710d313..0ae6bb6 100644
> --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
> +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
> @@ -1362,7 +1362,7 @@ static ssize_t kvm_htab_read(struct file *file, char __user *buf,
> 	lbuf = (unsigned long __user *)buf;
> 
> 	nb = 0;
> -	while (nb + sizeof(hdr) + HPTE_SIZE < count) {
> +	while (nb + sizeof(hdr) + HPTE_SIZE <= count) {
> 		/* Initialize header */
> 		hptr = (struct kvm_get_htab_header __user *)buf;
> 		hdr.n_valid = 0;
> @@ -1385,7 +1385,7 @@ static ssize_t kvm_htab_read(struct file *file, char __user *buf,
> 		/* Grab a series of valid entries */
> 		while (i < kvm->arch.hpt_npte &&
> 		       hdr.n_valid < 0xffff &&
> -		       nb + HPTE_SIZE < count &&
> +		       nb + HPTE_SIZE <= count &&
> 		       record_hpte(flags, hptp, hpte, revp, 1, first_pass)) {
> 			/* valid entry, write it out */
> 			++hdr.n_valid;
> -- 
> 1.8.1.2
>