Re: [PATCH] xen: fix logical error in tlb flushing

Jan Beulich
2012-08-24T15:16:46Z

>>> On 24.08.12 at 10:55, Alex Shi <alex.shi@intel.com> wrote:
> While TLB_FLUSH_ALL gets passed as 'end' argument to
> flush_tlb_others(), the Xen code was made to check its 'start'
> parameter. That may give a incorrect op.cmd to MMUEXT_INVLPG_MULTI
> instead of MMUEXT_TLB_FLUSH_MULTI. Then it causes some page can not
> be flushed from TLB.
>
> This patch fixed this issue.
>
> Reported-by: Jan Beulich <jbeulich@suse.com>
> Signed-off-by: Alex Shi <alex.shi@intel.com>

Acked-by: Jan Beulich <jbeulich@suse.com>

> ---
> arch/x86/xen/mmu.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
> index b65a761..5141d80 100644
> --- a/arch/x86/xen/mmu.c
> +++ b/arch/x86/xen/mmu.c
> @@ -1283,7 +1283,7 @@ static void xen_flush_tlb_others(const struct cpumask
> *cpus,
> cpumask_clear_cpu(smp_processor_id(), to_cpumask(args->mask));
>
> args->op.cmd = MMUEXT_TLB_FLUSH_MULTI;
> - if (start != TLB_FLUSH_ALL && (end - start) <= PAGE_SIZE) {
> + if (end != TLB_FLUSH_ALL && (end - start) <= PAGE_SIZE) {
> args->op.cmd = MMUEXT_INVLPG_MULTI;
> args->op.arg1.linear_addr = start;
> }
> --
> 1.7.5.4
>
> .