On 2021.07.16 18:41:38 +0800, Xiyu Yang wrote:
> refcount_t type and corresponding API can protect refcounters from
> accidental underflow and overflow and further use-after-free situations
>
Thanks for the patch. Is there any specific problem you run with current code?
Any shadow ppgtt error?
> Signed-off-by: Xiyu Yang <xiyuyang19@xxxxxxxxxxxx>
> Signed-off-by: Xin Tan <tanxin.ctf@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/gvt/gtt.c | 11 ++++++-----
> drivers/gpu/drm/i915/gvt/gtt.h | 3 ++-
> 2 files changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gvt/gtt.c b/drivers/gpu/drm/i915/gvt/gtt.c
> index cc2c05e18206..62f3daff5a36 100644
> --- a/drivers/gpu/drm/i915/gvt/gtt.c
> +++ b/drivers/gpu/drm/i915/gvt/gtt.c
> @@ -841,7 +841,7 @@ static struct intel_vgpu_ppgtt_spt *ppgtt_alloc_spt(
> }
>
> spt->vgpu = vgpu;
> - atomic_set(&spt->refcount, 1);
> + refcount_set(&spt->refcount, 1);
> INIT_LIST_HEAD(&spt->post_shadow_list);
>
> /*
> @@ -927,18 +927,19 @@ static struct intel_vgpu_ppgtt_spt *ppgtt_alloc_spt_gfn(
>
> static inline void ppgtt_get_spt(struct intel_vgpu_ppgtt_spt *spt)
> {
> - int v = atomic_read(&spt->refcount);
> + int v = refcount_read(&spt->refcount);
>
> trace_spt_refcount(spt->vgpu->id, "inc", spt, v, (v + 1));
> - atomic_inc(&spt->refcount);
> + refcount_inc(&spt->refcount);
> }
>
> static inline int ppgtt_put_spt(struct intel_vgpu_ppgtt_spt *spt)
> {
> - int v = atomic_read(&spt->refcount);
> + int v = refcount_read(&spt->refcount);
>
> trace_spt_refcount(spt->vgpu->id, "dec", spt, v, (v - 1));
> - return atomic_dec_return(&spt->refcount);
> + refcount_dec(&spt->refcount);
> + return refcount_read(&spt->refcount);
> }
>
> static int ppgtt_invalidate_spt(struct intel_vgpu_ppgtt_spt *spt);
> diff --git a/drivers/gpu/drm/i915/gvt/gtt.h b/drivers/gpu/drm/i915/gvt/gtt.h
> index 3bf45672ef98..944c2d0739df 100644
> --- a/drivers/gpu/drm/i915/gvt/gtt.h
> +++ b/drivers/gpu/drm/i915/gvt/gtt.h
> @@ -38,6 +38,7 @@
> #include <linux/kref.h>
> #include <linux/mutex.h>
> #include <linux/radix-tree.h>
> +#include <linux/refcount.h>
>
> #include "gt/intel_gtt.h"
>
> @@ -243,7 +244,7 @@ struct intel_vgpu_oos_page {
>
> /* Represent a vgpu shadow page table. */
> struct intel_vgpu_ppgtt_spt {
> - atomic_t refcount;
> + refcount_t refcount;
> struct intel_vgpu *vgpu;
>
> struct {
> --
> 2.7.4
>
> _______________________________________________
> intel-gvt-dev mailing list
> intel-gvt-dev@xxxxxxxxxxxxxxxxxxxxx
> https://lists.freedesktop.org/mailman/listinfo/intel-gvt-dev
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