lkml.org 
[lkml]   [2021]   [Jul]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] drm/i915/gvt: Convert from atomic_t to refcount_t on intel_vgpu_ppgtt_spt->refcount
Date
refcount_t type and corresponding API can protect refcounters from
accidental underflow and overflow and further use-after-free situations

Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
---
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
\
 
 \ /
  Last update: 2021-07-16 12:43    [W:0.066 / U:23.028 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site