On 2020/9/10 16:58, Christian König wrote:
Am 10.09.20 um 04:38 schrieb Jing Xiangfeng:
The macro 'DECLARE_NEXT_HOLE_ADDR' may hit a potential null-pointer
dereference. So use 'entry' after checking it.
I don't see a potential null-pointer dereference here.
Where should that be?
In current code，the "entry" pointer is checked after entry->rb_hole_addr.
Thanks
Christian.
Fixes: 5fad79fd66ff ("drm/mm: cleanup and improve next_hole_*_addr()")
Signed-off-by: Jing Xiangfeng <jingxiangfeng@xxxxxxxxxx>
---
drivers/gpu/drm/drm_mm.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c
index a4a04d246135..6fcf70f71962 100644
--- a/drivers/gpu/drm/drm_mm.c
+++ b/drivers/gpu/drm/drm_mm.c
@@ -392,11 +392,14 @@ first_hole(struct drm_mm *mm,
#define DECLARE_NEXT_HOLE_ADDR(name, first, last) \
static struct drm_mm_node *name(struct drm_mm_node *entry, u64
size) \
{ \
- struct rb_node *parent, *node = &entry->rb_hole_addr; \
+ struct rb_node *parent, *node; \
\
- if (!entry || RB_EMPTY_NODE(node)) \
+ if (!entry) \
return NULL; \
\
+ node = &entry->rb_hole_addr; \
+ if (RB_EMPTY_NODE(node)) \
+ return NULL; \
if (usable_hole_addr(node->first, size)) { \
node = node->first; \
while (usable_hole_addr(node->last, size)) \
.
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