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?

Christian.


Fixes: 5fad79fd66ff ("drm/mm: cleanup and improve next_hole_*_addr()")
Signed-off-by: Jing Xiangfeng <[email protected]>
---
  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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