Re: [PATCH v2 1/3] drm/mm: Ensure that the entry is not NULL before extracting rb_node

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




On 17/02/2022 07:50, Vivek Kasireddy wrote:
While looking for next holes suitable for an allocation, although,
it is highly unlikely, make sure that the DECLARE_NEXT_HOLE_ADDR
macro is using a valid node before it extracts the rb_node from it.

Was the need for this just a consequence of insufficient locking in the i915 patch?

Regards,

Tvrtko


Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx>
Cc: Christian König <christian.koenig@xxxxxxx>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@xxxxxxxxx>
---
  drivers/gpu/drm/drm_mm.c | 5 +++--
  1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c
index 8257f9d4f619..499d8874e4ed 100644
--- a/drivers/gpu/drm/drm_mm.c
+++ b/drivers/gpu/drm/drm_mm.c
@@ -389,11 +389,12 @@ 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 || RB_EMPTY_NODE(&entry->rb_hole_addr))		\
  		return NULL;						\
  									\
+	node = &entry->rb_hole_addr;					\
  	if (usable_hole_addr(node->first, size)) {			\
  		node = node->first;					\
  		while (usable_hole_addr(node->last, size))		\



[Index of Archives]     [Linux DRI Users]     [Linux Intel Graphics]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux