If the number of items to process in the request is zero, we can forgo duplicating, sorting the request and feeding it into the kernel and instead report success immediately. This prevents a NULL dereference of the sorted->items for the no-op request.

Fixes: ed44e0b9585c563905447eceed12af9c1c7ca8d4 Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Cc: Ville Syrjälä ville.syrjala@linux.intel.com Cc: Rob Clark robclark@freedesktop.org Cc: Daniel Stone daniels@collabora.com Cc: Emil Velikov emil.l.velikov@gmail.com --- xf86drmMode.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/xf86drmMode.c b/xf86drmMode.c index 529429e..fa21986 100644 --- a/xf86drmMode.c +++ b/xf86drmMode.c @@ -1289,7 +1289,7 @@ static int sort_req_list(const void *misc, const void *other) int drmModeAtomicCommit(int fd, drmModeAtomicReqPtr req, uint32_t flags, void *user_data) { - drmModeAtomicReqPtr sorted = drmModeAtomicDuplicate(req); + drmModeAtomicReqPtr sorted; struct drm_mode_atomic atomic; uint32_t *objs_ptr = NULL; uint32_t *count_props_ptr = NULL; @@ -1300,7 +1300,11 @@ int drmModeAtomicCommit(int fd, drmModeAtomicReqPtr req, uint32_t flags, int obj_idx = -1; int ret = -1;

- if (!sorted) + if (req->cursor == 0) + return 0; + + sorted = drmModeAtomicDuplicate(req); + if (sorted == NULL) return -ENOMEM;

memclear(atomic);