[PATCH] drm/msm: Fix legacy relocs path

From: Rob Clark
Date: Thu Feb 04 2021 - 17:54:57 EST


From: Rob Clark <robdclark@xxxxxxxxxxxx>

In moving code around, we ended up using the same pointer to
copy_from_user() the relocs tables as we used for the cmd table
entry, which is clearly not right. This went unnoticed because
modern mesa on non-ancent kernels does not actually use relocs.
But this broke ancient mesa on modern kernels.

Reported-by: Emil Velikov <emil.velikov@xxxxxxxxxxxxx>
Fixes: 20224d715a88 ("drm/msm/submit: Move copy_from_user ahead of locking bos")
Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
---
drivers/gpu/drm/msm/msm_gem_submit.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
index d04c349d8112..5480852bdeda 100644
--- a/drivers/gpu/drm/msm/msm_gem_submit.c
+++ b/drivers/gpu/drm/msm/msm_gem_submit.c
@@ -198,6 +198,8 @@ static int submit_lookup_cmds(struct msm_gem_submit *submit,
submit->cmd[i].idx = submit_cmd.submit_idx;
submit->cmd[i].nr_relocs = submit_cmd.nr_relocs;

+ userptr = u64_to_user_ptr(submit_cmd.relocs);
+
sz = array_size(submit_cmd.nr_relocs,
sizeof(struct drm_msm_gem_submit_reloc));
/* check for overflow: */
--
2.29.2