drm/msm: remove some dead code

This is supposed to test for integer overflow but it is wrong and
unnecessary.  The size_add()/mul() macros return SIZE_MAX when there is
an integer overflow.  This code saves the SIZE_MAX to a u64 and then
tests if the result is greater than SIZE_MAX which it never will be.
Fortunately, when we try to allocate SIZE_MAX bytes the allocation
will fail.  We even pass __GFP_NOWARN so the allocation fails
harmlessly and quietly.

Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Fixes: 2e6a8a1fe2b2 ("drm/msm: Add VM_BIND ioctl")
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/697596/
Link: https://lore.kernel.org/r/aWAMIhZLxUcecbLd@stanley.mountain
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>

diff --git a/drivers/gpu/drm/msm/msm_gem_vma.c b/drivers/gpu/drm/msm/msm_gem_vma.c
index 8f7c90167447ec03849550ef18f1f3571abbdc93..3a6c435d5105fcacd0d169b294ba34875f270767 100644 (file)
--- a/drivers/gpu/drm/msm/msm_gem_vma.c
+++ b/drivers/gpu/drm/msm/msm_gem_vma.c
@@ -950,15 +950,9 @@ vm_bind_job_create(struct drm_device *dev, struct drm_file *file,
                   struct msm_gpu_submitqueue *queue, uint32_t nr_ops)
 {
        struct msm_vm_bind_job *job;
-       uint64_t sz;
        int ret;
 
-       sz = struct_size(job, ops, nr_ops);
-
-       if (sz > SIZE_MAX)
-               return ERR_PTR(-ENOMEM);
-
-       job = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN);
+       job = kzalloc(struct_size(job, ops, nr_ops), GFP_KERNEL | __GFP_NOWARN);
        if (!job)
                return ERR_PTR(-ENOMEM);