drm/i915: Use memdup_user() instead of kmalloc() and copy_from_user()

Commit Message

Thorsten Blum Sept. 25, 2024, 2:17 p.m. UTC

Use memdup_user() instead of kmalloc() followed by copy_from_user() to
simplify set_context_image().

Fixes the following Coccinelle/coccicheck warning reported by
memdup_user.cocci:

  WARNING opportunity for memdup_user

Signed-off-by: Thorsten Blum <[e-mail]>
---
 drivers/gpu/drm/i915/gem/i915_gem_context.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

Patch

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index c0543c35cd6a..c1cc41e90502 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -2159,18 +2159,12 @@  static int set_context_image(struct i915_gem_context *ctx,
 		goto out_ce;
 	}
 
-	state = kmalloc(ce->engine->context_size, GFP_KERNEL);
-	if (!state) {
-		ret = -ENOMEM;
+	state = memdup_user(u64_to_user_ptr(user.image), ce->engine->context_size);
+	if (IS_ERR(state)) {
+		ret = PTR_ERR(state);
 		goto out_ce;
 	}
 
-	if (copy_from_user(state, u64_to_user_ptr(user.image),
-			   ce->engine->context_size)) {
-		ret = -EFAULT;
-		goto out_state;
-	}
-
 	shmem_state = shmem_create_from_data(ce->engine->name,
 					     state, ce->engine->context_size);
 	if (IS_ERR(shmem_state)) {