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

Thorsten Blum
2024-09-25T14:18:45Z

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 <thorsten.blum@linux.dev>
---
drivers/gpu/drm/i915/gem/i915_gem_context.c | 12 +++---------
1 file changed, 3 insertions(+), 9 deletions(-)

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)) {
--
2.46.1