Re: [PATCH] thunderbolt: debugfs: Replace get_zeroed_page() with kzalloc()

[Mike Rapoport <rppt@kernel.org>]

On Sat, Aug 08, 2026 at 10:38:29PM +0000, Mahad Ibrahim wrote:
> validate_and_copy_from_user() allocates a page to store data from
> userspace via get_zeroed_page(), and then returns it as a buffer.
> Neither the function itself nor its callers require struct page access.
> 
> This buffer can easily be allocated with kzalloc() as there is nothing
> special about it that requires going through the page allocator.
> kzalloc(), which internally reduces to kmalloc() with __GFP_ZERO,
> provides a better API and kfree() does not need to know the size of the
> freed object. Additionally it removes the casts of (void *) and
> (unsigned long) which only obfuscate the code.
> 
> Replace get_zeroed_page() with kzalloc() and free_page() with kfree().
> 
> Compile-tested only; no USB4 hardware available.
> 
> Link: https://lore.kernel.org/all/635405e4-9423-4a25-a6e7-e03c8ea0bcbe@redhat.com/
> Signed-off-by: Mahad Ibrahim <mahad.ibrahim.dev@gmail.com>

Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>

> ---
>  drivers/thunderbolt/debugfs.c | 28 ++++++++++++++--------------
>  1 file changed, 14 insertions(+), 14 deletions(-)

-- 
Sincerely yours,
Mike.