netdev - Re: [PATCH 16/39] convert __bpf_prog

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Message-ID: <20240807-wollust-entgleisen-e0ae07e6ae57@brauner>
Date: Wed, 7 Aug 2024 12:28:33 +0200
From: Christian Brauner <brauner@...nel.org>
To: viro@...nel.org
Cc: linux-fsdevel@...r.kernel.org, amir73il@...il.com, bpf@...r.kernel.org, 
	cgroups@...r.kernel.org, kvm@...r.kernel.org, netdev@...r.kernel.org, 
	torvalds@...ux-foundation.org
Subject: Re: [PATCH 16/39] convert __bpf_prog_get() to CLASS(fd, ...)

On Tue, Jul 30, 2024 at 01:16:02AM GMT, viro@...nel.org wrote:
> From: Al Viro <viro@...iv.linux.org.uk>
> 
> Irregularity here is fdput() not in the same scope as fdget();
> just fold ____bpf_prog_get() into its (only) caller and that's
> it...
> 
> Signed-off-by: Al Viro <viro@...iv.linux.org.uk>
> ---
>  kernel/bpf/syscall.c | 32 +++++++++++---------------------
>  1 file changed, 11 insertions(+), 21 deletions(-)
> 
> diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
> index 3093bf2cc266..c5b252c0faa8 100644
> --- a/kernel/bpf/syscall.c
> +++ b/kernel/bpf/syscall.c
> @@ -2407,18 +2407,6 @@ int bpf_prog_new_fd(struct bpf_prog *prog)
>  				O_RDWR | O_CLOEXEC);
>  }
>  
> -static struct bpf_prog *____bpf_prog_get(struct fd f)
> -{
> -	if (!fd_file(f))
> -		return ERR_PTR(-EBADF);
> -	if (fd_file(f)->f_op != &bpf_prog_fops) {
> -		fdput(f);
> -		return ERR_PTR(-EINVAL);
> -	}
> -
> -	return fd_file(f)->private_data;
> -}
> -
>  void bpf_prog_add(struct bpf_prog *prog, int i)
>  {
>  	atomic64_add(i, &prog->aux->refcnt);
> @@ -2474,20 +2462,22 @@ bool bpf_prog_get_ok(struct bpf_prog *prog,
>  static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
>  				       bool attach_drv)
>  {
> -	struct fd f = fdget(ufd);
> +	CLASS(fd, f)(ufd);
>  	struct bpf_prog *prog;
>  
> -	prog = ____bpf_prog_get(f);
> -	if (IS_ERR(prog))
> +	if (fd_empty(f))
> +		return ERR_PTR(-EBADF);
> +	if (fd_file(f)->f_op != &bpf_prog_fops)
> +		return ERR_PTR(-EINVAL);
> +
> +	prog = fd_file(f)->private_data;
> +	if (IS_ERR(prog))	// can that actually happen?
>  		return prog;

With or without that removed:

Reviewed-by: Christian Brauner <brauner@...nel.org>