netdev - Re: [Patch bpf-next 2/2] bpf: remove a redundant parameter of bpf_prog_free

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Message-ID: <Y8Zs8yU7rg2FtCBQ@krava>
Date:   Tue, 17 Jan 2023 10:40:03 +0100
From:   Jiri Olsa <olsajiri@...il.com>
To:     Cong Wang <xiyou.wangcong@...il.com>
Cc:     netdev@...r.kernel.org, bpf@...r.kernel.org,
        Cong Wang <cong.wang@...edance.com>,
        Alexei Starovoitov <ast@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>,
        John Fastabend <john.fastabend@...il.com>,
        Paul Moore <paul@...l-moore.com>
Subject: Re: [Patch bpf-next 2/2] bpf: remove a redundant parameter of
 bpf_prog_free_id()

On Mon, Jan 16, 2023 at 10:02:49PM -0800, Cong Wang wrote:
> From: Cong Wang <cong.wang@...edance.com>
> 
> The second parameter of bpf_prog_free_id() is always true,
> hence can be just eliminated.

hi,
Paul did this already:
  https://lore.kernel.org/bpf/20230106154400.74211-2-paul@paul-moore.com/

it's in bpf/master now

bpf_map_free_id change lgtm, but might be better
to sync with bpf/master first

jirka

> 
> Cc: Alexei Starovoitov <ast@...nel.org>
> Cc: Daniel Borkmann <daniel@...earbox.net>
> Cc: John Fastabend <john.fastabend@...il.com>
> Signed-off-by: Cong Wang <cong.wang@...edance.com>
> ---
>  include/linux/bpf.h  |  2 +-
>  kernel/bpf/offload.c |  2 +-
>  kernel/bpf/syscall.c | 23 +++++------------------
>  3 files changed, 7 insertions(+), 20 deletions(-)
> 
> diff --git a/include/linux/bpf.h b/include/linux/bpf.h
> index 3558c192871c..2c0d2383cea0 100644
> --- a/include/linux/bpf.h
> +++ b/include/linux/bpf.h
> @@ -1832,7 +1832,7 @@ void bpf_prog_inc(struct bpf_prog *prog);
>  struct bpf_prog * __must_check bpf_prog_inc_not_zero(struct bpf_prog *prog);
>  void bpf_prog_put(struct bpf_prog *prog);
>  
> -void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock);
> +void bpf_prog_free_id(struct bpf_prog *prog);
>  void bpf_map_free_id(struct bpf_map *map);
>  
>  struct btf_field *btf_record_find(const struct btf_record *rec,
> diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c
> index ae6d5a5c0798..658032e294ed 100644
> --- a/kernel/bpf/offload.c
> +++ b/kernel/bpf/offload.c
> @@ -217,7 +217,7 @@ static void __bpf_prog_offload_destroy(struct bpf_prog *prog)
>  		offload->offdev->ops->destroy(prog);
>  
>  	/* Make sure BPF_PROG_GET_NEXT_ID can't find this dead program */
> -	bpf_prog_free_id(prog, true);
> +	bpf_prog_free_id(prog);
>  
>  	list_del_init(&offload->offloads);
>  	kfree(offload);
> diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
> index 1eaa1a18aef7..b56f65328d9c 100644
> --- a/kernel/bpf/syscall.c
> +++ b/kernel/bpf/syscall.c
> @@ -1988,7 +1988,7 @@ static int bpf_prog_alloc_id(struct bpf_prog *prog)
>  	return id > 0 ? 0 : id;
>  }
>  
> -void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock)
> +void bpf_prog_free_id(struct bpf_prog *prog)
>  {
>  	unsigned long flags;
>  
> @@ -2000,18 +2000,10 @@ void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock)
>  	if (!prog->aux->id)
>  		return;
>  
> -	if (do_idr_lock)
> -		spin_lock_irqsave(&prog_idr_lock, flags);
> -	else
> -		__acquire(&prog_idr_lock);
> -
> +	spin_lock_irqsave(&prog_idr_lock, flags);
>  	idr_remove(&prog_idr, prog->aux->id);
>  	prog->aux->id = 0;
> -
> -	if (do_idr_lock)
> -		spin_unlock_irqrestore(&prog_idr_lock, flags);
> -	else
> -		__release(&prog_idr_lock);
> +	spin_unlock_irqrestore(&prog_idr_lock, flags);
>  }
>  
>  static void __bpf_prog_put_rcu(struct rcu_head *rcu)
> @@ -2057,13 +2049,13 @@ static void bpf_prog_put_deferred(struct work_struct *work)
>  	__bpf_prog_put_noref(prog, true);
>  }
>  
> -static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock)
> +void bpf_prog_put(struct bpf_prog *prog)
>  {
>  	struct bpf_prog_aux *aux = prog->aux;
>  
>  	if (atomic64_dec_and_test(&aux->refcnt)) {
>  		/* bpf_prog_free_id() must be called first */
> -		bpf_prog_free_id(prog, do_idr_lock);
> +		bpf_prog_free_id(prog);
>  
>  		if (in_irq() || irqs_disabled()) {
>  			INIT_WORK(&aux->work, bpf_prog_put_deferred);
> @@ -2073,11 +2065,6 @@ static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock)
>  		}
>  	}
>  }
> -
> -void bpf_prog_put(struct bpf_prog *prog)
> -{
> -	__bpf_prog_put(prog, true);
> -}
>  EXPORT_SYMBOL_GPL(bpf_prog_put);
>  
>  static int bpf_prog_release(struct inode *inode, struct file *filp)
> -- 
> 2.34.1
>