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Date:   Fri, 30 Sep 2022 17:27:09 +0100
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Subject: Re: [bpf-next v7 2/3] bpftool: Update doc (add autoattach to prog
 load)
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To:     Wang Yufen <wangyufen@huawei.com>, ast@kernel.org,
        daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev,
        song@kernel.org, yhs@fb.com, john.fastabend@gmail.com,
        kpsingh@kernel.org, sdf@google.com, haoluo@google.com,
        jolsa@kernel.org, davem@davemloft.net, kuba@kernel.org,
        hawk@kernel.org, nathan@kernel.org, ndesaulniers@google.com,
        trix@redhat.com
Cc:     bpf@vger.kernel.org, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org, llvm@lists.linux.dev
References: <1664277676-2228-1-git-send-email-wangyufen@huawei.com>
 <1664277676-2228-2-git-send-email-wangyufen@huawei.com>
From:   Quentin Monnet <quentin@isovalent.com>
In-Reply-To: <1664277676-2228-2-git-send-email-wangyufen@huawei.com>
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Tue Sep 27 2022 12:21:15 GMT+0100 ~ Wang Yufen <wangyufen@huawei.com>
> Add autoattach optional to prog load|loadall for supporting
> one-step load-attach-pin_link.
> 
> Signed-off-by: Wang Yufen <wangyufen@huawei.com>
> ---
>  tools/bpf/bpftool/Documentation/bpftool-prog.rst | 17 +++++++++++++++--
>  1 file changed, 15 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
> index eb1b2a2..b81d3d9 100644
> --- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst
> +++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
> @@ -31,7 +31,7 @@ PROG COMMANDS
>  |	**bpftool** **prog dump xlated** *PROG* [{**file** *FILE* | **opcodes** | **visual** | **linum**}]
>  |	**bpftool** **prog dump jited**  *PROG* [{**file** *FILE* | **opcodes** | **linum**}]
>  |	**bpftool** **prog pin** *PROG* *FILE*
> -|	**bpftool** **prog** { **load** | **loadall** } *OBJ* *PATH* [**type** *TYPE*] [**map** {**idx** *IDX* | **name** *NAME*} *MAP*] [**dev** *NAME*] [**pinmaps** *MAP_DIR*]
> +|	**bpftool** **prog** { **load** | **loadall** } *OBJ* *PATH* [**type** *TYPE*] [**map** {**idx** *IDX* | **name** *NAME*} *MAP*] [**dev** *NAME*] [**pinmaps** *MAP_DIR*] [**autoattach**]
>  |	**bpftool** **prog attach** *PROG* *ATTACH_TYPE* [*MAP*]
>  |	**bpftool** **prog detach** *PROG* *ATTACH_TYPE* [*MAP*]
>  |	**bpftool** **prog tracelog**
> @@ -131,7 +131,7 @@ DESCRIPTION
>  		  contain a dot character ('.'), which is reserved for future
>  		  extensions of *bpffs*.
>  
> -	**bpftool prog { load | loadall }** *OBJ* *PATH* [**type** *TYPE*] [**map** {**idx** *IDX* | **name** *NAME*} *MAP*] [**dev** *NAME*] [**pinmaps** *MAP_DIR*]
> +	**bpftool prog { load | loadall }** *OBJ* *PATH* [**type** *TYPE*] [**map** {**idx** *IDX* | **name** *NAME*} *MAP*] [**dev** *NAME*] [**pinmaps** *MAP_DIR*] [**autoattach**]
>  		  Load bpf program(s) from binary *OBJ* and pin as *PATH*.
>  		  **bpftool prog load** pins only the first program from the
>  		  *OBJ* as *PATH*. **bpftool prog loadall** pins all programs
> @@ -150,6 +150,19 @@ DESCRIPTION
>  		  Optional **pinmaps** argument can be provided to pin all
>  		  maps under *MAP_DIR* directory.
>  
> +		  If **autoattach** is specified program will be attached
> +		  before pin. In that case, only the link (representing the
> +		  program attached to its hook) is pinned, not the program as
> +		  such, so the path won't show in "**bpftool prog show -f**",

Nit: no need for double-quotes, the ** markup is enough.

> +		  only show in "**bpftool link show -f**". Also, this only works
> +		  when bpftool (libbpf) is able to infer all necessary information
> +		  from the objectfile, in particular, it's not supported for all

s/objectfile/object file/

> +		  program types. If the *OBJ* contains multiple programs and
> +		  *loadall* is used, if the program A in these programs does not

**loadall** (keyword)

> +		  support auto-attachi, will skip program A(do no operation on

auto-attach

> +		  program A), print a info message such as "Program A does not
> +		  support autoattach", and continue to autoattach the next program.

continue to auto-attach

> +
>  		  Note: *PATH* must be located in *bpffs* mount. It must not
>  		  contain a dot character ('.'), which is reserved for future
>  		  extensions of *bpffs*.