From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Wangnan (F)" Subject: Re: [PATCH net-next 2/2] tools lib bpf: export function to set type Date: Mon, 15 Aug 2016 11:41:26 +0800 Message-ID: <57B139E6.8080702@huawei.com> References: <1471090643-22403-1-git-send-email-eric@regit.org> <1471090643-22403-3-git-send-email-eric@regit.org> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Cc: Alexei Starovoitov To: Eric Leblond , Return-path: Received: from szxga01-in.huawei.com ([58.251.152.64]:62101 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752170AbcHODml (ORCPT ); Sun, 14 Aug 2016 23:42:41 -0400 In-Reply-To: <1471090643-22403-3-git-send-email-eric@regit.org> Sender: netdev-owner@vger.kernel.org List-ID: On 2016/8/13 20:17, Eric Leblond wrote: > Current API was not allowing the user to set a type like socket > filter. To avoid a setter function for each type, the patch simply > exports a set function that takes the type in parameter. > > Signed-off-by: Eric Leblond > --- > tools/lib/bpf/libbpf.c | 15 ++++++--------- > tools/lib/bpf/libbpf.h | 3 +++ > 2 files changed, 9 insertions(+), 9 deletions(-) > > diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c > index 7872ff6..ff2a8c6 100644 > --- a/tools/lib/bpf/libbpf.c > +++ b/tools/lib/bpf/libbpf.c > @@ -1336,26 +1336,23 @@ int bpf_program__nth_fd(struct bpf_program *prog, int n) > return fd; > } > > -static void bpf_program__set_type(struct bpf_program *prog, > +int bpf_program__set_type(struct bpf_program *prog, > enum bpf_prog_type type) > { > + if (!prog) > + return -EINVAL; > prog->type = type; > + return 0; > } > We'd better add a sanity check here to prevent setting invalid program type. Plase have a look at https://lkml.org/lkml/2015/12/17/13 > int bpf_program__set_tracepoint(struct bpf_program *prog) > { > - if (!prog) > - return -EINVAL; > - bpf_program__set_type(prog, BPF_PROG_TYPE_TRACEPOINT); > - return 0; > + return bpf_program__set_type(prog, BPF_PROG_TYPE_TRACEPOINT); > } > > int bpf_program__set_kprobe(struct bpf_program *prog) > { > - if (!prog) > - return -EINVAL; > - bpf_program__set_type(prog, BPF_PROG_TYPE_KPROBE); > - return 0; > + return bpf_program__set_type(prog, BPF_PROG_TYPE_KPROBE); > } > > static bool bpf_program__is_type(struct bpf_program *prog, > diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h > index a6c5cde..6a84d7a 100644 > --- a/tools/lib/bpf/libbpf.h > +++ b/tools/lib/bpf/libbpf.h > @@ -173,6 +173,9 @@ int bpf_program__set_kprobe(struct bpf_program *prog); > bool bpf_program__is_tracepoint(struct bpf_program *prog); > bool bpf_program__is_kprobe(struct bpf_program *prog); > > +int bpf_program__set_type(struct bpf_program *prog, > + enum bpf_prog_type type); > + This makes libbpf.h depend on kernel's uapi/linux/bpf.h. Although I did this in the above patch, I don't like this dependency. This is the reason why I introduce int bpf_program__set_tracepoint(struct bpf_program *prog); int bpf_program__set_kprobe(struct bpf_program *prog); bool bpf_program__is_tracepoint(struct bpf_program *prog); bool bpf_program__is_kprobe(struct bpf_program *prog); and hide bpf_program__set_type inside the .c file. Please add type setting functions, or pass int value to bpf_program__set_type and add sanity checking. Thank you.