From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 49484C433ED for ; Tue, 27 Apr 2021 03:28:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 15211613AA for ; Tue, 27 Apr 2021 03:28:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231363AbhD0D3X (ORCPT ); Mon, 26 Apr 2021 23:29:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49926 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230338AbhD0D3W (ORCPT ); Mon, 26 Apr 2021 23:29:22 -0400 Received: from mail-pl1-x62f.google.com (mail-pl1-x62f.google.com [IPv6:2607:f8b0:4864:20::62f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 78C2DC061574; Mon, 26 Apr 2021 20:28:40 -0700 (PDT) Received: by mail-pl1-x62f.google.com with SMTP id g16so13227452plq.3; Mon, 26 Apr 2021 20:28:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=dFqoaRhcb75hfHVlvsIcK2zrfB/Dl+cUosLD25YxuEk=; b=q8OlUsEiSahaZIX9O5rPCFeKmfM/lByVzj6rrylFRqtsqlY37x4HCnuvvJciLH6Kys UA5DKkzPFtAA1AlyQBKC3yjm7HkwxdAWOCxuoknlS/WNa9PtMPCdfqgvtrvibwQfQUmK GVBq7/oI4dyGgkJlHyPEJR0eQnvKJEbBTk0R2FGR3wqslNZeoy07VuLp3x1MZfrfIAlj ueDzK465vzauUuO+goTiLLyw5bYmXZhzKV7/0xyRHJgygGd18XZGNwa+RxLiIShSLx5f lyywmz2JJFxM2i+BOaR08vUTkoxGkzTPop66SJAu4+dBuQrDjOeDeqlgntcRK6Ln+Pz1 qozg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=dFqoaRhcb75hfHVlvsIcK2zrfB/Dl+cUosLD25YxuEk=; b=gttUk+V2XFnWURilRzEJ3UztYXbtfowNjpAqu/whwPqUHPXxPOlQqwu4wlFLak1LrB jea5TBesbgOZ6vc3ML63zty8NtA95CIwqhbFK8U9oZO9ykuormxeDtao97jrJY/33Hyb O3pRVIqfaICWs01ax6gJQc8PeaMdxjmjDrngvgdnsadA6MoaJUI62uXEkIsRyh1+RNlV AoxcqT54u1y+WMJ877h45V5tdecRQTAEUpHL/Z0Ato4njLgDABCsEYQhiUXmPEZBnmpi h8L4NUts1B3PXL9JZR6A+aMOGNq/Xp1lO3PULLK6mAkidVYmM/1zowYzWVZjhsqY6BXw jAhw== X-Gm-Message-State: AOAM530jyCpp+iznwYWqC314gLTNofUB6G7iX9JAIN2V+oJWyBIDjob7 9DD56gE9lMqV8doF+rx0Hm0= X-Google-Smtp-Source: ABdhPJwux3UJEoOP7OV//q/T11MmTjxiegyQugVqwdy85SxTeVgzPOS1da0kQ/sJllsOw47UyrkG5Q== X-Received: by 2002:a17:90b:60a:: with SMTP id gb10mr2619326pjb.71.1619494119780; Mon, 26 Apr 2021 20:28:39 -0700 (PDT) Received: from ast-mbp.dhcp.thefacebook.com ([2620:10d:c090:400::5:1ad0]) by smtp.gmail.com with ESMTPSA id g26sm918857pfq.186.2021.04.26.20.28.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Apr 2021 20:28:39 -0700 (PDT) Date: Mon, 26 Apr 2021 20:28:37 -0700 From: Alexei Starovoitov To: Andrii Nakryiko Cc: "David S. Miller" , Daniel Borkmann , Andrii Nakryiko , Networking , bpf , Kernel Team Subject: Re: [PATCH v2 bpf-next 15/16] bpftool: Use syscall/loader program in "prog load" and "gen skeleton" command. Message-ID: <20210427032837.mtaqbbptczd3dvck@ast-mbp.dhcp.thefacebook.com> References: <20210423002646.35043-1-alexei.starovoitov@gmail.com> <20210423002646.35043-16-alexei.starovoitov@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Mon, Apr 26, 2021 at 03:35:16PM -0700, Andrii Nakryiko wrote: > On Thu, Apr 22, 2021 at 5:27 PM Alexei Starovoitov > wrote: > > > > From: Alexei Starovoitov > > > > Add -L flag to bpftool to use libbpf gen_trace facility and syscall/loader program > > for skeleton generation and program loading. > > > > "bpftool gen skeleton -L" command will generate a "light skeleton" or "loader skeleton" > > that is similar to existing skeleton, but has one major difference: > > $ bpftool gen skeleton lsm.o > lsm.skel.h > > $ bpftool gen skeleton -L lsm.o > lsm.lskel.h > > $ diff lsm.skel.h lsm.lskel.h > > @@ -5,34 +4,34 @@ > > #define __LSM_SKEL_H__ > > > > #include > > -#include > > +#include > > > > The light skeleton does not use majority of libbpf infrastructure. > > It doesn't need libelf. It doesn't parse .o file. > > It only needs few sys_bpf wrappers. All of them are in bpf/bpf.h file. > > In future libbpf/bpf.c can be inlined into bpf.h, so not even libbpf.a would be > > needed to work with light skeleton. > > > > "bpftool prog load -L file.o" command is introduced for debugging of syscall/loader > > program generation. Just like the same command without -L it will try to load > > the programs from file.o into the kernel. It won't even try to pin them. > > > > "bpftool prog load -L -d file.o" command will provide additional debug messages > > on how syscall/loader program was generated. > > Also the execution of syscall/loader program will use bpf_trace_printk() for > > each step of loading BTF, creating maps, and loading programs. > > The user can do "cat /.../trace_pipe" for further debug. > > > > An example of fexit_sleep.lskel.h generated from progs/fexit_sleep.c: > > struct fexit_sleep { > > struct bpf_loader_ctx ctx; > > struct { > > struct bpf_map_desc bss; > > } maps; > > struct { > > struct bpf_prog_desc nanosleep_fentry; > > struct bpf_prog_desc nanosleep_fexit; > > } progs; > > struct { > > int nanosleep_fentry_fd; > > int nanosleep_fexit_fd; > > } links; > > struct fexit_sleep__bss { > > int pid; > > int fentry_cnt; > > int fexit_cnt; > > } *bss; > > }; > > > > Signed-off-by: Alexei Starovoitov > > --- > > tools/bpf/bpftool/Makefile | 2 +- > > tools/bpf/bpftool/gen.c | 313 +++++++++++++++++++++++++++--- > > tools/bpf/bpftool/main.c | 7 +- > > tools/bpf/bpftool/main.h | 1 + > > tools/bpf/bpftool/prog.c | 80 ++++++++ > > tools/bpf/bpftool/xlated_dumper.c | 3 + > > 6 files changed, 382 insertions(+), 24 deletions(-) > > > > [...] > > > @@ -268,6 +269,254 @@ static void codegen(const char *template, ...) > > free(s); > > } > > > > +static void print_hex(const char *obj_data, int file_sz) > > +{ > > + int i, len; > > + > > + /* embed contents of BPF object file */ > > nit: this comment should have stayed at the original place > > > + for (i = 0, len = 0; i < file_sz; i++) { > > + int w = obj_data[i] ? 4 : 2; > > + > > [...] > > > + bpf_object__for_each_map(map, obj) { > > + const char * ident; > > + > > + ident = get_map_ident(map); > > + if (!ident) > > + continue; > > + > > + if (!bpf_map__is_internal(map) || > > + !(bpf_map__def(map)->map_flags & BPF_F_MMAPABLE)) > > + continue; > > + > > + printf("\tskel->%1$s =\n" > > + "\t\tmmap(NULL, %2$zd, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED,\n" > > + "\t\t\tskel->maps.%1$s.map_fd, 0);\n", > > + ident, bpf_map_mmap_sz(map)); > > use codegen()? why? codegen() would add extra early \n for no good reason. > > + } > > + codegen("\ > > + \n\ > > + return 0; \n\ > > + } \n\ > > + \n\ > > + static inline struct %1$s * \n\ > > [...] > > > static int do_skeleton(int argc, char **argv) > > { > > char header_guard[MAX_OBJ_NAME_LEN + sizeof("__SKEL_H__")]; > > @@ -277,7 +526,7 @@ static int do_skeleton(int argc, char **argv) > > struct bpf_object *obj = NULL; > > const char *file, *ident; > > struct bpf_program *prog; > > - int fd, len, err = -1; > > + int fd, err = -1; > > struct bpf_map *map; > > struct btf *btf; > > struct stat st; > > @@ -359,7 +608,25 @@ static int do_skeleton(int argc, char **argv) > > } > > > > get_header_guard(header_guard, obj_name); > > - codegen("\ > > + if (use_loader) > > please use {} for such a long if/else, even if it's, technically, a > single-statement if I think it reads fine as-is, but, sure, I can add {} > > + codegen("\ > > + \n\ > > + /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ \n\ > > + /* THIS FILE IS AUTOGENERATED! */ \n\ > > + #ifndef %2$s \n\ > > + #define %2$s \n\ > > + \n\ > > + #include \n\ > > + #include \n\ > > + #include \n\ > > + \n\ > > + struct %1$s { \n\ > > + struct bpf_loader_ctx ctx; \n\ > > + ", > > + obj_name, header_guard > > + ); > > + else > > + codegen("\ > > \n\ > > /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ \n\ > > \n\ > > [...] --