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=-21.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 BE735C47080 for ; Tue, 1 Jun 2021 18:32:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A741A613BD for ; Tue, 1 Jun 2021 18:32:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234628AbhFASeP (ORCPT ); Tue, 1 Jun 2021 14:34:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:41602 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233397AbhFASeP (ORCPT ); Tue, 1 Jun 2021 14:34:15 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5142960C3E; Tue, 1 Jun 2021 18:32:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622572353; bh=Pzf4wFc/SN+2SFwdKoXDlFNJQ5E02CpTL2ZaaDQ/0ZY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=XS7eeKXKT4iiNow+6a/czKf//WqLNAVa0vSJVShgPQHfdCmyoGmlk4XAcgNpIC6j3 vwWd/RSclUCxzX8tV/YoXo5M1xyg1JrikgkY9If3kEh3miXq/d6MNSoEJuM60ix39k NvNxaht9Xsukn2yqH+HolG6Ke+Fx+wbuhmJhmCYYpMjt0CrUegO4KP3rhRYiK5TJal IkqlrYI6aQxniCTM9ynsy0JJhEMNbuARfQAV78o9s4QVWj2rYOfyDzd4vljkVuwyrh svK4YIogsJNJC763+O9Bdj33m5EPwqBpvqSXsYx0Pei8yuZvBzMrZffU0N4q2shUB/ lp0MjEtwpHUXQ== Received: by quaco.ghostprotocols.net (Postfix, from userid 1000) id 78FA94011C; Tue, 1 Jun 2021 15:32:31 -0300 (-03) Date: Tue, 1 Jun 2021 15:32:31 -0300 From: Arnaldo Carvalho de Melo To: Andrii Nakryiko Cc: Arnaldo Carvalho de Melo , Andrii Nakryiko , Jiri Olsa , Michal =?iso-8859-1?Q?Such=E1nek?= , dwarves@vger.kernel.org, bpf , Kernel Team , Michael Petlan Subject: Re: [RFT] Testing 1.22 Message-ID: References: <4615C288-2CFD-483E-AB98-B14A33631E2F@gmail.com> <4901AF88-0354-428B-9305-2EDC6F75C073@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Url: http://acmel.wordpress.com Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Em Tue, Jun 01, 2021 at 03:31:58PM -0300, Arnaldo Carvalho de Melo escreveu: > Em Fri, May 28, 2021 at 07:36:25PM -0700, Andrii Nakryiko escreveu: > > On Fri, May 28, 2021 at 12:45 PM Arnaldo Carvalho de Melo > > wrote: > > > > > > Em Thu, May 27, 2021 at 01:41:13PM -0700, Andrii Nakryiko escreveu: > > > > On Thu, May 27, 2021 at 12:57 PM Arnaldo wrote: > > > > > On May 27, 2021 4:14:17 PM GMT-03:00, Andrii Nakryiko wrote: > > > > > >If we make 1.22 mandatory there will be no good reason to make 1.23 > > > > > >mandatory again. So I will have absolutely no inclination to work on > > > > > >this, for example. So we are just wasting a chance to clean up the > > > > > >Kbuild story w.r.t. pahole. And we are talking about just a few days > > > > > >at most, while we do have a reasonable work around on the kernel side. > > > > > > > > So there were patches for stop using objcopy, which we thought could > > > > > uncover some can of worms, were there patches for the detached BTF > > > > > file? > > > > > > > No, there weren't, if I remember correctly. What's the concern, > > > > though? That detached BTF file isn't even an ELF, so it's > > > > btf__get_raw_data() and write it to the file. Done. > > > > > > See patch below, lightly tested, now working on making pahole accept raw > > > BTF files out of /sys/kernel/btf/ > > > > btf__parse() handles both ELF and raw BTF transparently. Then there is > > btf__parse_elf() and btf__parse_raw() for specifically ELF or raw. > > > > See all APIs at: > > https://github.com/libbpf/libbpf/blob/master/src/btf.h#L40 > > Ok, I was using: > > int btf_elf__load(struct btf_elf *btfe) > { > int err; > > libbpf_set_print(libbpf_log); > > /* free initial empty BTF */ > btf__free(btfe->btf); > if (btfe->raw_btf) > btfe->btf = btf__parse_raw_split(btfe->filename, btfe->base_btf); > else > btfe->btf = btf__parse_elf_split(btfe->filename, btfe->base_btf); > > err = libbpf_get_error(btfe->btf); > if (err) > return err; > > return 0; > } > > > but btf__parse(path, btfext_ptr) doesn't allow me to apss the base btf, > lemme see if there is a btf__parse_split... yeap, using that then... > - Arnaldo > > > > > > > Please test, and if works as expected, try to bolt this into the kbuild > > > process, as intended. > > > > I'm on PTO today, will try to get to this soon-ish. > > > > > > > > - Arnaldo > > > > > > commit b579a18a1ea0ee84b90b5302f597dda2edf2f61b > > > Author: Arnaldo Carvalho de Melo > > > Date: Fri May 28 16:41:30 2021 -0300 > > > > > > pahole: Allow encoding BTF into a detached file > > > > > > Previously the newly encoded BTF info was stored into a ELF section in > > > the file where the DWARF info was obtained, but it is useful to just > > > dump it into a separate file, do it. > > > > > > Requested-by: Andrii Nakryiko > > > Signed-off-by: Arnaldo Carvalho de Melo > > > > > > diff --git a/btf_encoder.c b/btf_encoder.c > > > index 033c927b537dad1e..bc3ac72968cea826 100644 > > > --- a/btf_encoder.c > > > +++ b/btf_encoder.c > > > @@ -21,6 +21,14 @@ > > > #include /* for qsort() and bsearch() */ > > > #include > > > > > > +#include > > > +#include > > > +#include > > > + > > > +#include > > > + > > > +#include > > > + > > > /* > > > * This corresponds to the same macro defined in > > > * include/linux/kallsyms.h > > > @@ -267,14 +275,62 @@ static struct btf_elf *btfe; > > > static uint32_t array_index_id; > > > static bool has_index_type; > > > > > > -int btf_encoder__encode() > > > +static int btf_encoder__dump(struct btf *btf, const char *filename) > > > +{ > > > + uint32_t raw_btf_size; > > > + const void *raw_btf_data; > > > + int fd, err; > > > + > > > + /* Empty file, nothing to do, so... done! */ > > > + if (btf__get_nr_types(btf) == 0) > > > + return 0; > > > + > > > + if (btf__dedup(btf, NULL, NULL)) { > > > + fprintf(stderr, "%s: btf__dedup failed!\n", __func__); > > > + return -1; > > > + } > > > + > > > + raw_btf_data = btf__get_raw_data(btf, &raw_btf_size); > > > + if (raw_btf_data == NULL) { > > > + fprintf(stderr, "%s: btf__get_raw_data failed!\n", __func__); > > > + return -1; > > > + } > > > + > > > + fd = open(filename, O_WRONLY | O_CREAT); > > > + if (fd < 0) { > > > + fprintf(stderr, "%s: Couldn't open %s for writing the raw BTF info: %s\n", __func__, filename, strerror(errno)); > > > + return -1; > > > + } > > > + err = write(fd, raw_btf_data, raw_btf_size); > > > + if (err < 0) > > > + fprintf(stderr, "%s: Couldn't open %s for writing the raw BTF info: %s\n", __func__, filename, strerror(errno)); > > > + > > > + close(fd); > > > + > > > + if (err != raw_btf_size) { > > > + fprintf(stderr, "%s: Could only write %d bytes to %s of raw BTF info out of %d, aborting\n", __func__, err, filename, raw_btf_size); > > > + unlink(filename); > > > + err = -1; > > > + } else { > > > + /* go from bytes written == raw_btf_size to an indication that all went fine */ > > > + err = 0; > > > + } > > > + > > > + return err; > > > +} > > > + > > > +int btf_encoder__encode(const char *filename) > > > { > > > int err; > > > > > > if (gobuffer__size(&btfe->percpu_secinfo) != 0) > > > btf_elf__add_datasec_type(btfe, PERCPU_SECTION, &btfe->percpu_secinfo); > > > > > > - err = btf_elf__encode(btfe, 0); > > > + if (filename == NULL) > > > + err = btf_elf__encode(btfe, 0); > > > + else > > > + err = btf_encoder__dump(btfe->btf, filename); > > > + > > > delete_functions(); > > > btf_elf__delete(btfe); > > > btfe = NULL; > > > @@ -412,7 +468,7 @@ static bool has_arg_names(struct cu *cu, struct ftype *ftype) > > > } > > > > > > int cu__encode_btf(struct cu *cu, int verbose, bool force, > > > - bool skip_encoding_vars) > > > + bool skip_encoding_vars, const char *detached_btf_filename) > > > { > > > uint32_t type_id_off; > > > uint32_t core_id; > > > @@ -425,7 +481,7 @@ int cu__encode_btf(struct cu *cu, int verbose, bool force, > > > btf_elf__force = force; > > > > > > if (btfe && strcmp(btfe->filename, cu->filename)) { > > > - err = btf_encoder__encode(); > > > + err = btf_encoder__encode(detached_btf_filename); > > > if (err) > > > goto out; > > > > > > diff --git a/btf_encoder.h b/btf_encoder.h > > > index 46fb2312fc0eea9b..bfc6085092028adc 100644 > > > --- a/btf_encoder.h > > > +++ b/btf_encoder.h > > > @@ -11,9 +11,9 @@ > > > > > > struct cu; > > > > > > -int btf_encoder__encode(); > > > +int btf_encoder__encode(const char *filename); > > > > > > int cu__encode_btf(struct cu *cu, int verbose, bool force, > > > - bool skip_encoding_vars); > > > + bool skip_encoding_vars, const char *detached_btf_filename); > > > > > > #endif /* _BTF_ENCODER_H_ */ > > > diff --git a/man-pages/pahole.1 b/man-pages/pahole.1 > > > index 2659fe6f231405d8..6e7ded59595f5ea7 100644 > > > --- a/man-pages/pahole.1 > > > +++ b/man-pages/pahole.1 > > > @@ -189,6 +189,10 @@ features such as BPF CO-RE (Compile Once - Run Everywhere). > > > > > > See \fIhttps://nakryiko.com/posts/bpf-portability-and-co-re/\fR. > > > > > > +.TP > > > +.B \-j, \-\-btf_encode_detached=FILENAME > > > +Same thing as -J/--btf_encode, but storing the raw BTF info into a separate file. > > > + > > > .TP > > > .B \-\-btf_encode_force > > > Ignore those symbols found invalid when encoding BTF. > > > diff --git a/pahole.c b/pahole.c > > > index 24659e2969c8fb85..1cbff6175b60af51 100644 > > > --- a/pahole.c > > > +++ b/pahole.c > > > @@ -26,6 +26,7 @@ > > > #include "lib/bpf/src/libbpf.h" > > > #include "pahole_strings.h" > > > > > > +static char *detached_btf_filename; > > > static bool btf_encode; > > > static bool ctf_encode; > > > static bool first_obj_only; > > > @@ -1152,6 +1153,12 @@ static const struct argp_option pahole__options[] = { > > > .key = 'J', > > > .doc = "Encode as BTF", > > > }, > > > + { > > > + .name = "btf_encode_detached", > > > + .key = 'j', > > > + .arg = "FILENAME", > > > + .doc = "Encode as BTF in a detached file", > > > + }, > > > { > > > .name = "skip_encoding_btf_vars", > > > .key = ARGP_skip_encoding_btf_vars, > > > @@ -1223,6 +1230,7 @@ static error_t pahole__options_parser(int key, char *arg, > > > conf_load.extra_dbg_info = 1; break; > > > case 'i': find_containers = 1; > > > class_name = arg; break; > > > + case 'j': detached_btf_filename = arg; // fallthru > > > case 'J': btf_encode = 1; > > > conf_load.get_addr_info = true; > > > no_bitfield_type_recode = true; break; > > > @@ -2458,7 +2466,7 @@ static enum load_steal_kind pahole_stealer(struct cu *cu, > > > > > > if (btf_encode) { > > > if (cu__encode_btf(cu, global_verbose, btf_encode_force, > > > - skip_encoding_btf_vars)) { > > > + skip_encoding_btf_vars, detached_btf_filename)) { > > > fprintf(stderr, "Encountered error while encoding BTF.\n"); > > > exit(1); > > > } > > > @@ -2872,7 +2880,7 @@ try_sole_arg_as_class_names: > > > header = NULL; > > > > > > if (btf_encode) { > > > - err = btf_encoder__encode(); > > > + err = btf_encoder__encode(detached_btf_filename); > > > if (err) { > > > fputs("Failed to encode BTF\n", stderr); > > > goto out_cus_delete; > > -- > > - Arnaldo -- - Arnaldo