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=-11.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 66753C31E5B for ; Mon, 17 Jun 2019 19:14:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2D985208C0 for ; Mon, 17 Jun 2019 19:14:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="AdkScDuy" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728832AbfFQTOO (ORCPT ); Mon, 17 Jun 2019 15:14:14 -0400 Received: from terminus.zytor.com ([198.137.202.136]:57831 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725829AbfFQTON (ORCPT ); Mon, 17 Jun 2019 15:14:13 -0400 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id x5HJDvkf3559031 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Mon, 17 Jun 2019 12:13:57 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 terminus.zytor.com x5HJDvkf3559031 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2019051801; t=1560798837; bh=A0bpck4xFWC7Lg4DIRaQcxjDX1sEtBmETVEWEt1YHjM=; h=Date:From:Cc:Reply-To:To:Subject:From; b=AdkScDuy+beOMK5Wi8FqolGbtCupv+uGlbmIakai9qQ84r1felx2hMMcUOvhFzvIe eSVI9kWmJsgEuCG7IBU4CsNLV3XCZgxeFNhba21ks11DuM/005X2KsbsYDahsKZxGK x7mEdQ+wyomrmroU0AZu80Pv9zgxKx3LYgijbEFMwcHtX7fJfdwOcC2xt/xjEFwNoB BjcT6savDZ5HwLFFXeTAGs/FkOMLtJ8O0aOVoyH6ybQW0hxjYTNoZr+vkKztYTMea8 mgX4gDje6AKyoNZlsUdZ00jK0jLProiUXlvqThguvOnlv/tFPkOgSoNKfYvrb7GONY c/gHOyKuCDWpA== Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id x5HJDuNj3559028; Mon, 17 Jun 2019 12:13:56 -0700 Date: Mon, 17 Jun 2019 12:13:56 -0700 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Arnaldo Carvalho de Melo Message-ID: Cc: mingo@kernel.org, brendan.d.gregg@gmail.com, lclaudio@redhat.com, acme@redhat.com, adrian.hunter@intel.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, hpa@zytor.com, namhyung@kernel.org, jolsa@kernel.org Reply-To: adrian.hunter@intel.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, hpa@zytor.com, namhyung@kernel.org, jolsa@kernel.org, mingo@kernel.org, brendan.d.gregg@gmail.com, lclaudio@redhat.com, acme@redhat.com To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] perf augmented_raw_syscalls: Change helper to consider just the augmented_filename part Git-Commit-ID: deaf4da48a67f73eb7d5d1802c14eaf58d33f2da X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: deaf4da48a67f73eb7d5d1802c14eaf58d33f2da Gitweb: https://git.kernel.org/tip/deaf4da48a67f73eb7d5d1802c14eaf58d33f2da Author: Arnaldo Carvalho de Melo AuthorDate: Tue, 4 Jun 2019 15:57:28 -0300 Committer: Arnaldo Carvalho de Melo CommitDate: Wed, 5 Jun 2019 09:48:54 -0300 perf augmented_raw_syscalls: Change helper to consider just the augmented_filename part So that we can use it for multiple args, baby steps not to step into the verifier toes. In the process make sure we handle -EFAULT from bpf_prog_read_str(), as this really is needed now that we'll handle more than one augmented argument, i.e. if there is failure, then we have the argument that fails have: (size = 0, err = -EFAULT, value = [] ) followed by the next, lets say that worked for a second pathname: (size = 4, err = 0, value = "/tmp" ) So we can skip the first while telling the user about the problem and then process the second. Cc: Adrian Hunter Cc: Brendan Gregg Cc: Jiri Olsa Cc: Luis Cláudio Gonçalves Cc: Namhyung Kim Link: https://lkml.kernel.org/n/tip-deyvqi39um6gp6hux6jovos8@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/examples/bpf/augmented_raw_syscalls.c | 46 +++++++++++++++++------- 1 file changed, 33 insertions(+), 13 deletions(-) diff --git a/tools/perf/examples/bpf/augmented_raw_syscalls.c b/tools/perf/examples/bpf/augmented_raw_syscalls.c index 356513e81ec1..5054b4bc9e55 100644 --- a/tools/perf/examples/bpf/augmented_raw_syscalls.c +++ b/tools/perf/examples/bpf/augmented_raw_syscalls.c @@ -47,7 +47,7 @@ struct syscall_exit_args { struct augmented_filename { unsigned int size; - int reserved; + int err; char value[PATH_MAX]; }; @@ -61,16 +61,28 @@ struct augmented_args_filename { bpf_map(augmented_filename_map, PERCPU_ARRAY, int, struct augmented_args_filename, 1); static inline -unsigned int augmented_args__read_filename(struct augmented_args_filename *augmented_args, - const void *filename_arg, unsigned int filename_len) +unsigned int augmented_filename__read(struct augmented_filename *augmented_filename, + const void *filename_arg, unsigned int filename_len) { - unsigned int len = sizeof(*augmented_args); + unsigned int len = sizeof(*augmented_filename); + int size = probe_read_str(&augmented_filename->value, filename_len, filename_arg); - augmented_args->filename.reserved = 0; - augmented_args->filename.size = probe_read_str(&augmented_args->filename.value, filename_len, filename_arg); - if (augmented_args->filename.size < sizeof(augmented_args->filename.value)) { - len -= sizeof(augmented_args->filename.value) - augmented_args->filename.size; - len &= sizeof(augmented_args->filename.value) - 1; + augmented_filename->size = augmented_filename->err = 0; + /* + * probe_read_str may return < 0, e.g. -EFAULT + * So we leave that in the augmented_filename->size that userspace will + */ + if (size > 0) { + len -= sizeof(augmented_filename->value) - size; + len &= sizeof(augmented_filename->value) - 1; + augmented_filename->size = size; + } else { + /* + * So that username notice the error while still being able + * to skip this augmented arg record + */ + augmented_filename->err = size; + len = offsetof(struct augmented_filename, value); } return len; @@ -80,7 +92,17 @@ SEC("raw_syscalls:sys_enter") int sys_enter(struct syscall_enter_args *args) { struct augmented_args_filename *augmented_args; - unsigned int len, filename_len; + /* + * We start len, the amount of data that will be in the perf ring + * buffer, if this is not filtered out by one of pid_filter__has(), + * syscall->enabled, etc, with the non-augmented raw syscall payload, + * i.e. sizeof(augmented_args->args). + * + * We'll add to this as we add augmented syscalls right after that + * initial, non-augmented raw_syscalls:sys_enter payload. + */ + unsigned int len = sizeof(augmented_args->args); + unsigned int filename_len; const void *filename_arg = NULL; struct syscall *syscall; int key = 0; @@ -198,9 +220,7 @@ processed 46 insns (limit 1000000) max_states_per_insn 0 total_states 12 peak_st loop_iter_last(5) if (filename_arg != NULL && filename_len <= sizeof(augmented_args->filename.value)) { - len = augmented_args__read_filename(augmented_args, filename_arg, filename_len); - } else { - len = sizeof(augmented_args->args); + len += augmented_filename__read(&augmented_args->filename, filename_arg, filename_len); } /* If perf_event_output fails, return non-zero so that it gets recorded unaugmented */