From patchwork Tue Apr 2 13:45:37 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Slavomir Kaslev X-Patchwork-Id: 10881779 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4712213B5 for ; Tue, 2 Apr 2019 13:45:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3851A27FA5 for ; Tue, 2 Apr 2019 13:45:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2D2B9288F3; Tue, 2 Apr 2019 13:45:58 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8A30F27FA5 for ; Tue, 2 Apr 2019 13:45:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731990AbfDBNp4 (ORCPT ); Tue, 2 Apr 2019 09:45:56 -0400 Received: from mail-wr1-f67.google.com ([209.85.221.67]:40526 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731818AbfDBNp4 (ORCPT ); Tue, 2 Apr 2019 09:45:56 -0400 Received: by mail-wr1-f67.google.com with SMTP id h4so16715606wre.7 for ; Tue, 02 Apr 2019 06:45:55 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=0a7gIALhhxU1fh2WoTbKDkB7fSOAZCCtoJCD3lSIXrI=; b=eyo/EXo4MjGSjy+1PpGZ2Mzv/NqFAR7PK/EyhTzjcVT+gXD9Q+mebB6tJ3Gu8ithKQ MMUrU6J4zLsS9q51Q1UmN5DYaKtug62p/IOX5ib0PZTg2HTJQ0aUkmQ37/OGa6CDdaWi vPIwsx5qXdTYGOVa8K38CwuINZS5oInny93+L56f9tniAyZG+Ll6mDj7eNEqEogNua5l zEJhfLi5vBiyD/T0QRoK0HZl/84rrnRt8+1qZrRSHPSJMtYOBPcogvq9fKNDybHbGZzM wXJPzuFEMEUYAvbMBjUfbSuzcFNbL6kNGuiH8y4Gdl66d6RLdPYen6yAFBmofhP7kcEE 4ZMA== X-Gm-Message-State: APjAAAUYwckJtblK3lfrR8D4iLC8gwJp8fDCKJo3UAhzAPO8248Y5eKA 2SC2wWl5P/aNiFdI8awBQw== X-Google-Smtp-Source: APXvYqzTkwIPKLIRY2xl72Qbhrq/FsqiQD7jtFGC35BvlVux2UuRDoFOM1uALSLMTjGULGkdhWPPpw== X-Received: by 2002:adf:ec87:: with SMTP id z7mr45120757wrn.44.1554212754298; Tue, 02 Apr 2019 06:45:54 -0700 (PDT) Received: from box.eng.vmware.com ([146.247.46.5]) by smtp.gmail.com with ESMTPSA id 17sm1765336wmk.39.2019.04.02.06.45.53 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 02 Apr 2019 06:45:53 -0700 (PDT) From: Slavomir Kaslev To: rostedt@goodmis.org Cc: linux-trace-devel@vger.kernel.org, slavomir.kaslev@gmail.com Subject: [RFC PATCH v9 08/11] trace-cmd: Add `trace-cmd setup-guest` command Date: Tue, 2 Apr 2019 16:45:37 +0300 Message-Id: <20190402134540.32321-9-kaslevs@vmware.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190402134540.32321-1-kaslevs@vmware.com> References: <20190402134540.32321-1-kaslevs@vmware.com> MIME-Version: 1.0 Sender: linux-trace-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Add `trace-cmd setup-guest` command that creates the necessary FIFOs for tracing a guest over FIFOs instead of vsockets. Signed-off-by: Slavomir Kaslev --- tracecmd/Makefile | 1 + tracecmd/include/trace-local.h | 6 ++ tracecmd/trace-cmd.c | 1 + tracecmd/trace-setup-guest.c | 178 +++++++++++++++++++++++++++++++++ tracecmd/trace-usage.c | 8 ++ 5 files changed, 194 insertions(+) create mode 100644 tracecmd/trace-setup-guest.c diff --git a/tracecmd/Makefile b/tracecmd/Makefile index 865b1c6..d3e3080 100644 --- a/tracecmd/Makefile +++ b/tracecmd/Makefile @@ -35,6 +35,7 @@ TRACE_CMD_OBJS += trace-msg.o ifeq ($(VSOCK_DEFINED), 1) TRACE_CMD_OBJS += trace-agent.o +TRACE_CMD_OBJS += trace-setup-guest.o endif ALL_OBJS := $(TRACE_CMD_OBJS:%.o=$(bdir)/%.o) diff --git a/tracecmd/include/trace-local.h b/tracecmd/include/trace-local.h index edcfee0..dd203b2 100644 --- a/tracecmd/include/trace-local.h +++ b/tracecmd/include/trace-local.h @@ -14,6 +14,10 @@ #define TRACE_AGENT_DEFAULT_PORT 823 +#define GUEST_PIPE_NAME "trace-pipe-cpu" +#define GUEST_DIR_FMT "/var/lib/trace-cmd/virt/%s" +#define GUEST_FIFO_FMT GUEST_DIR_FMT "/" GUEST_PIPE_NAME "%d" + extern int debug; extern int quiet; @@ -68,6 +72,8 @@ void trace_listen(int argc, char **argv); void trace_agent(int argc, char **argv); +void trace_setup_guest(int argc, char **argv); + void trace_restore(int argc, char **argv); void trace_clear(int argc, char **argv); diff --git a/tracecmd/trace-cmd.c b/tracecmd/trace-cmd.c index 3ae5e2e..4da82b4 100644 --- a/tracecmd/trace-cmd.c +++ b/tracecmd/trace-cmd.c @@ -85,6 +85,7 @@ struct command commands[] = { {"listen", trace_listen}, #ifdef VSOCK {"agent", trace_agent}, + {"setup-guest", trace_setup_guest}, #endif {"split", trace_split}, {"restore", trace_restore}, diff --git a/tracecmd/trace-setup-guest.c b/tracecmd/trace-setup-guest.c new file mode 100644 index 0000000..a6f58dc --- /dev/null +++ b/tracecmd/trace-setup-guest.c @@ -0,0 +1,178 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 VMware Inc, Slavomir Kaslev + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "trace-local.h" +#include "trace-msg.h" + +static int make_dir(const char *path, mode_t mode) +{ + char buf[PATH_MAX+2], *p; + + strncpy(buf, path, sizeof(buf)); + if (buf[PATH_MAX]) + return -E2BIG; + + for (p = buf; *p; p++) { + p += strspn(p, "/"); + p += strcspn(p, "/"); + *p = '\0'; + if (mkdir(buf, mode) < 0 && errno != EEXIST) + return -errno; + *p = '/'; + } + + return 0; +} + +static int make_fifo(const char *path, mode_t mode) +{ + struct stat st; + + if (!stat(path, &st)) { + if (S_ISFIFO(st.st_mode)) + return 0; + return -EEXIST; + } + + if (mkfifo(path, mode)) + return -errno; + return 0; +} + +static int make_guest_dir(const char *guest) +{ + char path[PATH_MAX]; + + snprintf(path, sizeof(path), GUEST_DIR_FMT, guest); + return make_dir(path, 0750); +} + +static int make_guest_fifo(const char *guest, int cpu, mode_t mode) +{ + static const char *exts[] = {".in", ".out"}; + char path[PATH_MAX]; + int i, ret = 0; + + for (i = 0; i < ARRAY_SIZE(exts); i++) { + snprintf(path, sizeof(path), GUEST_FIFO_FMT "%s", + guest, cpu, exts[i]); + ret = make_fifo(path, mode); + if (ret < 0) + break; + } + + return ret; +} + +static int make_guest_fifos(const char *guest, int nr_cpus, mode_t mode) +{ + int i, ret = 0; + mode_t mask; + + mask = umask(0); + for (i = 0; i < nr_cpus; i++) { + ret = make_guest_fifo(guest, i, mode); + if (ret < 0) + break; + } + umask(mask); + + return ret; +} + +static void do_setup_guest(const char *guest, int nr_cpus, mode_t mode, gid_t gid) +{ + gid_t save_egid; + int ret; + + if (gid != -1) { + save_egid = getegid(); + ret = setegid(gid); + if (ret < 0) + pdie("failed to set effective group ID"); + } + + ret = make_guest_dir(guest); + if (ret < 0) + pdie("failed to create guest directory for %s", guest); + + ret = make_guest_fifos(guest, nr_cpus, mode); + if (ret < 0) + pdie("failed to create FIFOs for %s", guest); + + if (gid != -1) { + ret = setegid(save_egid); + if (ret < 0) + pdie("failed to restore effective group ID"); + } +} + +void trace_setup_guest(int argc, char **argv) +{ + struct group *group; + mode_t mode = 0660; + int nr_cpus = -1; + gid_t gid = -1; + char *guest; + + if (argc < 2) + usage(argv); + + if (strcmp(argv[1], "setup-guest") != 0) + usage(argv); + + for (;;) { + int c, option_index = 0; + static struct option long_options[] = { + {"help", no_argument, NULL, '?'}, + {NULL, 0, NULL, 0} + }; + + c = getopt_long(argc-1, argv+1, "+hc:p:g:", + long_options, &option_index); + if (c == -1) + break; + switch (c) { + case 'h': + usage(argv); + break; + case 'c': + nr_cpus = atoi(optarg); + break; + case 'p': + mode = strtol(optarg, NULL, 8); + break; + case 'g': + group = getgrnam(optarg); + if (!group) + pdie("group %s does not exist", optarg); + gid = group->gr_gid; + break; + default: + usage(argv); + } + } + + if (optind != argc-2) + usage(argv); + + guest = argv[optind+1]; + + if (nr_cpus <= 0) + pdie("invalid number of cpus for guest %s", guest); + + do_setup_guest(guest, nr_cpus, mode, gid); +} diff --git a/tracecmd/trace-usage.c b/tracecmd/trace-usage.c index e845f50..7a8002f 100644 --- a/tracecmd/trace-usage.c +++ b/tracecmd/trace-usage.c @@ -246,6 +246,14 @@ static struct usage_help usage_help[] = { " -p port number to listen on.\n" " -D run in daemon mode.\n" }, + { + "setup-guest", + "create FIFOs for tracing guest VMs", + " %s setup-guest -c cpus[-p perm][-g group] guest\n" + " -c number of guest virtual CPUs\n" + " -p FIFOs permissions (default: 0660)\n" + " -g FIFOs group owner\n" + }, #endif { "list",