From patchwork Tue Sep 17 13:15:34 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Slavomir Kaslev X-Patchwork-Id: 11148871 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BB83F76 for ; Tue, 17 Sep 2019 13:15:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 993792171F for ; Tue, 17 Sep 2019 13:15:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727805AbfIQNP6 (ORCPT ); Tue, 17 Sep 2019 09:15:58 -0400 Received: from mail-wm1-f67.google.com ([209.85.128.67]:36592 "EHLO mail-wm1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726131AbfIQNP6 (ORCPT ); Tue, 17 Sep 2019 09:15:58 -0400 Received: by mail-wm1-f67.google.com with SMTP id t3so3139124wmj.1 for ; Tue, 17 Sep 2019 06:15:56 -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=MQS9m/ZLBFsoPLTKiVXXluztngr4AUZvnpubhlgwpFU=; b=UtquwVIQiZzsT7EiwVjlp6MsgZlVSBPyp5Yhw+2uRNKhfZVs+dgfEk03IZTS93yTSQ fjAVjZxVWgqFaQfoLPfx5AevhmNaYKROELWZxXHpV/3FDoY5T5HsBHOAuxAO1Qgz42kq 3AKaZqKzhMNEAE5VXZNoLO1ZO0HUHhIhlFpw9FV4T2orIEUTacEYERqOiKS1UAp4C04u 7jAU2h0MNgpW1pEDrPdgt8WrjepaiHMoLHLWRNkSZp7gRh0ZRcg7IdtHchLqYt10dQJ4 DcA0LzR94rekno9xLE0Yqps1Tt7QHkwJ/t0RLQ63YrOK+2mNFoIRThro3Gi1ev3+1C83 SR0g== X-Gm-Message-State: APjAAAUsLhui9HPS1ywiDP1J4DhBcXThGVVu2eQkyoNfG1q1f1kdljbs yAZzdvaq5tdmccr0lHgAvgKvkXqA3w== X-Google-Smtp-Source: APXvYqxSaEm9HSr1Yv3EYF+NxhGfLFr35PGoRC1ROgJ0U+qjyft1sPLKRFTmBykA4zCx+aln8QJDWA== X-Received: by 2002:a1c:7fcc:: with SMTP id a195mr3629992wmd.27.1568726155316; Tue, 17 Sep 2019 06:15:55 -0700 (PDT) Received: from box.eng.vmware.com ([146.247.46.5]) by smtp.gmail.com with ESMTPSA id d22sm1667265wmb.44.2019.09.17.06.15.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 17 Sep 2019 06:15:54 -0700 (PDT) From: Slavomir Kaslev To: rostedt@goodmis.org Cc: linux-trace-devel@vger.kernel.org Subject: [PATCH v14 09/13] trace-cmd: Add `trace-cmd setup-guest` command Date: Tue, 17 Sep 2019 16:15:34 +0300 Message-Id: <20190917131538.31926-10-kaslevs@vmware.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190917131538.31926-1-kaslevs@vmware.com> References: <20190917131538.31926-1-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 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 fb85e47..29a623b 100644 --- a/tracecmd/Makefile +++ b/tracecmd/Makefile @@ -33,6 +33,7 @@ TRACE_CMD_OBJS += trace-usage.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 00a8e38..4df8686 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 quiet; /* fix stupid glib guint64 typecasts and printf formats */ @@ -67,6 +71,8 @@ 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 cdaaadf..afc84a8 100644 --- a/tracecmd/trace-cmd.c +++ b/tracecmd/trace-cmd.c @@ -84,6 +84,7 @@ 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 da17df7..2caff0e 100644 --- a/tracecmd/trace-usage.c +++ b/tracecmd/trace-usage.c @@ -248,6 +248,14 @@ 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",