From patchwork Tue Jan 8 15:00:14 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Slavomir Kaslev X-Patchwork-Id: 10760239 Return-Path: Received: from mail-pf1-f195.google.com ([209.85.210.195]:37761 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727678AbfAHPAd (ORCPT ); Tue, 8 Jan 2019 10:00:33 -0500 Received: by mail-pf1-f195.google.com with SMTP id y126so2058964pfb.4 for ; Tue, 08 Jan 2019 07:00:32 -0800 (PST) From: Slavomir Kaslev To: linux-trace-devel@vger.kernel.org Cc: rostedt@goodmis.org, ykaradzhov@vmware.com, tstoyanov@vmware.com Subject: [PATCH v2 5/6] trace-cmd: Add TRACE_REQ and TRACE_RESP messages Date: Tue, 8 Jan 2019 17:00:14 +0200 Message-Id: <20190108150015.21327-6-kaslevs@vmware.com> In-Reply-To: <20190108150015.21327-1-kaslevs@vmware.com> References: <20190108150015.21327-1-kaslevs@vmware.com> MIME-Version: 1.0 Sender: linux-trace-devel-owner@vger.kernel.org List-ID: Content-Length: 6307 Add TRACE_REQ and TRACE_RESP messages which are used for initiating guest VM tracing. Signed-off-by: Slavomir Kaslev --- include/trace-cmd/trace-cmd.h | 12 +++ tracecmd/trace-msg.c | 185 +++++++++++++++++++++++++++++++++- 2 files changed, 196 insertions(+), 1 deletion(-) diff --git a/include/trace-cmd/trace-cmd.h b/include/trace-cmd/trace-cmd.h index c1b18fa..fae6ceb 100644 --- a/include/trace-cmd/trace-cmd.h +++ b/include/trace-cmd/trace-cmd.h @@ -337,6 +337,18 @@ int tracecmd_msg_collect_data(struct tracecmd_msg_handle *msg_handle, int ofd); bool tracecmd_msg_done(struct tracecmd_msg_handle *msg_handle); void tracecmd_msg_set_done(struct tracecmd_msg_handle *msg_handle); +int tracecmd_msg_send_trace_req(struct tracecmd_msg_handle *msg_handle, + int argc, char **argv); +int tracecmd_msg_recv_trace_req(struct tracecmd_msg_handle *msg_handle, + int *argc, char ***argv); + +int tracecmd_msg_send_trace_resp(struct tracecmd_msg_handle *msg_handle, + int nr_cpus, int page_size, int *ports); +int tracecmd_msg_recv_trace_resp(struct tracecmd_msg_handle *msg_handle, + int *nr_cpus, int *page_size, int **ports); + +int tracecmd_msg_wait_close(struct tracecmd_msg_handle *msg_handle); + /* --- Plugin handling --- */ extern struct tep_plugin_option trace_ftrace_options[]; diff --git a/tracecmd/trace-msg.c b/tracecmd/trace-msg.c index edde582..35d1d0e 100644 --- a/tracecmd/trace-msg.c +++ b/tracecmd/trace-msg.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include #include @@ -79,6 +80,16 @@ struct tracecmd_msg_rinit { be32 cpus; } __attribute__((packed)); +struct tracecmd_msg_trace_req { + be32 flags; + be32 argc; +} __attribute__((packed)); + +struct tracecmd_msg_trace_resp { + be32 cpus; + be32 page_size; +} __attribute__((packed)); + struct tracecmd_msg_header { be32 size; be32 cmd; @@ -90,7 +101,9 @@ struct tracecmd_msg_header { C(TINIT, 1, sizeof(struct tracecmd_msg_tinit)), \ C(RINIT, 2, sizeof(struct tracecmd_msg_rinit)), \ C(SEND_DATA, 3, 0), \ - C(FIN_DATA, 4, 0), + C(FIN_DATA, 4, 0), \ + C(TRACE_REQ, 5, sizeof(struct tracecmd_msg_trace_req)), \ + C(TRACE_RESP, 6, sizeof(struct tracecmd_msg_trace_resp)), #undef C #define C(a,b,c) MSG_##a = b @@ -122,6 +135,8 @@ struct tracecmd_msg { union { struct tracecmd_msg_tinit tinit; struct tracecmd_msg_rinit rinit; + struct tracecmd_msg_trace_req trace_req; + struct tracecmd_msg_trace_resp trace_resp; }; union { struct tracecmd_msg_opt *opt; @@ -715,3 +730,171 @@ error: msg_free(&msg); return ret; } + +static int make_trace_req(struct tracecmd_msg *msg, int argc, char **argv) +{ + size_t args_size = 0; + char *p; + int i; + + for (i = 0; i < argc; i++) + args_size += strlen(argv[i]) + 1; + + msg->hdr.size = htonl(ntohl(msg->hdr.size) + args_size); + msg->trace_req.argc = htonl(argc); + msg->buf = calloc(args_size, 1); + if (!msg->buf) + return -ENOMEM; + + p = msg->buf; + for (i = 0; i < argc; i++) + p = stpcpy(p, argv[i]) + 1; + + return 0; +} + +int tracecmd_msg_send_trace_req(struct tracecmd_msg_handle *msg_handle, + int argc, char **argv) +{ + struct tracecmd_msg msg; + int ret; + + tracecmd_msg_init(MSG_TRACE_REQ, &msg); + ret = make_trace_req(&msg, argc, argv); + if (ret) + return ret; + + return tracecmd_msg_send(msg_handle->fd, &msg); +} + + /* + * NOTE: On success, the returned `argv` should be freed with: + * free(argv[0]); + * free(argv); + */ +int tracecmd_msg_recv_trace_req(struct tracecmd_msg_handle *msg_handle, + int *argc, char ***argv) +{ + struct tracecmd_msg msg; + char *p, *buf_end; + size_t buf_len; + int i, ret; + + ret = tracecmd_msg_recv(msg_handle->fd, &msg); + if (ret < 0) + return ret; + + if (ntohl(msg.hdr.cmd) != MSG_TRACE_REQ) + goto out; + + if (ntohl(msg.trace_req.argc) < 0) + goto out; + + buf_len = ntohl(msg.hdr.size) - MSG_HDR_LEN - ntohl(msg.hdr.cmd_size); + buf_end = (char *)msg.buf + buf_len; + p = msg.buf; + *argc = ntohl(msg.trace_req.argc); + *argv = calloc(*argc, sizeof(**argv)); + for (i = 0; i < *argc; i++) { + if (p >= buf_end) { + ret = -1; + free(*argv); + goto out; + } + + (*argv)[i] = p; + p = strchr(p, '\0'); + p++; + } + + ret = 0; + msg.buf = NULL; + +out: + msg_free(&msg); + return ret; +} + +static int make_trace_resp(struct tracecmd_msg *msg, + int page_size, int nr_cpus, int *ports) +{ + int ports_size = nr_cpus * sizeof(*msg->port_array); + int i; + + msg->hdr.size = htonl(ntohl(msg->hdr.size) + ports_size); + msg->trace_resp.cpus = htonl(nr_cpus); + msg->trace_resp.page_size = htonl(page_size); + + msg->port_array = malloc(ports_size); + if (!msg->port_array) + return -ENOMEM; + + for (i = 0; i < nr_cpus; i++) + msg->port_array[i] = htonl(ports[i]); + + return 0; +} + +int tracecmd_msg_send_trace_resp(struct tracecmd_msg_handle *msg_handle, + int nr_cpus, int page_size, int *ports) +{ + struct tracecmd_msg msg; + int ret; + + tracecmd_msg_init(MSG_TRACE_RESP, &msg); + ret = make_trace_resp(&msg, page_size, nr_cpus, ports); + if (ret < 0) + return ret; + + return tracecmd_msg_send(msg_handle->fd, &msg); +} + +int tracecmd_msg_recv_trace_resp(struct tracecmd_msg_handle *msg_handle, + int *nr_cpus, int *page_size, int **ports) +{ + struct tracecmd_msg msg; + size_t buf_len; + int i, ret; + + ret = tracecmd_msg_recv(msg_handle->fd, &msg); + if (ret < 0) + return ret; + + if (ntohl(msg.hdr.cmd) != MSG_TRACE_RESP) { + ret = -1; + goto out; + } + + buf_len = ntohl(msg.hdr.size) - MSG_HDR_LEN - ntohl(msg.hdr.cmd_size); + if (buf_len <= 0 || + buf_len != sizeof(*msg.port_array) * ntohl(msg.trace_resp.cpus)) { + ret = -1; + goto out; + } + + *nr_cpus = ntohl(msg.trace_resp.cpus); + *page_size = ntohl(msg.trace_resp.page_size); + *ports = calloc(*nr_cpus, sizeof(**ports)); + for (i = 0; i < *nr_cpus; i++) + (*ports)[i] = ntohl(msg.port_array[i]); + + ret = 0; + +out: + msg_free(&msg); + return ret; +} + +int tracecmd_msg_wait_close(struct tracecmd_msg_handle *msg_handle) +{ + char buf[BUFSIZ]; + int ret; + + for (;;) { + ret = read(msg_handle->fd, buf, sizeof(buf)); + if (ret <= 0) + return ret; + } + + return -1; +}