From patchwork Wed Oct 17 07:43:15 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tzvetomir Stoyanov X-Patchwork-Id: 10759609 Return-Path: Received: from mail-eopbgr710081.outbound.protection.outlook.com ([40.107.71.81]:11840 "EHLO NAM05-BY2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726994AbeJQPhn (ORCPT ); Wed, 17 Oct 2018 11:37:43 -0400 From: Tzvetomir Stoyanov To: "rostedt@goodmis.org" CC: "linux-trace-devel@vger.kernel.org" , Tzvetomir Stoyanov Subject: [PATCH v2] Introduce new libtracevent API: tep_override_comm() Date: Wed, 17 Oct 2018 07:43:15 +0000 Message-ID: <20181017074302.13767-1-tstoyanov@vmware.com> Content-Language: en-US MIME-Version: 1.0 Sender: linux-trace-devel-owner@vger.kernel.org List-ID: Content-Length: 4755 From: Tzvetomir Stoyanov (VMware) Added a new API of tracevent library: tep_override_comm() It registers a pid / comm mapping. If a mapping with the same pid already exists, the entry is updated with the new comm. Signed-off-by: Tzvetomir Stoyanov (VMware) --- include/traceevent/event-parse.h | 1 + lib/traceevent/event-parse.c | 69 +++++++++++++++++++++++++------- 2 files changed, 55 insertions(+), 15 deletions(-) diff --git a/include/traceevent/event-parse.h b/include/traceevent/event-parse.h index 18652c8..147efbc 100644 --- a/include/traceevent/event-parse.h +++ b/include/traceevent/event-parse.h @@ -435,6 +435,7 @@ int tep_set_function_resolver(struct tep_handle *pevent, tep_func_resolver_t *func, void *priv); void tep_reset_function_resolver(struct tep_handle *pevent); int tep_register_comm(struct tep_handle *pevent, const char *comm, int pid); +int tep_override_comm(struct tep_handle *pevent, const char *comm, int pid); int tep_register_trace_clock(struct tep_handle *pevent, const char *trace_clock); int tep_register_function(struct tep_handle *pevent, char *name, unsigned long long addr, char *mod); diff --git a/lib/traceevent/event-parse.c b/lib/traceevent/event-parse.c index d889a62..73662d0 100644 --- a/lib/traceevent/event-parse.c +++ b/lib/traceevent/event-parse.c @@ -233,11 +233,13 @@ int tep_pid_is_registered(struct tep_handle *pevent, int pid) * we must add this pid. This is much slower than when cmdlines * are added before the array is initialized. */ -static int add_new_comm(struct tep_handle *pevent, const char *comm, int pid) +static int add_new_comm(struct tep_handle *pevent, + const char *comm, int pid, bool override) { struct cmdline *cmdlines = pevent->cmdlines; - const struct cmdline *cmdline; + struct cmdline *cmdline; struct cmdline key; + char *new_comm; if (!pid) return 0; @@ -248,8 +250,19 @@ static int add_new_comm(struct tep_handle *pevent, const char *comm, int pid) cmdline = bsearch(&key, pevent->cmdlines, pevent->cmdline_count, sizeof(*pevent->cmdlines), cmdline_cmp); if (cmdline) { - errno = EEXIST; - return -1; + if (!override) { + errno = EEXIST; + return -1; + } + new_comm = strdup(comm); + if(!new_comm) { + errno = ENOMEM; + return -1; + } + free(cmdline->comm); + cmdline->comm = new_comm; + + return 0; } cmdlines = realloc(cmdlines, sizeof(*cmdlines) * (pevent->cmdline_count + 1)); @@ -276,21 +289,13 @@ static int add_new_comm(struct tep_handle *pevent, const char *comm, int pid) return 0; } -/** - * tep_register_comm - register a pid / comm mapping - * @pevent: handle for the pevent - * @comm: the command line to register - * @pid: the pid to map the command line to - * - * This adds a mapping to search for command line names with - * a given pid. The comm is duplicated. - */ -int tep_register_comm(struct tep_handle *pevent, const char *comm, int pid) +static int _tep_register_comm(struct tep_handle *pevent, + const char *comm, int pid, bool override) { struct cmdline_list *item; if (pevent->cmdlines) - return add_new_comm(pevent, comm, pid); + return add_new_comm(pevent, comm, pid, override); item = malloc(sizeof(*item)); if (!item) @@ -313,6 +318,40 @@ int tep_register_comm(struct tep_handle *pevent, const char *comm, int pid) return 0; } +/** + * tep_register_comm - register a pid / comm mapping + * @pevent: handle for the pevent + * @comm: the command line to register + * @pid: the pid to map the command line to + * + * This adds a mapping to search for command line names with + * a given pid. The comm is duplicated. If a command with the same pid + * already exist, -1 is returned and errno is set to EEXIST + */ +int tep_register_comm(struct tep_handle *pevent, const char *comm, int pid) +{ + return _tep_register_comm(pevent, comm, pid, false); +} + +/** + * tep_override_comm - register a pid / comm mapping + * @pevent: handle for the pevent + * @comm: the command line to register + * @pid: the pid to map the command line to + * + * This adds a mapping to search for command line names with + * a given pid. The comm is duplicated. If a command with the same pid + * already exist, the command string is udapted with the new one + */ +int tep_override_comm(struct tep_handle *pevent, const char *comm, int pid) +{ + if (!pevent->cmdlines && cmdline_init(pevent)) { + errno = ENOMEM; + return -1; + } + return _tep_register_comm(pevent, comm, pid, true); +} + int tep_register_trace_clock(struct tep_handle *pevent, const char *trace_clock) { pevent->trace_clock = strdup(trace_clock);