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From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org, linux-trace-devel@vger.kernel.org
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>,
	Ingo Molnar <mingo@kernel.org>, Jiri Olsa <jolsa@redhat.com>,
	Namhyung Kim <namhyung@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Julia Cartwright <julia@ni.com>,
	"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>
Subject: [PATCH v2 11/15] tools lib traceevent: Add plugin for decoding syscalls/sys_enter_futex
Date: Thu, 02 Jul 2020 14:53:55 -0400
Message-ID: <20200702185705.127175788@goodmis.org> (raw)
In-Reply-To: <20200702185344.913492689@goodmis.org>

From: Julia Cartwright <julia@ni.com>

The futex syscall is a complicated one.  It supports thirteen
multiplexed operations, each with different semantics and encodings for
the syscalls six arguments.

Manually decoding these arguments is tedious and error prone.

This plugin provides symbolic names for futex operations, futex flags,
and tries to be intelligent about the intent of specific arguments (for
example, waking operations use 'val' as an integer count, not just an
arbitrary value).

It doesn't do a full decode of the FUTEX_WAKE_OP's 'val3' argument,
however, this is a good starting point.

Link: http://lkml.kernel.org/r/20171207025649.12160-1-julia@ni.com
Link: http://lore.kernel.org/linux-trace-devel/20200702174950.123454-3-tz.stoyanov@gmail.com

Signed-off-by: Julia Cartwright <julia@ni.com>
[ Ported from trace-cmd.git ]
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 tools/lib/traceevent/plugins/Build          |   1 +
 tools/lib/traceevent/plugins/Makefile       |   1 +
 tools/lib/traceevent/plugins/plugin_futex.c | 137 ++++++++++++++++++++
 3 files changed, 139 insertions(+)
 create mode 100644 tools/lib/traceevent/plugins/plugin_futex.c

diff --git a/tools/lib/traceevent/plugins/Build b/tools/lib/traceevent/plugins/Build
index b866f231a536..dd4da823c38f 100644
--- a/tools/lib/traceevent/plugins/Build
+++ b/tools/lib/traceevent/plugins/Build
@@ -5,6 +5,7 @@ plugin_kvm-y          += plugin_kvm.o
 plugin_mac80211-y     += plugin_mac80211.o
 plugin_sched_switch-y += plugin_sched_switch.o
 plugin_function-y     += plugin_function.o
+plugin_futex-y        += plugin_futex.o
 plugin_xen-y          += plugin_xen.o
 plugin_scsi-y         += plugin_scsi.o
 plugin_cfg80211-y     += plugin_cfg80211.o
diff --git a/tools/lib/traceevent/plugins/Makefile b/tools/lib/traceevent/plugins/Makefile
index 8e72707e8630..946a4d31fcaf 100644
--- a/tools/lib/traceevent/plugins/Makefile
+++ b/tools/lib/traceevent/plugins/Makefile
@@ -134,6 +134,7 @@ PLUGINS += plugin_kvm.so
 PLUGINS += plugin_mac80211.so
 PLUGINS += plugin_sched_switch.so
 PLUGINS += plugin_function.so
+PLUGINS += plugin_futex.so
 PLUGINS += plugin_xen.so
 PLUGINS += plugin_scsi.so
 PLUGINS += plugin_cfg80211.so
diff --git a/tools/lib/traceevent/plugins/plugin_futex.c b/tools/lib/traceevent/plugins/plugin_futex.c
new file mode 100644
index 000000000000..5d76df141401
--- /dev/null
+++ b/tools/lib/traceevent/plugins/plugin_futex.c
@@ -0,0 +1,137 @@
+/*
+ * Copyright (C) 2017 National Instruments Corp.
+ *
+ * Author: Julia Cartwright <julia@ni.com>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License (not later!)
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program; if not,  see <http://www.gnu.org/licenses>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <linux/futex.h>
+
+#include "event-parse.h"
+
+#define ARRAY_SIZE(_a) (sizeof(_a) / sizeof((_a)[0]))
+
+struct futex_args {
+	unsigned long long	uaddr;
+	unsigned long long	op;
+	unsigned long long	val;
+	unsigned long long	utime; /* or val2 */
+	unsigned long long	uaddr2;
+	unsigned long long	val3;
+};
+
+struct futex_op {
+	const char	*name;
+	const char	*fmt_val;
+	const char	*fmt_utime;
+	const char	*fmt_uaddr2;
+	const char	*fmt_val3;
+};
+
+static const struct futex_op futex_op_tbl[] = {
+	{            "FUTEX_WAIT", " val=0x%08llx", " utime=0x%08llx",               NULL,             NULL },
+	{            "FUTEX_WAKE",     " val=%llu",              NULL,               NULL,             NULL },
+	{              "FUTEX_FD",     " val=%llu",              NULL,               NULL,             NULL },
+	{         "FUTEX_REQUEUE",     " val=%llu",      " val2=%llu", " uaddr2=0x%08llx",             NULL },
+	{     "FUTEX_CMP_REQUEUE",     " val=%llu",      " val2=%llu", " uaddr2=0x%08llx", " val3=0x%08llx" },
+	{         "FUTEX_WAKE_OP",     " val=%llu",      " val2=%llu", " uaddr2=0x%08llx", " val3=0x%08llx" },
+	{         "FUTEX_LOCK_PI",            NULL, " utime=0x%08llx",               NULL,             NULL },
+	{       "FUTEX_UNLOCK_PI",            NULL,              NULL,               NULL,             NULL },
+	{      "FUTEX_TRYLOCK_PI",            NULL,              NULL,               NULL,             NULL },
+	{     "FUTEX_WAIT_BITSET", " val=0x%08llx", " utime=0x%08llx",               NULL, " val3=0x%08llx" },
+	{     "FUTEX_WAKE_BITSET",     " val=%llu",              NULL,               NULL, " val3=0x%08llx" },
+	{ "FUTEX_WAIT_REQUEUE_PI", " val=0x%08llx", " utime=0x%08llx", " uaddr2=0x%08llx", " val3=0x%08llx" },
+	{  "FUTEX_CMP_REQUEUE_PI",     " val=%llu",      " val2=%llu", " uaddr2=0x%08llx", " val3=0x%08llx" },
+};
+
+
+static void futex_print(struct trace_seq *s, const struct futex_args *args,
+			const struct futex_op *fop)
+{
+	trace_seq_printf(s, " uaddr=0x%08llx", args->uaddr);
+
+	if (fop->fmt_val)
+		trace_seq_printf(s, fop->fmt_val, args->val);
+
+	if (fop->fmt_utime)
+		trace_seq_printf(s,fop->fmt_utime, args->utime);
+
+	if (fop->fmt_uaddr2)
+		trace_seq_printf(s, fop->fmt_uaddr2, args->uaddr2);
+
+	if (fop->fmt_val3)
+		trace_seq_printf(s, fop->fmt_val3, args->val3);
+}
+
+static int futex_handler(struct trace_seq *s, struct tep_record *record,
+			 struct tep_event *event, void *context)
+{
+	const struct futex_op *fop;
+	struct futex_args args;
+	unsigned long long cmd;
+
+	if (tep_get_field_val(s, event, "uaddr", record, &args.uaddr, 1))
+		return 1;
+
+	if (tep_get_field_val(s, event, "op", record, &args.op, 1))
+		return 1;
+
+	if (tep_get_field_val(s, event, "val", record, &args.val, 1))
+		return 1;
+
+	if (tep_get_field_val(s, event, "utime", record, &args.utime, 1))
+		return 1;
+
+	if (tep_get_field_val(s, event, "uaddr2", record, &args.uaddr2, 1))
+		return 1;
+
+	if (tep_get_field_val(s, event, "val3", record, &args.val3, 1))
+		return 1;
+
+	cmd = args.op & FUTEX_CMD_MASK;
+	if (cmd >= ARRAY_SIZE(futex_op_tbl))
+		return 1;
+
+	fop = &futex_op_tbl[cmd];
+
+	trace_seq_printf(s, "op=%s", fop->name);
+
+	if (args.op & FUTEX_PRIVATE_FLAG)
+		trace_seq_puts(s, "|FUTEX_PRIVATE_FLAG");
+
+	if (args.op & FUTEX_CLOCK_REALTIME)
+		trace_seq_puts(s, "|FUTEX_CLOCK_REALTIME");
+
+	futex_print(s, &args, fop);
+	return 0;
+}
+
+int TEP_PLUGIN_LOADER(struct tep_handle *tep)
+{
+	tep_register_event_handler(tep, -1, "syscalls", "sys_enter_futex",
+				   futex_handler, NULL);
+	return 0;
+}
+
+void TEP_PLUGIN_UNLOADER(struct tep_handle *tep)
+{
+	tep_unregister_event_handler(tep, -1, "syscalls", "sys_enter_futex",
+				     futex_handler, NULL);
+}
-- 
2.26.2



  parent reply index

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-02 18:53 [PATCH v2 00/15] tools lib traceevent: Patches from the trace-cmd repo Steven Rostedt
2020-07-02 18:53 ` [PATCH v2 01/15] tools lib traceevent: Add API to read time information from kbuffer Steven Rostedt
2020-07-03 11:31   ` Arnaldo Carvalho de Melo
2020-07-03 16:18     ` Steven Rostedt
2020-07-02 18:53 ` [PATCH v2 02/15] tools lib traceevent: Add proper KBUFFER_TYPE_TIME_STAMP handling Steven Rostedt
2020-07-02 18:53 ` [PATCH v2 03/15] tools lib traceevent: Add tep_load_plugins_hook() API Steven Rostedt
2020-07-07 14:55   ` Namhyung Kim
2020-07-07 15:35     ` Steven Rostedt
2020-07-02 18:53 ` [PATCH v2 04/15] tools lib traceevent: Add interface for options to plugins Steven Rostedt
2020-07-07 15:03   ` Namhyung Kim
2020-07-02 18:53 ` [PATCH v2 05/15] tools lib traceevent: Introduced new traceevent API, for adding new plugins directories Steven Rostedt
2020-07-07 15:06   ` Namhyung Kim
2020-07-07 15:24     ` Steven Rostedt
2020-07-08  0:02       ` Namhyung Kim
2020-07-02 18:53 ` [PATCH v2 06/15] tools lib traceevent: Add support for more printk format specifiers Steven Rostedt
2020-07-07 15:09   ` Namhyung Kim
2020-07-02 18:53 ` [PATCH v2 07/15] tools lib traceevent: Optimize pretty_print() function Steven Rostedt
2020-07-07 15:11   ` Namhyung Kim
2020-07-07 15:31     ` Steven Rostedt
2020-07-02 18:53 ` [PATCH v2 08/15] tools lib traceevent: Add plugin for tlb_flush Steven Rostedt
2020-07-02 18:53 ` [PATCH v2 09/15] tools lib traceevent: Add more SVM exit reasons Steven Rostedt
2020-07-02 18:53 ` [PATCH v2 10/15] tools lib traceevent: Add offset option for function plugin Steven Rostedt
2020-07-02 18:53 ` Steven Rostedt [this message]
2020-07-02 18:53 ` [PATCH v2 12/15] tools lib traceevent: Move kernel_stack event handler to "function" plugin Steven Rostedt
2020-07-02 18:53 ` [PATCH v2 13/15] tools lib traceevent: Add builtin handler for trace_marker_raw Steven Rostedt
2020-07-02 18:53 ` [PATCH v2 14/15] tools lib traceevent: Change to SPDX License format Steven Rostedt
2020-07-02 18:53 ` [PATCH v2 15/15] tools lib traceevent: Fix reporting of unknown SVM exit reasons Steven Rostedt
2020-07-08  2:02 ` [PATCH v2 00/15] tools lib traceevent: Patches from the trace-cmd repo Namhyung Kim

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