Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1753545AbbGIMhN (ORCPT <rfc822;w@1wt.eu>);
	Thu, 9 Jul 2015 08:37:13 -0400
Received: from szxga02-in.huawei.com ([119.145.14.65]:58449 "EHLO
	szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1753445AbbGIMgf (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Thu, 9 Jul 2015 08:36:35 -0400
From: Wang Nan <wangnan0@huawei.com>
To: <acme@kernel.org>, <ast@plumgrid.com>
CC: <linux-kernel@vger.kernel.org>, <lizefan@huawei.com>, <hekuang@huawei.com>,
        <xiakaixu@huawei.com>, <pi3orama@163.com>
Subject: [PATCH 39/39] perf tools: Support attach BPF program on uprobe events
Date: Thu, 9 Jul 2015 12:35:42 +0000
Message-ID: <1436445342-1402-40-git-send-email-wangnan0@huawei.com>
X-Mailer: git-send-email 1.8.3.4
In-Reply-To: <1436445342-1402-1-git-send-email-wangnan0@huawei.com>
References: <1436445342-1402-1-git-send-email-wangnan0@huawei.com>
MIME-Version: 1.0
Content-Type: text/plain
X-Originating-IP: [10.107.197.200]
X-CFilter-Loop: Reflected
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
Content-Length: 3414
Lines: 135

This patch appends new syntax to BPF object section name to support
probing at uprobe event. Now we can use BPF program like this:

 SEC(
 "target=/lib64/libc.so.6\n"
 "libcwrite=__write"
 )
 int libcwrite(void *ctx)
 {
     return 1;
 }

Where, in section name of a program, before the main config string,
we can use 'key=value' style options. Now the only option key "target"
is for uprobe probing.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
---
 tools/perf/util/bpf-loader.c | 88 ++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 81 insertions(+), 7 deletions(-)

diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index 0a4e9ec..f5b2344 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -75,6 +75,84 @@ bpf_prog_priv__clear(struct bpf_program *prog __maybe_unused,
 }
 
 static int
+do_config(const char *key, const char *value,
+	  struct perf_probe_event *pev)
+{
+	pr_debug("config bpf program: %s=%s\n", key, value);
+	if (strcmp(key, "target") == 0) {
+		pev->uprobes = true;
+		pev->target = strdup(value);
+		return 0;
+	}
+
+	pr_warning("BPF: WARNING: invalid config option in object: %s=%s\n",
+		   key, value);
+	pr_warning("\tHint: Currently only valid option is 'target=<file>'\n");
+	return 0;
+}
+
+static const char *
+parse_config_kvpair(const char *config_str, struct perf_probe_event *pev)
+{
+	char *text = strdup(config_str);
+	char *sep, *line;
+	const char *main_str = NULL;
+	int err = 0;
+
+	if (!text) {
+		pr_err("No enough memory: dup config_str failed\n");
+		return NULL;
+	}
+
+	line = text;
+	while ((sep = strchr(line, '\n'))) {
+		char *equ;
+
+		*sep = '\0';
+		equ = strchr(line, '=');
+		if (!equ) {
+			pr_warning("WARNING: invalid config in BPF object: %s\n",
+				   line);
+			pr_warning("\tShould be 'key=value'.\n");
+			goto nextline;
+		}
+		*equ = '\0';
+
+		err = do_config(line, equ + 1, pev);
+		if (err)
+			break;
+nextline:
+		line = sep + 1;
+	}
+
+	if (!err)
+		main_str = config_str + (line - text);
+	free(text);
+
+	return main_str;
+}
+
+static int
+parse_config(const char *config_str, struct perf_probe_event *pev)
+{
+	const char *main_str;
+	int err;
+
+	main_str = parse_config_kvpair(config_str, pev);
+	if (!main_str)
+		return -EINVAL;
+
+	err = parse_perf_probe_command(main_str, pev);
+	if (err < 0) {
+		pr_err("bpf: '%s' is not a valid config string\n",
+		       config_str);
+		/* parse failed, don't need clear pev. */
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int
 config_bpf_program(struct bpf_program *prog)
 {
 	struct perf_probe_event *pev = alloc_perf_probe_event();
@@ -93,13 +171,9 @@ config_bpf_program(struct bpf_program *prog)
 	}
 
 	pr_debug("bpf: config program '%s'\n", config_str);
-	err = parse_perf_probe_command(config_str, pev);
-	if (err < 0) {
-		pr_err("bpf: '%s' is not a valid config string\n",
-		       config_str);
-		/* parse failed, don't need clear pev. */
-		return -EINVAL;
-	}
+	err = parse_config(config_str, pev);
+	if (err)
+		return err;
 
 	if (pev->group && strcmp(pev->group, PERF_BPF_PROBE_GROUP)) {
 		pr_err("bpf: '%s': group for event is set and not '%s'.\n",
-- 
1.8.3.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/