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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 20/39] perf tools: Parse probe points of eBPF programs during preparation
Date: Thu, 9 Jul 2015 12:35:23 +0000	[thread overview]
Message-ID: <1436445342-1402-21-git-send-email-wangnan0@huawei.com> (raw)
In-Reply-To: <1436445342-1402-1-git-send-email-wangnan0@huawei.com>

This patch parses section name of each program, and creates
corresponding 'struct perf_probe_event' structure.

parse_perf_probe_command() is used to do the main parsing works.
Parsing result is stored into a global array. This is because
add_perf_probe_events() is non-reentrantable. In following patch,
add_perf_probe_events will be introduced to insert kprobes. It accepts
an array of 'struct perf_probe_event' and do all works in one call.

Define PERF_BPF_PROBE_GROUP as "perf_bpf_probe", which will be used
as group name of all eBPF probing points.

This patch utilizes bpf_program__set_private(), bind perf_probe_event
with bpf program by private field.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
---
 tools/perf/util/bpf-loader.c | 126 ++++++++++++++++++++++++++++++++++++++++++-
 tools/perf/util/bpf-loader.h |   2 +
 2 files changed, 126 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index 61d3adf..e33995d 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -10,6 +10,8 @@
 #include "debug.h"
 #include "bpf-loader.h"
 #include "llvm-utils.h"
+#include "probe-event.h"
+#include "probe-finder.h"
 
 #define DEFINE_PRINT_FN(name, level) \
 static int libbpf_##name(const char *fmt, ...)	\
@@ -29,9 +31,122 @@ DEFINE_PRINT_FN(debug, 1)
 
 static bool libbpf_initialized;
 
+static struct perf_probe_event probe_event_array[MAX_PROBES];
+static size_t nr_probe_events;
+
+static struct perf_probe_event *
+alloc_perf_probe_event(void)
+{
+	struct perf_probe_event *pev;
+	int n = nr_probe_events;
+
+	if (n >= MAX_PROBES) {
+		pr_err("bpf: too many events, increase MAX_PROBES\n");
+		return NULL;
+	}
+
+	nr_probe_events = n + 1;
+	pev = &probe_event_array[n];
+	bzero(pev, sizeof(*pev));
+	return pev;
+}
+
+struct bpf_prog_priv {
+	struct perf_probe_event *pev;
+};
+
+static void
+bpf_prog_priv__clear(struct bpf_program *prog __maybe_unused,
+			  void *_priv)
+{
+	struct bpf_prog_priv *priv = _priv;
+
+	if (priv->pev)
+		clear_perf_probe_event(priv->pev);
+	free(priv);
+}
+
+static int
+config_bpf_program(struct bpf_program *prog)
+{
+	struct perf_probe_event *pev = alloc_perf_probe_event();
+	struct bpf_prog_priv *priv = NULL;
+	const char *config_str;
+	int err;
+
+	/* pr_err has been done by alloc_perf_probe_event */
+	if (!pev)
+		return -ENOMEM;
+
+	config_str = bpf_program__title(prog, false);
+	if (!config_str) {
+		pr_err("bpf: unable to get title for program\n");
+		return -EINVAL;
+	}
+
+	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;
+	}
+
+	if (pev->group && strcmp(pev->group, PERF_BPF_PROBE_GROUP)) {
+		pr_err("bpf: '%s': group for event is set and not '%s'.\n",
+		       config_str, PERF_BPF_PROBE_GROUP);
+		err = -EINVAL;
+		goto errout;
+	} else if (!pev->group)
+		pev->group = strdup(PERF_BPF_PROBE_GROUP);
+
+	if (!pev->group) {
+		pr_err("bpf: strdup failed\n");
+		err = -ENOMEM;
+		goto errout;
+	}
+
+	if (!pev->event) {
+		pr_err("bpf: '%s': event name is missing\n",
+		       config_str);
+		err = -EINVAL;
+		goto errout;
+	}
+
+	pr_debug("bpf: config '%s' is ok\n", config_str);
+
+	priv = calloc(1, sizeof(*priv));
+	if (!priv) {
+		pr_err("bpf: failed to alloc memory\n");
+		err = -ENOMEM;
+		goto errout;
+	}
+
+	priv->pev = pev;
+
+	err = bpf_program__set_private(prog, priv,
+				       bpf_prog_priv__clear);
+	if (err) {
+		pr_err("bpf: set program private failed\n");
+		err = -ENOMEM;
+		goto errout;
+	}
+	return 0;
+
+errout:
+	if (pev)
+		clear_perf_probe_event(pev);
+	if (priv)
+		free(priv);
+	return err;
+}
+
 int bpf__prepare_load(const char *filename, bool source)
 {
 	struct bpf_object *obj;
+	struct bpf_program *prog;
+	int err = 0;
 
 	if (!libbpf_initialized)
 		libbpf_set_print(libbpf_warning,
@@ -41,7 +156,6 @@ int bpf__prepare_load(const char *filename, bool source)
 	if (source) {
 		void *obj_buf;
 		size_t obj_buf_sz;
-		int err;
 
 		err = llvm__compile_bpf(filename, &obj_buf, &obj_buf_sz);
 		if (err)
@@ -56,12 +170,20 @@ int bpf__prepare_load(const char *filename, bool source)
 		return -EINVAL;
 	}
 
+	bpf_object__for_each_program(prog, obj) {
+		err = config_bpf_program(prog);
+		if (err)
+			goto errout;
+	}
+
 	/*
 	 * Throw object pointer away: it will be retrived using
 	 * bpf_objects iterater.
 	 */
-
 	return 0;
+errout:
+	bpf_object__close(obj);
+	return err;
 }
 
 void bpf__clear(void)
diff --git a/tools/perf/util/bpf-loader.h b/tools/perf/util/bpf-loader.h
index 5566be0..5a3c954 100644
--- a/tools/perf/util/bpf-loader.h
+++ b/tools/perf/util/bpf-loader.h
@@ -8,6 +8,8 @@
 #include <linux/compiler.h>
 #include "debug.h"
 
+#define PERF_BPF_PROBE_GROUP "perf_bpf_probe"
+
 #ifdef HAVE_LIBBPF_SUPPORT
 int bpf__prepare_load(const char *filename, bool source);
 
-- 
1.8.3.4


  parent reply	other threads:[~2015-07-09 12:36 UTC|newest]

Thread overview: 78+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-07-09 12:35 [GIT PULL 00/39] perf tools: filtering events using eBPF programs Wang Nan
2015-07-09 12:35 ` [PATCH 01/39] bpf tools: Collect symbol table from SHT_SYMTAB section Wang Nan
2015-07-09 12:35 ` [PATCH 02/39] bpf tools: Collect eBPF programs from their own sections Wang Nan
2015-07-09 15:58   ` Arnaldo Carvalho de Melo
2015-07-10  3:07     ` Wangnan (F)
2015-07-13 19:51       ` Arnaldo Carvalho de Melo
2015-07-14  3:58         ` Wangnan (F)
2015-07-09 12:35 ` [PATCH 03/39] bpf tools: Collect relocation sections from SHT_REL sections Wang Nan
2015-07-09 12:35 ` [PATCH 04/39] bpf tools: Record map accessing instructions for each program Wang Nan
2015-07-09 12:35 ` [PATCH 05/39] bpf tools: Add bpf.c/h for common bpf operations Wang Nan
2015-07-09 12:35 ` [PATCH 06/39] bpf tools: Create eBPF maps defined in an object file Wang Nan
2015-07-13 19:54   ` Arnaldo Carvalho de Melo
2015-07-14  3:59     ` Wangnan (F)
2015-07-09 12:35 ` [PATCH 07/39] bpf tools: Relocate eBPF programs Wang Nan
2015-07-09 12:35 ` [PATCH 08/39] bpf tools: Introduce bpf_load_program() to bpf.c Wang Nan
2015-07-09 12:35 ` [PATCH 09/39] bpf tools: Load eBPF programs in object files into kernel Wang Nan
2015-07-09 12:35 ` [PATCH 10/39] bpf tools: Introduce accessors for struct bpf_program Wang Nan
2015-07-09 12:35 ` [PATCH 11/39] bpf tools: Link all bpf objects onto a list Wang Nan
2015-07-09 12:35 ` [PATCH 12/39] perf tools: Introduce llvm config options Wang Nan
2015-07-21 11:13   ` [PATCH 12/39 update] " Wang Nan
2015-08-08  8:16     ` [tip:perf/core] " tip-bot for Wang Nan
2015-07-09 12:35 ` [PATCH 13/39] perf tools: Call clang to compile C source to object code Wang Nan
2015-07-09 12:35 ` [PATCH 14/39] perf tools: Auto detecting kernel build directory Wang Nan
2015-07-13 21:46   ` Arnaldo Carvalho de Melo
2015-07-14  6:56     ` Wangnan (F)
2015-07-14  7:16       ` Wangnan (F)
2015-07-09 12:35 ` [PATCH 15/39] perf tools: Auto detecting kernel include options Wang Nan
2015-08-08  8:17   ` [tip:perf/core] " tip-bot for Wang Nan
2015-07-09 12:35 ` [PATCH 16/39] perf tests: Add LLVM test for eBPF on-the-fly compiling Wang Nan
2015-07-15 10:54   ` [PATCH updated " Wang Nan
2015-07-22  4:46   ` [PATCH 16/39 RESEND] " Wang Nan
2015-07-09 12:35 ` [PATCH 17/39] perf tools: Make perf depend on libbpf Wang Nan
2015-07-09 12:35 ` [PATCH 18/39] perf record: Enable passing bpf object file to --event Wang Nan
2015-07-09 12:35 ` [PATCH 19/39] perf record: Compile scriptlets if pass '.c' " Wang Nan
2015-07-09 12:35 ` Wang Nan [this message]
2015-07-09 12:35 ` [PATCH 21/39] perf probe: Attach trace_probe_event with perf_probe_event Wang Nan
2015-07-09 12:35 ` [PATCH 22/39] perf record: Probe at kprobe points Wang Nan
2015-07-09 12:35 ` [PATCH 23/39] perf record: Load all eBPF object into kernel Wang Nan
2015-07-09 12:35 ` [PATCH 24/39] perf tools: Add bpf_fd field to evsel and config it Wang Nan
2015-07-09 12:35 ` [PATCH 25/39] perf tools: Attach eBPF program to perf event Wang Nan
2015-07-09 12:35 ` [PATCH 26/39] perf tools: Suppress probing messages when probing by BPF loading Wang Nan
2015-07-09 12:35 ` [PATCH 27/39] perf record: Add clang options for compiling BPF scripts Wang Nan
2015-07-09 12:35 ` [PATCH 28/39] bpf tools: Load a program with different instances using preprocessor Wang Nan
2015-07-13  5:44   ` Wangnan (F)
2015-07-09 12:35 ` [PATCH 29/39] perf tools: Fix probe-event.h include Wang Nan
2015-07-09 12:35 ` [PATCH 30/39] perf probe: Reset args and nargs for probe_trace_event when failure Wang Nan
2015-07-09 12:35 ` [PATCH 31/39] perf tools: Move linux/filter.h to tools/include Wang Nan
2015-07-09 12:35 ` [PATCH 32/39] perf tools: Add BPF_PROLOGUE config options for further patches Wang Nan
2015-07-09 12:35 ` [PATCH 33/39] perf tools: Introduce arch_get_reg_info() for x86 Wang Nan
2015-07-09 12:35 ` [PATCH 34/39] perf tools: Add prologue for BPF programs for fetching arguments Wang Nan
2015-07-09 12:35 ` [PATCH 35/39] perf tools: Generate prologue for BPF programs Wang Nan
2015-07-09 12:35 ` [PATCH 36/39] perf tools: Use same BPF program if arguments are identical Wang Nan
2015-07-09 12:35 ` [PATCH 37/39] perf record: Support custom vmlinux path Wang Nan
2015-07-09 12:35 ` [PATCH 38/39] perf probe: Init symbol as kprobe if any event is kprobe Wang Nan
2015-07-09 12:35 ` [PATCH 39/39] perf tools: Support attach BPF program on uprobe events Wang Nan
2015-07-14 15:36 ` perf test LLVM was: Re: [GIT PULL 00/39] perf tools: filtering events using eBPF programs Arnaldo Carvalho de Melo
2015-07-15 10:49   ` Wangnan (F)
2015-07-15 11:20     ` Arnaldo Carvalho de Melo
2015-07-17  2:34       ` Wangnan (F)
     [not found]         ` <CA+JHD93=ZMFP0gB1NqTXGBjTfSyYC-53Uj7r11gQJnKtQRKcDg@mail.gmail.com>
2015-07-21 11:09           ` Wangnan (F)
2015-07-21 11:41             ` Arnaldo Carvalho de Melo
2015-07-22  4:40               ` Wangnan (F)
2015-07-31 15:35                 ` perf eBPF patch ordering. was: " Arnaldo Carvalho de Melo
2015-07-31 20:31                   ` Arnaldo Carvalho de Melo
2015-08-03  2:37                     ` Wangnan (F)
2015-08-03 15:07                       ` Arnaldo Carvalho de Melo
2015-08-03 15:19                         ` Arnaldo Carvalho de Melo
2015-08-03 15:53                           ` pi3orama
2015-08-03 16:11                             ` Arnaldo Carvalho de Melo
2015-08-03 19:49                               ` Arnaldo Carvalho de Melo
2015-08-04  5:28                                 ` Wangnan (F)
2015-08-04 10:39                                   ` Wangnan (F)
2015-08-04 15:55                                     ` Arnaldo Carvalho de Melo
2015-08-04 16:11                                       ` Arnaldo Carvalho de Melo
2015-08-04 16:13                                         ` pi3orama
2015-08-06  1:44                                         ` Wangnan (F)
2015-08-06 14:46                                           ` Arnaldo Carvalho de Melo
2015-08-06 15:58                                             ` Arnaldo Carvalho de Melo

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