add javagc and memleak code

src/15-javagc/.gitignore

@@ -0,0 +1,8 @@
+.vscode
+package.json
+*.o
+*.skel.json
+*.skel.yaml
+package.yaml
+ecli
+javagc

src/15-javagc/Makefile

@@ -0,0 +1,141 @@
+# SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+OUTPUT := .output
+CLANG ?= clang
+LIBBPF_SRC := $(abspath ../../libbpf/src)
+BPFTOOL_SRC := $(abspath ../../bpftool/src)
+LIBBPF_OBJ := $(abspath $(OUTPUT)/libbpf.a)
+BPFTOOL_OUTPUT ?= $(abspath $(OUTPUT)/bpftool)
+BPFTOOL ?= $(BPFTOOL_OUTPUT)/bootstrap/bpftool
+LIBBLAZESYM_SRC := $(abspath ../../blazesym/)
+LIBBLAZESYM_OBJ := $(abspath $(OUTPUT)/libblazesym.a)
+LIBBLAZESYM_HEADER := $(abspath $(OUTPUT)/blazesym.h)
+ARCH ?= $(shell uname -m | sed 's/x86_64/x86/' \
+			 | sed 's/arm.*/arm/' \
+			 | sed 's/aarch64/arm64/' \
+			 | sed 's/ppc64le/powerpc/' \
+			 | sed 's/mips.*/mips/' \
+			 | sed 's/riscv64/riscv/' \
+			 | sed 's/loongarch64/loongarch/')
+VMLINUX := ../../vmlinux/$(ARCH)/vmlinux.h
+# Use our own libbpf API headers and Linux UAPI headers distributed with
+# libbpf to avoid dependency on system-wide headers, which could be missing or
+# outdated
+INCLUDES := -I$(OUTPUT) -I../../libbpf/include/uapi -I$(dir $(VMLINUX))
+CFLAGS := -g -Wall
+ALL_LDFLAGS := $(LDFLAGS) $(EXTRA_LDFLAGS)
+
+APPS = javagc # minimal minimal_legacy uprobe kprobe fentry usdt sockfilter tc ksyscall
+
+CARGO ?= $(shell which cargo)
+ifeq ($(strip $(CARGO)),)
+BZS_APPS :=
+else
+BZS_APPS := # profile
+APPS += $(BZS_APPS)
+# Required by libblazesym
+ALL_LDFLAGS += -lrt -ldl -lpthread -lm
+endif
+
+# Get Clang's default includes on this system. We'll explicitly add these dirs
+# to the includes list when compiling with `-target bpf` because otherwise some
+# architecture-specific dirs will be "missing" on some architectures/distros -
+# headers such as asm/types.h, asm/byteorder.h, asm/socket.h, asm/sockios.h,
+# sys/cdefs.h etc. might be missing.
+#
+# Use '-idirafter': Don't interfere with include mechanics except where the
+# build would have failed anyways.
+CLANG_BPF_SYS_INCLUDES ?= $(shell $(CLANG) -v -E - </dev/null 2>&1 \
+	| sed -n '/<...> search starts here:/,/End of search list./{ s| \(/.*\)|-idirafter \1|p }')
+
+ifeq ($(V),1)
+	Q =
+	msg =
+else
+	Q = @
+	msg = @printf '  %-8s %s%s\n'					\
+		      "$(1)"						\
+		      "$(patsubst $(abspath $(OUTPUT))/%,%,$(2))"	\
+		      "$(if $(3), $(3))";
+	MAKEFLAGS += --no-print-directory
+endif
+
+define allow-override
+  $(if $(or $(findstring environment,$(origin $(1))),\
+            $(findstring command line,$(origin $(1)))),,\
+    $(eval $(1) = $(2)))
+endef
+
+$(call allow-override,CC,$(CROSS_COMPILE)cc)
+$(call allow-override,LD,$(CROSS_COMPILE)ld)
+
+.PHONY: all
+all: $(APPS)
+
+.PHONY: clean
+clean:
+	$(call msg,CLEAN)
+	$(Q)rm -rf $(OUTPUT) $(APPS)
+
+$(OUTPUT) $(OUTPUT)/libbpf $(BPFTOOL_OUTPUT):
+	$(call msg,MKDIR,$@)
+	$(Q)mkdir -p $@
+
+# Build libbpf
+$(LIBBPF_OBJ): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(OUTPUT)/libbpf
+	$(call msg,LIB,$@)
+	$(Q)$(MAKE) -C $(LIBBPF_SRC) BUILD_STATIC_ONLY=1		      \
+		    OBJDIR=$(dir $@)/libbpf DESTDIR=$(dir $@)		      \
+		    INCLUDEDIR= LIBDIR= UAPIDIR=			      \
+		    install
+
+# Build bpftool
+$(BPFTOOL): | $(BPFTOOL_OUTPUT)
+	$(call msg,BPFTOOL,$@)
+	$(Q)$(MAKE) ARCH= CROSS_COMPILE= OUTPUT=$(BPFTOOL_OUTPUT)/ -C $(BPFTOOL_SRC) bootstrap
+
+
+$(LIBBLAZESYM_SRC)/target/release/libblazesym.a::
+	$(Q)cd $(LIBBLAZESYM_SRC) && $(CARGO) build --features=cheader,dont-generate-test-files --release
+
+$(LIBBLAZESYM_OBJ): $(LIBBLAZESYM_SRC)/target/release/libblazesym.a | $(OUTPUT)
+	$(call msg,LIB, $@)
+	$(Q)cp $(LIBBLAZESYM_SRC)/target/release/libblazesym.a $@
+
+$(LIBBLAZESYM_HEADER): $(LIBBLAZESYM_SRC)/target/release/libblazesym.a | $(OUTPUT)
+	$(call msg,LIB,$@)
+	$(Q)cp $(LIBBLAZESYM_SRC)/target/release/blazesym.h $@
+
+# Build BPF code
+$(OUTPUT)/%.bpf.o: %.bpf.c $(LIBBPF_OBJ) $(wildcard %.h) $(VMLINUX) | $(OUTPUT) $(BPFTOOL)
+	$(call msg,BPF,$@)
+	$(Q)$(CLANG) -g -O2 -target bpf -D__TARGET_ARCH_$(ARCH)		      \
+		     $(INCLUDES) $(CLANG_BPF_SYS_INCLUDES)		      \
+		     -c $(filter %.c,$^) -o $(patsubst %.bpf.o,%.tmp.bpf.o,$@)
+	$(Q)$(BPFTOOL) gen object $@ $(patsubst %.bpf.o,%.tmp.bpf.o,$@)
+
+# Generate BPF skeletons
+$(OUTPUT)/%.skel.h: $(OUTPUT)/%.bpf.o | $(OUTPUT) $(BPFTOOL)
+	$(call msg,GEN-SKEL,$@)
+	$(Q)$(BPFTOOL) gen skeleton $< > $@
+
+# Build user-space code
+$(patsubst %,$(OUTPUT)/%.o,$(APPS)): %.o: %.skel.h
+
+$(OUTPUT)/%.o: %.c $(wildcard %.h) | $(OUTPUT)
+	$(call msg,CC,$@)
+	$(Q)$(CC) $(CFLAGS) $(INCLUDES) -c $(filter %.c,$^) -o $@
+
+$(patsubst %,$(OUTPUT)/%.o,$(BZS_APPS)): $(LIBBLAZESYM_HEADER)
+
+$(BZS_APPS): $(LIBBLAZESYM_OBJ)
+
+# Build application binary
+$(APPS): %: $(OUTPUT)/%.o $(LIBBPF_OBJ) | $(OUTPUT)
+	$(call msg,BINARY,$@)
+	$(Q)$(CC) $(CFLAGS) $^ $(ALL_LDFLAGS) -lelf -lz -o $@
+
+# delete failed targets
+.DELETE_ON_ERROR:
+
+# keep intermediate (.skel.h, .bpf.o, etc) targets
+.SECONDARY:

src/15-javagc/README.md

@@ -1,3 +1,35 @@
 # eBPF 入门实践教程：使用 usdt 捕获用户态 Java GC 事件耗时
 
+## usdt 介绍
 
+TODO
+
+## java GC 
+
+TODO
+
+## 安装依赖
+
+构建示例需要 clang、libelf 和 zlib。包名在不同的发行版中可能会有所不同。
+
+在 Ubuntu/Debian 上，你需要执行以下命令：
+
+```shell
+sudo apt install clang libelf1 libelf-dev zlib1g-dev
+```
+
+在 CentOS/Fedora 上，你需要执行以下命令：
+
+```shell
+sudo dnf install clang elfutils-libelf elfutils-libelf-devel zlib-devel
+```
+
+## 编译运行
+
+编译运行上述代码：
+
+TODO
+
+## 总结
+
+TODO

src/15-javagc/javagc.bpf.c

@@ -0,0 +1,81 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+/* Copyright (c) 2022 Chen Tao */
+#include <vmlinux.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_core_read.h>
+#include <bpf/usdt.bpf.h>
+#include "javagc.h"
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(max_entries, 100);
+	__type(key, uint32_t);
+	__type(value, struct data_t);
+} data_map SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
+	__type(key, int);
+	__type(value, int);
+} perf_map SEC(".maps");
+
+__u32 time;
+
+static int gc_start(struct pt_regs *ctx)
+{
+	struct data_t data = {};
+
+	data.cpu = bpf_get_smp_processor_id();
+	data.pid = bpf_get_current_pid_tgid() >> 32;
+	data.ts = bpf_ktime_get_ns();
+	bpf_map_update_elem(&data_map, &data.pid, &data, 0);
+	return 0;
+}
+
+static int gc_end(struct pt_regs *ctx)
+{
+	struct data_t data = {};
+	struct data_t *p;
+	__u32 val;
+
+	data.cpu = bpf_get_smp_processor_id();
+	data.pid = bpf_get_current_pid_tgid() >> 32;
+	data.ts = bpf_ktime_get_ns();
+	p = bpf_map_lookup_elem(&data_map, &data.pid);
+	if (!p)
+		return 0;
+
+	val = data.ts - p->ts;
+	if (val > time) {
+		data.ts = val;
+		bpf_perf_event_output(ctx, &perf_map, BPF_F_CURRENT_CPU, &data, sizeof(data));
+	}
+	bpf_map_delete_elem(&data_map, &data.pid);
+	return 0;
+}
+
+SEC("usdt")
+int handle_gc_start(struct pt_regs *ctx)
+{
+	return gc_start(ctx);
+}
+
+SEC("usdt")
+int handle_gc_end(struct pt_regs *ctx)
+{
+	return gc_end(ctx);
+}
+
+SEC("usdt")
+int handle_mem_pool_gc_start(struct pt_regs *ctx)
+{
+	return gc_start(ctx);
+}
+
+SEC("usdt")
+int handle_mem_pool_gc_end(struct pt_regs *ctx)
+{
+	return gc_end(ctx);
+}
+
+char LICENSE[] SEC("license") = "Dual BSD/GPL";

src/15-javagc/javagc.c

@@ -0,0 +1,243 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+/*
+ * Copyright (c) 2022 Chen Tao
+ * Based on ugc from BCC by Sasha Goldshtein
+ * Create: Wed Jun 29 16:00:19 2022
+ */
+#include <stdio.h>
+#include <ctype.h>
+#include <argp.h>
+#include <signal.h>
+#include <unistd.h>
+#include <time.h>
+#include <sys/resource.h>
+#include <bpf/libbpf.h>
+#include <errno.h>
+#include "javagc.skel.h"
+#include "javagc.h"
+
+#define BINARY_PATH_SIZE (256)
+#define PERF_BUFFER_PAGES (32)
+#define PERF_POLL_TIMEOUT_MS (200)
+
+static struct env {
+	pid_t pid;
+	int time;
+	bool exiting;
+	bool verbose;
+} env = {
+	.pid = -1,
+	.time = 1000,
+	.exiting = false,
+	.verbose = false,
+};
+
+const char *argp_program_version = "javagc 0.1";
+const char *argp_program_bug_address =
+	"https://github.com/iovisor/bcc/tree/master/libbpf-tools";
+
+const char argp_program_doc[] =
+"Monitor javagc time cost.\n"
+"\n"
+"USAGE: javagc [--help] [-p PID] [-t GC time]\n"
+"\n"
+"EXAMPLES:\n"
+"javagc -p 185         # trace PID 185 only\n"
+"javagc -p 185 -t 100  # trace PID 185 java gc time beyond 100us\n";
+
+static const struct argp_option opts[] = {
+	{ "pid", 'p', "PID", 0, "Trace this PID only" },
+	{ "time", 't', "TIME", 0, "Java gc time" },
+	{ "verbose", 'v', NULL, 0, "Verbose debug output" },
+	{ NULL, 'h', NULL, OPTION_HIDDEN, "Show the full help" },
+	{},
+};
+
+static error_t parse_arg(int key, char *arg, struct argp_state *state)
+{
+	int err = 0;
+
+	switch (key) {
+	case 'h':
+		argp_state_help(state, stderr, ARGP_HELP_STD_HELP);
+		break;
+	case 'v':
+		env.verbose = true;
+		break;
+	case 'p':
+		errno = 0;
+		env.pid = strtol(arg, NULL, 10);
+		if (errno) {
+			err = errno;
+			fprintf(stderr, "invalid PID: %s\n", arg);
+			argp_usage(state);
+		}
+		break;
+	case 't':
+		errno = 0;
+		env.time = strtol(arg, NULL, 10);
+		if (errno) {
+			err = errno;
+			fprintf(stderr, "invalid time: %s\n", arg);
+			argp_usage(state);
+		}
+		break;
+	default:
+		return ARGP_ERR_UNKNOWN;
+	}
+	return err;
+}
+
+static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args)
+{
+	if (level == LIBBPF_DEBUG && ! env.verbose)
+		return 0;
+
+	return vfprintf(stderr, format, args);
+}
+
+static void handle_event(void *ctx, int cpu, void *data, __u32 data_sz)
+{
+	struct data_t *e = (struct data_t *)data;
+	struct tm *tm = NULL;
+	char ts[16];
+	time_t t;
+
+	time(&t);
+	tm = localtime(&t);
+	strftime(ts, sizeof(ts), "%H:%M:%S", tm);
+	printf("%-8s %-7d %-7d %-7lld\n", ts, e->cpu, e->pid, e->ts/1000);
+}
+
+static void handle_lost_events(void *ctx, int cpu, __u64 data_sz)
+{
+	printf("lost data\n");
+}
+
+static void sig_handler(int sig)
+{
+	env.exiting = true;
+}
+
+static int get_jvmso_path(char *path)
+{
+	char mode[16], line[128], buf[64];
+	size_t seg_start, seg_end, seg_off;
+	FILE *f;
+	int i = 0;
+
+	sprintf(buf, "/proc/%d/maps", env.pid);
+	f = fopen(buf, "r");
+	if (!f)
+		return -1;
+
+	while (fscanf(f, "%zx-%zx %s %zx %*s %*d%[^\n]\n",
+			&seg_start, &seg_end, mode, &seg_off, line) == 5) {
+		i = 0;
+		while (isblank(line[i]))
+			i++;
+		if (strstr(line + i, "libjvm.so")) {
+			break;
+		}
+	}
+
+	strcpy(path, line + i);
+	fclose(f);
+
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	static const struct argp argp = {
+		.options = opts,
+		.parser = parse_arg,
+		.doc = argp_program_doc,
+	};
+	char binary_path[BINARY_PATH_SIZE] = {0};
+	struct javagc_bpf *skel = NULL;
+	int err;
+	struct perf_buffer *pb = NULL;
+
+	err = argp_parse(&argp, argc, argv, 0, NULL, NULL);
+	if (err)
+		return err;
+
+	/*
+	* libbpf will auto load the so if it in /usr/lib64 /usr/lib etc,
+	* but the jvmso not there.
+	*/
+	err = get_jvmso_path(binary_path);
+	if (err)
+		return err;
+
+	libbpf_set_print(libbpf_print_fn);
+
+	skel = javagc_bpf__open();
+	if (!skel) {
+		fprintf(stderr, "Failed to open BPF skeleton\n");
+		return 1;
+	}
+	skel->bss->time = env.time * 1000;
+
+	err = javagc_bpf__load(skel);
+	if (err) {
+		fprintf(stderr, "Failed to load and verify BPF skeleton\n");
+		goto cleanup;
+	}
+
+	skel->links.handle_mem_pool_gc_start = bpf_program__attach_usdt(skel->progs.handle_gc_start, env.pid,
+									binary_path, "hotspot", "mem__pool__gc__begin", NULL);
+	if (!skel->links.handle_mem_pool_gc_start) {
+		err = errno;
+		fprintf(stderr, "attach usdt mem__pool__gc__begin failed: %s\n", strerror(err));
+		goto cleanup;
+	}
+
+	skel->links.handle_mem_pool_gc_end = bpf_program__attach_usdt(skel->progs.handle_gc_end, env.pid,
+								binary_path, "hotspot", "mem__pool__gc__end", NULL);
+	if (!skel->links.handle_mem_pool_gc_end) {
+		err = errno;
+		fprintf(stderr, "attach usdt mem__pool__gc__end failed: %s\n", strerror(err));
+		goto cleanup;
+	}
+
+	skel->links.handle_gc_start = bpf_program__attach_usdt(skel->progs.handle_gc_start, env.pid,
+									binary_path, "hotspot", "gc__begin", NULL);
+	if (!skel->links.handle_gc_start) {
+		err = errno;
+		fprintf(stderr, "attach usdt gc__begin failed: %s\n", strerror(err));
+		goto cleanup;
+	}
+
+	skel->links.handle_gc_end = bpf_program__attach_usdt(skel->progs.handle_gc_end, env.pid,
+				binary_path, "hotspot", "gc__end", NULL);
+	if (!skel->links.handle_gc_end) {
+		err = errno;
+		fprintf(stderr, "attach usdt gc__end failed: %s\n", strerror(err));
+		goto cleanup;
+	}
+
+	signal(SIGINT, sig_handler);
+	printf("Tracing javagc time... Hit Ctrl-C to end.\n");
+	printf("%-8s %-7s %-7s %-7s\n",
+	       "TIME", "CPU", "PID", "GC TIME");
+
+	pb = perf_buffer__new(bpf_map__fd(skel->maps.perf_map), PERF_BUFFER_PAGES,
+			handle_event, handle_lost_events, NULL, NULL);
+	while (!env.exiting) {
+		err = perf_buffer__poll(pb, PERF_POLL_TIMEOUT_MS);
+		if (err < 0 && err != -EINTR) {
+			fprintf(stderr, "error polling perf buffer: %s\n", strerror(-err));
+			goto cleanup;
+		}
+		/* reset err to return 0 if exiting */
+		err = 0;
+	}
+
+cleanup:
+	perf_buffer__free(pb);
+	javagc_bpf__destroy(skel);
+
+	return err != 0;
+}

src/15-javagc/javagc.h

@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+/* Copyright (c) 2022 Chen Tao */
+#ifndef __JAVAGC_H
+#define __JAVAGC_H
+
+struct data_t {
+    __u32 cpu;
+    __u32 pid;
+    __u64 ts;
+};
+
+#endif /* __JAVAGC_H */