Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf updates from Ingo Molnar:
 "Main perf kernel side changes:

   - uprobes updates/fixes.  (Oleg Nesterov)

   - Add PERF_RECORD_SWITCH to indicate context switches and use it in
     tooling.  (Adrian Hunter)

   - Support BPF programs attached to uprobes and first steps for BPF
     tooling support.  (Wang Nan)

   - x86 generic x86 MSR-to-perf PMU driver.  (Andy Lutomirski)

   - x86 Intel PT, LBR and BTS updates.  (Alexander Shishkin)

   - x86 Intel Skylake support.  (Andi Kleen)

   - x86 Intel Knights Landing (KNL) RAPL support.  (Dasaratharaman
     Chandramouli)

   - x86 Intel Broadwell-DE uncore support.  (Kan Liang)

   - x86 hw breakpoints robustization (Andy Lutomirski)

  Main perf tooling side changes:

   - Support Intel PT in several tools, enabling the use of the
     processor trace feature introduced in Intel Broadwell processors:
     (Adrian Hunter)

       # dmesg | grep Performance
       # [0.188477] Performance Events: PEBS fmt2+, 16-deep LBR, Broadwell events, full-width counters, Intel PMU driver.
       # perf record -e intel_pt//u -a sleep 1
       [ perf record: Woken up 1 times to write data ]
       [ perf record: Captured and wrote 0.216 MB perf.data ]
       # perf script # then navigate in the tool output to some area, like this one:
       184 1030 dl_main (/usr/lib64/ld-2.17.so) => 7f21ba661440 dl_main (/usr/lib64/ld-2.17.so)
       185 1457 dl_main (/usr/lib64/ld-2.17.so) => 7f21ba669f10 _dl_new_object (/usr/lib64/ld-2.17.so)
       186 9f37 _dl_new_object (/usr/lib64/ld-2.17.so) => 7f21ba677b90 strlen (/usr/lib64/ld-2.17.so)
       187 7ba3 strlen (/usr/lib64/ld-2.17.so) => 7f21ba677c75 strlen (/usr/lib64/ld-2.17.so)
       188 7c78 strlen (/usr/lib64/ld-2.17.so) => 7f21ba669f3c _dl_new_object (/usr/lib64/ld-2.17.so)
       189 9f8a _dl_new_object (/usr/lib64/ld-2.17.so) => 7f21ba65fab0 calloc@plt (/usr/lib64/ld-2.17.so)
       190 fab0 calloc@plt (/usr/lib64/ld-2.17.so) => 7f21ba675e70 calloc (/usr/lib64/ld-2.17.so)
       191 5e87 calloc (/usr/lib64/ld-2.17.so) => 7f21ba65fa90 malloc@plt (/usr/lib64/ld-2.17.so)
       192 fa90 malloc@plt (/usr/lib64/ld-2.17.so) => 7f21ba675e60 malloc (/usr/lib64/ld-2.17.so)
       193 5e68 malloc (/usr/lib64/ld-2.17.so) => 7f21ba65fa80 __libc_memalign@plt (/usr/lib64/ld-2.17.so)
       194 fa80 __libc_memalign@plt (/usr/lib64/ld-2.17.so) => 7f21ba675d50 __libc_memalign (/usr/lib64/ld-2.17.so)
       195 5d63 __libc_memalign (/usr/lib64/ld-2.17.so) => 7f21ba675e20 __libc_memalign (/usr/lib64/ld-2.17.so)
       196 5e40 __libc_memalign (/usr/lib64/ld-2.17.so) => 7f21ba675d73 __libc_memalign (/usr/lib64/ld-2.17.so)
       197 5d97 __libc_memalign (/usr/lib64/ld-2.17.so) => 7f21ba675e18 __libc_memalign (/usr/lib64/ld-2.17.so)
       198 5e1e __libc_memalign (/usr/lib64/ld-2.17.so) => 7f21ba675df9 __libc_memalign (/usr/lib64/ld-2.17.so)
       199 5e10 __libc_memalign (/usr/lib64/ld-2.17.so) => 7f21ba669f8f _dl_new_object (/usr/lib64/ld-2.17.so)
       200 9fc2 _dl_new_object (/usr/lib64/ld-2.17.so) =>  7f21ba678e70 memcpy (/usr/lib64/ld-2.17.so)
       201 8e8c memcpy (/usr/lib64/ld-2.17.so) => 7f21ba678ea0 memcpy (/usr/lib64/ld-2.17.so)

   - Add support for using several Intel PT features (CYC, MTC packets),
     the relevant documentation was updated in:
         tools/perf/Documentation/intel-pt.txt
     briefly describing those packets, its purposes, how to configure
     them in the event config terms and relevant external documentation
     for further reading.  (Adrian Hunter)

   - Introduce support for probing at an absolute address, for user and
     kernel 'perf probe's, useful when one have the symbol maps on a
     developer machine but not on an embedded system.  (Wang Nan)

   - Add Intel BTS support, with a call-graph script to show it and PT
     in use in a GUI using 'perf script' python scripting with
     postgresql and Qt.  (Adrian Hunter)

   - Allow selecting the type of callchains per event, including
     disabling callchains in all but one entry in an event list, to save
     space, and also to ask for the callchains collected in one event to
     be used in other events.  (Kan Liang)

   - Beautify more syscall arguments in 'perf trace': (Arnaldo Carvalho
     de Melo)
       * A bunch more translate file/pathnames from pointers to strings.
       * Convert numbers to strings for the 'keyctl' syscall 'option'
         arg.
       * Add missing 'clockid' entries.

   - Introduce 'srcfile' sort key: (Andi Kleen)

       # perf record -F 10000 usleep 1
       # perf report --stdio --dsos '[kernel.vmlinux]' -s srcfile
       <SNIP>
       # Overhead  Source File
          26.49%  copy_page_64.S
           5.49%  signal.c
           0.51%  msr.h
       #

     It can be combined with other fields, for instance, experiment with
     '-s srcfile,symbol'.

     There are some oddities in some distros and with some specific
     DSOs, being investigated, so your mileage may vary.

   - Support per-event 'freq' term: (Namhyung Kim)

       $ perf record -e 'cpu/instructions,freq=1234/',cycles -c 1000 sleep 1
       $ perf evlist -F
       cpu/instructions,freq=1234/: sample_freq=1234
       cycles: sample_period=1000
       $

   - Deref sys_enter pointer args with contents from probe:vfs_getname,
     showing pathnames instead of pointers in many syscalls in 'perf
     trace'.  (Arnaldo Carvalho de Melo)

   - Stop collecting /proc/kallsyms in perf.data files, saving about
     4.5MB on a typical x86-64 system, use the the symbol resolution
     routines used in all the other tools (report, top, etc) now that we
     can ask libtraceevent to use perf's symbol resolution code.
     (Arnaldo Carvalho de Melo)

   - Allow filtering out of perf's PID via 'perf record --exclude-perf'.
     (Wang Nan)

   - 'perf trace' now supports syscall groups, like strace, i.e:

       $ trace -e file touch file

     Will expand 'file' into multiple, file related, syscalls.  More
     work needed to add extra groups for other syscall groups, and also
     to complement what was added for the 'file' group, included as a
     proof of concept.  (Arnaldo Carvalho de Melo)

   - Add lock_pi stresser to 'perf bench futex', to test the kernel code
     related to FUTEX_(UN)LOCK_PI.  (Davidlohr Bueso)

   - Let user have timestamps with per-thread recording in 'perf record'
     (Adrian Hunter)

   - ... and tons of other changes, see the shortlog and the Git log for
     details"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (240 commits)
  perf evlist: Add backpointer for perf_env to evlist
  perf tools: Rename perf_session_env to perf_env
  perf tools: Do not change lib/api/fs/debugfs directly
  perf tools: Add tracing_path and remove unneeded functions
  perf buildid: Introduce sysfs/filename__sprintf_build_id
  perf evsel: Add a backpointer to the evlist a evsel is in
  perf trace: Add header with copyright and background info
  perf scripts python: Add new compaction-times script
  perf stat: Get correct cpu id for print_aggr
  tools lib traceeveent: Allow for negative numbers in print format
  perf script: Add --[no-]-demangle/--[no-]-demangle-kernel
  tracing/uprobes: Do not print '0x (null)' when offset is 0
  perf probe: Support probing at absolute address
  perf probe: Fix error reported when offset without function
  perf probe: Fix list result when address is zero
  perf probe: Fix list result when symbol can't be found
  tools build: Allow duplicate objects in the object list
  perf tools: Remove export.h from MANIFEST
  perf probe: Prevent segfault when reading probe point with absolute address
  perf tools: Update Intel PT documentation
  ...

10 files changed, 1522 insertions, 3 deletions

diff --git a/tools/lib/api/fs/debugfs.c b/tools/lib/api/fs/debugfs.c
index 8305b3e9d48e..eb7cf4d18f8a 100644
--- a/tools/lib/api/fs/debugfs.c
+++ b/tools/lib/api/fs/debugfs.c
@@ -12,6 +12,7 @@
 #include <linux/kernel.h>
 
 #include "debugfs.h"
+#include "tracefs.h"
 
 #ifndef DEBUGFS_DEFAULT_PATH
 #define DEBUGFS_DEFAULT_PATH		"/sys/kernel/debug"
@@ -94,11 +95,21 @@ int debugfs__strerror_open(int err, char *buf, size_t size, const char *filename
 			 "Hint:\tIs the debugfs filesystem mounted?\n"
 			 "Hint:\tTry 'sudo mount -t debugfs nodev /sys/kernel/debug'");
 		break;
-	case EACCES:
+	case EACCES: {
+		const char *mountpoint = debugfs_mountpoint;
+
+		if (!access(debugfs_mountpoint, R_OK) && strncmp(filename, "tracing/", 8) == 0) {
+			const char *tracefs_mntpoint = tracefs_find_mountpoint();
+
+			if (tracefs_mntpoint)
+				mountpoint = tracefs_mntpoint;
+		}
+
 		snprintf(buf, size,
 			 "Error:\tNo permissions to read %s/%s\n"
 			 "Hint:\tTry 'sudo mount -o remount,mode=755 %s'\n",
-			 debugfs_mountpoint, filename, debugfs_mountpoint);
+			 debugfs_mountpoint, filename, mountpoint);
+	}
 		break;
 	default:
 		snprintf(buf, size, "%s", strerror_r(err, sbuf, sizeof(sbuf)));
diff --git a/tools/lib/bpf/.gitignore b/tools/lib/bpf/.gitignore
new file mode 100644
index 000000000000..812aeedaea38
--- /dev/null
+++ b/tools/lib/bpf/.gitignore
@@ -0,0 +1,2 @@
+libbpf_version.h
+FEATURE-DUMP
diff --git a/tools/lib/bpf/Build b/tools/lib/bpf/Build
new file mode 100644
index 000000000000..d8749756352d
--- /dev/null
+++ b/tools/lib/bpf/Build
@@ -0,0 +1 @@
+libbpf-y := libbpf.o bpf.o
diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
new file mode 100644
index 000000000000..f68d23a0b487
--- /dev/null
+++ b/tools/lib/bpf/Makefile
@@ -0,0 +1,195 @@
+# Most of this file is copied from tools/lib/traceevent/Makefile
+
+BPF_VERSION = 0
+BPF_PATCHLEVEL = 0
+BPF_EXTRAVERSION = 1
+
+MAKEFLAGS += --no-print-directory
+
+
+# Makefiles suck: This macro sets a default value of $(2) for the
+# variable named by $(1), unless the variable has been set by
+# environment or command line. This is necessary for CC and AR
+# because make sets default values, so the simpler ?= approach
+# won't work as expected.
+define allow-override
+  $(if $(or $(findstring environment,$(origin $(1))),\
+            $(findstring command line,$(origin $(1)))),,\
+    $(eval $(1) = $(2)))
+endef
+
+# Allow setting CC and AR, or setting CROSS_COMPILE as a prefix.
+$(call allow-override,CC,$(CROSS_COMPILE)gcc)
+$(call allow-override,AR,$(CROSS_COMPILE)ar)
+
+INSTALL = install
+
+# Use DESTDIR for installing into a different root directory.
+# This is useful for building a package. The program will be
+# installed in this directory as if it was the root directory.
+# Then the build tool can move it later.
+DESTDIR ?=
+DESTDIR_SQ = '$(subst ','\'',$(DESTDIR))'
+
+LP64 := $(shell echo __LP64__ | ${CC} ${CFLAGS} -E -x c - | tail -n 1)
+ifeq ($(LP64), 1)
+  libdir_relative = lib64
+else
+  libdir_relative = lib
+endif
+
+prefix ?= /usr/local
+libdir = $(prefix)/$(libdir_relative)
+man_dir = $(prefix)/share/man
+man_dir_SQ = '$(subst ','\'',$(man_dir))'
+
+export man_dir man_dir_SQ INSTALL
+export DESTDIR DESTDIR_SQ
+
+include ../../scripts/Makefile.include
+
+# copy a bit from Linux kbuild
+
+ifeq ("$(origin V)", "command line")
+  VERBOSE = $(V)
+endif
+ifndef VERBOSE
+  VERBOSE = 0
+endif
+
+ifeq ($(srctree),)
+srctree := $(patsubst %/,%,$(dir $(shell pwd)))
+srctree := $(patsubst %/,%,$(dir $(srctree)))
+srctree := $(patsubst %/,%,$(dir $(srctree)))
+#$(info Determined 'srctree' to be $(srctree))
+endif
+
+FEATURE_DISPLAY = libelf libelf-getphdrnum libelf-mmap bpf
+FEATURE_TESTS = libelf bpf
+
+INCLUDES = -I. -I$(srctree)/tools/include -I$(srctree)/arch/$(ARCH)/include/uapi -I$(srctree)/include/uapi
+FEATURE_CHECK_CFLAGS-bpf = $(INCLUDES)
+
+include $(srctree)/tools/build/Makefile.feature
+
+export prefix libdir src obj
+
+# Shell quotes
+libdir_SQ = $(subst ','\'',$(libdir))
+libdir_relative_SQ = $(subst ','\'',$(libdir_relative))
+plugin_dir_SQ = $(subst ','\'',$(plugin_dir))
+
+LIB_FILE = libbpf.a libbpf.so
+
+VERSION		= $(BPF_VERSION)
+PATCHLEVEL	= $(BPF_PATCHLEVEL)
+EXTRAVERSION	= $(BPF_EXTRAVERSION)
+
+OBJ		= $@
+N		=
+
+LIBBPF_VERSION = $(BPF_VERSION).$(BPF_PATCHLEVEL).$(BPF_EXTRAVERSION)
+
+# Set compile option CFLAGS
+ifdef EXTRA_CFLAGS
+  CFLAGS := $(EXTRA_CFLAGS)
+else
+  CFLAGS := -g -Wall
+endif
+
+ifeq ($(feature-libelf-mmap), 1)
+  override CFLAGS += -DHAVE_LIBELF_MMAP_SUPPORT
+endif
+
+ifeq ($(feature-libelf-getphdrnum), 1)
+  override CFLAGS += -DHAVE_ELF_GETPHDRNUM_SUPPORT
+endif
+
+# Append required CFLAGS
+override CFLAGS += $(EXTRA_WARNINGS)
+override CFLAGS += -Werror -Wall
+override CFLAGS += -fPIC
+override CFLAGS += $(INCLUDES)
+
+ifeq ($(VERBOSE),1)
+  Q =
+else
+  Q = @
+endif
+
+# Disable command line variables (CFLAGS) overide from top
+# level Makefile (perf), otherwise build Makefile will get
+# the same command line setup.
+MAKEOVERRIDES=
+
+export srctree OUTPUT CC LD CFLAGS V
+build := -f $(srctree)/tools/build/Makefile.build dir=. obj
+
+BPF_IN    := $(OUTPUT)libbpf-in.o
+LIB_FILE := $(addprefix $(OUTPUT),$(LIB_FILE))
+
+CMD_TARGETS = $(LIB_FILE)
+
+TARGETS = $(CMD_TARGETS)
+
+all: $(VERSION_FILES) all_cmd
+
+all_cmd: $(CMD_TARGETS)
+
+$(BPF_IN): force elfdep bpfdep
+	$(Q)$(MAKE) $(build)=libbpf
+
+$(OUTPUT)libbpf.so: $(BPF_IN)
+	$(QUIET_LINK)$(CC) --shared $^ -o $@
+
+$(OUTPUT)libbpf.a: $(BPF_IN)
+	$(QUIET_LINK)$(RM) $@; $(AR) rcs $@ $^
+
+define update_dir
+  (echo $1 > $@.tmp;				\
+   if [ -r $@ ] && cmp -s $@ $@.tmp; then	\
+     rm -f $@.tmp;				\
+   else						\
+     echo '  UPDATE                 $@';	\
+     mv -f $@.tmp $@;				\
+   fi);
+endef
+
+define do_install
+	if [ ! -d '$(DESTDIR_SQ)$2' ]; then		\
+		$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$2';	\
+	fi;						\
+	$(INSTALL) $1 '$(DESTDIR_SQ)$2'
+endef
+
+install_lib: all_cmd
+	$(call QUIET_INSTALL, $(LIB_FILE)) \
+		$(call do_install,$(LIB_FILE),$(libdir_SQ))
+
+install: install_lib
+
+### Cleaning rules
+
+config-clean:
+	$(call QUIET_CLEAN, config)
+	$(Q)$(MAKE) -C $(srctree)/tools/build/feature/ clean >/dev/null
+
+clean:
+	$(call QUIET_CLEAN, libbpf) $(RM) *.o *~ $(TARGETS) *.a *.so $(VERSION_FILES) .*.d \
+		$(RM) LIBBPF-CFLAGS
+	$(call QUIET_CLEAN, core-gen) $(RM) $(OUTPUT)FEATURE-DUMP
+
+
+
+PHONY += force elfdep bpfdep
+force:
+
+elfdep:
+	@if [ "$(feature-libelf)" != "1" ]; then echo "No libelf found"; exit -1 ; fi
+
+bpfdep:
+	@if [ "$(feature-bpf)" != "1" ]; then echo "BPF API too old"; exit -1 ; fi
+
+# Declare the contents of the .PHONY variable as phony.  We keep that
+# information in a variable so we can use it in if_changed and friends.
+.PHONY: $(PHONY)
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
new file mode 100644
index 000000000000..a6331050ab79
--- /dev/null
+++ b/tools/lib/bpf/bpf.c
@@ -0,0 +1,85 @@
+/*
+ * common eBPF ELF operations.
+ *
+ * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
+ * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
+ * Copyright (C) 2015 Huawei Inc.
+ */
+
+#include <stdlib.h>
+#include <memory.h>
+#include <unistd.h>
+#include <asm/unistd.h>
+#include <linux/bpf.h>
+#include "bpf.h"
+
+/*
+ * When building perf, unistd.h is override. Define __NR_bpf is
+ * required to be defined.
+ */
+#ifndef __NR_bpf
+# if defined(__i386__)
+#  define __NR_bpf 357
+# elif defined(__x86_64__)
+#  define __NR_bpf 321
+# elif defined(__aarch64__)
+#  define __NR_bpf 280
+# else
+#  error __NR_bpf not defined. libbpf does not support your arch.
+# endif
+#endif
+
+static __u64 ptr_to_u64(void *ptr)
+{
+	return (__u64) (unsigned long) ptr;
+}
+
+static int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr,
+		   unsigned int size)
+{
+	return syscall(__NR_bpf, cmd, attr, size);
+}
+
+int bpf_create_map(enum bpf_map_type map_type, int key_size,
+		   int value_size, int max_entries)
+{
+	union bpf_attr attr;
+
+	memset(&attr, '\0', sizeof(attr));
+
+	attr.map_type = map_type;
+	attr.key_size = key_size;
+	attr.value_size = value_size;
+	attr.max_entries = max_entries;
+
+	return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
+}
+
+int bpf_load_program(enum bpf_prog_type type, struct bpf_insn *insns,
+		     size_t insns_cnt, char *license,
+		     u32 kern_version, char *log_buf, size_t log_buf_sz)
+{
+	int fd;
+	union bpf_attr attr;
+
+	bzero(&attr, sizeof(attr));
+	attr.prog_type = type;
+	attr.insn_cnt = (__u32)insns_cnt;
+	attr.insns = ptr_to_u64(insns);
+	attr.license = ptr_to_u64(license);
+	attr.log_buf = ptr_to_u64(NULL);
+	attr.log_size = 0;
+	attr.log_level = 0;
+	attr.kern_version = kern_version;
+
+	fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
+	if (fd >= 0 || !log_buf || !log_buf_sz)
+		return fd;
+
+	/* Try again with log */
+	attr.log_buf = ptr_to_u64(log_buf);
+	attr.log_size = log_buf_sz;
+	attr.log_level = 1;
+	log_buf[0] = 0;
+	return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
+}
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
new file mode 100644
index 000000000000..854b7361b784
--- /dev/null
+++ b/tools/lib/bpf/bpf.h
@@ -0,0 +1,23 @@
+/*
+ * common eBPF ELF operations.
+ *
+ * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
+ * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
+ * Copyright (C) 2015 Huawei Inc.
+ */
+#ifndef __BPF_BPF_H
+#define __BPF_BPF_H
+
+#include <linux/bpf.h>
+
+int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size,
+		   int max_entries);
+
+/* Recommend log buffer size */
+#define BPF_LOG_BUF_SIZE 65536
+int bpf_load_program(enum bpf_prog_type type, struct bpf_insn *insns,
+		     size_t insns_cnt, char *license,
+		     u32 kern_version, char *log_buf,
+		     size_t log_buf_sz);
+
+#endif
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
new file mode 100644
index 000000000000..4fa4bc4505f5
--- /dev/null
+++ b/tools/lib/bpf/libbpf.c
@@ -0,0 +1,1037 @@
+/*
+ * Common eBPF ELF object loading operations.
+ *
+ * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
+ * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
+ * Copyright (C) 2015 Huawei Inc.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <inttypes.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <asm/unistd.h>
+#include <linux/kernel.h>
+#include <linux/bpf.h>
+#include <linux/list.h>
+#include <libelf.h>
+#include <gelf.h>
+
+#include "libbpf.h"
+#include "bpf.h"
+
+#define __printf(a, b)	__attribute__((format(printf, a, b)))
+
+__printf(1, 2)
+static int __base_pr(const char *format, ...)
+{
+	va_list args;
+	int err;
+
+	va_start(args, format);
+	err = vfprintf(stderr, format, args);
+	va_end(args);
+	return err;
+}
+
+static __printf(1, 2) libbpf_print_fn_t __pr_warning = __base_pr;
+static __printf(1, 2) libbpf_print_fn_t __pr_info = __base_pr;
+static __printf(1, 2) libbpf_print_fn_t __pr_debug;
+
+#define __pr(func, fmt, ...)	\
+do {				\
+	if ((func))		\
+		(func)("libbpf: " fmt, ##__VA_ARGS__); \
+} while (0)
+
+#define pr_warning(fmt, ...)	__pr(__pr_warning, fmt, ##__VA_ARGS__)
+#define pr_info(fmt, ...)	__pr(__pr_info, fmt, ##__VA_ARGS__)
+#define pr_debug(fmt, ...)	__pr(__pr_debug, fmt, ##__VA_ARGS__)
+
+void libbpf_set_print(libbpf_print_fn_t warn,
+		      libbpf_print_fn_t info,
+		      libbpf_print_fn_t debug)
+{
+	__pr_warning = warn;
+	__pr_info = info;
+	__pr_debug = debug;
+}
+
+/* Copied from tools/perf/util/util.h */
+#ifndef zfree
+# define zfree(ptr) ({ free(*ptr); *ptr = NULL; })
+#endif
+
+#ifndef zclose
+# define zclose(fd) ({			\
+	int ___err = 0;			\
+	if ((fd) >= 0)			\
+		___err = close((fd));	\
+	fd = -1;			\
+	___err; })
+#endif
+
+#ifdef HAVE_LIBELF_MMAP_SUPPORT
+# define LIBBPF_ELF_C_READ_MMAP ELF_C_READ_MMAP
+#else
+# define LIBBPF_ELF_C_READ_MMAP ELF_C_READ
+#endif
+
+/*
+ * bpf_prog should be a better name but it has been used in
+ * linux/filter.h.
+ */
+struct bpf_program {
+	/* Index in elf obj file, for relocation use. */
+	int idx;
+	char *section_name;
+	struct bpf_insn *insns;
+	size_t insns_cnt;
+
+	struct {
+		int insn_idx;
+		int map_idx;
+	} *reloc_desc;
+	int nr_reloc;
+
+	int fd;
+
+	struct bpf_object *obj;
+	void *priv;
+	bpf_program_clear_priv_t clear_priv;
+};
+
+static LIST_HEAD(bpf_objects_list);
+
+struct bpf_object {
+	char license[64];
+	u32 kern_version;
+	void *maps_buf;
+	size_t maps_buf_sz;
+
+	struct bpf_program *programs;
+	size_t nr_programs;
+	int *map_fds;
+	/*
+	 * This field is required because maps_buf will be freed and
+	 * maps_buf_sz will be set to 0 after loaded.
+	 */
+	size_t nr_map_fds;
+	bool loaded;
+
+	/*
+	 * Information when doing elf related work. Only valid if fd
+	 * is valid.
+	 */
+	struct {
+		int fd;
+		void *obj_buf;
+		size_t obj_buf_sz;
+		Elf *elf;
+		GElf_Ehdr ehdr;
+		Elf_Data *symbols;
+		struct {
+			GElf_Shdr shdr;
+			Elf_Data *data;
+		} *reloc;
+		int nr_reloc;
+	} efile;
+	/*
+	 * All loaded bpf_object is linked in a list, which is
+	 * hidden to caller. bpf_objects__<func> handlers deal with
+	 * all objects.
+	 */
+	struct list_head list;
+	char path[];
+};
+#define obj_elf_valid(o)	((o)->efile.elf)
+
+static void bpf_program__unload(struct bpf_program *prog)
+{
+	if (!prog)
+		return;
+
+	zclose(prog->fd);
+}
+
+static void bpf_program__exit(struct bpf_program *prog)
+{
+	if (!prog)
+		return;
+
+	if (prog->clear_priv)
+		prog->clear_priv(prog, prog->priv);
+
+	prog->priv = NULL;
+	prog->clear_priv = NULL;
+
+	bpf_program__unload(prog);
+	zfree(&prog->section_name);
+	zfree(&prog->insns);
+	zfree(&prog->reloc_desc);
+
+	prog->nr_reloc = 0;
+	prog->insns_cnt = 0;
+	prog->idx = -1;
+}
+
+static int
+bpf_program__init(void *data, size_t size, char *name, int idx,
+		    struct bpf_program *prog)
+{
+	if (size < sizeof(struct bpf_insn)) {
+		pr_warning("corrupted section '%s'\n", name);
+		return -EINVAL;
+	}
+
+	bzero(prog, sizeof(*prog));
+
+	prog->section_name = strdup(name);
+	if (!prog->section_name) {
+		pr_warning("failed to alloc name for prog %s\n",
+			   name);
+		goto errout;
+	}
+
+	prog->insns = malloc(size);
+	if (!prog->insns) {
+		pr_warning("failed to alloc insns for %s\n", name);
+		goto errout;
+	}
+	prog->insns_cnt = size / sizeof(struct bpf_insn);
+	memcpy(prog->insns, data,
+	       prog->insns_cnt * sizeof(struct bpf_insn));
+	prog->idx = idx;
+	prog->fd = -1;
+
+	return 0;
+errout:
+	bpf_program__exit(prog);
+	return -ENOMEM;
+}
+
+static int
+bpf_object__add_program(struct bpf_object *obj, void *data, size_t size,
+			char *name, int idx)
+{
+	struct bpf_program prog, *progs;
+	int nr_progs, err;
+
+	err = bpf_program__init(data, size, name, idx, &prog);
+	if (err)
+		return err;
+
+	progs = obj->programs;
+	nr_progs = obj->nr_programs;
+
+	progs = realloc(progs, sizeof(progs[0]) * (nr_progs + 1));
+	if (!progs) {
+		/*
+		 * In this case the original obj->programs
+		 * is still valid, so don't need special treat for
+		 * bpf_close_object().
+		 */
+		pr_warning("failed to alloc a new program '%s'\n",
+			   name);
+		bpf_program__exit(&prog);
+		return -ENOMEM;
+	}
+
+	pr_debug("found program %s\n", prog.section_name);
+	obj->programs = progs;
+	obj->nr_programs = nr_progs + 1;
+	prog.obj = obj;
+	progs[nr_progs] = prog;
+	return 0;
+}
+
+static struct bpf_object *bpf_object__new(const char *path,
+					  void *obj_buf,
+					  size_t obj_buf_sz)
+{
+	struct bpf_object *obj;
+
+	obj = calloc(1, sizeof(struct bpf_object) + strlen(path) + 1);
+	if (!obj) {
+		pr_warning("alloc memory failed for %s\n", path);
+		return NULL;
+	}
+
+	strcpy(obj->path, path);
+	obj->efile.fd = -1;
+
+	/*
+	 * Caller of this function should also calls
+	 * bpf_object__elf_finish() after data collection to return
+	 * obj_buf to user. If not, we should duplicate the buffer to
+	 * avoid user freeing them before elf finish.
+	 */
+	obj->efile.obj_buf = obj_buf;
+	obj->efile.obj_buf_sz = obj_buf_sz;
+
+	obj->loaded = false;
+
+	INIT_LIST_HEAD(&obj->list);
+	list_add(&obj->list, &bpf_objects_list);
+	return obj;
+}
+
+static void bpf_object__elf_finish(struct bpf_object *obj)
+{
+	if (!obj_elf_valid(obj))
+		return;
+
+	if (obj->efile.elf) {
+		elf_end(obj->efile.elf);
+		obj->efile.elf = NULL;
+	}
+	obj->efile.symbols = NULL;
+
+	zfree(&obj->efile.reloc);
+	obj->efile.nr_reloc = 0;
+	zclose(obj->efile.fd);
+	obj->efile.obj_buf = NULL;
+	obj->efile.obj_buf_sz = 0;
+}
+
+static int bpf_object__elf_init(struct bpf_object *obj)
+{
+	int err = 0;
+	GElf_Ehdr *ep;
+
+	if (obj_elf_valid(obj)) {
+		pr_warning("elf init: internal error\n");
+		return -EEXIST;
+	}
+
+	if (obj->efile.obj_buf_sz > 0) {
+		/*
+		 * obj_buf should have been validated by
+		 * bpf_object__open_buffer().
+		 */
+		obj->efile.elf = elf_memory(obj->efile.obj_buf,
+					    obj->efile.obj_buf_sz);
+	} else {
+		obj->efile.fd = open(obj->path, O_RDONLY);
+		if (obj->efile.fd < 0) {
+			pr_warning("failed to open %s: %s\n", obj->path,
+					strerror(errno));
+			return -errno;
+		}
+
+		obj->efile.elf = elf_begin(obj->efile.fd,
+				LIBBPF_ELF_C_READ_MMAP,
+				NULL);
+	}
+
+	if (!obj->efile.elf) {
+		pr_warning("failed to open %s as ELF file\n",
+				obj->path);
+		err = -EINVAL;
+		goto errout;
+	}
+
+	if (!gelf_getehdr(obj->efile.elf, &obj->efile.ehdr)) {
+		pr_warning("failed to get EHDR from %s\n",
+				obj->path);
+		err = -EINVAL;
+		goto errout;
+	}
+	ep = &obj->efile.ehdr;
+
+	if ((ep->e_type != ET_REL) || (ep->e_machine != 0)) {
+		pr_warning("%s is not an eBPF object file\n",
+			obj->path);
+		err = -EINVAL;
+		goto errout;
+	}
+
+	return 0;
+errout:
+	bpf_object__elf_finish(obj);
+	return err;
+}
+
+static int
+bpf_object__check_endianness(struct bpf_object *obj)
+{
+	static unsigned int const endian = 1;
+
+	switch (obj->efile.ehdr.e_ident[EI_DATA]) {
+	case ELFDATA2LSB:
+		/* We are big endian, BPF obj is little endian. */
+		if (*(unsigned char const *)&endian != 1)
+			goto mismatch;
+		break;
+
+	case ELFDATA2MSB:
+		/* We are little endian, BPF obj is big endian. */
+		if (*(unsigned char const *)&endian != 0)
+			goto mismatch;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+
+mismatch:
+	pr_warning("Error: endianness mismatch.\n");
+	return -EINVAL;
+}
+
+static int
+bpf_object__init_license(struct bpf_object *obj,
+			 void *data, size_t size)
+{
+	memcpy(obj->license, data,
+	       min(size, sizeof(obj->license) - 1));
+	pr_debug("license of %s is %s\n", obj->path, obj->license);
+	return 0;
+}
+
+static int
+bpf_object__init_kversion(struct bpf_object *obj,
+			  void *data, size_t size)
+{
+	u32 kver;
+
+	if (size != sizeof(kver)) {
+		pr_warning("invalid kver section in %s\n", obj->path);
+		return -EINVAL;
+	}
+	memcpy(&kver, data, sizeof(kver));
+	obj->kern_version = kver;
+	pr_debug("kernel version of %s is %x\n", obj->path,
+		 obj->kern_version);
+	return 0;
+}
+
+static int
+bpf_object__init_maps(struct bpf_object *obj, void *data,
+		      size_t size)
+{
+	if (size == 0) {
+		pr_debug("%s doesn't need map definition\n",
+			 obj->path);
+		return 0;
+	}
+
+	obj->maps_buf = malloc(size);
+	if (!obj->maps_buf) {
+		pr_warning("malloc maps failed: %s\n", obj->path);
+		return -ENOMEM;
+	}
+
+	obj->maps_buf_sz = size;
+	memcpy(obj->maps_buf, data, size);
+	pr_debug("maps in %s: %ld bytes\n", obj->path, (long)size);
+	return 0;
+}
+
+static int bpf_object__elf_collect(struct bpf_object *obj)
+{
+	Elf *elf = obj->efile.elf;
+	GElf_Ehdr *ep = &obj->efile.ehdr;
+	Elf_Scn *scn = NULL;
+	int idx = 0, err = 0;
+
+	/* Elf is corrupted/truncated, avoid calling elf_strptr. */
+	if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL)) {
+		pr_warning("failed to get e_shstrndx from %s\n",
+			   obj->path);
+		return -EINVAL;
+	}
+
+	while ((scn = elf_nextscn(elf, scn)) != NULL) {
+		char *name;
+		GElf_Shdr sh;
+		Elf_Data *data;
+
+		idx++;
+		if (gelf_getshdr(scn, &sh) != &sh) {
+			pr_warning("failed to get section header from %s\n",
+				   obj->path);
+			err = -EINVAL;
+			goto out;
+		}
+
+		name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name);
+		if (!name) {
+			pr_warning("failed to get section name from %s\n",
+				   obj->path);
+			err = -EINVAL;
+			goto out;
+		}
+
+		data = elf_getdata(scn, 0);
+		if (!data) {
+			pr_warning("failed to get section data from %s(%s)\n",
+				   name, obj->path);
+			err = -EINVAL;
+			goto out;
+		}
+		pr_debug("section %s, size %ld, link %d, flags %lx, type=%d\n",
+			 name, (unsigned long)data->d_size,
+			 (int)sh.sh_link, (unsigned long)sh.sh_flags,
+			 (int)sh.sh_type);
+
+		if (strcmp(name, "license") == 0)
+			err = bpf_object__init_license(obj,
+						       data->d_buf,
+						       data->d_size);
+		else if (strcmp(name, "version") == 0)
+			err = bpf_object__init_kversion(obj,
+							data->d_buf,
+							data->d_size);
+		else if (strcmp(name, "maps") == 0)
+			err = bpf_object__init_maps(obj, data->d_buf,
+						    data->d_size);
+		else if (sh.sh_type == SHT_SYMTAB) {
+			if (obj->efile.symbols) {
+				pr_warning("bpf: multiple SYMTAB in %s\n",
+					   obj->path);
+				err = -EEXIST;
+			} else
+				obj->efile.symbols = data;
+		} else if ((sh.sh_type == SHT_PROGBITS) &&
+			   (sh.sh_flags & SHF_EXECINSTR) &&
+			   (data->d_size > 0)) {
+			err = bpf_object__add_program(obj, data->d_buf,
+						      data->d_size, name, idx);
+			if (err) {
+				char errmsg[128];
+				strerror_r(-err, errmsg, sizeof(errmsg));
+				pr_warning("failed to alloc program %s (%s): %s",
+					   name, obj->path, errmsg);
+			}
+		} else if (sh.sh_type == SHT_REL) {
+			void *reloc = obj->efile.reloc;
+			int nr_reloc = obj->efile.nr_reloc + 1;
+
+			reloc = realloc(reloc,
+					sizeof(*obj->efile.reloc) * nr_reloc);
+			if (!reloc) {
+				pr_warning("realloc failed\n");
+				err = -ENOMEM;
+			} else {
+				int n = nr_reloc - 1;
+
+				obj->efile.reloc = reloc;
+				obj->efile.nr_reloc = nr_reloc;
+
+				obj->efile.reloc[n].shdr = sh;
+				obj->efile.reloc[n].data = data;
+			}
+		}
+		if (err)
+			goto out;
+	}
+out:
+	return err;
+}
+
+static struct bpf_program *
+bpf_object__find_prog_by_idx(struct bpf_object *obj, int idx)
+{
+	struct bpf_program *prog;
+	size_t i;
+
+	for (i = 0; i < obj->nr_programs; i++) {
+		prog = &obj->programs[i];
+		if (prog->idx == idx)
+			return prog;
+	}
+	return NULL;
+}
+
+static int
+bpf_program__collect_reloc(struct bpf_program *prog,
+			   size_t nr_maps, GElf_Shdr *shdr,
+			   Elf_Data *data, Elf_Data *symbols)
+{
+	int i, nrels;
+
+	pr_debug("collecting relocating info for: '%s'\n",
+		 prog->section_name);
+	nrels = shdr->sh_size / shdr->sh_entsize;
+
+	prog->reloc_desc = malloc(sizeof(*prog->reloc_desc) * nrels);
+	if (!prog->reloc_desc) {
+		pr_warning("failed to alloc memory in relocation\n");
+		return -ENOMEM;
+	}
+	prog->nr_reloc = nrels;
+
+	for (i = 0; i < nrels; i++) {
+		GElf_Sym sym;
+		GElf_Rel rel;
+		unsigned int insn_idx;
+		struct bpf_insn *insns = prog->insns;
+		size_t map_idx;
+
+		if (!gelf_getrel(data, i, &rel)) {
+			pr_warning("relocation: failed to get %d reloc\n", i);
+			return -EINVAL;
+		}
+
+		insn_idx = rel.r_offset / sizeof(struct bpf_insn);
+		pr_debug("relocation: insn_idx=%u\n", insn_idx);
+
+		if (!gelf_getsym(symbols,
+				 GELF_R_SYM(rel.r_info),
+				 &sym)) {
+			pr_warning("relocation: symbol %"PRIx64" not found\n",
+				   GELF_R_SYM(rel.r_info));
+			return -EINVAL;
+		}
+
+		if (insns[insn_idx].code != (BPF_LD | BPF_IMM | BPF_DW)) {
+			pr_warning("bpf: relocation: invalid relo for insns[%d].code 0x%x\n",
+				   insn_idx, insns[insn_idx].code);
+			return -EINVAL;
+		}
+
+		map_idx = sym.st_value / sizeof(struct bpf_map_def);
+		if (map_idx >= nr_maps) {
+			pr_warning("bpf relocation: map_idx %d large than %d\n",
+				   (int)map_idx, (int)nr_maps - 1);
+			return -EINVAL;
+		}
+
+		prog->reloc_desc[i].insn_idx = insn_idx;
+		prog->reloc_desc[i].map_idx = map_idx;
+	}
+	return 0;
+}
+
+static int
+bpf_object__create_maps(struct bpf_object *obj)
+{
+	unsigned int i;
+	size_t nr_maps;
+	int *pfd;
+
+	nr_maps = obj->maps_buf_sz / sizeof(struct bpf_map_def);
+	if (!obj->maps_buf || !nr_maps) {
+		pr_debug("don't need create maps for %s\n",
+			 obj->path);
+		return 0;
+	}
+
+	obj->map_fds = malloc(sizeof(int) * nr_maps);
+	if (!obj->map_fds) {
+		pr_warning("realloc perf_bpf_map_fds failed\n");
+		return -ENOMEM;
+	}
+	obj->nr_map_fds = nr_maps;
+
+	/* fill all fd with -1 */
+	memset(obj->map_fds, -1, sizeof(int) * nr_maps);
+
+	pfd = obj->map_fds;
+	for (i = 0; i < nr_maps; i++) {
+		struct bpf_map_def def;
+
+		def = *(struct bpf_map_def *)(obj->maps_buf +
+				i * sizeof(struct bpf_map_def));
+
+		*pfd = bpf_create_map(def.type,
+				      def.key_size,
+				      def.value_size,
+				      def.max_entries);
+		if (*pfd < 0) {
+			size_t j;
+			int err = *pfd;
+
+			pr_warning("failed to create map: %s\n",
+				   strerror(errno));
+			for (j = 0; j < i; j++)
+				zclose(obj->map_fds[j]);
+			obj->nr_map_fds = 0;
+			zfree(&obj->map_fds);
+			return err;
+		}
+		pr_debug("create map: fd=%d\n", *pfd);
+		pfd++;
+	}
+
+	zfree(&obj->maps_buf);
+	obj->maps_buf_sz = 0;
+	return 0;
+}
+
+static int
+bpf_program__relocate(struct bpf_program *prog, int *map_fds)
+{
+	int i;
+
+	if (!prog || !prog->reloc_desc)
+		return 0;
+
+	for (i = 0; i < prog->nr_reloc; i++) {
+		int insn_idx, map_idx;
+		struct bpf_insn *insns = prog->insns;
+
+		insn_idx = prog->reloc_desc[i].insn_idx;
+		map_idx = prog->reloc_desc[i].map_idx;
+
+		if (insn_idx >= (int)prog->insns_cnt) {
+			pr_warning("relocation out of range: '%s'\n",
+				   prog->section_name);
+			return -ERANGE;
+		}
+		insns[insn_idx].src_reg = BPF_PSEUDO_MAP_FD;
+		insns[insn_idx].imm = map_fds[map_idx];
+	}
+
+	zfree(&prog->reloc_desc);
+	prog->nr_reloc = 0;
+	return 0;
+}
+
+
+static int
+bpf_object__relocate(struct bpf_object *obj)
+{
+	struct bpf_program *prog;
+	size_t i;
+	int err;
+
+	for (i = 0; i < obj->nr_programs; i++) {
+		prog = &obj->programs[i];
+
+		err = bpf_program__relocate(prog, obj->map_fds);
+		if (err) {
+			pr_warning("failed to relocate '%s'\n",
+				   prog->section_name);
+			return err;
+		}
+	}
+	return 0;
+}
+
+static int bpf_object__collect_reloc(struct bpf_object *obj)
+{
+	int i, err;
+
+	if (!obj_elf_valid(obj)) {
+		pr_warning("Internal error: elf object is closed\n");
+		return -EINVAL;
+	}
+
+	for (i = 0; i < obj->efile.nr_reloc; i++) {
+		GElf_Shdr *shdr = &obj->efile.reloc[i].shdr;
+		Elf_Data *data = obj->efile.reloc[i].data;
+		int idx = shdr->sh_info;
+		struct bpf_program *prog;
+		size_t nr_maps = obj->maps_buf_sz /
+				 sizeof(struct bpf_map_def);
+
+		if (shdr->sh_type != SHT_REL) {
+			pr_warning("internal error at %d\n", __LINE__);
+			return -EINVAL;
+		}
+
+		prog = bpf_object__find_prog_by_idx(obj, idx);
+		if (!prog) {
+			pr_warning("relocation failed: no %d section\n",
+				   idx);
+			return -ENOENT;
+		}
+
+		err = bpf_program__collect_reloc(prog, nr_maps,
+						 shdr, data,
+						 obj->efile.symbols);
+		if (err)
+			return -EINVAL;
+	}
+	return 0;
+}
+
+static int
+load_program(struct bpf_insn *insns, int insns_cnt,
+	     char *license, u32 kern_version, int *pfd)
+{
+	int ret;
+	char *log_buf;
+
+	if (!insns || !insns_cnt)
+		return -EINVAL;
+
+	log_buf = malloc(BPF_LOG_BUF_SIZE);
+	if (!log_buf)
+		pr_warning("Alloc log buffer for bpf loader error, continue without log\n");
+
+	ret = bpf_load_program(BPF_PROG_TYPE_KPROBE, insns,
+			       insns_cnt, license, kern_version,
+			       log_buf, BPF_LOG_BUF_SIZE);
+
+	if (ret >= 0) {
+		*pfd = ret;
+		ret = 0;
+		goto out;
+	}
+
+	ret = -EINVAL;
+	pr_warning("load bpf program failed: %s\n", strerror(errno));
+
+	if (log_buf) {
+		pr_warning("-- BEGIN DUMP LOG ---\n");
+		pr_warning("\n%s\n", log_buf);
+		pr_warning("-- END LOG --\n");
+	}
+
+out:
+	free(log_buf);
+	return ret;
+}
+
+static int
+bpf_program__load(struct bpf_program *prog,
+		  char *license, u32 kern_version)
+{
+	int err, fd;
+
+	err = load_program(prog->insns, prog->insns_cnt,
+			   license, kern_version, &fd);
+	if (!err)
+		prog->fd = fd;
+
+	if (err)
+		pr_warning("failed to load program '%s'\n",
+			   prog->section_name);
+	zfree(&prog->insns);
+	prog->insns_cnt = 0;
+	return err;
+}
+
+static int
+bpf_object__load_progs(struct bpf_object *obj)
+{
+	size_t i;
+	int err;
+
+	for (i = 0; i < obj->nr_programs; i++) {
+		err = bpf_program__load(&obj->programs[i],
+					obj->license,
+					obj->kern_version);
+		if (err)
+			return err;
+	}
+	return 0;
+}
+
+static int bpf_object__validate(struct bpf_object *obj)
+{
+	if (obj->kern_version == 0) {
+		pr_warning("%s doesn't provide kernel version\n",
+			   obj->path);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static struct bpf_object *
+__bpf_object__open(const char *path, void *obj_buf, size_t obj_buf_sz)
+{
+	struct bpf_object *obj;
+
+	if (elf_version(EV_CURRENT) == EV_NONE) {
+		pr_warning("failed to init libelf for %s\n", path);
+		return NULL;
+	}
+
+	obj = bpf_object__new(path, obj_buf, obj_buf_sz);
+	if (!obj)
+		return NULL;
+
+	if (bpf_object__elf_init(obj))
+		goto out;
+	if (bpf_object__check_endianness(obj))
+		goto out;
+	if (bpf_object__elf_collect(obj))
+		goto out;
+	if (bpf_object__collect_reloc(obj))
+		goto out;
+	if (bpf_object__validate(obj))
+		goto out;
+
+	bpf_object__elf_finish(obj);
+	return obj;
+out:
+	bpf_object__close(obj);
+	return NULL;
+}
+
+struct bpf_object *bpf_object__open(const char *path)
+{
+	/* param validation */
+	if (!path)
+		return NULL;
+
+	pr_debug("loading %s\n", path);
+
+	return __bpf_object__open(path, NULL, 0);
+}
+
+struct bpf_object *bpf_object__open_buffer(void *obj_buf,
+					   size_t obj_buf_sz)
+{
+	/* param validation */
+	if (!obj_buf || obj_buf_sz <= 0)
+		return NULL;
+
+	pr_debug("loading object from buffer\n");
+
+	return __bpf_object__open("[buffer]", obj_buf, obj_buf_sz);
+}
+
+int bpf_object__unload(struct bpf_object *obj)
+{
+	size_t i;
+
+	if (!obj)
+		return -EINVAL;
+
+	for (i = 0; i < obj->nr_map_fds; i++)
+		zclose(obj->map_fds[i]);
+	zfree(&obj->map_fds);
+	obj->nr_map_fds = 0;
+
+	for (i = 0; i < obj->nr_programs; i++)
+		bpf_program__unload(&obj->programs[i]);
+
+	return 0;
+}
+
+int bpf_object__load(struct bpf_object *obj)
+{
+	if (!obj)
+		return -EINVAL;
+
+	if (obj->loaded) {
+		pr_warning("object should not be loaded twice\n");
+		return -EINVAL;
+	}
+
+	obj->loaded = true;
+	if (bpf_object__create_maps(obj))
+		goto out;
+	if (bpf_object__relocate(obj))
+		goto out;
+	if (bpf_object__load_progs(obj))
+		goto out;
+
+	return 0;
+out:
+	bpf_object__unload(obj);
+	pr_warning("failed to load object '%s'\n", obj->path);
+	return -EINVAL;
+}
+
+void bpf_object__close(struct bpf_object *obj)
+{
+	size_t i;
+
+	if (!obj)
+		return;
+
+	bpf_object__elf_finish(obj);
+	bpf_object__unload(obj);
+
+	zfree(&obj->maps_buf);
+
+	if (obj->programs && obj->nr_programs) {
+		for (i = 0; i < obj->nr_programs; i++)
+			bpf_program__exit(&obj->programs[i]);
+	}
+	zfree(&obj->programs);
+
+	list_del(&obj->list);
+	free(obj);
+}
+
+struct bpf_object *
+bpf_object__next(struct bpf_object *prev)
+{
+	struct bpf_object *next;
+
+	if (!prev)
+		next = list_first_entry(&bpf_objects_list,
+					struct bpf_object,
+					list);
+	else
+		next = list_next_entry(prev, list);
+
+	/* Empty list is noticed here so don't need checking on entry. */
+	if (&next->list == &bpf_objects_list)
+		return NULL;
+
+	return next;
+}
+
+struct bpf_program *
+bpf_program__next(struct bpf_program *prev, struct bpf_object *obj)
+{
+	size_t idx;
+
+	if (!obj->programs)
+		return NULL;
+	/* First handler */
+	if (prev == NULL)
+		return &obj->programs[0];
+
+	if (prev->obj != obj) {
+		pr_warning("error: program handler doesn't match object\n");
+		return NULL;
+	}
+
+	idx = (prev - obj->programs) + 1;
+	if (idx >= obj->nr_programs)
+		return NULL;
+	return &obj->programs[idx];
+}
+
+int bpf_program__set_private(struct bpf_program *prog,
+			     void *priv,
+			     bpf_program_clear_priv_t clear_priv)
+{
+	if (prog->priv && prog->clear_priv)
+		prog->clear_priv(prog, prog->priv);
+
+	prog->priv = priv;
+	prog->clear_priv = clear_priv;
+	return 0;
+}
+
+int bpf_program__get_private(struct bpf_program *prog, void **ppriv)
+{
+	*ppriv = prog->priv;
+	return 0;
+}
+
+const char *bpf_program__title(struct bpf_program *prog, bool dup)
+{
+	const char *title;
+
+	title = prog->section_name;
+	if (dup) {
+		title = strdup(title);
+		if (!title) {
+			pr_warning("failed to strdup program title\n");
+			return NULL;
+		}
+	}
+
+	return title;
+}
+
+int bpf_program__fd(struct bpf_program *prog)
+{
+	return prog->fd;
+}
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
new file mode 100644
index 000000000000..ea8adc206b62
--- /dev/null
+++ b/tools/lib/bpf/libbpf.h
@@ -0,0 +1,81 @@
+/*
+ * Common eBPF ELF object loading operations.
+ *
+ * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
+ * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
+ * Copyright (C) 2015 Huawei Inc.
+ */
+#ifndef __BPF_LIBBPF_H
+#define __BPF_LIBBPF_H
+
+#include <stdio.h>
+#include <stdbool.h>
+
+/*
+ * In include/linux/compiler-gcc.h, __printf is defined. However
+ * it should be better if libbpf.h doesn't depend on Linux header file.
+ * So instead of __printf, here we use gcc attribute directly.
+ */
+typedef int (*libbpf_print_fn_t)(const char *, ...)
+	__attribute__((format(printf, 1, 2)));
+
+void libbpf_set_print(libbpf_print_fn_t warn,
+		      libbpf_print_fn_t info,
+		      libbpf_print_fn_t debug);
+
+/* Hide internal to user */
+struct bpf_object;
+
+struct bpf_object *bpf_object__open(const char *path);
+struct bpf_object *bpf_object__open_buffer(void *obj_buf,
+					   size_t obj_buf_sz);
+void bpf_object__close(struct bpf_object *object);
+
+/* Load/unload object into/from kernel */
+int bpf_object__load(struct bpf_object *obj);
+int bpf_object__unload(struct bpf_object *obj);
+
+struct bpf_object *bpf_object__next(struct bpf_object *prev);
+#define bpf_object__for_each_safe(pos, tmp)			\
+	for ((pos) = bpf_object__next(NULL),		\
+		(tmp) = bpf_object__next(pos);		\
+	     (pos) != NULL;				\
+	     (pos) = (tmp), (tmp) = bpf_object__next(tmp))
+
+/* Accessors of bpf_program. */
+struct bpf_program;
+struct bpf_program *bpf_program__next(struct bpf_program *prog,
+				      struct bpf_object *obj);
+
+#define bpf_object__for_each_program(pos, obj)		\
+	for ((pos) = bpf_program__next(NULL, (obj));	\
+	     (pos) != NULL;				\
+	     (pos) = bpf_program__next((pos), (obj)))
+
+typedef void (*bpf_program_clear_priv_t)(struct bpf_program *,
+					 void *);
+
+int bpf_program__set_private(struct bpf_program *prog, void *priv,
+			     bpf_program_clear_priv_t clear_priv);
+
+int bpf_program__get_private(struct bpf_program *prog,
+			     void **ppriv);
+
+const char *bpf_program__title(struct bpf_program *prog, bool dup);
+
+int bpf_program__fd(struct bpf_program *prog);
+
+/*
+ * We don't need __attribute__((packed)) now since it is
+ * unnecessary for 'bpf_map_def' because they are all aligned.
+ * In addition, using it will trigger -Wpacked warning message,
+ * and will be treated as an error due to -Werror.
+ */
+struct bpf_map_def {
+	unsigned int type;
+	unsigned int key_size;
+	unsigned int value_size;
+	unsigned int max_entries;
+};
+
+#endif
diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index cc25f059ab3d..4d885934b919 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -418,7 +418,7 @@ static int func_map_init(struct pevent *pevent)
 }
 
 static struct func_map *
-find_func(struct pevent *pevent, unsigned long long addr)
+__find_func(struct pevent *pevent, unsigned long long addr)
 {
 	struct func_map *func;
 	struct func_map key;
@@ -434,6 +434,71 @@ find_func(struct pevent *pevent, unsigned long long addr)
 	return func;
 }
 
+struct func_resolver {
+	pevent_func_resolver_t *func;
+	void		       *priv;
+	struct func_map	       map;
+};
+
+/**
+ * pevent_set_function_resolver - set an alternative function resolver
+ * @pevent: handle for the pevent
+ * @resolver: function to be used
+ * @priv: resolver function private state.
+ *
+ * Some tools may have already a way to resolve kernel functions, allow them to
+ * keep using it instead of duplicating all the entries inside
+ * pevent->funclist.
+ */
+int pevent_set_function_resolver(struct pevent *pevent,
+				 pevent_func_resolver_t *func, void *priv)
+{
+	struct func_resolver *resolver = malloc(sizeof(*resolver));
+
+	if (resolver == NULL)
+		return -1;
+
+	resolver->func = func;
+	resolver->priv = priv;
+
+	free(pevent->func_resolver);
+	pevent->func_resolver = resolver;
+
+	return 0;
+}
+
+/**
+ * pevent_reset_function_resolver - reset alternative function resolver
+ * @pevent: handle for the pevent
+ *
+ * Stop using whatever alternative resolver was set, use the default
+ * one instead.
+ */
+void pevent_reset_function_resolver(struct pevent *pevent)
+{
+	free(pevent->func_resolver);
+	pevent->func_resolver = NULL;
+}
+
+static struct func_map *
+find_func(struct pevent *pevent, unsigned long long addr)
+{
+	struct func_map *map;
+
+	if (!pevent->func_resolver)
+		return __find_func(pevent, addr);
+
+	map = &pevent->func_resolver->map;
+	map->mod  = NULL;
+	map->addr = addr;
+	map->func = pevent->func_resolver->func(pevent->func_resolver->priv,
+						&map->addr, &map->mod);
+	if (map->func == NULL)
+		return NULL;
+
+	return map;
+}
+
 /**
  * pevent_find_function - find a function by a given address
  * @pevent: handle for the pevent
@@ -1680,6 +1745,9 @@ process_cond(struct event_format *event, struct print_arg *top, char **tok)
 	type = process_arg(event, left, &token);
 
  again:
+	if (type == EVENT_ERROR)
+		goto out_free;
+
 	/* Handle other operations in the arguments */
 	if (type == EVENT_OP && strcmp(token, ":") != 0) {
 		type = process_op(event, left, &token);
@@ -1939,6 +2007,12 @@ process_op(struct event_format *event, struct print_arg *arg, char **tok)
 			goto out_warn_free;
 
 		type = process_arg_token(event, right, tok, type);
+		if (type == EVENT_ERROR) {
+			free_arg(right);
+			/* token was freed in process_arg_token() via *tok */
+			token = NULL;
+			goto out_free;
+		}
 
 		if (right->type == PRINT_OP &&
 		    get_op_prio(arg->op.op) < get_op_prio(right->op.op)) {
@@ -4754,6 +4828,7 @@ static void pretty_print(struct trace_seq *s, void *data, int size, struct event
 			case 'z':
 			case 'Z':
 			case '0' ... '9':
+			case '-':
 				goto cont_process;
 			case 'p':
 				if (pevent->long_size == 4)
@@ -6564,6 +6639,7 @@ void pevent_free(struct pevent *pevent)
 	free(pevent->trace_clock);
 	free(pevent->events);
 	free(pevent->sort_events);
+	free(pevent->func_resolver);
 
 	free(pevent);
 }
diff --git a/tools/lib/traceevent/event-parse.h b/tools/lib/traceevent/event-parse.h
index 063b1971eb35..204befb05a17 100644
--- a/tools/lib/traceevent/event-parse.h
+++ b/tools/lib/traceevent/event-parse.h
@@ -453,6 +453,10 @@ struct cmdline_list;
 struct func_map;
 struct func_list;
 struct event_handler;
+struct func_resolver;
+
+typedef char *(pevent_func_resolver_t)(void *priv,
+				       unsigned long long *addrp, char **modp);
 
 struct pevent {
 	int ref_count;
@@ -481,6 +485,7 @@ struct pevent {
 	int cmdline_count;
 
 	struct func_map *func_map;
+	struct func_resolver *func_resolver;
 	struct func_list *funclist;
 	unsigned int func_count;
 
@@ -611,6 +616,9 @@ enum trace_flag_type {
 	TRACE_FLAG_SOFTIRQ		= 0x10,
 };
 
+int pevent_set_function_resolver(struct pevent *pevent,
+				 pevent_func_resolver_t *func, void *priv);
+void pevent_reset_function_resolver(struct pevent *pevent);
 int pevent_register_comm(struct pevent *pevent, const char *comm, int pid);
 int pevent_register_trace_clock(struct pevent *pevent, const char *trace_clock);
 int pevent_register_function(struct pevent *pevent, char *name,