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

Pull perf updates from Thomas Gleixner:
 "Mostly updates to the perf tool plus two fixes to the kernel core code:

   - Handle tracepoint filters correctly for inherited events (Peter
     Zijlstra)

   - Prevent a deadlock in perf_lock_task_context (Paul McKenney)

   - Add missing newlines to some pr_err() calls (Arnaldo Carvalho de
     Melo)

   - Print full source file paths when using 'perf annotate --print-line
     --full-paths' (Michael Petlan)

   - Fix 'perf probe -d' when just one out of uprobes and kprobes is
     enabled (Wang Nan)

   - Add compiler.h to list.h to fix 'make perf-tar-src-pkg' generated
     tarballs, i.e. out of tree building (Arnaldo Carvalho de Melo)

   - Add the llvm-src-base.c and llvm-src-kbuild.c files, generated by
     the 'perf test' LLVM entries, when running it in-tree, to
     .gitignore (Yunlong Song)

   - libbpf error reporting improvements, using a strerror interface to
     more precisely tell the user about problems with the provided
     scriptlet, be it in C or as a ready made object file (Wang Nan)

   - Do not be case sensitive when searching for matching 'perf test'
     entries (Arnaldo Carvalho de Melo)

   - Inform the user about objdump failures in 'perf annotate' (Andi
     Kleen)

   - Improve the LLVM 'perf test' entry, introduce a new ones for BPF
     and kbuild tests to check the environment used by clang to compile
     .c scriptlets (Wang Nan)"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
  perf/x86/intel/rapl: Remove the unused RAPL_EVENT_DESC() macro
  tools include: Add compiler.h to list.h
  perf probe: Verify parameters in two functions
  perf session: Add missing newlines to some pr_err() calls
  perf annotate: Support full source file paths for srcline fix
  perf test: Add llvm-src-base.c and llvm-src-kbuild.c to .gitignore
  perf: Fix inherited events vs. tracepoint filters
  perf: Disable IRQs across RCU RS CS that acquires scheduler lock
  perf test: Do not be case sensitive when searching for matching tests
  perf test: Add 'perf test BPF'
  perf test: Enhance the LLVM tests: add kbuild test
  perf test: Enhance the LLVM test: update basic BPF test program
  perf bpf: Improve BPF related error messages
  perf tools: Make fetch_kernel_version() publicly available
  bpf tools: Add new API bpf_object__get_kversion()
  bpf tools: Improve libbpf error reporting
  perf probe: Cleanup find_perf_probe_point_from_map to reduce redundancy
  perf annotate: Inform the user about objdump failures in --stdio
  perf stat: Make stat options global
  perf sched latency: Fix thread pid reuse issue
  ...

arch/x86/kernel/cpu/perf_event_intel_rapl.c

@@ -107,12 +107,6 @@ static ssize_t __rapl_##_var##_show(struct kobject *kobj,	\
 static struct kobj_attribute format_attr_##_var =		\
 	__ATTR(_name, 0444, __rapl_##_var##_show, NULL)
 
-#define RAPL_EVENT_DESC(_name, _config)				\
-{								\
-	.attr	= __ATTR(_name, 0444, rapl_event_show, NULL),	\
-	.config	= _config,					\
-}
-
 #define RAPL_CNTR_WIDTH 32 /* 32-bit rapl counters */
 
 #define RAPL_EVENT_ATTR_STR(_name, v, str)				\

kernel/events/core.c

@@ -1050,13 +1050,13 @@ perf_lock_task_context(struct task_struct *task, int ctxn, unsigned long *flags)
 	/*
 	 * One of the few rules of preemptible RCU is that one cannot do
 	 * rcu_read_unlock() while holding a scheduler (or nested) lock when
-	 * part of the read side critical section was preemptible -- see
+	 * part of the read side critical section was irqs-enabled -- see
 	 * rcu_read_unlock_special().
 	 *
 	 * Since ctx->lock nests under rq->lock we must ensure the entire read
-	 * side critical section is non-preemptible.
+	 * side critical section has interrupts disabled.
 	 */
-	preempt_disable();
+	local_irq_save(*flags);
 	rcu_read_lock();
 	ctx = rcu_dereference(task->perf_event_ctxp[ctxn]);
 	if (ctx) {
@@ -1070,21 +1070,22 @@ perf_lock_task_context(struct task_struct *task, int ctxn, unsigned long *flags)
 		 * if so.  If we locked the right context, then it
 		 * can't get swapped on us any more.
 		 */
-		raw_spin_lock_irqsave(&ctx->lock, *flags);
+		raw_spin_lock(&ctx->lock);
 		if (ctx != rcu_dereference(task->perf_event_ctxp[ctxn])) {
-			raw_spin_unlock_irqrestore(&ctx->lock, *flags);
+			raw_spin_unlock(&ctx->lock);
 			rcu_read_unlock();
-			preempt_enable();
+			local_irq_restore(*flags);
 			goto retry;
 		}
 
 		if (!atomic_inc_not_zero(&ctx->refcount)) {
-			raw_spin_unlock_irqrestore(&ctx->lock, *flags);
+			raw_spin_unlock(&ctx->lock);
 			ctx = NULL;
 		}
 	}
 	rcu_read_unlock();
-	preempt_enable();
+	if (!ctx)
+		local_irq_restore(*flags);
 	return ctx;
 }
 
@@ -6913,6 +6914,10 @@ static int perf_tp_filter_match(struct perf_event *event,
 {
 	void *record = data->raw->data;
 
+	/* only top level events have filters set */
+	if (event->parent)
+		event = event->parent;
+
 	if (likely(!event->filter) || filter_match_preds(event->filter, record))
 		return 1;
 	return 0;

tools/include/linux/list.h

+#include <linux/compiler.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
 

tools/lib/bpf/.gitignore

 libbpf_version.h
-FEATURE-DUMP
+FEATURE-DUMP.libbpf

tools/lib/bpf/Makefile

@@ -180,7 +180,7 @@ config-clean:
 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
+	$(call QUIET_CLEAN, core-gen) $(RM) $(OUTPUT)FEATURE-DUMP.libbpf
 
 
 

tools/lib/bpf/libbpf.h

@@ -10,6 +10,26 @@
 
 #include <stdio.h>
 #include <stdbool.h>
+#include <linux/err.h>
+
+enum libbpf_errno {
+	__LIBBPF_ERRNO__START = 4000,
+
+	/* Something wrong in libelf */
+	LIBBPF_ERRNO__LIBELF = __LIBBPF_ERRNO__START,
+	LIBBPF_ERRNO__FORMAT,	/* BPF object format invalid */
+	LIBBPF_ERRNO__KVERSION,	/* Incorrect or no 'version' section */
+	LIBBPF_ERRNO__ENDIAN,	/* Endian missmatch */
+	LIBBPF_ERRNO__INTERNAL,	/* Internal error in libbpf */
+	LIBBPF_ERRNO__RELOC,	/* Relocation failed */
+	LIBBPF_ERRNO__LOAD,	/* Load program failure for unknown reason */
+	LIBBPF_ERRNO__VERIFY,	/* Kernel verifier blocks program loading */
+	LIBBPF_ERRNO__PROG2BIG,	/* Program too big */
+	LIBBPF_ERRNO__KVER,	/* Incorrect kernel version */
+	__LIBBPF_ERRNO__END,
+};
+
+int libbpf_strerror(int err, char *buf, size_t size);
 
 /*
  * In include/linux/compiler-gcc.h, __printf is defined. However
@@ -36,6 +56,7 @@ void bpf_object__close(struct bpf_object *object);
 int bpf_object__load(struct bpf_object *obj);
 int bpf_object__unload(struct bpf_object *obj);
 const char *bpf_object__get_name(struct bpf_object *obj);
+unsigned int bpf_object__get_kversion(struct bpf_object *obj);
 
 struct bpf_object *bpf_object__next(struct bpf_object *prev);
 #define bpf_object__for_each_safe(pos, tmp)			\
@@ -63,7 +84,7 @@ int bpf_program__set_private(struct bpf_program *prog, void *priv,
 int bpf_program__get_private(struct bpf_program *prog,
 			     void **ppriv);
 
-const char *bpf_program__title(struct bpf_program *prog, bool dup);
+const char *bpf_program__title(struct bpf_program *prog, bool needs_copy);
 
 int bpf_program__fd(struct bpf_program *prog);
 

tools/perf/Documentation/perf-trace.txt

@@ -62,7 +62,6 @@ OPTIONS
 --verbose=::
         Verbosity level.
 
--i::
 --no-inherit::
 	Child tasks do not inherit counters.
 

tools/perf/Makefile

@@ -78,7 +78,7 @@ clean:
 # The build-test target is not really parallel, don't print the jobs info:
 #
 build-test:
-	@$(MAKE) -f tests/make --no-print-directory
+	@$(MAKE) SHUF=1 -f tests/make --no-print-directory
 
 #
 # All other targets get passed through:

tools/perf/builtin-sched.c

@@ -1203,12 +1203,13 @@ static void output_lat_thread(struct perf_sched *sched, struct work_atoms *work_
 
 static int pid_cmp(struct work_atoms *l, struct work_atoms *r)
 {
+	if (l->thread == r->thread)
+		return 0;
 	if (l->thread->tid < r->thread->tid)
 		return -1;
 	if (l->thread->tid > r->thread->tid)
 		return 1;
-
-	return 0;
+	return (int)(l->thread - r->thread);
 }
 
 static int avg_cmp(struct work_atoms *l, struct work_atoms *r)

tools/perf/tests/.gitignore

+llvm-src-base.c
+llvm-src-kbuild.c

tools/perf/tests/Build

@@ -31,9 +31,24 @@ perf-y += sample-parsing.o
 perf-y += parse-no-sample-id-all.o
 perf-y += kmod-path.o
 perf-y += thread-map.o
-perf-y += llvm.o
+perf-y += llvm.o llvm-src-base.o llvm-src-kbuild.o
+perf-y += bpf.o
 perf-y += topology.o
 
+$(OUTPUT)tests/llvm-src-base.c: tests/bpf-script-example.c
+	$(call rule_mkdir)
+	$(Q)echo '#include <tests/llvm.h>' > $@
+	$(Q)echo 'const char test_llvm__bpf_base_prog[] =' >> $@
+	$(Q)sed -e 's/"/\\"/g' -e 's/\(.*\)/"\1\\n"/g' $< >> $@
+	$(Q)echo ';' >> $@
+
+$(OUTPUT)tests/llvm-src-kbuild.c: tests/bpf-script-test-kbuild.c
+	$(call rule_mkdir)
+	$(Q)echo '#include <tests/llvm.h>' > $@
+	$(Q)echo 'const char test_llvm__bpf_test_kbuild_prog[] =' >> $@
+	$(Q)sed -e 's/"/\\"/g' -e 's/\(.*\)/"\1\\n"/g' $< >> $@
+	$(Q)echo ';' >> $@
+
 ifeq ($(ARCH),$(filter $(ARCH),x86 arm arm64))
 perf-$(CONFIG_DWARF_UNWIND) += dwarf-unwind.o
 endif

tools/perf/tests/attr.c

@@ -171,6 +171,5 @@ int test__attr(void)
 	    !lstat(path_perf, &st))
 		return run_dir(path_dir, path_perf);
 
-	fprintf(stderr, " (omitted)");
-	return 0;
+	return TEST_SKIP;
 }

tools/perf/tests/bpf-script-example.c

+/*
+ * bpf-script-example.c
+ * Test basic LLVM building
+ */
 #ifndef LINUX_VERSION_CODE
 # error Need LINUX_VERSION_CODE
 # error Example: for 4.2 kernel, put 'clang-opt="-DLINUX_VERSION_CODE=0x40200" into llvm section of ~/.perfconfig'

tools/perf/tests/bpf-script-test-kbuild.c

+/*
+ * bpf-script-test-kbuild.c
+ * Test include from kernel header
+ */
+#ifndef LINUX_VERSION_CODE
+# error Need LINUX_VERSION_CODE
+# error Example: for 4.2 kernel, put 'clang-opt="-DLINUX_VERSION_CODE=0x40200" into llvm section of ~/.perfconfig'
+#endif
+#define SEC(NAME) __attribute__((section(NAME), used))
+
+#include <uapi/linux/fs.h>
+#include <uapi/asm/ptrace.h>
+
+SEC("func=vfs_llseek")
+int bpf_func__vfs_llseek(void *ctx)
+{
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+int _version SEC("version") = LINUX_VERSION_CODE;

tools/perf/tests/bpf.c

+#include <stdio.h>
+#include <sys/epoll.h>
+#include <util/bpf-loader.h>
+#include <util/evlist.h>
+#include "tests.h"
+#include "llvm.h"
+#include "debug.h"
+#define NR_ITERS       111
+
+#ifdef HAVE_LIBBPF_SUPPORT
+
+static int epoll_pwait_loop(void)
+{
+	int i;
+
+	/* Should fail NR_ITERS times */
+	for (i = 0; i < NR_ITERS; i++)
+		epoll_pwait(-(i + 1), NULL, 0, 0, NULL);
+	return 0;
+}
+
+static struct {
+	enum test_llvm__testcase prog_id;
+	const char *desc;
+	const char *name;
+	const char *msg_compile_fail;
+	const char *msg_load_fail;
+	int (*target_func)(void);
+	int expect_result;
+} bpf_testcase_table[] = {
+	{
+		LLVM_TESTCASE_BASE,
+		"Test basic BPF filtering",
+		"[basic_bpf_test]",
+		"fix 'perf test LLVM' first",
+		"load bpf object failed",
+		&epoll_pwait_loop,
+		(NR_ITERS + 1) / 2,
+	},
+};
+
+static int do_test(struct bpf_object *obj, int (*func)(void),
+		   int expect)
+{
+	struct record_opts opts = {
+		.target = {
+			.uid = UINT_MAX,
+			.uses_mmap = true,
+		},
+		.freq	      = 0,
+		.mmap_pages   = 256,
+		.default_interval = 1,
+	};
+
+	char pid[16];
+	char sbuf[STRERR_BUFSIZE];
+	struct perf_evlist *evlist;
+	int i, ret = TEST_FAIL, err = 0, count = 0;
+
+	struct parse_events_evlist parse_evlist;
+	struct parse_events_error parse_error;
+
+	bzero(&parse_error, sizeof(parse_error));
+	bzero(&parse_evlist, sizeof(parse_evlist));
+	parse_evlist.error = &parse_error;
+	INIT_LIST_HEAD(&parse_evlist.list);
+
+	err = parse_events_load_bpf_obj(&parse_evlist, &parse_evlist.list, obj);
+	if (err || list_empty(&parse_evlist.list)) {
+		pr_debug("Failed to add events selected by BPF\n");
+		if (!err)
+			return TEST_FAIL;
+	}
+
+	snprintf(pid, sizeof(pid), "%d", getpid());
+	pid[sizeof(pid) - 1] = '\0';
+	opts.target.tid = opts.target.pid = pid;
+
+	/* Instead of perf_evlist__new_default, don't add default events */
+	evlist = perf_evlist__new();
+	if (!evlist) {
+		pr_debug("No ehough memory to create evlist\n");
+		return TEST_FAIL;
+	}
+
+	err = perf_evlist__create_maps(evlist, &opts.target);
+	if (err < 0) {
+		pr_debug("Not enough memory to create thread/cpu maps\n");
+		goto out_delete_evlist;
+	}
+
+	perf_evlist__splice_list_tail(evlist, &parse_evlist.list);
+	evlist->nr_groups = parse_evlist.nr_groups;
+
+	perf_evlist__config(evlist, &opts);
+
+	err = perf_evlist__open(evlist);
+	if (err < 0) {
+		pr_debug("perf_evlist__open: %s\n",
+			 strerror_r(errno, sbuf, sizeof(sbuf)));
+		goto out_delete_evlist;
+	}
+
+	err = perf_evlist__mmap(evlist, opts.mmap_pages, false);
+	if (err < 0) {
+		pr_debug("perf_evlist__mmap: %s\n",
+			 strerror_r(errno, sbuf, sizeof(sbuf)));
+		goto out_delete_evlist;
+	}
+
+	perf_evlist__enable(evlist);
+	(*func)();
+	perf_evlist__disable(evlist);
+
+	for (i = 0; i < evlist->nr_mmaps; i++) {
+		union perf_event *event;
+
+		while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) {
+			const u32 type = event->header.type;
+
+			if (type == PERF_RECORD_SAMPLE)
+				count ++;
+		}
+	}
+
+	if (count != expect)
+		pr_debug("BPF filter result incorrect\n");
+
+	ret = TEST_OK;
+
+out_delete_evlist:
+	perf_evlist__delete(evlist);
+	return ret;
+}
+
+static struct bpf_object *
+prepare_bpf(void *obj_buf, size_t obj_buf_sz, const char *name)
+{
+	struct bpf_object *obj;
+
+	obj = bpf__prepare_load_buffer(obj_buf, obj_buf_sz, name);
+	if (IS_ERR(obj)) {
+		pr_debug("Compile BPF program failed.\n");
+		return NULL;
+	}
+	return obj;
+}
+
+static int __test__bpf(int index)
+{
+	int ret;
+	void *obj_buf;
+	size_t obj_buf_sz;
+	struct bpf_object *obj;
+
+	ret = test_llvm__fetch_bpf_obj(&obj_buf, &obj_buf_sz,
+				       bpf_testcase_table[index].prog_id,
+				       true);
+	if (ret != TEST_OK || !obj_buf || !obj_buf_sz) {
+		pr_debug("Unable to get BPF object, %s\n",
+			 bpf_testcase_table[index].msg_compile_fail);
+		if (index == 0)
+			return TEST_SKIP;
+		else
+			return TEST_FAIL;
+	}
+
+	obj = prepare_bpf(obj_buf, obj_buf_sz,
+			  bpf_testcase_table[index].name);
+	if (!obj) {
+		ret = TEST_FAIL;
+		goto out;
+	}
+
+	ret = do_test(obj,
+		      bpf_testcase_table[index].target_func,
+		      bpf_testcase_table[index].expect_result);
+out:
+	bpf__clear();
+	return ret;
+}
+
+int test__bpf(void)
+{
+	unsigned int i;
+	int err;
+
+	if (geteuid() != 0) {
+		pr_debug("Only root can run BPF test\n");
+		return TEST_SKIP;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(bpf_testcase_table); i++) {
+		err = __test__bpf(i);
+
+		if (err != TEST_OK)
+			return err;
+	}
+
+	return TEST_OK;
+}
+
+#else
+int test__bpf(void)
+{
+	pr_debug("Skip BPF test because BPF support is not compiled\n");
+	return TEST_SKIP;
+}
+#endif

tools/perf/tests/builtin-test.c

@@ -165,6 +165,10 @@ static struct test generic_tests[] = {
 		.desc = "Test topology in session",
 		.func = test_session_topology,
 	},
+	{
+		.desc = "Test BPF filter",
+		.func = test__bpf,
+	},
 	{
 		.func = NULL,
 	},
@@ -192,7 +196,7 @@ static bool perf_test__matches(struct test *test, int curr, int argc, const char
 			continue;
 		}
 
-		if (strstr(test->desc, argv[i]))
+		if (strcasestr(test->desc, argv[i]))
 			return true;
 	}
 

tools/perf/tests/code-reading.c

@@ -613,16 +613,16 @@ int test__code_reading(void)
 	case TEST_CODE_READING_OK:
 		return 0;
 	case TEST_CODE_READING_NO_VMLINUX:
-		fprintf(stderr, " (no vmlinux)");
+		pr_debug("no vmlinux\n");
 		return 0;
 	case TEST_CODE_READING_NO_KCORE:
-		fprintf(stderr, " (no kcore)");
+		pr_debug("no kcore\n");
 		return 0;
 	case TEST_CODE_READING_NO_ACCESS:
-		fprintf(stderr, " (no access)");
+		pr_debug("no access\n");
 		return 0;
 	case TEST_CODE_READING_NO_KERNEL_OBJ:
-		fprintf(stderr, " (no kernel obj)");
+		pr_debug("no kernel obj\n");
 		return 0;
 	default:
 		return -1;

tools/perf/tests/keep-tracking.c

@@ -90,8 +90,8 @@ int test__keep_tracking(void)
 	evsel->attr.enable_on_exec = 0;
 
 	if (perf_evlist__open(evlist) < 0) {
-		fprintf(stderr, " (not supported)");
-		err = 0;
+		pr_debug("Unable to open dummy and cycles event\n");
+		err = TEST_SKIP;
 		goto out_err;
 	}
 

tools/perf/tests/llvm.c

@@ -2,6 +2,7 @@
 #include <bpf/libbpf.h>
 #include <util/llvm-utils.h>
 #include <util/cache.h>
+#include "llvm.h"
 #include "tests.h"
 #include "debug.h"
 
@@ -11,42 +12,58 @@ static int perf_config_cb(const char *var, const char *val,
 	return perf_default_config(var, val, arg);
 }
 
-/*
- * Randomly give it a "version" section since we don't really load it
- * into kernel
- */
-static const char test_bpf_prog[] =
-	"__attribute__((section(\"do_fork\"), used)) "
-	"int fork(void *ctx) {return 0;} "
-	"char _license[] __attribute__((section(\"license\"), used)) = \"GPL\";"
-	"int _version __attribute__((section(\"version\"), used)) = 0x40100;";
-
 #ifdef HAVE_LIBBPF_SUPPORT
 static int test__bpf_parsing(void *obj_buf, size_t obj_buf_sz)
 {
 	struct bpf_object *obj;
 
 	obj = bpf_object__open_buffer(obj_buf, obj_buf_sz, NULL);
-	if (!obj)
-		return -1;
+	if (IS_ERR(obj))
+		return TEST_FAIL;
 	bpf_object__close(obj);
-	return 0;
+	return TEST_OK;
 }
 #else
 static int test__bpf_parsing(void *obj_buf __maybe_unused,
 			     size_t obj_buf_sz __maybe_unused)
 {
-	fprintf(stderr, " (skip bpf parsing)");
-	return 0;
+	pr_debug("Skip bpf parsing\n");
+	return TEST_OK;
 }
 #endif
 
-int test__llvm(void)
+static struct {
+	const char *source;
+	const char *desc;
+} bpf_source_table[__LLVM_TESTCASE_MAX] = {
+	[LLVM_TESTCASE_BASE] = {
+		.source = test_llvm__bpf_base_prog,
+		.desc = "Basic BPF llvm compiling test",
+	},
+	[LLVM_TESTCASE_KBUILD] = {
+		.source = test_llvm__bpf_test_kbuild_prog,
+		.desc = "Test kbuild searching",
+	},
+};
+
+
+int
+test_llvm__fetch_bpf_obj(void **p_obj_buf,
+			 size_t *p_obj_buf_sz,
+			 enum test_llvm__testcase index,
+			 bool force)
 {
-	char *tmpl_new, *clang_opt_new;
-	void *obj_buf;
-	size_t obj_buf_sz;
-	int err, old_verbose;
+	const char *source;
+	const char *desc;
+	const char *tmpl_old, *clang_opt_old;
+	char *tmpl_new = NULL, *clang_opt_new = NULL;
+	int err, old_verbose, ret = TEST_FAIL;
+
+	if (index >= __LLVM_TESTCASE_MAX)
+		return TEST_FAIL;
+
+	source = bpf_source_table[index].source;
+	desc = bpf_source_table[index].desc;
 
 	perf_config(perf_config_cb, NULL);
 
@@ -54,45 +71,100 @@ int test__llvm(void)
 	 * Skip this test if user's .perfconfig doesn't set [llvm] section
 	 * and clang is not found in $PATH, and this is not perf test -v
 	 */
-	if (verbose == 0 && !llvm_param.user_set_param && llvm__search_clang()) {
-		fprintf(stderr, " (no clang, try 'perf test -v LLVM')");
+	if (!force && (verbose == 0 &&
+		       !llvm_param.user_set_param &&
+		       llvm__search_clang())) {
+		pr_debug("No clang and no verbosive, skip this test\n");
 		return TEST_SKIP;
 	}
 
-	old_verbose = verbose;
 	/*
 	 * llvm is verbosity when error. Suppress all error output if
 	 * not 'perf test -v'.
 	 */
+	old_verbose = verbose;
 	if (verbose == 0)
 		verbose = -1;
 
+	*p_obj_buf = NULL;
+	*p_obj_buf_sz = 0;
+
 	if (!llvm_param.clang_bpf_cmd_template)
-		return -1;
+		goto out;
 
 	if (!llvm_param.clang_opt)
 		llvm_param.clang_opt = strdup("");
 
-	err = asprintf(&tmpl_new, "echo '%s' | %s", test_bpf_prog,
-		       llvm_param.clang_bpf_cmd_template);
+	err = asprintf(&tmpl_new, "echo '%s' | %s%s", source,
+		       llvm_param.clang_bpf_cmd_template,
+		       old_verbose ? "" : " 2>/dev/null");
 	if (err < 0)
-		return -1;
+		goto out;
 	err = asprintf(&clang_opt_new, "-xc %s", llvm_param.clang_opt);
 	if (err < 0)
-		return -1;
+		goto out;
 
+	tmpl_old = llvm_param.clang_bpf_cmd_template;
 	llvm_param.clang_bpf_cmd_template = tmpl_new;
+	clang_opt_old = llvm_param.clang_opt;
 	llvm_param.clang_opt = clang_opt_new;
-	err = llvm__compile_bpf("-", &obj_buf, &obj_buf_sz);
+
+	err = llvm__compile_bpf("-", p_obj_buf, p_obj_buf_sz);
+
+	llvm_param.clang_bpf_cmd_template = tmpl_old;
+	llvm_param.clang_opt = clang_opt_old;
 
 	verbose = old_verbose;
-	if (err) {
-		if (!verbose)
-			fprintf(stderr, " (use -v to see error message)");
-		return -1;
-	}
+	if (err)
+		goto out;
+
+	ret = TEST_OK;
+out:
+	free(tmpl_new);
+	free(clang_opt_new);
+	if (ret != TEST_OK)
+		pr_debug("Failed to compile test case: '%s'\n", desc);
+	return ret;
+}
+
+int test__llvm(void)
+{
+	enum test_llvm__testcase i;
 
-	err = test__bpf_parsing(obj_buf, obj_buf_sz);
+	for (i = 0; i < __LLVM_TESTCASE_MAX; i++) {
+		int ret;
+		void *obj_buf = NULL;
+		size_t obj_buf_sz = 0;
+
+		ret = test_llvm__fetch_bpf_obj(&obj_buf, &obj_buf_sz,
+					       i, false);
+
+		if (ret == TEST_OK) {
+			ret = test__bpf_parsing(obj_buf, obj_buf_sz);
+			if (ret != TEST_OK)
+				pr_debug("Failed to parse test case '%s'\n",
+					 bpf_source_table[i].desc);
+		}
 		free(obj_buf);
-	return err;
+
+		switch (ret) {
+		case TEST_SKIP:
+			return TEST_SKIP;
+		case TEST_OK:
+			break;
+		default:
+			/*
+			 * Test 0 is the basic LLVM test. If test 0
+			 * fail, the basic LLVM support not functional
+			 * so the whole test should fail. If other test
+			 * case fail, it can be fixed by adjusting
+			 * config so don't report error.
+			 */
+			if (i == 0)
+				return TEST_FAIL;
+			else
+				return TEST_SKIP;
+		}
+	}
+	return TEST_OK;
 }

tools/perf/tests/llvm.h

+#ifndef PERF_TEST_LLVM_H
+#define PERF_TEST_LLVM_H
+
+#include <stddef.h> /* for size_t */
+#include <stdbool.h> /* for bool */
+
+extern const char test_llvm__bpf_base_prog[];
+extern const char test_llvm__bpf_test_kbuild_prog[];
+
+enum test_llvm__testcase {
+	LLVM_TESTCASE_BASE,
+	LLVM_TESTCASE_KBUILD,
+	__LLVM_TESTCASE_MAX,
+};
+
+int test_llvm__fetch_bpf_obj(void **p_obj_buf, size_t *p_obj_buf_sz,
+			     enum test_llvm__testcase index, bool force);
+#endif

tools/perf/tests/make

@@ -221,6 +221,11 @@ test_O = $(if $(test_$1),$(test_$1),$(test_default_O))
 
 all:
 
+ifdef SHUF
+run := $(shell shuf -e $(run))
+run_O := $(shell shuf -e $(run_O))
+endif
+
 ifdef DEBUG
 d := $(info run   $(run))
 d := $(info run_O $(run_O))

tools/perf/tests/switch-tracking.c

@@ -366,7 +366,7 @@ int test__switch_tracking(void)
 
 	/* Third event */
 	if (!perf_evlist__can_select_event(evlist, sched_switch)) {
-		fprintf(stderr, " (no sched_switch)");
+		pr_debug("No sched_switch\n");
 		err = 0;
 		goto out;
 	}
@@ -442,7 +442,7 @@ int test__switch_tracking(void)
 	}
 
 	if (perf_evlist__open(evlist) < 0) {
-		fprintf(stderr, " (not supported)");
+		pr_debug("Not supported\n");
 		err = 0;
 		goto out;
 	}

tools/perf/tests/tests.h

@@ -66,6 +66,7 @@ int test__fdarray__add(void);
 int test__kmod_path__parse(void);
 int test__thread_map(void);
 int test__llvm(void);
+int test__bpf(void);
 int test_session_topology(void);
 
 #if defined(__arm__) || defined(__aarch64__)

tools/perf/util/annotate.c

@@ -1084,6 +1084,7 @@ int symbol__annotate(struct symbol *sym, struct map *map, size_t privsize)
 	struct kcore_extract kce;
 	bool delete_extract = false;
 	int lineno = 0;
+	int nline;
 
 	if (filename)
 		symbol__join_symfs(symfs_filename, filename);
@@ -1179,6 +1180,9 @@ int symbol__annotate(struct symbol *sym, struct map *map, size_t privsize)
 
 		ret = decompress_to_file(m.ext, symfs_filename, fd);
 
+		if (ret)
+			pr_err("Cannot decompress %s %s\n", m.ext, symfs_filename);
+
 		free(m.ext);
 		close(fd);
 
@@ -1204,13 +1208,25 @@ int symbol__annotate(struct symbol *sym, struct map *map, size_t privsize)
 	pr_debug("Executing: %s\n", command);
 
 	file = popen(command, "r");
-	if (!file)
+	if (!file) {
+		pr_err("Failure running %s\n", command);
+		/*
+		 * If we were using debug info should retry with
+		 * original binary.
+		 */
 		goto out_remove_tmp;
+	}
 
-	while (!feof(file))
+	nline = 0;
+	while (!feof(file)) {
 		if (symbol__parse_objdump_line(sym, map, file, privsize,
 			    &lineno) < 0)
 			break;
+		nline++;
+	}
+
+	if (nline == 0)
+		pr_err("No output from %s\n", command);
 
 	/*
 	 * kallsyms does not have symbol sizes so there may a nop at the end.
@@ -1604,6 +1620,7 @@ int symbol__tty_annotate(struct symbol *sym, struct map *map,
 	len = symbol__size(sym);
 
 	if (print_lines) {
+		srcline_full_filename = full_paths;
 		symbol__get_source_line(sym, map, evsel, &source_line, len);
 		print_summary(&source_line, dso->long_name);
 	}

tools/perf/util/bpf-loader.c

@@ -26,18 +26,40 @@ static int libbpf_##name(const char *fmt, ...)	\
 	return ret;				\
 }
 
-DEFINE_PRINT_FN(warning, 0)
-DEFINE_PRINT_FN(info, 0)
+DEFINE_PRINT_FN(warning, 1)
+DEFINE_PRINT_FN(info, 1)
 DEFINE_PRINT_FN(debug, 1)
 
 struct bpf_prog_priv {
 	struct perf_probe_event pev;
 };
 
+static bool libbpf_initialized;
+
+struct bpf_object *
+bpf__prepare_load_buffer(void *obj_buf, size_t obj_buf_sz, const char *name)
+{
+	struct bpf_object *obj;
+
+	if (!libbpf_initialized) {
+		libbpf_set_print(libbpf_warning,
+				 libbpf_info,
+				 libbpf_debug);
+		libbpf_initialized = true;
+	}
+
+	obj = bpf_object__open_buffer(obj_buf, obj_buf_sz, name);
+	if (IS_ERR(obj)) {
+		pr_debug("bpf: failed to load buffer\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	return obj;
+}
+
 struct bpf_object *bpf__prepare_load(const char *filename, bool source)
 {
 	struct bpf_object *obj;
-	static bool libbpf_initialized;
 
 	if (!libbpf_initialized) {
 		libbpf_set_print(libbpf_warning,
@@ -53,15 +75,15 @@ struct bpf_object *bpf__prepare_load(const char *filename, bool source)
 
 		err = llvm__compile_bpf(filename, &obj_buf, &obj_buf_sz);
 		if (err)
-			return ERR_PTR(err);
+			return ERR_PTR(-BPF_LOADER_ERRNO__COMPILE);
 		obj = bpf_object__open_buffer(obj_buf, obj_buf_sz, filename);
 		free(obj_buf);
 	} else
 		obj = bpf_object__open(filename);
 
-	if (!obj) {
+	if (IS_ERR(obj)) {
 		pr_debug("bpf: failed to load %s\n", filename);
-		return ERR_PTR(-EINVAL);
+		return obj;
 	}
 
 	return obj;
@@ -96,9 +118,9 @@ config_bpf_program(struct bpf_program *prog)
 	int err;
 
 	config_str = bpf_program__title(prog, false);
-	if (!config_str) {
+	if (IS_ERR(config_str)) {
 		pr_debug("bpf: unable to get title for program\n");
-		return -EINVAL;
+		return PTR_ERR(config_str);
 	}
 
 	priv = calloc(sizeof(*priv), 1);
@@ -113,14 +135,14 @@ config_bpf_program(struct bpf_program *prog)
 	if (err < 0) {
 		pr_debug("bpf: '%s' is not a valid config string\n",
 			 config_str);
-		err = -EINVAL;
+		err = -BPF_LOADER_ERRNO__CONFIG;
 		goto errout;
 	}
 
 	if (pev->group && strcmp(pev->group, PERF_BPF_PROBE_GROUP)) {
 		pr_debug("bpf: '%s': group for event is set and not '%s'.\n",
 			 config_str, PERF_BPF_PROBE_GROUP);
-		err = -EINVAL;
+		err = -BPF_LOADER_ERRNO__GROUP;
 		goto errout;
 	} else if (!pev->group)
 		pev->group = strdup(PERF_BPF_PROBE_GROUP);
@@ -132,9 +154,9 @@ config_bpf_program(struct bpf_program *prog)
 	}
 
 	if (!pev->event) {
-		pr_debug("bpf: '%s': event name is missing\n",
+		pr_debug("bpf: '%s': event name is missing. Section name should be 'key=value'\n",
 			 config_str);
-		err = -EINVAL;
+		err = -BPF_LOADER_ERRNO__EVENTNAME;
 		goto errout;
 	}
 	pr_debug("bpf: config '%s' is ok\n", config_str);
@@ -285,7 +307,7 @@ int bpf__foreach_tev(struct bpf_object *obj,
 				(void **)&priv);
 		if (err || !priv) {
 			pr_debug("bpf: failed to get private field\n");
-			return -EINVAL;
+			return -BPF_LOADER_ERRNO__INTERNAL;
 		}
 
 		pev = &priv->pev;
@@ -308,13 +330,57 @@ int bpf__foreach_tev(struct bpf_object *obj,
 	return 0;
 }
 
+#define ERRNO_OFFSET(e)		((e) - __BPF_LOADER_ERRNO__START)
+#define ERRCODE_OFFSET(c)	ERRNO_OFFSET(BPF_LOADER_ERRNO__##c)
+#define NR_ERRNO	(__BPF_LOADER_ERRNO__END - __BPF_LOADER_ERRNO__START)
+
+static const char *bpf_loader_strerror_table[NR_ERRNO] = {
+	[ERRCODE_OFFSET(CONFIG)]	= "Invalid config string",
+	[ERRCODE_OFFSET(GROUP)]		= "Invalid group name",
+	[ERRCODE_OFFSET(EVENTNAME)]	= "No event name found in config string",
+	[ERRCODE_OFFSET(INTERNAL)]	= "BPF loader internal error",
+	[ERRCODE_OFFSET(COMPILE)]	= "Error when compiling BPF scriptlet",
+};
+
+static int
+bpf_loader_strerror(int err, char *buf, size_t size)
+{
+	char sbuf[STRERR_BUFSIZE];
+	const char *msg;
+
+	if (!buf || !size)
+		return -1;
+
+	err = err > 0 ? err : -err;
+
+	if (err >= __LIBBPF_ERRNO__START)
+		return libbpf_strerror(err, buf, size);
+
+	if (err >= __BPF_LOADER_ERRNO__START && err < __BPF_LOADER_ERRNO__END) {
+		msg = bpf_loader_strerror_table[ERRNO_OFFSET(err)];
+		snprintf(buf, size, "%s", msg);
+		buf[size - 1] = '\0';
+		return 0;
+	}
+
+	if (err >= __BPF_LOADER_ERRNO__END)
+		snprintf(buf, size, "Unknown bpf loader error %d", err);
+	else
+		snprintf(buf, size, "%s",
+			 strerror_r(err, sbuf, sizeof(sbuf)));
+
+	buf[size - 1] = '\0';
+	return -1;
+}
+
 #define bpf__strerror_head(err, buf, size) \
 	char sbuf[STRERR_BUFSIZE], *emsg;\
 	if (!size)\
 		return 0;\
 	if (err < 0)\
 		err = -err;\
-	emsg = strerror_r(err, sbuf, sizeof(sbuf));\
+	bpf_loader_strerror(err, sbuf, sizeof(sbuf));\
+	emsg = sbuf;\
 	switch (err) {\
 	default:\
 		scnprintf(buf, size, "%s", emsg);\
@@ -330,23 +396,62 @@ int bpf__foreach_tev(struct bpf_object *obj,
 	}\
 	buf[size - 1] = '\0';
 
+int bpf__strerror_prepare_load(const char *filename, bool source,
+			       int err, char *buf, size_t size)
+{
+	size_t n;
+	int ret;
+
+	n = snprintf(buf, size, "Failed to load %s%s: ",
+			 filename, source ? " from source" : "");
+	if (n >= size) {
+		buf[size - 1] = '\0';
+		return 0;
+	}
+	buf += n;
+	size -= n;
+
+	ret = bpf_loader_strerror(err, buf, size);
+	buf[size - 1] = '\0';
+	return ret;
+}
+
 int bpf__strerror_probe(struct bpf_object *obj __maybe_unused,
 			int err, char *buf, size_t size)
 {
 	bpf__strerror_head(err, buf, size);
 	bpf__strerror_entry(EEXIST, "Probe point exist. Try use 'perf probe -d \"*\"'");
-	bpf__strerror_entry(EPERM, "You need to be root, and /proc/sys/kernel/kptr_restrict should be 0\n");
-	bpf__strerror_entry(ENOENT, "You need to check probing points in BPF file\n");
+	bpf__strerror_entry(EACCES, "You need to be root");
+	bpf__strerror_entry(EPERM, "You need to be root, and /proc/sys/kernel/kptr_restrict should be 0");
+	bpf__strerror_entry(ENOENT, "You need to check probing points in BPF file");
 	bpf__strerror_end(buf, size);
 	return 0;
 }
 
-int bpf__strerror_load(struct bpf_object *obj __maybe_unused,
+int bpf__strerror_load(struct bpf_object *obj,
 		       int err, char *buf, size_t size)
 {
 	bpf__strerror_head(err, buf, size);
-	bpf__strerror_entry(EINVAL, "%s: Are you root and runing a CONFIG_BPF_SYSCALL kernel?",
-			    emsg)
+	case LIBBPF_ERRNO__KVER: {
+		unsigned int obj_kver = bpf_object__get_kversion(obj);
+		unsigned int real_kver;
+
+		if (fetch_kernel_version(&real_kver, NULL, 0)) {
+			scnprintf(buf, size, "Unable to fetch kernel version");
+			break;
+		}
+
+		if (obj_kver != real_kver) {
+			scnprintf(buf, size,
+				  "'version' ("KVER_FMT") doesn't match running kernel ("KVER_FMT")",
+				  KVER_PARAM(obj_kver),
+				  KVER_PARAM(real_kver));
+			break;
+		}
+
+		scnprintf(buf, size, "Failed to load program for unknown reason");
+		break;
+	}
 	bpf__strerror_end(buf, size);
 	return 0;
 }

tools/perf/util/bpf-loader.h

@@ -8,9 +8,21 @@
 #include <linux/compiler.h>
 #include <linux/err.h>
 #include <string.h>
+#include <bpf/libbpf.h>
 #include "probe-event.h"
 #include "debug.h"
 
+enum bpf_loader_errno {
+	__BPF_LOADER_ERRNO__START = __LIBBPF_ERRNO__START - 100,
+	/* Invalid config string */
+	BPF_LOADER_ERRNO__CONFIG = __BPF_LOADER_ERRNO__START,
+	BPF_LOADER_ERRNO__GROUP,	/* Invalid group name */
+	BPF_LOADER_ERRNO__EVENTNAME,	/* Event name is missing */
+	BPF_LOADER_ERRNO__INTERNAL,	/* BPF loader internal error */
+	BPF_LOADER_ERRNO__COMPILE,	/* Error when compiling BPF scriptlet */
+	__BPF_LOADER_ERRNO__END,
+};
+
 struct bpf_object;
 #define PERF_BPF_PROBE_GROUP "perf_bpf_probe"
 
@@ -19,6 +31,11 @@ typedef int (*bpf_prog_iter_callback_t)(struct probe_trace_event *tev,
 
 #ifdef HAVE_LIBBPF_SUPPORT
 struct bpf_object *bpf__prepare_load(const char *filename, bool source);
+int bpf__strerror_prepare_load(const char *filename, bool source,
+			       int err, char *buf, size_t size);
+
+struct bpf_object *bpf__prepare_load_buffer(void *obj_buf, size_t obj_buf_sz,
+					    const char *name);
 
 void bpf__clear(void);
 
@@ -41,6 +58,13 @@ bpf__prepare_load(const char *filename __maybe_unused,
 	return ERR_PTR(-ENOTSUP);
 }
 
+static inline struct bpf_object *
+bpf__prepare_load_buffer(void *obj_buf __maybe_unused,
+					   size_t obj_buf_sz __maybe_unused)
+{
+	return ERR_PTR(-ENOTSUP);
+}
+
 static inline void bpf__clear(void) { }
 
 static inline int bpf__probe(struct bpf_object *obj __maybe_unused) { return 0;}
@@ -67,6 +91,15 @@ __bpf_strerror(char *buf, size_t size)
 	return 0;
 }
 
+static inline
+int bpf__strerror_prepare_load(const char *filename __maybe_unused,
+			       bool source __maybe_unused,
+			       int err __maybe_unused,
+			       char *buf, size_t size)
+{
+	return __bpf_strerror(buf, size);
+}
+
 static inline int
 bpf__strerror_probe(struct bpf_object *obj __maybe_unused,
 		    int err __maybe_unused,

tools/perf/util/llvm-utils.c

@@ -4,17 +4,18 @@
  */
 
 #include <stdio.h>
-#include <sys/utsname.h>
 #include "util.h"
 #include "debug.h"
 #include "llvm-utils.h"
 #include "cache.h"
 
 #define CLANG_BPF_CMD_DEFAULT_TEMPLATE				\
-		"$CLANG_EXEC -D__KERNEL__ $CLANG_OPTIONS "	\
-		"$KERNEL_INC_OPTIONS -Wno-unused-value "	\
-		"-Wno-pointer-sign -working-directory "		\
-		"$WORKING_DIR -c \"$CLANG_SOURCE\" -target bpf -O2 -o -"
+		"$CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS "\
+		"-DLINUX_VERSION_CODE=$LINUX_VERSION_CODE "	\
+		"$CLANG_OPTIONS $KERNEL_INC_OPTIONS "		\
+		"-Wno-unused-value -Wno-pointer-sign "		\
+		"-working-directory $WORKING_DIR "		\
+		"-c \"$CLANG_SOURCE\" -target bpf -O2 -o -"
 
 struct llvm_param llvm_param = {
 	.clang_path = "clang",
@@ -214,18 +215,19 @@ static int detect_kbuild_dir(char **kbuild_dir)
 	const char *suffix_dir = "";
 
 	char *autoconf_path;
-	struct utsname utsname;
 
 	int err;
 
 	if (!test_dir) {
-		err = uname(&utsname);
-		if (err) {
-			pr_warning("uname failed: %s\n", strerror(errno));
+		/* _UTSNAME_LENGTH is 65 */
+		char release[128];
+
+		err = fetch_kernel_version(NULL, release,
+					   sizeof(release));
+		if (err)
 			return -EINVAL;
-		}
 
-		test_dir = utsname.release;
+		test_dir = release;
 		prefix_dir = "/lib/modules/";
 		suffix_dir = "/build";
 	}
@@ -326,13 +328,15 @@ get_kbuild_opts(char **kbuild_dir, char **kbuild_include_opts)
 int llvm__compile_bpf(const char *path, void **p_obj_buf,
 		      size_t *p_obj_buf_sz)
 {
-	int err;
-	char clang_path[PATH_MAX];
+	size_t obj_buf_sz;
+	void *obj_buf = NULL;
+	int err, nr_cpus_avail;
+	unsigned int kernel_version;
+	char linux_version_code_str[64];
 	const char *clang_opt = llvm_param.clang_opt;
-	const char *template = llvm_param.clang_bpf_cmd_template;
+	char clang_path[PATH_MAX], nr_cpus_avail_str[64];
 	char *kbuild_dir = NULL, *kbuild_include_opts = NULL;
-	void *obj_buf = NULL;
-	size_t obj_buf_sz;
+	const char *template = llvm_param.clang_bpf_cmd_template;
 
 	if (!template)
 		template = CLANG_BPF_CMD_DEFAULT_TEMPLATE;
@@ -354,6 +358,24 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf,
 	 */
 	get_kbuild_opts(&kbuild_dir, &kbuild_include_opts);
 
+	nr_cpus_avail = sysconf(_SC_NPROCESSORS_CONF);
+	if (nr_cpus_avail <= 0) {
+		pr_err(
+"WARNING:\tunable to get available CPUs in this system: %s\n"
+"        \tUse 128 instead.\n", strerror(errno));
+		nr_cpus_avail = 128;
+	}
+	snprintf(nr_cpus_avail_str, sizeof(nr_cpus_avail_str), "%d",
+		 nr_cpus_avail);
+
+	if (fetch_kernel_version(&kernel_version, NULL, 0))
+		kernel_version = 0;
+
+	snprintf(linux_version_code_str, sizeof(linux_version_code_str),
+		 "0x%x", kernel_version);
+
+	force_set_env("NR_CPUS", nr_cpus_avail_str);
+	force_set_env("LINUX_VERSION_CODE", linux_version_code_str);
 	force_set_env("CLANG_EXEC", clang_path);
 	force_set_env("CLANG_OPTIONS", clang_opt);
 	force_set_env("KERNEL_INC_OPTIONS", kbuild_include_opts);

tools/perf/util/map.c

@@ -644,6 +644,12 @@ size_t map_groups__fprintf(struct map_groups *mg, FILE *fp)
 	return printed;
 }
 
+static void __map_groups__insert(struct map_groups *mg, struct map *map)
+{
+	__maps__insert(&mg->maps[map->type], map);
+	map->groups = mg;
+}
+
 static int maps__fixup_overlappings(struct maps *maps, struct map *map, FILE *fp)
 {
 	struct rb_root *root;
@@ -682,7 +688,7 @@ static int maps__fixup_overlappings(struct maps *maps, struct map *map, FILE *fp
 			}
 
 			before->end = map->start;
-			__maps__insert(maps, before);
+			__map_groups__insert(pos->groups, before);
 			if (verbose >= 2)
 				map__fprintf(before, fp);
 		}
@@ -696,7 +702,7 @@ static int maps__fixup_overlappings(struct maps *maps, struct map *map, FILE *fp
 			}
 
 			after->start = map->end;
-			__maps__insert(maps, after);
+			__map_groups__insert(pos->groups, after);
 			if (verbose >= 2)
 				map__fprintf(after, fp);
 		}

tools/perf/util/parse-events.c

@@ -632,19 +632,20 @@ int parse_events_load_bpf(struct parse_events_evlist *data,
 	struct bpf_object *obj;
 
 	obj = bpf__prepare_load(bpf_file_name, source);
-	if (IS_ERR(obj) || !obj) {
+	if (IS_ERR(obj)) {
 		char errbuf[BUFSIZ];
 		int err;
 
-		err = obj ? PTR_ERR(obj) : -EINVAL;
+		err = PTR_ERR(obj);
 
 		if (err == -ENOTSUP)
 			snprintf(errbuf, sizeof(errbuf),
 				 "BPF support is not compiled");
 		else
-			snprintf(errbuf, sizeof(errbuf),
-				 "BPF object file '%s' is invalid",
-				 bpf_file_name);
+			bpf__strerror_prepare_load(bpf_file_name,
+						   source,
+						   -err, errbuf,
+						   sizeof(errbuf));
 
 		data->error->help = strdup("(add -v to see detail)");
 		data->error->str = strdup(errbuf);

tools/perf/util/probe-event.c

@@ -1895,9 +1895,8 @@ static int find_perf_probe_point_from_map(struct probe_trace_point *tp,
 		sym = map__find_symbol(map, addr, NULL);
 	} else {
 		if (tp->symbol && !addr) {
-			ret = kernel_get_symbol_address_by_name(tp->symbol,
-							&addr, true, false);
-			if (ret < 0)
+			if (kernel_get_symbol_address_by_name(tp->symbol,
+						&addr, true, false) < 0)
 				goto out;
 		}
 		if (addr) {
@@ -1905,6 +1904,7 @@ static int find_perf_probe_point_from_map(struct probe_trace_point *tp,
 			sym = __find_kernel_function(addr, &map);
 		}
 	}
+
 	if (!sym)
 		goto out;
 

tools/perf/util/probe-file.c

@@ -138,6 +138,9 @@ struct strlist *probe_file__get_rawlist(int fd)
 	char *p;
 	struct strlist *sl;
 
+	if (fd < 0)
+		return NULL;
+
 	sl = strlist__new(NULL, NULL);
 
 	fp = fdopen(dup(fd), "r");
@@ -271,6 +274,9 @@ int probe_file__get_events(int fd, struct strfilter *filter,
 	const char *p;
 	int ret = -ENOENT;
 
+	if (!plist)
+		return -EINVAL;
+
 	namelist = __probe_file__get_namelist(fd, true);
 	if (!namelist)
 		return -ENOENT;

tools/perf/util/session.c

@@ -29,7 +29,7 @@ static int perf_session__open(struct perf_session *session)
 	struct perf_data_file *file = session->file;
 
 	if (perf_session__read_header(session) < 0) {
-		pr_err("incompatible file format (rerun with -v to learn more)");
+		pr_err("incompatible file format (rerun with -v to learn more)\n");
 		return -1;
 	}
 
@@ -37,17 +37,17 @@ static int perf_session__open(struct perf_session *session)
 		return 0;
 
 	if (!perf_evlist__valid_sample_type(session->evlist)) {
-		pr_err("non matching sample_type");
+		pr_err("non matching sample_type\n");
 		return -1;
 	}
 
 	if (!perf_evlist__valid_sample_id_all(session->evlist)) {
-		pr_err("non matching sample_id_all");
+		pr_err("non matching sample_id_all\n");
 		return -1;
 	}
 
 	if (!perf_evlist__valid_read_format(session->evlist)) {
-		pr_err("non matching read_format");
+		pr_err("non matching read_format\n");
 		return -1;
 	}
 

tools/perf/util/stat-shadow.c

@@ -413,6 +413,11 @@ void perf_stat__print_shadow_stats(FILE *out, struct perf_evsel *evsel,
 			ratio = total / avg;
 
 		fprintf(out, " # %8.0f cycles / elision       ", ratio);
+	} else if (perf_evsel__match(evsel, SOFTWARE, SW_TASK_CLOCK)) {
+		if ((ratio = avg_stats(&walltime_nsecs_stats)) != 0)
+			fprintf(out, " # %8.3f CPUs utilized          ", avg / ratio);
+		else
+			fprintf(out, "                                   ");
 	} else if (runtime_nsecs_stats[cpu].n != 0) {
 		char unit = 'M';
 

tools/perf/util/util.c

@@ -3,6 +3,7 @@
 #include "debug.h"
 #include <api/fs/fs.h>
 #include <sys/mman.h>
+#include <sys/utsname.h>
 #ifdef HAVE_BACKTRACE_SUPPORT
 #include <execinfo.h>
 #endif
@@ -665,3 +666,32 @@ bool find_process(const char *name)
 	closedir(dir);
 	return ret ? false : true;
 }
+
+int
+fetch_kernel_version(unsigned int *puint, char *str,
+		     size_t str_size)
+{
+	struct utsname utsname;
+	int version, patchlevel, sublevel, err;
+
+	if (uname(&utsname))
+		return -1;
+
+	if (str && str_size) {
+		strncpy(str, utsname.release, str_size);
+		str[str_size - 1] = '\0';
+	}
+
+	err = sscanf(utsname.release, "%d.%d.%d",
+		     &version, &patchlevel, &sublevel);
+
+	if (err != 3) {
+		pr_debug("Unablt to get kernel version from uname '%s'\n",
+			 utsname.release);
+		return -1;
+	}
+
+	if (puint)
+		*puint = (version << 16) + (patchlevel << 8) + sublevel;
+	return 0;
+}

tools/perf/util/util.h

@@ -350,4 +350,12 @@ static inline char *asprintf_expr_not_in_ints(const char *var, size_t nints, int
 
 int get_stack_size(const char *str, unsigned long *_size);
 
+int fetch_kernel_version(unsigned int *puint,
+			 char *str, size_t str_sz);
+#define KVER_VERSION(x)		(((x) >> 16) & 0xff)
+#define KVER_PATCHLEVEL(x)	(((x) >> 8) & 0xff)
+#define KVER_SUBLEVEL(x)	((x) & 0xff)
+#define KVER_FMT	"%d.%d.%d"
+#define KVER_PARAM(x)	KVER_VERSION(x), KVER_PATCHLEVEL(x), KVER_SUBLEVEL(x)
+
 #endif /* GIT_COMPAT_UTIL_H */