Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2954 insertions, 0 deletions

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
new file mode 100644
index 000000000..11a2aa808
--- /dev/null
+++ b/tools/perf/util/evsel.c
@@ -0,0 +1,2954 @@
+/*
+ * Copyright (C) 2011, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
+ *
+ * Parts came from builtin-{top,stat,record}.c, see those files for further
+ * copyright notes.
+ *
+ * Released under the GPL v2. (and only v2, not any later version)
+ */
+
+#include <byteswap.h>
+#include <errno.h>
+#include <inttypes.h>
+#include <linux/bitops.h>
+#include <api/fs/fs.h>
+#include <api/fs/tracing_path.h>
+#include <traceevent/event-parse.h>
+#include <linux/hw_breakpoint.h>
+#include <linux/perf_event.h>
+#include <linux/compiler.h>
+#include <linux/err.h>
+#include <sys/ioctl.h>
+#include <sys/resource.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include "asm/bug.h"
+#include "callchain.h"
+#include "cgroup.h"
+#include "event.h"
+#include "evsel.h"
+#include "evlist.h"
+#include "util.h"
+#include "cpumap.h"
+#include "thread_map.h"
+#include "target.h"
+#include "perf_regs.h"
+#include "debug.h"
+#include "trace-event.h"
+#include "stat.h"
+#include "memswap.h"
+#include "util/parse-branch-options.h"
+
+#include "sane_ctype.h"
+
+struct perf_missing_features perf_missing_features;
+
+static clockid_t clockid;
+
+static int perf_evsel__no_extra_init(struct perf_evsel *evsel __maybe_unused)
+{
+	return 0;
+}
+
+void __weak test_attr__ready(void) { }
+
+static void perf_evsel__no_extra_fini(struct perf_evsel *evsel __maybe_unused)
+{
+}
+
+static struct {
+	size_t	size;
+	int	(*init)(struct perf_evsel *evsel);
+	void	(*fini)(struct perf_evsel *evsel);
+} perf_evsel__object = {
+	.size = sizeof(struct perf_evsel),
+	.init = perf_evsel__no_extra_init,
+	.fini = perf_evsel__no_extra_fini,
+};
+
+int perf_evsel__object_config(size_t object_size,
+			      int (*init)(struct perf_evsel *evsel),
+			      void (*fini)(struct perf_evsel *evsel))
+{
+
+	if (object_size == 0)
+		goto set_methods;
+
+	if (perf_evsel__object.size > object_size)
+		return -EINVAL;
+
+	perf_evsel__object.size = object_size;
+
+set_methods:
+	if (init != NULL)
+		perf_evsel__object.init = init;
+
+	if (fini != NULL)
+		perf_evsel__object.fini = fini;
+
+	return 0;
+}
+
+#define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
+
+int __perf_evsel__sample_size(u64 sample_type)
+{
+	u64 mask = sample_type & PERF_SAMPLE_MASK;
+	int size = 0;
+	int i;
+
+	for (i = 0; i < 64; i++) {
+		if (mask & (1ULL << i))
+			size++;
+	}
+
+	size *= sizeof(u64);
+
+	return size;
+}
+
+/**
+ * __perf_evsel__calc_id_pos - calculate id_pos.
+ * @sample_type: sample type
+ *
+ * This function returns the position of the event id (PERF_SAMPLE_ID or
+ * PERF_SAMPLE_IDENTIFIER) in a sample event i.e. in the array of struct
+ * sample_event.
+ */
+static int __perf_evsel__calc_id_pos(u64 sample_type)
+{
+	int idx = 0;
+
+	if (sample_type & PERF_SAMPLE_IDENTIFIER)
+		return 0;
+
+	if (!(sample_type & PERF_SAMPLE_ID))
+		return -1;
+
+	if (sample_type & PERF_SAMPLE_IP)
+		idx += 1;
+
+	if (sample_type & PERF_SAMPLE_TID)
+		idx += 1;
+
+	if (sample_type & PERF_SAMPLE_TIME)
+		idx += 1;
+
+	if (sample_type & PERF_SAMPLE_ADDR)
+		idx += 1;
+
+	return idx;
+}
+
+/**
+ * __perf_evsel__calc_is_pos - calculate is_pos.
+ * @sample_type: sample type
+ *
+ * This function returns the position (counting backwards) of the event id
+ * (PERF_SAMPLE_ID or PERF_SAMPLE_IDENTIFIER) in a non-sample event i.e. if
+ * sample_id_all is used there is an id sample appended to non-sample events.
+ */
+static int __perf_evsel__calc_is_pos(u64 sample_type)
+{
+	int idx = 1;
+
+	if (sample_type & PERF_SAMPLE_IDENTIFIER)
+		return 1;
+
+	if (!(sample_type & PERF_SAMPLE_ID))
+		return -1;
+
+	if (sample_type & PERF_SAMPLE_CPU)
+		idx += 1;
+
+	if (sample_type & PERF_SAMPLE_STREAM_ID)
+		idx += 1;
+
+	return idx;
+}
+
+void perf_evsel__calc_id_pos(struct perf_evsel *evsel)
+{
+	evsel->id_pos = __perf_evsel__calc_id_pos(evsel->attr.sample_type);
+	evsel->is_pos = __perf_evsel__calc_is_pos(evsel->attr.sample_type);
+}
+
+void __perf_evsel__set_sample_bit(struct perf_evsel *evsel,
+				  enum perf_event_sample_format bit)
+{
+	if (!(evsel->attr.sample_type & bit)) {
+		evsel->attr.sample_type |= bit;
+		evsel->sample_size += sizeof(u64);
+		perf_evsel__calc_id_pos(evsel);
+	}
+}
+
+void __perf_evsel__reset_sample_bit(struct perf_evsel *evsel,
+				    enum perf_event_sample_format bit)
+{
+	if (evsel->attr.sample_type & bit) {
+		evsel->attr.sample_type &= ~bit;
+		evsel->sample_size -= sizeof(u64);
+		perf_evsel__calc_id_pos(evsel);
+	}
+}
+
+void perf_evsel__set_sample_id(struct perf_evsel *evsel,
+			       bool can_sample_identifier)
+{
+	if (can_sample_identifier) {
+		perf_evsel__reset_sample_bit(evsel, ID);
+		perf_evsel__set_sample_bit(evsel, IDENTIFIER);
+	} else {
+		perf_evsel__set_sample_bit(evsel, ID);
+	}
+	evsel->attr.read_format |= PERF_FORMAT_ID;
+}
+
+/**
+ * perf_evsel__is_function_event - Return whether given evsel is a function
+ * trace event
+ *
+ * @evsel - evsel selector to be tested
+ *
+ * Return %true if event is function trace event
+ */
+bool perf_evsel__is_function_event(struct perf_evsel *evsel)
+{
+#define FUNCTION_EVENT "ftrace:function"
+
+	return evsel->name &&
+	       !strncmp(FUNCTION_EVENT, evsel->name, sizeof(FUNCTION_EVENT));
+
+#undef FUNCTION_EVENT
+}
+
+void perf_evsel__init(struct perf_evsel *evsel,
+		      struct perf_event_attr *attr, int idx)
+{
+	evsel->idx	   = idx;
+	evsel->tracking	   = !idx;
+	evsel->attr	   = *attr;
+	evsel->leader	   = evsel;
+	evsel->unit	   = "";
+	evsel->scale	   = 1.0;
+	evsel->evlist	   = NULL;
+	evsel->bpf_fd	   = -1;
+	INIT_LIST_HEAD(&evsel->node);
+	INIT_LIST_HEAD(&evsel->config_terms);
+	perf_evsel__object.init(evsel);
+	evsel->sample_size = __perf_evsel__sample_size(attr->sample_type);
+	perf_evsel__calc_id_pos(evsel);
+	evsel->cmdline_group_boundary = false;
+	evsel->metric_expr   = NULL;
+	evsel->metric_name   = NULL;
+	evsel->metric_events = NULL;
+	evsel->collect_stat  = false;
+	evsel->pmu_name      = NULL;
+}
+
+struct perf_evsel *perf_evsel__new_idx(struct perf_event_attr *attr, int idx)
+{
+	struct perf_evsel *evsel = zalloc(perf_evsel__object.size);
+
+	if (!evsel)
+		return NULL;
+	perf_evsel__init(evsel, attr, idx);
+
+	if (perf_evsel__is_bpf_output(evsel)) {
+		evsel->attr.sample_type |= (PERF_SAMPLE_RAW | PERF_SAMPLE_TIME |
+					    PERF_SAMPLE_CPU | PERF_SAMPLE_PERIOD),
+		evsel->attr.sample_period = 1;
+	}
+
+	if (perf_evsel__is_clock(evsel)) {
+		/*
+		 * The evsel->unit points to static alias->unit
+		 * so it's ok to use static string in here.
+		 */
+		static const char *unit = "msec";
+
+		evsel->unit = unit;
+		evsel->scale = 1e-6;
+	}
+
+	return evsel;
+}
+
+static bool perf_event_can_profile_kernel(void)
+{
+	return geteuid() == 0 || perf_event_paranoid() == -1;
+}
+
+struct perf_evsel *perf_evsel__new_cycles(bool precise)
+{
+	struct perf_event_attr attr = {
+		.type	= PERF_TYPE_HARDWARE,
+		.config	= PERF_COUNT_HW_CPU_CYCLES,
+		.exclude_kernel	= !perf_event_can_profile_kernel(),
+	};
+	struct perf_evsel *evsel;
+
+	event_attr_init(&attr);
+
+	if (!precise)
+		goto new_event;
+	/*
+	 * Unnamed union member, not supported as struct member named
+	 * initializer in older compilers such as gcc 4.4.7
+	 *
+	 * Just for probing the precise_ip:
+	 */
+	attr.sample_period = 1;
+
+	perf_event_attr__set_max_precise_ip(&attr);
+	/*
+	 * Now let the usual logic to set up the perf_event_attr defaults
+	 * to kick in when we return and before perf_evsel__open() is called.
+	 */
+	attr.sample_period = 0;
+new_event:
+	evsel = perf_evsel__new(&attr);
+	if (evsel == NULL)
+		goto out;
+
+	/* use asprintf() because free(evsel) assumes name is allocated */
+	if (asprintf(&evsel->name, "cycles%s%s%.*s",
+		     (attr.precise_ip || attr.exclude_kernel) ? ":" : "",
+		     attr.exclude_kernel ? "u" : "",
+		     attr.precise_ip ? attr.precise_ip + 1 : 0, "ppp") < 0)
+		goto error_free;
+out:
+	return evsel;
+error_free:
+	perf_evsel__delete(evsel);
+	evsel = NULL;
+	goto out;
+}
+
+/*
+ * Returns pointer with encoded error via <linux/err.h> interface.
+ */
+struct perf_evsel *perf_evsel__newtp_idx(const char *sys, const char *name, int idx)
+{
+	struct perf_evsel *evsel = zalloc(perf_evsel__object.size);
+	int err = -ENOMEM;
+
+	if (evsel == NULL) {
+		goto out_err;
+	} else {
+		struct perf_event_attr attr = {
+			.type	       = PERF_TYPE_TRACEPOINT,
+			.sample_type   = (PERF_SAMPLE_RAW | PERF_SAMPLE_TIME |
+					  PERF_SAMPLE_CPU | PERF_SAMPLE_PERIOD),
+		};
+
+		if (asprintf(&evsel->name, "%s:%s", sys, name) < 0)
+			goto out_free;
+
+		evsel->tp_format = trace_event__tp_format(sys, name);
+		if (IS_ERR(evsel->tp_format)) {
+			err = PTR_ERR(evsel->tp_format);
+			goto out_free;
+		}
+
+		event_attr_init(&attr);
+		attr.config = evsel->tp_format->id;
+		attr.sample_period = 1;
+		perf_evsel__init(evsel, &attr, idx);
+	}
+
+	return evsel;
+
+out_free:
+	zfree(&evsel->name);
+	free(evsel);
+out_err:
+	return ERR_PTR(err);
+}
+
+const char *perf_evsel__hw_names[PERF_COUNT_HW_MAX] = {
+	"cycles",
+	"instructions",
+	"cache-references",
+	"cache-misses",
+	"branches",
+	"branch-misses",
+	"bus-cycles",
+	"stalled-cycles-frontend",
+	"stalled-cycles-backend",
+	"ref-cycles",
+};
+
+static const char *__perf_evsel__hw_name(u64 config)
+{
+	if (config < PERF_COUNT_HW_MAX && perf_evsel__hw_names[config])
+		return perf_evsel__hw_names[config];
+
+	return "unknown-hardware";
+}
+
+static int perf_evsel__add_modifiers(struct perf_evsel *evsel, char *bf, size_t size)
+{
+	int colon = 0, r = 0;
+	struct perf_event_attr *attr = &evsel->attr;
+	bool exclude_guest_default = false;
+
+#define MOD_PRINT(context, mod)	do {					\
+		if (!attr->exclude_##context) {				\
+			if (!colon) colon = ++r;			\
+			r += scnprintf(bf + r, size - r, "%c", mod);	\
+		} } while(0)
+
+	if (attr->exclude_kernel || attr->exclude_user || attr->exclude_hv) {
+		MOD_PRINT(kernel, 'k');
+		MOD_PRINT(user, 'u');
+		MOD_PRINT(hv, 'h');
+		exclude_guest_default = true;
+	}
+
+	if (attr->precise_ip) {
+		if (!colon)
+			colon = ++r;
+		r += scnprintf(bf + r, size - r, "%.*s", attr->precise_ip, "ppp");
+		exclude_guest_default = true;
+	}
+
+	if (attr->exclude_host || attr->exclude_guest == exclude_guest_default) {
+		MOD_PRINT(host, 'H');
+		MOD_PRINT(guest, 'G');
+	}
+#undef MOD_PRINT
+	if (colon)
+		bf[colon - 1] = ':';
+	return r;
+}
+
+static int perf_evsel__hw_name(struct perf_evsel *evsel, char *bf, size_t size)
+{
+	int r = scnprintf(bf, size, "%s", __perf_evsel__hw_name(evsel->attr.config));
+	return r + perf_evsel__add_modifiers(evsel, bf + r, size - r);
+}
+
+const char *perf_evsel__sw_names[PERF_COUNT_SW_MAX] = {
+	"cpu-clock",
+	"task-clock",
+	"page-faults",
+	"context-switches",
+	"cpu-migrations",
+	"minor-faults",
+	"major-faults",
+	"alignment-faults",
+	"emulation-faults",
+	"dummy",
+};
+
+static const char *__perf_evsel__sw_name(u64 config)
+{
+	if (config < PERF_COUNT_SW_MAX && perf_evsel__sw_names[config])
+		return perf_evsel__sw_names[config];
+	return "unknown-software";
+}
+
+static int perf_evsel__sw_name(struct perf_evsel *evsel, char *bf, size_t size)
+{
+	int r = scnprintf(bf, size, "%s", __perf_evsel__sw_name(evsel->attr.config));
+	return r + perf_evsel__add_modifiers(evsel, bf + r, size - r);
+}
+
+static int __perf_evsel__bp_name(char *bf, size_t size, u64 addr, u64 type)
+{
+	int r;
+
+	r = scnprintf(bf, size, "mem:0x%" PRIx64 ":", addr);
+
+	if (type & HW_BREAKPOINT_R)
+		r += scnprintf(bf + r, size - r, "r");
+
+	if (type & HW_BREAKPOINT_W)
+		r += scnprintf(bf + r, size - r, "w");
+
+	if (type & HW_BREAKPOINT_X)
+		r += scnprintf(bf + r, size - r, "x");
+
+	return r;
+}
+
+static int perf_evsel__bp_name(struct perf_evsel *evsel, char *bf, size_t size)
+{
+	struct perf_event_attr *attr = &evsel->attr;
+	int r = __perf_evsel__bp_name(bf, size, attr->bp_addr, attr->bp_type);
+	return r + perf_evsel__add_modifiers(evsel, bf + r, size - r);
+}
+
+const char *perf_evsel__hw_cache[PERF_COUNT_HW_CACHE_MAX]
+				[PERF_EVSEL__MAX_ALIASES] = {
+ { "L1-dcache",	"l1-d",		"l1d",		"L1-data",		},
+ { "L1-icache",	"l1-i",		"l1i",		"L1-instruction",	},
+ { "LLC",	"L2",							},
+ { "dTLB",	"d-tlb",	"Data-TLB",				},
+ { "iTLB",	"i-tlb",	"Instruction-TLB",			},
+ { "branch",	"branches",	"bpu",		"btb",		"bpc",	},
+ { "node",								},
+};
+
+const char *perf_evsel__hw_cache_op[PERF_COUNT_HW_CACHE_OP_MAX]
+				   [PERF_EVSEL__MAX_ALIASES] = {
+ { "load",	"loads",	"read",					},
+ { "store",	"stores",	"write",				},
+ { "prefetch",	"prefetches",	"speculative-read", "speculative-load",	},
+};
+
+const char *perf_evsel__hw_cache_result[PERF_COUNT_HW_CACHE_RESULT_MAX]
+				       [PERF_EVSEL__MAX_ALIASES] = {
+ { "refs",	"Reference",	"ops",		"access",		},
+ { "misses",	"miss",							},
+};
+
+#define C(x)		PERF_COUNT_HW_CACHE_##x
+#define CACHE_READ	(1 << C(OP_READ))
+#define CACHE_WRITE	(1 << C(OP_WRITE))
+#define CACHE_PREFETCH	(1 << C(OP_PREFETCH))
+#define COP(x)		(1 << x)
+
+/*
+ * cache operartion stat
+ * L1I : Read and prefetch only
+ * ITLB and BPU : Read-only
+ */
+static unsigned long perf_evsel__hw_cache_stat[C(MAX)] = {
+ [C(L1D)]	= (CACHE_READ | CACHE_WRITE | CACHE_PREFETCH),
+ [C(L1I)]	= (CACHE_READ | CACHE_PREFETCH),
+ [C(LL)]	= (CACHE_READ | CACHE_WRITE | CACHE_PREFETCH),
+ [C(DTLB)]	= (CACHE_READ | CACHE_WRITE | CACHE_PREFETCH),
+ [C(ITLB)]	= (CACHE_READ),
+ [C(BPU)]	= (CACHE_READ),
+ [C(NODE)]	= (CACHE_READ | CACHE_WRITE | CACHE_PREFETCH),
+};
+
+bool perf_evsel__is_cache_op_valid(u8 type, u8 op)
+{
+	if (perf_evsel__hw_cache_stat[type] & COP(op))
+		return true;	/* valid */
+	else
+		return false;	/* invalid */
+}
+
+int __perf_evsel__hw_cache_type_op_res_name(u8 type, u8 op, u8 result,
+					    char *bf, size_t size)
+{
+	if (result) {
+		return scnprintf(bf, size, "%s-%s-%s", perf_evsel__hw_cache[type][0],
+				 perf_evsel__hw_cache_op[op][0],
+				 perf_evsel__hw_cache_result[result][0]);
+	}
+
+	return scnprintf(bf, size, "%s-%s", perf_evsel__hw_cache[type][0],
+			 perf_evsel__hw_cache_op[op][1]);
+}
+
+static int __perf_evsel__hw_cache_name(u64 config, char *bf, size_t size)
+{
+	u8 op, result, type = (config >>  0) & 0xff;
+	const char *err = "unknown-ext-hardware-cache-type";
+
+	if (type >= PERF_COUNT_HW_CACHE_MAX)
+		goto out_err;
+
+	op = (config >>  8) & 0xff;
+	err = "unknown-ext-hardware-cache-op";
+	if (op >= PERF_COUNT_HW_CACHE_OP_MAX)
+		goto out_err;
+
+	result = (config >> 16) & 0xff;
+	err = "unknown-ext-hardware-cache-result";
+	if (result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
+		goto out_err;
+
+	err = "invalid-cache";
+	if (!perf_evsel__is_cache_op_valid(type, op))
+		goto out_err;
+
+	return __perf_evsel__hw_cache_type_op_res_name(type, op, result, bf, size);
+out_err:
+	return scnprintf(bf, size, "%s", err);
+}
+
+static int perf_evsel__hw_cache_name(struct perf_evsel *evsel, char *bf, size_t size)
+{
+	int ret = __perf_evsel__hw_cache_name(evsel->attr.config, bf, size);
+	return ret + perf_evsel__add_modifiers(evsel, bf + ret, size - ret);
+}
+
+static int perf_evsel__raw_name(struct perf_evsel *evsel, char *bf, size_t size)
+{
+	int ret = scnprintf(bf, size, "raw 0x%" PRIx64, evsel->attr.config);
+	return ret + perf_evsel__add_modifiers(evsel, bf + ret, size - ret);
+}
+
+const char *perf_evsel__name(struct perf_evsel *evsel)
+{
+	char bf[128];
+
+	if (!evsel)
+		goto out_unknown;
+
+	if (evsel->name)
+		return evsel->name;
+
+	switch (evsel->attr.type) {
+	case PERF_TYPE_RAW:
+		perf_evsel__raw_name(evsel, bf, sizeof(bf));
+		break;
+
+	case PERF_TYPE_HARDWARE:
+		perf_evsel__hw_name(evsel, bf, sizeof(bf));
+		break;
+
+	case PERF_TYPE_HW_CACHE:
+		perf_evsel__hw_cache_name(evsel, bf, sizeof(bf));
+		break;
+
+	case PERF_TYPE_SOFTWARE:
+		perf_evsel__sw_name(evsel, bf, sizeof(bf));
+		break;
+
+	case PERF_TYPE_TRACEPOINT:
+		scnprintf(bf, sizeof(bf), "%s", "unknown tracepoint");
+		break;
+
+	case PERF_TYPE_BREAKPOINT:
+		perf_evsel__bp_name(evsel, bf, sizeof(bf));
+		break;
+
+	default:
+		scnprintf(bf, sizeof(bf), "unknown attr type: %d",
+			  evsel->attr.type);
+		break;
+	}
+
+	evsel->name = strdup(bf);
+
+	if (evsel->name)
+		return evsel->name;
+out_unknown:
+	return "unknown";
+}
+
+const char *perf_evsel__group_name(struct perf_evsel *evsel)
+{
+	return evsel->group_name ?: "anon group";
+}
+
+/*
+ * Returns the group details for the specified leader,
+ * with following rules.
+ *
+ *  For record -e '{cycles,instructions}'
+ *    'anon group { cycles:u, instructions:u }'
+ *
+ *  For record -e 'cycles,instructions' and report --group
+ *    'cycles:u, instructions:u'
+ */
+int perf_evsel__group_desc(struct perf_evsel *evsel, char *buf, size_t size)
+{
+	int ret = 0;
+	struct perf_evsel *pos;
+	const char *group_name = perf_evsel__group_name(evsel);
+
+	if (!evsel->forced_leader)
+		ret = scnprintf(buf, size, "%s { ", group_name);
+
+	ret += scnprintf(buf + ret, size - ret, "%s",
+			 perf_evsel__name(evsel));
+
+	for_each_group_member(pos, evsel)
+		ret += scnprintf(buf + ret, size - ret, ", %s",
+				 perf_evsel__name(pos));
+
+	if (!evsel->forced_leader)
+		ret += scnprintf(buf + ret, size - ret, " }");
+
+	return ret;
+}
+
+static void __perf_evsel__config_callchain(struct perf_evsel *evsel,
+					   struct record_opts *opts,
+					   struct callchain_param *param)
+{
+	bool function = perf_evsel__is_function_event(evsel);
+	struct perf_event_attr *attr = &evsel->attr;
+
+	perf_evsel__set_sample_bit(evsel, CALLCHAIN);
+
+	attr->sample_max_stack = param->max_stack;
+
+	if (param->record_mode == CALLCHAIN_LBR) {
+		if (!opts->branch_stack) {
+			if (attr->exclude_user) {
+				pr_warning("LBR callstack option is only available "
+					   "to get user callchain information. "
+					   "Falling back to framepointers.\n");
+			} else {
+				perf_evsel__set_sample_bit(evsel, BRANCH_STACK);
+				attr->branch_sample_type = PERF_SAMPLE_BRANCH_USER |
+							PERF_SAMPLE_BRANCH_CALL_STACK |
+							PERF_SAMPLE_BRANCH_NO_CYCLES |
+							PERF_SAMPLE_BRANCH_NO_FLAGS;
+			}
+		} else
+			 pr_warning("Cannot use LBR callstack with branch stack. "
+				    "Falling back to framepointers.\n");
+	}
+
+	if (param->record_mode == CALLCHAIN_DWARF) {
+		if (!function) {
+			perf_evsel__set_sample_bit(evsel, REGS_USER);
+			perf_evsel__set_sample_bit(evsel, STACK_USER);
+			attr->sample_regs_user |= PERF_REGS_MASK;
+			attr->sample_stack_user = param->dump_size;
+			attr->exclude_callchain_user = 1;
+		} else {
+			pr_info("Cannot use DWARF unwind for function trace event,"
+				" falling back to framepointers.\n");
+		}
+	}
+
+	if (function) {
+		pr_info("Disabling user space callchains for function trace event.\n");
+		attr->exclude_callchain_user = 1;
+	}
+}
+
+void perf_evsel__config_callchain(struct perf_evsel *evsel,
+				  struct record_opts *opts,
+				  struct callchain_param *param)
+{
+	if (param->enabled)
+		return __perf_evsel__config_callchain(evsel, opts, param);
+}
+
+static void
+perf_evsel__reset_callgraph(struct perf_evsel *evsel,
+			    struct callchain_param *param)
+{
+	struct perf_event_attr *attr = &evsel->attr;
+
+	perf_evsel__reset_sample_bit(evsel, CALLCHAIN);
+	if (param->record_mode == CALLCHAIN_LBR) {
+		perf_evsel__reset_sample_bit(evsel, BRANCH_STACK);
+		attr->branch_sample_type &= ~(PERF_SAMPLE_BRANCH_USER |
+					      PERF_SAMPLE_BRANCH_CALL_STACK);
+	}
+	if (param->record_mode == CALLCHAIN_DWARF) {
+		perf_evsel__reset_sample_bit(evsel, REGS_USER);
+		perf_evsel__reset_sample_bit(evsel, STACK_USER);
+	}
+}
+
+static void apply_config_terms(struct perf_evsel *evsel,
+			       struct record_opts *opts, bool track)
+{
+	struct perf_evsel_config_term *term;
+	struct list_head *config_terms = &evsel->config_terms;
+	struct perf_event_attr *attr = &evsel->attr;
+	/* callgraph default */
+	struct callchain_param param = {
+		.record_mode = callchain_param.record_mode,
+	};
+	u32 dump_size = 0;
+	int max_stack = 0;
+	const char *callgraph_buf = NULL;
+
+	list_for_each_entry(term, config_terms, list) {
+		switch (term->type) {
+		case PERF_EVSEL__CONFIG_TERM_PERIOD:
+			if (!(term->weak && opts->user_interval != ULLONG_MAX)) {
+				attr->sample_period = term->val.period;
+				attr->freq = 0;
+				perf_evsel__reset_sample_bit(evsel, PERIOD);
+			}
+			break;
+		case PERF_EVSEL__CONFIG_TERM_FREQ:
+			if (!(term->weak && opts->user_freq != UINT_MAX)) {
+				attr->sample_freq = term->val.freq;
+				attr->freq = 1;
+				perf_evsel__set_sample_bit(evsel, PERIOD);
+			}
+			break;
+		case PERF_EVSEL__CONFIG_TERM_TIME:
+			if (term->val.time)
+				perf_evsel__set_sample_bit(evsel, TIME);
+			else
+				perf_evsel__reset_sample_bit(evsel, TIME);
+			break;
+		case PERF_EVSEL__CONFIG_TERM_CALLGRAPH:
+			callgraph_buf = term->val.callgraph;
+			break;
+		case PERF_EVSEL__CONFIG_TERM_BRANCH:
+			if (term->val.branch && strcmp(term->val.branch, "no")) {
+				perf_evsel__set_sample_bit(evsel, BRANCH_STACK);
+				parse_branch_str(term->val.branch,
+						 &attr->branch_sample_type);
+			} else
+				perf_evsel__reset_sample_bit(evsel, BRANCH_STACK);
+			break;
+		case PERF_EVSEL__CONFIG_TERM_STACK_USER:
+			dump_size = term->val.stack_user;
+			break;
+		case PERF_EVSEL__CONFIG_TERM_MAX_STACK:
+			max_stack = term->val.max_stack;
+			break;
+		case PERF_EVSEL__CONFIG_TERM_INHERIT:
+			/*
+			 * attr->inherit should has already been set by
+			 * perf_evsel__config. If user explicitly set
+			 * inherit using config terms, override global
+			 * opt->no_inherit setting.
+			 */
+			attr->inherit = term->val.inherit ? 1 : 0;
+			break;
+		case PERF_EVSEL__CONFIG_TERM_OVERWRITE:
+			attr->write_backward = term->val.overwrite ? 1 : 0;
+			break;
+		case PERF_EVSEL__CONFIG_TERM_DRV_CFG:
+			break;
+		default:
+			break;
+		}
+	}
+
+	/* User explicitly set per-event callgraph, clear the old setting and reset. */
+	if ((callgraph_buf != NULL) || (dump_size > 0) || max_stack) {
+		bool sample_address = false;
+
+		if (max_stack) {
+			param.max_stack = max_stack;
+			if (callgraph_buf == NULL)
+				callgraph_buf = "fp";
+		}
+
+		/* parse callgraph parameters */
+		if (callgraph_buf != NULL) {
+			if (!strcmp(callgraph_buf, "no")) {
+				param.enabled = false;
+				param.record_mode = CALLCHAIN_NONE;
+			} else {
+				param.enabled = true;
+				if (parse_callchain_record(callgraph_buf, &param)) {
+					pr_err("per-event callgraph setting for %s failed. "
+					       "Apply callgraph global setting for it\n",
+					       evsel->name);
+					return;
+				}
+				if (param.record_mode == CALLCHAIN_DWARF)
+					sample_address = true;
+			}
+		}
+		if (dump_size > 0) {
+			dump_size = round_up(dump_size, sizeof(u64));
+			param.dump_size = dump_size;
+		}
+
+		/* If global callgraph set, clear it */
+		if (callchain_param.enabled)
+			perf_evsel__reset_callgraph(evsel, &callchain_param);
+
+		/* set perf-event callgraph */
+		if (param.enabled) {
+			if (sample_address) {
+				perf_evsel__set_sample_bit(evsel, ADDR);
+				perf_evsel__set_sample_bit(evsel, DATA_SRC);
+				evsel->attr.mmap_data = track;
+			}
+			perf_evsel__config_callchain(evsel, opts, &param);
+		}
+	}
+}
+
+static bool is_dummy_event(struct perf_evsel *evsel)
+{
+	return (evsel->attr.type == PERF_TYPE_SOFTWARE) &&
+	       (evsel->attr.config == PERF_COUNT_SW_DUMMY);
+}
+
+/*
+ * The enable_on_exec/disabled value strategy:
+ *
+ *  1) For any type of traced program:
+ *    - all independent events and group leaders are disabled
+ *    - all group members are enabled
+ *
+ *     Group members are ruled by group leaders. They need to
+ *     be enabled, because the group scheduling relies on that.
+ *
+ *  2) For traced programs executed by perf:
+ *     - all independent events and group leaders have
+ *       enable_on_exec set
+ *     - we don't specifically enable or disable any event during
+ *       the record command
+ *
+ *     Independent events and group leaders are initially disabled
+ *     and get enabled by exec. Group members are ruled by group
+ *     leaders as stated in 1).
+ *
+ *  3) For traced programs attached by perf (pid/tid):
+ *     - we specifically enable or disable all events during
+ *       the record command
+ *
+ *     When attaching events to already running traced we
+ *     enable/disable events specifically, as there's no
+ *     initial traced exec call.
+ */
+void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts,
+			struct callchain_param *callchain)
+{
+	struct perf_evsel *leader = evsel->leader;
+	struct perf_event_attr *attr = &evsel->attr;
+	int track = evsel->tracking;
+	bool per_cpu = opts->target.default_per_cpu && !opts->target.per_thread;
+
+	attr->sample_id_all = perf_missing_features.sample_id_all ? 0 : 1;
+	attr->inherit	    = !opts->no_inherit;
+	attr->write_backward = opts->overwrite ? 1 : 0;
+
+	perf_evsel__set_sample_bit(evsel, IP);
+	perf_evsel__set_sample_bit(evsel, TID);
+
+	if (evsel->sample_read) {
+		perf_evsel__set_sample_bit(evsel, READ);
+
+		/*
+		 * We need ID even in case of single event, because
+		 * PERF_SAMPLE_READ process ID specific data.
+		 */
+		perf_evsel__set_sample_id(evsel, false);
+
+		/*
+		 * Apply group format only if we belong to group
+		 * with more than one members.
+		 */
+		if (leader->nr_members > 1) {
+			attr->read_format |= PERF_FORMAT_GROUP;
+			attr->inherit = 0;
+		}
+	}
+
+	/*
+	 * We default some events to have a default interval. But keep
+	 * it a weak assumption overridable by the user.
+	 */
+	if (!attr->sample_period || (opts->user_freq != UINT_MAX ||
+				     opts->user_interval != ULLONG_MAX)) {
+		if (opts->freq) {
+			perf_evsel__set_sample_bit(evsel, PERIOD);
+			attr->freq		= 1;
+			attr->sample_freq	= opts->freq;
+		} else {
+			attr->sample_period = opts->default_interval;
+		}
+	}
+
+	/*
+	 * Disable sampling for all group members other
+	 * than leader in case leader 'leads' the sampling.
+	 */
+	if ((leader != evsel) && leader->sample_read) {
+		attr->freq           = 0;
+		attr->sample_freq    = 0;
+		attr->sample_period  = 0;
+		attr->write_backward = 0;
+	}
+
+	if (opts->no_samples)
+		attr->sample_freq = 0;
+
+	if (opts->inherit_stat) {
+		evsel->attr.read_format |=
+			PERF_FORMAT_TOTAL_TIME_ENABLED |
+			PERF_FORMAT_TOTAL_TIME_RUNNING |
+			PERF_FORMAT_ID;
+		attr->inherit_stat = 1;
+	}
+
+	if (opts->sample_address) {
+		perf_evsel__set_sample_bit(evsel, ADDR);
+		attr->mmap_data = track;
+	}
+
+	/*
+	 * We don't allow user space callchains for  function trace
+	 * event, due to issues with page faults while tracing page
+	 * fault handler and its overall trickiness nature.
+	 */
+	if (perf_evsel__is_function_event(evsel))
+		evsel->attr.exclude_callchain_user = 1;
+
+	if (callchain && callchain->enabled && !evsel->no_aux_samples)
+		perf_evsel__config_callchain(evsel, opts, callchain);
+
+	if (opts->sample_intr_regs) {
+		attr->sample_regs_intr = opts->sample_intr_regs;
+		perf_evsel__set_sample_bit(evsel, REGS_INTR);
+	}
+
+	if (opts->sample_user_regs) {
+		attr->sample_regs_user |= opts->sample_user_regs;
+		perf_evsel__set_sample_bit(evsel, REGS_USER);
+	}
+
+	if (target__has_cpu(&opts->target) || opts->sample_cpu)
+		perf_evsel__set_sample_bit(evsel, CPU);
+
+	/*
+	 * When the user explicitly disabled time don't force it here.
+	 */
+	if (opts->sample_time &&
+	    (!perf_missing_features.sample_id_all &&
+	    (!opts->no_inherit || target__has_cpu(&opts->target) || per_cpu ||
+	     opts->sample_time_set)))
+		perf_evsel__set_sample_bit(evsel, TIME);
+
+	if (opts->raw_samples && !evsel->no_aux_samples) {
+		perf_evsel__set_sample_bit(evsel, TIME);
+		perf_evsel__set_sample_bit(evsel, RAW);
+		perf_evsel__set_sample_bit(evsel, CPU);
+	}
+
+	if (opts->sample_address)
+		perf_evsel__set_sample_bit(evsel, DATA_SRC);
+
+	if (opts->sample_phys_addr)
+		perf_evsel__set_sample_bit(evsel, PHYS_ADDR);
+
+	if (opts->no_buffering) {
+		attr->watermark = 0;
+		attr->wakeup_events = 1;
+	}
+	if (opts->branch_stack && !evsel->no_aux_samples) {
+		perf_evsel__set_sample_bit(evsel, BRANCH_STACK);
+		attr->branch_sample_type = opts->branch_stack;
+	}
+
+	if (opts->sample_weight)
+		perf_evsel__set_sample_bit(evsel, WEIGHT);
+
+	attr->task  = track;
+	attr->mmap  = track;
+	attr->mmap2 = track && !perf_missing_features.mmap2;
+	attr->comm  = track;
+
+	if (opts->record_namespaces)
+		attr->namespaces  = track;
+
+	if (opts->record_switch_events)
+		attr->context_switch = track;
+
+	if (opts->sample_transaction)
+		perf_evsel__set_sample_bit(evsel, TRANSACTION);
+
+	if (opts->running_time) {
+		evsel->attr.read_format |=
+			PERF_FORMAT_TOTAL_TIME_ENABLED |
+			PERF_FORMAT_TOTAL_TIME_RUNNING;
+	}
+
+	/*
+	 * XXX see the function comment above
+	 *
+	 * Disabling only independent events or group leaders,
+	 * keeping group members enabled.
+	 */
+	if (perf_evsel__is_group_leader(evsel))
+		attr->disabled = 1;
+
+	/*
+	 * Setting enable_on_exec for independent events and
+	 * group leaders for traced executed by perf.
+	 */
+	if (target__none(&opts->target) && perf_evsel__is_group_leader(evsel) &&
+		!opts->initial_delay)
+		attr->enable_on_exec = 1;
+
+	if (evsel->immediate) {
+		attr->disabled = 0;
+		attr->enable_on_exec = 0;
+	}
+
+	clockid = opts->clockid;
+	if (opts->use_clockid) {
+		attr->use_clockid = 1;
+		attr->clockid = opts->clockid;
+	}
+
+	if (evsel->precise_max)
+		perf_event_attr__set_max_precise_ip(attr);
+
+	if (opts->all_user) {
+		attr->exclude_kernel = 1;
+		attr->exclude_user   = 0;
+	}
+
+	if (opts->all_kernel) {
+		attr->exclude_kernel = 0;
+		attr->exclude_user   = 1;
+	}
+
+	if (evsel->own_cpus || evsel->unit)
+		evsel->attr.read_format |= PERF_FORMAT_ID;
+
+	/*
+	 * Apply event specific term settings,
+	 * it overloads any global configuration.
+	 */
+	apply_config_terms(evsel, opts, track);
+
+	evsel->ignore_missing_thread = opts->ignore_missing_thread;
+
+	/* The --period option takes the precedence. */
+	if (opts->period_set) {
+		if (opts->period)
+			perf_evsel__set_sample_bit(evsel, PERIOD);
+		else
+			perf_evsel__reset_sample_bit(evsel, PERIOD);
+	}
+
+	/*
+	 * For initial_delay, a dummy event is added implicitly.
+	 * The software event will trigger -EOPNOTSUPP error out,
+	 * if BRANCH_STACK bit is set.
+	 */
+	if (opts->initial_delay && is_dummy_event(evsel))
+		perf_evsel__reset_sample_bit(evsel, BRANCH_STACK);
+}
+
+static int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
+{
+	if (evsel->system_wide)
+		nthreads = 1;
+
+	evsel->fd = xyarray__new(ncpus, nthreads, sizeof(int));
+
+	if (evsel->fd) {
+		int cpu, thread;
+		for (cpu = 0; cpu < ncpus; cpu++) {
+			for (thread = 0; thread < nthreads; thread++) {
+				FD(evsel, cpu, thread) = -1;
+			}
+		}
+	}
+
+	return evsel->fd != NULL ? 0 : -ENOMEM;
+}
+
+static int perf_evsel__run_ioctl(struct perf_evsel *evsel,
+			  int ioc,  void *arg)
+{
+	int cpu, thread;
+
+	for (cpu = 0; cpu < xyarray__max_x(evsel->fd); cpu++) {
+		for (thread = 0; thread < xyarray__max_y(evsel->fd); thread++) {
+			int fd = FD(evsel, cpu, thread),
+			    err = ioctl(fd, ioc, arg);
+
+			if (err)
+				return err;
+		}
+	}
+
+	return 0;
+}
+
+int perf_evsel__apply_filter(struct perf_evsel *evsel, const char *filter)
+{
+	return perf_evsel__run_ioctl(evsel,
+				     PERF_EVENT_IOC_SET_FILTER,
+				     (void *)filter);
+}
+
+int perf_evsel__set_filter(struct perf_evsel *evsel, const char *filter)
+{
+	char *new_filter = strdup(filter);
+
+	if (new_filter != NULL) {
+		free(evsel->filter);
+		evsel->filter = new_filter;
+		return 0;
+	}
+
+	return -1;
+}
+
+static int perf_evsel__append_filter(struct perf_evsel *evsel,
+				     const char *fmt, const char *filter)
+{
+	char *new_filter;
+
+	if (evsel->filter == NULL)
+		return perf_evsel__set_filter(evsel, filter);
+
+	if (asprintf(&new_filter, fmt, evsel->filter, filter) > 0) {
+		free(evsel->filter);
+		evsel->filter = new_filter;
+		return 0;
+	}
+
+	return -1;
+}
+
+int perf_evsel__append_tp_filter(struct perf_evsel *evsel, const char *filter)
+{
+	return perf_evsel__append_filter(evsel, "(%s) && (%s)", filter);
+}
+
+int perf_evsel__append_addr_filter(struct perf_evsel *evsel, const char *filter)
+{
+	return perf_evsel__append_filter(evsel, "%s,%s", filter);
+}
+
+int perf_evsel__enable(struct perf_evsel *evsel)
+{
+	return perf_evsel__run_ioctl(evsel,
+				     PERF_EVENT_IOC_ENABLE,
+				     0);
+}
+
+int perf_evsel__disable(struct perf_evsel *evsel)
+{
+	return perf_evsel__run_ioctl(evsel,
+				     PERF_EVENT_IOC_DISABLE,
+				     0);
+}
+
+int perf_evsel__alloc_id(struct perf_evsel *evsel, int ncpus, int nthreads)
+{
+	if (ncpus == 0 || nthreads == 0)
+		return 0;
+
+	if (evsel->system_wide)
+		nthreads = 1;
+
+	evsel->sample_id = xyarray__new(ncpus, nthreads, sizeof(struct perf_sample_id));
+	if (evsel->sample_id == NULL)
+		return -ENOMEM;
+
+	evsel->id = zalloc(ncpus * nthreads * sizeof(u64));
+	if (evsel->id == NULL) {
+		xyarray__delete(evsel->sample_id);
+		evsel->sample_id = NULL;
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static void perf_evsel__free_fd(struct perf_evsel *evsel)
+{
+	xyarray__delete(evsel->fd);
+	evsel->fd = NULL;
+}
+
+static void perf_evsel__free_id(struct perf_evsel *evsel)
+{
+	xyarray__delete(evsel->sample_id);
+	evsel->sample_id = NULL;
+	zfree(&evsel->id);
+}
+
+static void perf_evsel__free_config_terms(struct perf_evsel *evsel)
+{
+	struct perf_evsel_config_term *term, *h;
+
+	list_for_each_entry_safe(term, h, &evsel->config_terms, list) {
+		list_del(&term->list);
+		free(term);
+	}
+}
+
+void perf_evsel__close_fd(struct perf_evsel *evsel)
+{
+	int cpu, thread;
+
+	for (cpu = 0; cpu < xyarray__max_x(evsel->fd); cpu++)
+		for (thread = 0; thread < xyarray__max_y(evsel->fd); ++thread) {
+			close(FD(evsel, cpu, thread));
+			FD(evsel, cpu, thread) = -1;
+		}
+}
+
+void perf_evsel__exit(struct perf_evsel *evsel)
+{
+	assert(list_empty(&evsel->node));
+	assert(evsel->evlist == NULL);
+	perf_evsel__free_counts(evsel);
+	perf_evsel__free_fd(evsel);
+	perf_evsel__free_id(evsel);
+	perf_evsel__free_config_terms(evsel);
+	cgroup__put(evsel->cgrp);
+	cpu_map__put(evsel->cpus);
+	cpu_map__put(evsel->own_cpus);
+	thread_map__put(evsel->threads);
+	zfree(&evsel->group_name);
+	zfree(&evsel->name);
+	zfree(&evsel->pmu_name);
+	zfree(&evsel->per_pkg_mask);
+	zfree(&evsel->metric_events);
+	perf_evsel__object.fini(evsel);
+}
+
+void perf_evsel__delete(struct perf_evsel *evsel)
+{
+	perf_evsel__exit(evsel);
+	free(evsel);
+}
+
+void perf_evsel__compute_deltas(struct perf_evsel *evsel, int cpu, int thread,
+				struct perf_counts_values *count)
+{
+	struct perf_counts_values tmp;
+
+	if (!evsel->prev_raw_counts)
+		return;
+
+	if (cpu == -1) {
+		tmp = evsel->prev_raw_counts->aggr;
+		evsel->prev_raw_counts->aggr = *count;
+	} else {
+		tmp = *perf_counts(evsel->prev_raw_counts, cpu, thread);
+		*perf_counts(evsel->prev_raw_counts, cpu, thread) = *count;
+	}
+
+	count->val = count->val - tmp.val;
+	count->ena = count->ena - tmp.ena;
+	count->run = count->run - tmp.run;
+}
+
+void perf_counts_values__scale(struct perf_counts_values *count,
+			       bool scale, s8 *pscaled)
+{
+	s8 scaled = 0;
+
+	if (scale) {
+		if (count->run == 0) {
+			scaled = -1;
+			count->val = 0;
+		} else if (count->run < count->ena) {
+			scaled = 1;
+			count->val = (u64)((double) count->val * count->ena / count->run + 0.5);
+		}
+	} else
+		count->ena = count->run = 0;
+
+	if (pscaled)
+		*pscaled = scaled;
+}
+
+static int perf_evsel__read_size(struct perf_evsel *evsel)
+{
+	u64 read_format = evsel->attr.read_format;
+	int entry = sizeof(u64); /* value */
+	int size = 0;
+	int nr = 1;
+
+	if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
+		size += sizeof(u64);
+
+	if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
+		size += sizeof(u64);
+
+	if (read_format & PERF_FORMAT_ID)
+		entry += sizeof(u64);
+
+	if (read_format & PERF_FORMAT_GROUP) {
+		nr = evsel->nr_members;
+		size += sizeof(u64);
+	}
+
+	size += entry * nr;
+	return size;
+}
+
+int perf_evsel__read(struct perf_evsel *evsel, int cpu, int thread,
+		     struct perf_counts_values *count)
+{
+	size_t size = perf_evsel__read_size(evsel);
+
+	memset(count, 0, sizeof(*count));
+
+	if (FD(evsel, cpu, thread) < 0)
+		return -EINVAL;
+
+	if (readn(FD(evsel, cpu, thread), count->values, size) <= 0)
+		return -errno;
+
+	return 0;
+}
+
+static int
+perf_evsel__read_one(struct perf_evsel *evsel, int cpu, int thread)
+{
+	struct perf_counts_values *count = perf_counts(evsel->counts, cpu, thread);
+
+	return perf_evsel__read(evsel, cpu, thread, count);
+}
+
+static void
+perf_evsel__set_count(struct perf_evsel *counter, int cpu, int thread,
+		      u64 val, u64 ena, u64 run)
+{
+	struct perf_counts_values *count;
+
+	count = perf_counts(counter->counts, cpu, thread);
+
+	count->val    = val;
+	count->ena    = ena;
+	count->run    = run;
+	count->loaded = true;
+}
+
+static int
+perf_evsel__process_group_data(struct perf_evsel *leader,
+			       int cpu, int thread, u64 *data)
+{
+	u64 read_format = leader->attr.read_format;
+	struct sample_read_value *v;
+	u64 nr, ena = 0, run = 0, i;
+
+	nr = *data++;
+
+	if (nr != (u64) leader->nr_members)
+		return -EINVAL;
+
+	if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
+		ena = *data++;
+
+	if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
+		run = *data++;
+
+	v = (struct sample_read_value *) data;
+
+	perf_evsel__set_count(leader, cpu, thread,
+			      v[0].value, ena, run);
+
+	for (i = 1; i < nr; i++) {
+		struct perf_evsel *counter;
+
+		counter = perf_evlist__id2evsel(leader->evlist, v[i].id);
+		if (!counter)
+			return -EINVAL;
+
+		perf_evsel__set_count(counter, cpu, thread,
+				      v[i].value, ena, run);
+	}
+
+	return 0;
+}
+
+static int
+perf_evsel__read_group(struct perf_evsel *leader, int cpu, int thread)
+{
+	struct perf_stat_evsel *ps = leader->stats;
+	u64 read_format = leader->attr.read_format;
+	int size = perf_evsel__read_size(leader);
+	u64 *data = ps->group_data;
+
+	if (!(read_format & PERF_FORMAT_ID))
+		return -EINVAL;
+
+	if (!perf_evsel__is_group_leader(leader))
+		return -EINVAL;
+
+	if (!data) {
+		data = zalloc(size);
+		if (!data)
+			return -ENOMEM;
+
+		ps->group_data = data;
+	}
+
+	if (FD(leader, cpu, thread) < 0)
+		return -EINVAL;
+
+	if (readn(FD(leader, cpu, thread), data, size) <= 0)
+		return -errno;
+
+	return perf_evsel__process_group_data(leader, cpu, thread, data);
+}
+
+int perf_evsel__read_counter(struct perf_evsel *evsel, int cpu, int thread)
+{
+	u64 read_format = evsel->attr.read_format;
+
+	if (read_format & PERF_FORMAT_GROUP)
+		return perf_evsel__read_group(evsel, cpu, thread);
+	else
+		return perf_evsel__read_one(evsel, cpu, thread);
+}
+
+int __perf_evsel__read_on_cpu(struct perf_evsel *evsel,
+			      int cpu, int thread, bool scale)
+{
+	struct perf_counts_values count;
+	size_t nv = scale ? 3 : 1;
+
+	if (FD(evsel, cpu, thread) < 0)
+		return -EINVAL;
+
+	if (evsel->counts == NULL && perf_evsel__alloc_counts(evsel, cpu + 1, thread + 1) < 0)
+		return -ENOMEM;
+
+	if (readn(FD(evsel, cpu, thread), &count, nv * sizeof(u64)) <= 0)
+		return -errno;
+
+	perf_evsel__compute_deltas(evsel, cpu, thread, &count);
+	perf_counts_values__scale(&count, scale, NULL);
+	*perf_counts(evsel->counts, cpu, thread) = count;
+	return 0;
+}
+
+static int get_group_fd(struct perf_evsel *evsel, int cpu, int thread)
+{
+	struct perf_evsel *leader = evsel->leader;
+	int fd;
+
+	if (perf_evsel__is_group_leader(evsel))
+		return -1;
+
+	/*
+	 * Leader must be already processed/open,
+	 * if not it's a bug.
+	 */
+	BUG_ON(!leader->fd);
+
+	fd = FD(leader, cpu, thread);
+	BUG_ON(fd == -1);
+
+	return fd;
+}
+
+struct bit_names {
+	int bit;
+	const char *name;
+};
+
+static void __p_bits(char *buf, size_t size, u64 value, struct bit_names *bits)
+{
+	bool first_bit = true;
+	int i = 0;
+
+	do {
+		if (value & bits[i].bit) {
+			buf += scnprintf(buf, size, "%s%s", first_bit ? "" : "|", bits[i].name);
+			first_bit = false;
+		}
+	} while (bits[++i].name != NULL);
+}
+
+static void __p_sample_type(char *buf, size_t size, u64 value)
+{
+#define bit_name(n) { PERF_SAMPLE_##n, #n }
+	struct bit_names bits[] = {
+		bit_name(IP), bit_name(TID), bit_name(TIME), bit_name(ADDR),
+		bit_name(READ), bit_name(CALLCHAIN), bit_name(ID), bit_name(CPU),
+		bit_name(PERIOD), bit_name(STREAM_ID), bit_name(RAW),
+		bit_name(BRANCH_STACK), bit_name(REGS_USER), bit_name(STACK_USER),
+		bit_name(IDENTIFIER), bit_name(REGS_INTR), bit_name(DATA_SRC),
+		bit_name(WEIGHT), bit_name(PHYS_ADDR),
+		{ .name = NULL, }
+	};
+#undef bit_name
+	__p_bits(buf, size, value, bits);
+}
+
+static void __p_branch_sample_type(char *buf, size_t size, u64 value)
+{
+#define bit_name(n) { PERF_SAMPLE_BRANCH_##n, #n }
+	struct bit_names bits[] = {
+		bit_name(USER), bit_name(KERNEL), bit_name(HV), bit_name(ANY),
+		bit_name(ANY_CALL), bit_name(ANY_RETURN), bit_name(IND_CALL),
+		bit_name(ABORT_TX), bit_name(IN_TX), bit_name(NO_TX),
+		bit_name(COND), bit_name(CALL_STACK), bit_name(IND_JUMP),
+		bit_name(CALL), bit_name(NO_FLAGS), bit_name(NO_CYCLES),
+		{ .name = NULL, }
+	};
+#undef bit_name
+	__p_bits(buf, size, value, bits);
+}
+
+static void __p_read_format(char *buf, size_t size, u64 value)
+{
+#define bit_name(n) { PERF_FORMAT_##n, #n }
+	struct bit_names bits[] = {
+		bit_name(TOTAL_TIME_ENABLED), bit_name(TOTAL_TIME_RUNNING),
+		bit_name(ID), bit_name(GROUP),
+		{ .name = NULL, }
+	};
+#undef bit_name
+	__p_bits(buf, size, value, bits);
+}
+
+#define BUF_SIZE		1024
+
+#define p_hex(val)		snprintf(buf, BUF_SIZE, "%#"PRIx64, (uint64_t)(val))
+#define p_unsigned(val)		snprintf(buf, BUF_SIZE, "%"PRIu64, (uint64_t)(val))
+#define p_signed(val)		snprintf(buf, BUF_SIZE, "%"PRId64, (int64_t)(val))
+#define p_sample_type(val)	__p_sample_type(buf, BUF_SIZE, val)
+#define p_branch_sample_type(val) __p_branch_sample_type(buf, BUF_SIZE, val)
+#define p_read_format(val)	__p_read_format(buf, BUF_SIZE, val)
+
+#define PRINT_ATTRn(_n, _f, _p)				\
+do {							\
+	if (attr->_f) {					\
+		_p(attr->_f);				\
+		ret += attr__fprintf(fp, _n, buf, priv);\
+	}						\
+} while (0)
+
+#define PRINT_ATTRf(_f, _p)	PRINT_ATTRn(#_f, _f, _p)
+
+int perf_event_attr__fprintf(FILE *fp, struct perf_event_attr *attr,
+			     attr__fprintf_f attr__fprintf, void *priv)
+{
+	char buf[BUF_SIZE];
+	int ret = 0;
+
+	PRINT_ATTRf(type, p_unsigned);
+	PRINT_ATTRf(size, p_unsigned);
+	PRINT_ATTRf(config, p_hex);
+	PRINT_ATTRn("{ sample_period, sample_freq }", sample_period, p_unsigned);
+	PRINT_ATTRf(sample_type, p_sample_type);
+	PRINT_ATTRf(read_format, p_read_format);
+
+	PRINT_ATTRf(disabled, p_unsigned);
+	PRINT_ATTRf(inherit, p_unsigned);
+	PRINT_ATTRf(pinned, p_unsigned);
+	PRINT_ATTRf(exclusive, p_unsigned);
+	PRINT_ATTRf(exclude_user, p_unsigned);
+	PRINT_ATTRf(exclude_kernel, p_unsigned);
+	PRINT_ATTRf(exclude_hv, p_unsigned);
+	PRINT_ATTRf(exclude_idle, p_unsigned);
+	PRINT_ATTRf(mmap, p_unsigned);
+	PRINT_ATTRf(comm, p_unsigned);
+	PRINT_ATTRf(freq, p_unsigned);
+	PRINT_ATTRf(inherit_stat, p_unsigned);
+	PRINT_ATTRf(enable_on_exec, p_unsigned);
+	PRINT_ATTRf(task, p_unsigned);
+	PRINT_ATTRf(watermark, p_unsigned);
+	PRINT_ATTRf(precise_ip, p_unsigned);
+	PRINT_ATTRf(mmap_data, p_unsigned);
+	PRINT_ATTRf(sample_id_all, p_unsigned);
+	PRINT_ATTRf(exclude_host, p_unsigned);
+	PRINT_ATTRf(exclude_guest, p_unsigned);
+	PRINT_ATTRf(exclude_callchain_kernel, p_unsigned);
+	PRINT_ATTRf(exclude_callchain_user, p_unsigned);
+	PRINT_ATTRf(mmap2, p_unsigned);
+	PRINT_ATTRf(comm_exec, p_unsigned);
+	PRINT_ATTRf(use_clockid, p_unsigned);
+	PRINT_ATTRf(context_switch, p_unsigned);
+	PRINT_ATTRf(write_backward, p_unsigned);
+	PRINT_ATTRf(namespaces, p_unsigned);
+
+	PRINT_ATTRn("{ wakeup_events, wakeup_watermark }", wakeup_events, p_unsigned);
+	PRINT_ATTRf(bp_type, p_unsigned);
+	PRINT_ATTRn("{ bp_addr, config1 }", bp_addr, p_hex);
+	PRINT_ATTRn("{ bp_len, config2 }", bp_len, p_hex);
+	PRINT_ATTRf(branch_sample_type, p_branch_sample_type);
+	PRINT_ATTRf(sample_regs_user, p_hex);
+	PRINT_ATTRf(sample_stack_user, p_unsigned);
+	PRINT_ATTRf(clockid, p_signed);
+	PRINT_ATTRf(sample_regs_intr, p_hex);
+	PRINT_ATTRf(aux_watermark, p_unsigned);
+	PRINT_ATTRf(sample_max_stack, p_unsigned);
+
+	return ret;
+}
+
+static int __open_attr__fprintf(FILE *fp, const char *name, const char *val,
+				void *priv __maybe_unused)
+{
+	return fprintf(fp, "  %-32s %s\n", name, val);
+}
+
+static void perf_evsel__remove_fd(struct perf_evsel *pos,
+				  int nr_cpus, int nr_threads,
+				  int thread_idx)
+{
+	for (int cpu = 0; cpu < nr_cpus; cpu++)
+		for (int thread = thread_idx; thread < nr_threads - 1; thread++)
+			FD(pos, cpu, thread) = FD(pos, cpu, thread + 1);
+}
+
+static int update_fds(struct perf_evsel *evsel,
+		      int nr_cpus, int cpu_idx,
+		      int nr_threads, int thread_idx)
+{
+	struct perf_evsel *pos;
+
+	if (cpu_idx >= nr_cpus || thread_idx >= nr_threads)
+		return -EINVAL;
+
+	evlist__for_each_entry(evsel->evlist, pos) {
+		nr_cpus = pos != evsel ? nr_cpus : cpu_idx;
+
+		perf_evsel__remove_fd(pos, nr_cpus, nr_threads, thread_idx);
+
+		/*
+		 * Since fds for next evsel has not been created,
+		 * there is no need to iterate whole event list.
+		 */
+		if (pos == evsel)
+			break;
+	}
+	return 0;
+}
+
+static bool ignore_missing_thread(struct perf_evsel *evsel,
+				  int nr_cpus, int cpu,
+				  struct thread_map *threads,
+				  int thread, int err)
+{
+	pid_t ignore_pid = thread_map__pid(threads, thread);
+
+	if (!evsel->ignore_missing_thread)
+		return false;
+
+	/* The system wide setup does not work with threads. */
+	if (evsel->system_wide)
+		return false;
+
+	/* The -ESRCH is perf event syscall errno for pid's not found. */
+	if (err != -ESRCH)
+		return false;
+
+	/* If there's only one thread, let it fail. */
+	if (threads->nr == 1)
+		return false;
+
+	/*
+	 * We should remove fd for missing_thread first
+	 * because thread_map__remove() will decrease threads->nr.
+	 */
+	if (update_fds(evsel, nr_cpus, cpu, threads->nr, thread))
+		return false;
+
+	if (thread_map__remove(threads, thread))
+		return false;
+
+	pr_warning("WARNING: Ignored open failure for pid %d\n",
+		   ignore_pid);
+	return true;
+}
+
+int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
+		     struct thread_map *threads)
+{
+	int cpu, thread, nthreads;
+	unsigned long flags = PERF_FLAG_FD_CLOEXEC;
+	int pid = -1, err;
+	enum { NO_CHANGE, SET_TO_MAX, INCREASED_MAX } set_rlimit = NO_CHANGE;
+
+	if (perf_missing_features.write_backward && evsel->attr.write_backward)
+		return -EINVAL;
+
+	if (cpus == NULL) {
+		static struct cpu_map *empty_cpu_map;
+
+		if (empty_cpu_map == NULL) {
+			empty_cpu_map = cpu_map__dummy_new();
+			if (empty_cpu_map == NULL)
+				return -ENOMEM;
+		}
+
+		cpus = empty_cpu_map;
+	}
+
+	if (threads == NULL) {
+		static struct thread_map *empty_thread_map;
+
+		if (empty_thread_map == NULL) {
+			empty_thread_map = thread_map__new_by_tid(-1);
+			if (empty_thread_map == NULL)
+				return -ENOMEM;
+		}
+
+		threads = empty_thread_map;
+	}
+
+	if (evsel->system_wide)
+		nthreads = 1;
+	else
+		nthreads = threads->nr;
+
+	if (evsel->fd == NULL &&
+	    perf_evsel__alloc_fd(evsel, cpus->nr, nthreads) < 0)
+		return -ENOMEM;
+
+	if (evsel->cgrp) {
+		flags |= PERF_FLAG_PID_CGROUP;
+		pid = evsel->cgrp->fd;
+	}
+
+fallback_missing_features:
+	if (perf_missing_features.clockid_wrong)
+		evsel->attr.clockid = CLOCK_MONOTONIC; /* should always work */
+	if (perf_missing_features.clockid) {
+		evsel->attr.use_clockid = 0;
+		evsel->attr.clockid = 0;
+	}
+	if (perf_missing_features.cloexec)
+		flags &= ~(unsigned long)PERF_FLAG_FD_CLOEXEC;
+	if (perf_missing_features.mmap2)
+		evsel->attr.mmap2 = 0;
+	if (perf_missing_features.exclude_guest)
+		evsel->attr.exclude_guest = evsel->attr.exclude_host = 0;
+	if (perf_missing_features.lbr_flags)
+		evsel->attr.branch_sample_type &= ~(PERF_SAMPLE_BRANCH_NO_FLAGS |
+				     PERF_SAMPLE_BRANCH_NO_CYCLES);
+	if (perf_missing_features.group_read && evsel->attr.inherit)
+		evsel->attr.read_format &= ~(PERF_FORMAT_GROUP|PERF_FORMAT_ID);
+retry_sample_id:
+	if (perf_missing_features.sample_id_all)
+		evsel->attr.sample_id_all = 0;
+
+	if (verbose >= 2) {
+		fprintf(stderr, "%.60s\n", graph_dotted_line);
+		fprintf(stderr, "perf_event_attr:\n");
+		perf_event_attr__fprintf(stderr, &evsel->attr, __open_attr__fprintf, NULL);
+		fprintf(stderr, "%.60s\n", graph_dotted_line);
+	}
+
+	for (cpu = 0; cpu < cpus->nr; cpu++) {
+
+		for (thread = 0; thread < nthreads; thread++) {
+			int fd, group_fd;
+
+			if (!evsel->cgrp && !evsel->system_wide)
+				pid = thread_map__pid(threads, thread);
+
+			group_fd = get_group_fd(evsel, cpu, thread);
+retry_open:
+			pr_debug2("sys_perf_event_open: pid %d  cpu %d  group_fd %d  flags %#lx",
+				  pid, cpus->map[cpu], group_fd, flags);
+
+			test_attr__ready();
+
+			fd = sys_perf_event_open(&evsel->attr, pid, cpus->map[cpu],
+						 group_fd, flags);
+
+			FD(evsel, cpu, thread) = fd;
+
+			if (fd < 0) {
+				err = -errno;
+
+				if (ignore_missing_thread(evsel, cpus->nr, cpu, threads, thread, err)) {
+					/*
+					 * We just removed 1 thread, so take a step
+					 * back on thread index and lower the upper
+					 * nthreads limit.
+					 */
+					nthreads--;
+					thread--;
+
+					/* ... and pretend like nothing have happened. */
+					err = 0;
+					continue;
+				}
+
+				pr_debug2("\nsys_perf_event_open failed, error %d\n",
+					  err);
+				goto try_fallback;
+			}
+
+			pr_debug2(" = %d\n", fd);
+
+			if (evsel->bpf_fd >= 0) {
+				int evt_fd = fd;
+				int bpf_fd = evsel->bpf_fd;
+
+				err = ioctl(evt_fd,
+					    PERF_EVENT_IOC_SET_BPF,
+					    bpf_fd);
+				if (err && errno != EEXIST) {
+					pr_err("failed to attach bpf fd %d: %s\n",
+					       bpf_fd, strerror(errno));
+					err = -EINVAL;
+					goto out_close;
+				}
+			}
+
+			set_rlimit = NO_CHANGE;
+
+			/*
+			 * If we succeeded but had to kill clockid, fail and
+			 * have perf_evsel__open_strerror() print us a nice
+			 * error.
+			 */
+			if (perf_missing_features.clockid ||
+			    perf_missing_features.clockid_wrong) {
+				err = -EINVAL;
+				goto out_close;
+			}
+		}
+	}
+
+	return 0;
+
+try_fallback:
+	/*
+	 * perf stat needs between 5 and 22 fds per CPU. When we run out
+	 * of them try to increase the limits.
+	 */
+	if (err == -EMFILE && set_rlimit < INCREASED_MAX) {
+		struct rlimit l;
+		int old_errno = errno;
+
+		if (getrlimit(RLIMIT_NOFILE, &l) == 0) {
+			if (set_rlimit == NO_CHANGE)
+				l.rlim_cur = l.rlim_max;
+			else {
+				l.rlim_cur = l.rlim_max + 1000;
+				l.rlim_max = l.rlim_cur;
+			}
+			if (setrlimit(RLIMIT_NOFILE, &l) == 0) {
+				set_rlimit++;
+				errno = old_errno;
+				goto retry_open;
+			}
+		}
+		errno = old_errno;
+	}
+
+	if (err != -EINVAL || cpu > 0 || thread > 0)
+		goto out_close;
+
+	/*
+	 * Must probe features in the order they were added to the
+	 * perf_event_attr interface.
+	 */
+	if (!perf_missing_features.write_backward && evsel->attr.write_backward) {
+		perf_missing_features.write_backward = true;
+		pr_debug2("switching off write_backward\n");
+		goto out_close;
+	} else if (!perf_missing_features.clockid_wrong && evsel->attr.use_clockid) {
+		perf_missing_features.clockid_wrong = true;
+		pr_debug2("switching off clockid\n");
+		goto fallback_missing_features;
+	} else if (!perf_missing_features.clockid && evsel->attr.use_clockid) {
+		perf_missing_features.clockid = true;
+		pr_debug2("switching off use_clockid\n");
+		goto fallback_missing_features;
+	} else if (!perf_missing_features.cloexec && (flags & PERF_FLAG_FD_CLOEXEC)) {
+		perf_missing_features.cloexec = true;
+		pr_debug2("switching off cloexec flag\n");
+		goto fallback_missing_features;
+	} else if (!perf_missing_features.mmap2 && evsel->attr.mmap2) {
+		perf_missing_features.mmap2 = true;
+		pr_debug2("switching off mmap2\n");
+		goto fallback_missing_features;
+	} else if (!perf_missing_features.exclude_guest &&
+		   (evsel->attr.exclude_guest || evsel->attr.exclude_host)) {
+		perf_missing_features.exclude_guest = true;
+		pr_debug2("switching off exclude_guest, exclude_host\n");
+		goto fallback_missing_features;
+	} else if (!perf_missing_features.sample_id_all) {
+		perf_missing_features.sample_id_all = true;
+		pr_debug2("switching off sample_id_all\n");
+		goto retry_sample_id;
+	} else if (!perf_missing_features.lbr_flags &&
+			(evsel->attr.branch_sample_type &
+			 (PERF_SAMPLE_BRANCH_NO_CYCLES |
+			  PERF_SAMPLE_BRANCH_NO_FLAGS))) {
+		perf_missing_features.lbr_flags = true;
+		pr_debug2("switching off branch sample type no (cycles/flags)\n");
+		goto fallback_missing_features;
+	} else if (!perf_missing_features.group_read &&
+		    evsel->attr.inherit &&
+		   (evsel->attr.read_format & PERF_FORMAT_GROUP) &&
+		   perf_evsel__is_group_leader(evsel)) {
+		perf_missing_features.group_read = true;
+		pr_debug2("switching off group read\n");
+		goto fallback_missing_features;
+	}
+out_close:
+	if (err)
+		threads->err_thread = thread;
+
+	do {
+		while (--thread >= 0) {
+			close(FD(evsel, cpu, thread));
+			FD(evsel, cpu, thread) = -1;
+		}
+		thread = nthreads;
+	} while (--cpu >= 0);
+	return err;
+}
+
+void perf_evsel__close(struct perf_evsel *evsel)
+{
+	if (evsel->fd == NULL)
+		return;
+
+	perf_evsel__close_fd(evsel);
+	perf_evsel__free_fd(evsel);
+}
+
+int perf_evsel__open_per_cpu(struct perf_evsel *evsel,
+			     struct cpu_map *cpus)
+{
+	return perf_evsel__open(evsel, cpus, NULL);
+}
+
+int perf_evsel__open_per_thread(struct perf_evsel *evsel,
+				struct thread_map *threads)
+{
+	return perf_evsel__open(evsel, NULL, threads);
+}
+
+static int perf_evsel__parse_id_sample(const struct perf_evsel *evsel,
+				       const union perf_event *event,
+				       struct perf_sample *sample)
+{
+	u64 type = evsel->attr.sample_type;
+	const u64 *array = event->sample.array;
+	bool swapped = evsel->needs_swap;
+	union u64_swap u;
+
+	array += ((event->header.size -
+		   sizeof(event->header)) / sizeof(u64)) - 1;
+
+	if (type & PERF_SAMPLE_IDENTIFIER) {
+		sample->id = *array;
+		array--;
+	}
+
+	if (type & PERF_SAMPLE_CPU) {
+		u.val64 = *array;
+		if (swapped) {
+			/* undo swap of u64, then swap on individual u32s */
+			u.val64 = bswap_64(u.val64);
+			u.val32[0] = bswap_32(u.val32[0]);
+		}
+
+		sample->cpu = u.val32[0];
+		array--;
+	}
+
+	if (type & PERF_SAMPLE_STREAM_ID) {
+		sample->stream_id = *array;
+		array--;
+	}
+
+	if (type & PERF_SAMPLE_ID) {
+		sample->id = *array;
+		array--;
+	}
+
+	if (type & PERF_SAMPLE_TIME) {
+		sample->time = *array;
+		array--;
+	}
+
+	if (type & PERF_SAMPLE_TID) {
+		u.val64 = *array;
+		if (swapped) {
+			/* undo swap of u64, then swap on individual u32s */
+			u.val64 = bswap_64(u.val64);
+			u.val32[0] = bswap_32(u.val32[0]);
+			u.val32[1] = bswap_32(u.val32[1]);
+		}
+
+		sample->pid = u.val32[0];
+		sample->tid = u.val32[1];
+		array--;
+	}
+
+	return 0;
+}
+
+static inline bool overflow(const void *endp, u16 max_size, const void *offset,
+			    u64 size)
+{
+	return size > max_size || offset + size > endp;
+}
+
+#define OVERFLOW_CHECK(offset, size, max_size)				\
+	do {								\
+		if (overflow(endp, (max_size), (offset), (size)))	\
+			return -EFAULT;					\
+	} while (0)
+
+#define OVERFLOW_CHECK_u64(offset) \
+	OVERFLOW_CHECK(offset, sizeof(u64), sizeof(u64))
+
+static int
+perf_event__check_size(union perf_event *event, unsigned int sample_size)
+{
+	/*
+	 * The evsel's sample_size is based on PERF_SAMPLE_MASK which includes
+	 * up to PERF_SAMPLE_PERIOD.  After that overflow() must be used to
+	 * check the format does not go past the end of the event.
+	 */
+	if (sample_size + sizeof(event->header) > event->header.size)
+		return -EFAULT;
+
+	return 0;
+}
+
+int perf_evsel__parse_sample(struct perf_evsel *evsel, union perf_event *event,
+			     struct perf_sample *data)
+{
+	u64 type = evsel->attr.sample_type;
+	bool swapped = evsel->needs_swap;
+	const u64 *array;
+	u16 max_size = event->header.size;
+	const void *endp = (void *)event + max_size;
+	u64 sz;
+
+	/*
+	 * used for cross-endian analysis. See git commit 65014ab3
+	 * for why this goofiness is needed.
+	 */
+	union u64_swap u;
+
+	memset(data, 0, sizeof(*data));
+	data->cpu = data->pid = data->tid = -1;
+	data->stream_id = data->id = data->time = -1ULL;
+	data->period = evsel->attr.sample_period;
+	data->cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
+	data->misc    = event->header.misc;
+	data->id = -1ULL;
+	data->data_src = PERF_MEM_DATA_SRC_NONE;
+
+	if (event->header.type != PERF_RECORD_SAMPLE) {
+		if (!evsel->attr.sample_id_all)
+			return 0;
+		return perf_evsel__parse_id_sample(evsel, event, data);
+	}
+
+	array = event->sample.array;
+
+	if (perf_event__check_size(event, evsel->sample_size))
+		return -EFAULT;
+
+	if (type & PERF_SAMPLE_IDENTIFIER) {
+		data->id = *array;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_IP) {
+		data->ip = *array;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_TID) {
+		u.val64 = *array;
+		if (swapped) {
+			/* undo swap of u64, then swap on individual u32s */
+			u.val64 = bswap_64(u.val64);
+			u.val32[0] = bswap_32(u.val32[0]);
+			u.val32[1] = bswap_32(u.val32[1]);
+		}
+
+		data->pid = u.val32[0];
+		data->tid = u.val32[1];
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_TIME) {
+		data->time = *array;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_ADDR) {
+		data->addr = *array;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_ID) {
+		data->id = *array;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_STREAM_ID) {
+		data->stream_id = *array;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_CPU) {
+
+		u.val64 = *array;
+		if (swapped) {
+			/* undo swap of u64, then swap on individual u32s */
+			u.val64 = bswap_64(u.val64);
+			u.val32[0] = bswap_32(u.val32[0]);
+		}
+
+		data->cpu = u.val32[0];
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_PERIOD) {
+		data->period = *array;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_READ) {
+		u64 read_format = evsel->attr.read_format;
+
+		OVERFLOW_CHECK_u64(array);
+		if (read_format & PERF_FORMAT_GROUP)
+			data->read.group.nr = *array;
+		else
+			data->read.one.value = *array;
+
+		array++;
+
+		if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
+			OVERFLOW_CHECK_u64(array);
+			data->read.time_enabled = *array;
+			array++;
+		}
+
+		if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
+			OVERFLOW_CHECK_u64(array);
+			data->read.time_running = *array;
+			array++;
+		}
+
+		/* PERF_FORMAT_ID is forced for PERF_SAMPLE_READ */
+		if (read_format & PERF_FORMAT_GROUP) {
+			const u64 max_group_nr = UINT64_MAX /
+					sizeof(struct sample_read_value);
+
+			if (data->read.group.nr > max_group_nr)
+				return -EFAULT;
+			sz = data->read.group.nr *
+			     sizeof(struct sample_read_value);
+			OVERFLOW_CHECK(array, sz, max_size);
+			data->read.group.values =
+					(struct sample_read_value *)array;
+			array = (void *)array + sz;
+		} else {
+			OVERFLOW_CHECK_u64(array);
+			data->read.one.id = *array;
+			array++;
+		}
+	}
+
+	if (evsel__has_callchain(evsel)) {
+		const u64 max_callchain_nr = UINT64_MAX / sizeof(u64);
+
+		OVERFLOW_CHECK_u64(array);
+		data->callchain = (struct ip_callchain *)array++;
+		if (data->callchain->nr > max_callchain_nr)
+			return -EFAULT;
+		sz = data->callchain->nr * sizeof(u64);
+		OVERFLOW_CHECK(array, sz, max_size);
+		array = (void *)array + sz;
+	}
+
+	if (type & PERF_SAMPLE_RAW) {
+		OVERFLOW_CHECK_u64(array);
+		u.val64 = *array;
+
+		/*
+		 * Undo swap of u64, then swap on individual u32s,
+		 * get the size of the raw area and undo all of the
+		 * swap. The pevent interface handles endianity by
+		 * itself.
+		 */
+		if (swapped) {
+			u.val64 = bswap_64(u.val64);
+			u.val32[0] = bswap_32(u.val32[0]);
+			u.val32[1] = bswap_32(u.val32[1]);
+		}
+		data->raw_size = u.val32[0];
+
+		/*
+		 * The raw data is aligned on 64bits including the
+		 * u32 size, so it's safe to use mem_bswap_64.
+		 */
+		if (swapped)
+			mem_bswap_64((void *) array, data->raw_size);
+
+		array = (void *)array + sizeof(u32);
+
+		OVERFLOW_CHECK(array, data->raw_size, max_size);
+		data->raw_data = (void *)array;
+		array = (void *)array + data->raw_size;
+	}
+
+	if (type & PERF_SAMPLE_BRANCH_STACK) {
+		const u64 max_branch_nr = UINT64_MAX /
+					  sizeof(struct branch_entry);
+
+		OVERFLOW_CHECK_u64(array);
+		data->branch_stack = (struct branch_stack *)array++;
+
+		if (data->branch_stack->nr > max_branch_nr)
+			return -EFAULT;
+		sz = data->branch_stack->nr * sizeof(struct branch_entry);
+		OVERFLOW_CHECK(array, sz, max_size);
+		array = (void *)array + sz;
+	}
+
+	if (type & PERF_SAMPLE_REGS_USER) {
+		OVERFLOW_CHECK_u64(array);
+		data->user_regs.abi = *array;
+		array++;
+
+		if (data->user_regs.abi) {
+			u64 mask = evsel->attr.sample_regs_user;
+
+			sz = hweight_long(mask) * sizeof(u64);
+			OVERFLOW_CHECK(array, sz, max_size);
+			data->user_regs.mask = mask;
+			data->user_regs.regs = (u64 *)array;
+			array = (void *)array + sz;
+		}
+	}
+
+	if (type & PERF_SAMPLE_STACK_USER) {
+		OVERFLOW_CHECK_u64(array);
+		sz = *array++;
+
+		data->user_stack.offset = ((char *)(array - 1)
+					  - (char *) event);
+
+		if (!sz) {
+			data->user_stack.size = 0;
+		} else {
+			OVERFLOW_CHECK(array, sz, max_size);
+			data->user_stack.data = (char *)array;
+			array = (void *)array + sz;
+			OVERFLOW_CHECK_u64(array);
+			data->user_stack.size = *array++;
+			if (WARN_ONCE(data->user_stack.size > sz,
+				      "user stack dump failure\n"))
+				return -EFAULT;
+		}
+	}
+
+	if (type & PERF_SAMPLE_WEIGHT) {
+		OVERFLOW_CHECK_u64(array);
+		data->weight = *array;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_DATA_SRC) {
+		OVERFLOW_CHECK_u64(array);
+		data->data_src = *array;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_TRANSACTION) {
+		OVERFLOW_CHECK_u64(array);
+		data->transaction = *array;
+		array++;
+	}
+
+	data->intr_regs.abi = PERF_SAMPLE_REGS_ABI_NONE;
+	if (type & PERF_SAMPLE_REGS_INTR) {
+		OVERFLOW_CHECK_u64(array);
+		data->intr_regs.abi = *array;
+		array++;
+
+		if (data->intr_regs.abi != PERF_SAMPLE_REGS_ABI_NONE) {
+			u64 mask = evsel->attr.sample_regs_intr;
+
+			sz = hweight_long(mask) * sizeof(u64);
+			OVERFLOW_CHECK(array, sz, max_size);
+			data->intr_regs.mask = mask;
+			data->intr_regs.regs = (u64 *)array;
+			array = (void *)array + sz;
+		}
+	}
+
+	data->phys_addr = 0;
+	if (type & PERF_SAMPLE_PHYS_ADDR) {
+		data->phys_addr = *array;
+		array++;
+	}
+
+	return 0;
+}
+
+int perf_evsel__parse_sample_timestamp(struct perf_evsel *evsel,
+				       union perf_event *event,
+				       u64 *timestamp)
+{
+	u64 type = evsel->attr.sample_type;
+	const u64 *array;
+
+	if (!(type & PERF_SAMPLE_TIME))
+		return -1;
+
+	if (event->header.type != PERF_RECORD_SAMPLE) {
+		struct perf_sample data = {
+			.time = -1ULL,
+		};
+
+		if (!evsel->attr.sample_id_all)
+			return -1;
+		if (perf_evsel__parse_id_sample(evsel, event, &data))
+			return -1;
+
+		*timestamp = data.time;
+		return 0;
+	}
+
+	array = event->sample.array;
+
+	if (perf_event__check_size(event, evsel->sample_size))
+		return -EFAULT;
+
+	if (type & PERF_SAMPLE_IDENTIFIER)
+		array++;
+
+	if (type & PERF_SAMPLE_IP)
+		array++;
+
+	if (type & PERF_SAMPLE_TID)
+		array++;
+
+	if (type & PERF_SAMPLE_TIME)
+		*timestamp = *array;
+
+	return 0;
+}
+
+size_t perf_event__sample_event_size(const struct perf_sample *sample, u64 type,
+				     u64 read_format)
+{
+	size_t sz, result = sizeof(struct sample_event);
+
+	if (type & PERF_SAMPLE_IDENTIFIER)
+		result += sizeof(u64);
+
+	if (type & PERF_SAMPLE_IP)
+		result += sizeof(u64);
+
+	if (type & PERF_SAMPLE_TID)
+		result += sizeof(u64);
+
+	if (type & PERF_SAMPLE_TIME)
+		result += sizeof(u64);
+
+	if (type & PERF_SAMPLE_ADDR)
+		result += sizeof(u64);
+
+	if (type & PERF_SAMPLE_ID)
+		result += sizeof(u64);
+
+	if (type & PERF_SAMPLE_STREAM_ID)
+		result += sizeof(u64);
+
+	if (type & PERF_SAMPLE_CPU)
+		result += sizeof(u64);
+
+	if (type & PERF_SAMPLE_PERIOD)
+		result += sizeof(u64);
+
+	if (type & PERF_SAMPLE_READ) {
+		result += sizeof(u64);
+		if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
+			result += sizeof(u64);
+		if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
+			result += sizeof(u64);
+		/* PERF_FORMAT_ID is forced for PERF_SAMPLE_READ */
+		if (read_format & PERF_FORMAT_GROUP) {
+			sz = sample->read.group.nr *
+			     sizeof(struct sample_read_value);
+			result += sz;
+		} else {
+			result += sizeof(u64);
+		}
+	}
+
+	if (type & PERF_SAMPLE_CALLCHAIN) {
+		sz = (sample->callchain->nr + 1) * sizeof(u64);
+		result += sz;
+	}
+
+	if (type & PERF_SAMPLE_RAW) {
+		result += sizeof(u32);
+		result += sample->raw_size;
+	}
+
+	if (type & PERF_SAMPLE_BRANCH_STACK) {
+		sz = sample->branch_stack->nr * sizeof(struct branch_entry);
+		sz += sizeof(u64);
+		result += sz;
+	}
+
+	if (type & PERF_SAMPLE_REGS_USER) {
+		if (sample->user_regs.abi) {
+			result += sizeof(u64);
+			sz = hweight_long(sample->user_regs.mask) * sizeof(u64);
+			result += sz;
+		} else {
+			result += sizeof(u64);
+		}
+	}
+
+	if (type & PERF_SAMPLE_STACK_USER) {
+		sz = sample->user_stack.size;
+		result += sizeof(u64);
+		if (sz) {
+			result += sz;
+			result += sizeof(u64);
+		}
+	}
+
+	if (type & PERF_SAMPLE_WEIGHT)
+		result += sizeof(u64);
+
+	if (type & PERF_SAMPLE_DATA_SRC)
+		result += sizeof(u64);
+
+	if (type & PERF_SAMPLE_TRANSACTION)
+		result += sizeof(u64);
+
+	if (type & PERF_SAMPLE_REGS_INTR) {
+		if (sample->intr_regs.abi) {
+			result += sizeof(u64);
+			sz = hweight_long(sample->intr_regs.mask) * sizeof(u64);
+			result += sz;
+		} else {
+			result += sizeof(u64);
+		}
+	}
+
+	if (type & PERF_SAMPLE_PHYS_ADDR)
+		result += sizeof(u64);
+
+	return result;
+}
+
+int perf_event__synthesize_sample(union perf_event *event, u64 type,
+				  u64 read_format,
+				  const struct perf_sample *sample)
+{
+	u64 *array;
+	size_t sz;
+	/*
+	 * used for cross-endian analysis. See git commit 65014ab3
+	 * for why this goofiness is needed.
+	 */
+	union u64_swap u;
+
+	array = event->sample.array;
+
+	if (type & PERF_SAMPLE_IDENTIFIER) {
+		*array = sample->id;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_IP) {
+		*array = sample->ip;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_TID) {
+		u.val32[0] = sample->pid;
+		u.val32[1] = sample->tid;
+		*array = u.val64;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_TIME) {
+		*array = sample->time;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_ADDR) {
+		*array = sample->addr;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_ID) {
+		*array = sample->id;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_STREAM_ID) {
+		*array = sample->stream_id;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_CPU) {
+		u.val32[0] = sample->cpu;
+		u.val32[1] = 0;
+		*array = u.val64;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_PERIOD) {
+		*array = sample->period;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_READ) {
+		if (read_format & PERF_FORMAT_GROUP)
+			*array = sample->read.group.nr;
+		else
+			*array = sample->read.one.value;
+		array++;
+
+		if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
+			*array = sample->read.time_enabled;
+			array++;
+		}
+
+		if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
+			*array = sample->read.time_running;
+			array++;
+		}
+
+		/* PERF_FORMAT_ID is forced for PERF_SAMPLE_READ */
+		if (read_format & PERF_FORMAT_GROUP) {
+			sz = sample->read.group.nr *
+			     sizeof(struct sample_read_value);
+			memcpy(array, sample->read.group.values, sz);
+			array = (void *)array + sz;
+		} else {
+			*array = sample->read.one.id;
+			array++;
+		}
+	}
+
+	if (type & PERF_SAMPLE_CALLCHAIN) {
+		sz = (sample->callchain->nr + 1) * sizeof(u64);
+		memcpy(array, sample->callchain, sz);
+		array = (void *)array + sz;
+	}
+
+	if (type & PERF_SAMPLE_RAW) {
+		u.val32[0] = sample->raw_size;
+		*array = u.val64;
+		array = (void *)array + sizeof(u32);
+
+		memcpy(array, sample->raw_data, sample->raw_size);
+		array = (void *)array + sample->raw_size;
+	}
+
+	if (type & PERF_SAMPLE_BRANCH_STACK) {
+		sz = sample->branch_stack->nr * sizeof(struct branch_entry);
+		sz += sizeof(u64);
+		memcpy(array, sample->branch_stack, sz);
+		array = (void *)array + sz;
+	}
+
+	if (type & PERF_SAMPLE_REGS_USER) {
+		if (sample->user_regs.abi) {
+			*array++ = sample->user_regs.abi;
+			sz = hweight_long(sample->user_regs.mask) * sizeof(u64);
+			memcpy(array, sample->user_regs.regs, sz);
+			array = (void *)array + sz;
+		} else {
+			*array++ = 0;
+		}
+	}
+
+	if (type & PERF_SAMPLE_STACK_USER) {
+		sz = sample->user_stack.size;
+		*array++ = sz;
+		if (sz) {
+			memcpy(array, sample->user_stack.data, sz);
+			array = (void *)array + sz;
+			*array++ = sz;
+		}
+	}
+
+	if (type & PERF_SAMPLE_WEIGHT) {
+		*array = sample->weight;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_DATA_SRC) {
+		*array = sample->data_src;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_TRANSACTION) {
+		*array = sample->transaction;
+		array++;
+	}
+
+	if (type & PERF_SAMPLE_REGS_INTR) {
+		if (sample->intr_regs.abi) {
+			*array++ = sample->intr_regs.abi;
+			sz = hweight_long(sample->intr_regs.mask) * sizeof(u64);
+			memcpy(array, sample->intr_regs.regs, sz);
+			array = (void *)array + sz;
+		} else {
+			*array++ = 0;
+		}
+	}
+
+	if (type & PERF_SAMPLE_PHYS_ADDR) {
+		*array = sample->phys_addr;
+		array++;
+	}
+
+	return 0;
+}
+
+struct format_field *perf_evsel__field(struct perf_evsel *evsel, const char *name)
+{
+	return tep_find_field(evsel->tp_format, name);
+}
+
+void *perf_evsel__rawptr(struct perf_evsel *evsel, struct perf_sample *sample,
+			 const char *name)
+{
+	struct format_field *field = perf_evsel__field(evsel, name);
+	int offset;
+
+	if (!field)
+		return NULL;
+
+	offset = field->offset;
+
+	if (field->flags & FIELD_IS_DYNAMIC) {
+		offset = *(int *)(sample->raw_data + field->offset);
+		offset &= 0xffff;
+	}
+
+	return sample->raw_data + offset;
+}
+
+u64 format_field__intval(struct format_field *field, struct perf_sample *sample,
+			 bool needs_swap)
+{
+	u64 value;
+	void *ptr = sample->raw_data + field->offset;
+
+	switch (field->size) {
+	case 1:
+		return *(u8 *)ptr;
+	case 2:
+		value = *(u16 *)ptr;
+		break;
+	case 4:
+		value = *(u32 *)ptr;
+		break;
+	case 8:
+		memcpy(&value, ptr, sizeof(u64));
+		break;
+	default:
+		return 0;
+	}
+
+	if (!needs_swap)
+		return value;
+
+	switch (field->size) {
+	case 2:
+		return bswap_16(value);
+	case 4:
+		return bswap_32(value);
+	case 8:
+		return bswap_64(value);
+	default:
+		return 0;
+	}
+
+	return 0;
+}
+
+u64 perf_evsel__intval(struct perf_evsel *evsel, struct perf_sample *sample,
+		       const char *name)
+{
+	struct format_field *field = perf_evsel__field(evsel, name);
+
+	if (!field)
+		return 0;
+
+	return field ? format_field__intval(field, sample, evsel->needs_swap) : 0;
+}
+
+bool perf_evsel__fallback(struct perf_evsel *evsel, int err,
+			  char *msg, size_t msgsize)
+{
+	int paranoid;
+
+	if ((err == ENOENT || err == ENXIO || err == ENODEV) &&
+	    evsel->attr.type   == PERF_TYPE_HARDWARE &&
+	    evsel->attr.config == PERF_COUNT_HW_CPU_CYCLES) {
+		/*
+		 * If it's cycles then fall back to hrtimer based
+		 * cpu-clock-tick sw counter, which is always available even if
+		 * no PMU support.
+		 *
+		 * PPC returns ENXIO until 2.6.37 (behavior changed with commit
+		 * b0a873e).
+		 */
+		scnprintf(msg, msgsize, "%s",
+"The cycles event is not supported, trying to fall back to cpu-clock-ticks");
+
+		evsel->attr.type   = PERF_TYPE_SOFTWARE;
+		evsel->attr.config = PERF_COUNT_SW_CPU_CLOCK;
+
+		zfree(&evsel->name);
+		return true;
+	} else if (err == EACCES && !evsel->attr.exclude_kernel &&
+		   (paranoid = perf_event_paranoid()) > 1) {
+		const char *name = perf_evsel__name(evsel);
+		char *new_name;
+		const char *sep = ":";
+
+		/* Is there already the separator in the name. */
+		if (strchr(name, '/') ||
+		    strchr(name, ':'))
+			sep = "";
+
+		if (asprintf(&new_name, "%s%su", name, sep) < 0)
+			return false;
+
+		if (evsel->name)
+			free(evsel->name);
+		evsel->name = new_name;
+		scnprintf(msg, msgsize,
+"kernel.perf_event_paranoid=%d, trying to fall back to excluding kernel samples", paranoid);
+		evsel->attr.exclude_kernel = 1;
+
+		return true;
+	}
+
+	return false;
+}
+
+static bool find_process(const char *name)
+{
+	size_t len = strlen(name);
+	DIR *dir;
+	struct dirent *d;
+	int ret = -1;
+
+	dir = opendir(procfs__mountpoint());
+	if (!dir)
+		return false;
+
+	/* Walk through the directory. */
+	while (ret && (d = readdir(dir)) != NULL) {
+		char path[PATH_MAX];
+		char *data;
+		size_t size;
+
+		if ((d->d_type != DT_DIR) ||
+		     !strcmp(".", d->d_name) ||
+		     !strcmp("..", d->d_name))
+			continue;
+
+		scnprintf(path, sizeof(path), "%s/%s/comm",
+			  procfs__mountpoint(), d->d_name);
+
+		if (filename__read_str(path, &data, &size))
+			continue;
+
+		ret = strncmp(name, data, len);
+		free(data);
+	}
+
+	closedir(dir);
+	return ret ? false : true;
+}
+
+int perf_evsel__open_strerror(struct perf_evsel *evsel, struct target *target,
+			      int err, char *msg, size_t size)
+{
+	char sbuf[STRERR_BUFSIZE];
+	int printed = 0;
+
+	switch (err) {
+	case EPERM:
+	case EACCES:
+		if (err == EPERM)
+			printed = scnprintf(msg, size,
+				"No permission to enable %s event.\n\n",
+				perf_evsel__name(evsel));
+
+		return scnprintf(msg + printed, size - printed,
+		 "You may not have permission to collect %sstats.\n\n"
+		 "Consider tweaking /proc/sys/kernel/perf_event_paranoid,\n"
+		 "which controls use of the performance events system by\n"
+		 "unprivileged users (without CAP_SYS_ADMIN).\n\n"
+		 "The current value is %d:\n\n"
+		 "  -1: Allow use of (almost) all events by all users\n"
+		 "      Ignore mlock limit after perf_event_mlock_kb without CAP_IPC_LOCK\n"
+		 ">= 0: Disallow ftrace function tracepoint by users without CAP_SYS_ADMIN\n"
+		 "      Disallow raw tracepoint access by users without CAP_SYS_ADMIN\n"
+		 ">= 1: Disallow CPU event access by users without CAP_SYS_ADMIN\n"
+		 ">= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN\n\n"
+		 "To make this setting permanent, edit /etc/sysctl.conf too, e.g.:\n\n"
+		 "	kernel.perf_event_paranoid = -1\n" ,
+				 target->system_wide ? "system-wide " : "",
+				 perf_event_paranoid());
+	case ENOENT:
+		return scnprintf(msg, size, "The %s event is not supported.",
+				 perf_evsel__name(evsel));
+	case EMFILE:
+		return scnprintf(msg, size, "%s",
+			 "Too many events are opened.\n"
+			 "Probably the maximum number of open file descriptors has been reached.\n"
+			 "Hint: Try again after reducing the number of events.\n"
+			 "Hint: Try increasing the limit with 'ulimit -n <limit>'");
+	case ENOMEM:
+		if (evsel__has_callchain(evsel) &&
+		    access("/proc/sys/kernel/perf_event_max_stack", F_OK) == 0)
+			return scnprintf(msg, size,
+					 "Not enough memory to setup event with callchain.\n"
+					 "Hint: Try tweaking /proc/sys/kernel/perf_event_max_stack\n"
+					 "Hint: Current value: %d", sysctl__max_stack());
+		break;
+	case ENODEV:
+		if (target->cpu_list)
+			return scnprintf(msg, size, "%s",
+	 "No such device - did you specify an out-of-range profile CPU?");
+		break;
+	case EOPNOTSUPP:
+		if (evsel->attr.sample_period != 0)
+			return scnprintf(msg, size,
+	"%s: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat'",
+					 perf_evsel__name(evsel));
+		if (evsel->attr.precise_ip)
+			return scnprintf(msg, size, "%s",
+	"\'precise\' request may not be supported. Try removing 'p' modifier.");
+#if defined(__i386__) || defined(__x86_64__)
+		if (evsel->attr.type == PERF_TYPE_HARDWARE)
+			return scnprintf(msg, size, "%s",
+	"No hardware sampling interrupt available.\n");
+#endif
+		break;
+	case EBUSY:
+		if (find_process("oprofiled"))
+			return scnprintf(msg, size,
+	"The PMU counters are busy/taken by another profiler.\n"
+	"We found oprofile daemon running, please stop it and try again.");
+		break;
+	case EINVAL:
+		if (evsel->attr.write_backward && perf_missing_features.write_backward)
+			return scnprintf(msg, size, "Reading from overwrite event is not supported by this kernel.");
+		if (perf_missing_features.clockid)
+			return scnprintf(msg, size, "clockid feature not supported.");
+		if (perf_missing_features.clockid_wrong)
+			return scnprintf(msg, size, "wrong clockid (%d).", clockid);
+		break;
+	default:
+		break;
+	}
+
+	return scnprintf(msg, size,
+	"The sys_perf_event_open() syscall returned with %d (%s) for event (%s).\n"
+	"/bin/dmesg | grep -i perf may provide additional information.\n",
+			 err, str_error_r(err, sbuf, sizeof(sbuf)),
+			 perf_evsel__name(evsel));
+}
+
+struct perf_env *perf_evsel__env(struct perf_evsel *evsel)
+{
+	if (evsel && evsel->evlist)
+		return evsel->evlist->env;
+	return NULL;
+}