Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 489 insertions, 0 deletions

diff --git a/tools/perf/util/expr.c b/tools/perf/util/expr.c
new file mode 100644
index 000000000..8aef3c741
--- /dev/null
+++ b/tools/perf/util/expr.c
@@ -0,0 +1,489 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdbool.h>
+#include <assert.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include "metricgroup.h"
+#include "debug.h"
+#include "evlist.h"
+#include "expr.h"
+#include "smt.h"
+#include "tool_pmu.h"
+#include <util/expr-bison.h>
+#include <util/expr-flex.h>
+#include "util/hashmap.h"
+#include "util/header.h"
+#include "util/pmu.h"
+#include <perf/cpumap.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/zalloc.h>
+#include <ctype.h>
+#include <math.h>
+
+struct expr_id_data {
+	union {
+		struct {
+			double val;
+			int source_count;
+			int aggr_nr;
+		} val;
+		struct {
+			double val;
+			const char *metric_name;
+			const char *metric_expr;
+		} ref;
+	};
+
+	enum {
+		/* Holding a double value. */
+		EXPR_ID_DATA__VALUE,
+		/* Reference to another metric. */
+		EXPR_ID_DATA__REF,
+		/* A reference but the value has been computed. */
+		EXPR_ID_DATA__REF_VALUE,
+	} kind;
+};
+
+static size_t key_hash(long key, void *ctx __maybe_unused)
+{
+	const char *str = (const char *)key;
+	size_t hash = 0;
+
+	while (*str != '\0') {
+		hash *= 31;
+		hash += *str;
+		str++;
+	}
+	return hash;
+}
+
+static bool key_equal(long key1, long key2, void *ctx __maybe_unused)
+{
+	return !strcmp((const char *)key1, (const char *)key2);
+}
+
+struct hashmap *ids__new(void)
+{
+	struct hashmap *hash;
+
+	hash = hashmap__new(key_hash, key_equal, NULL);
+	if (IS_ERR(hash))
+		return NULL;
+	return hash;
+}
+
+void ids__free(struct hashmap *ids)
+{
+	struct hashmap_entry *cur;
+	size_t bkt;
+
+	if (ids == NULL)
+		return;
+
+	hashmap__for_each_entry(ids, cur, bkt) {
+		zfree(&cur->pkey);
+		zfree(&cur->pvalue);
+	}
+
+	hashmap__free(ids);
+}
+
+int ids__insert(struct hashmap *ids, const char *id)
+{
+	struct expr_id_data *data_ptr = NULL, *old_data = NULL;
+	char *old_key = NULL;
+	int ret;
+
+	ret = hashmap__set(ids, id, data_ptr, &old_key, &old_data);
+	if (ret)
+		free(data_ptr);
+	free(old_key);
+	free(old_data);
+	return ret;
+}
+
+struct hashmap *ids__union(struct hashmap *ids1, struct hashmap *ids2)
+{
+	size_t bkt;
+	struct hashmap_entry *cur;
+	int ret;
+	struct expr_id_data *old_data = NULL;
+	char *old_key = NULL;
+
+	if (!ids1)
+		return ids2;
+
+	if (!ids2)
+		return ids1;
+
+	if (hashmap__size(ids1) <  hashmap__size(ids2)) {
+		struct hashmap *tmp = ids1;
+
+		ids1 = ids2;
+		ids2 = tmp;
+	}
+	hashmap__for_each_entry(ids2, cur, bkt) {
+		ret = hashmap__set(ids1, cur->key, cur->value, &old_key, &old_data);
+		free(old_key);
+		free(old_data);
+
+		if (ret) {
+			hashmap__free(ids1);
+			hashmap__free(ids2);
+			return NULL;
+		}
+	}
+	hashmap__free(ids2);
+	return ids1;
+}
+
+/* Caller must make sure id is allocated */
+int expr__add_id(struct expr_parse_ctx *ctx, const char *id)
+{
+	return ids__insert(ctx->ids, id);
+}
+
+/* Caller must make sure id is allocated */
+int expr__add_id_val(struct expr_parse_ctx *ctx, const char *id, double val)
+{
+	return expr__add_id_val_source_count(ctx, id, val, /*source_count=*/1);
+}
+
+/* Caller must make sure id is allocated */
+int expr__add_id_val_source_count_aggr_nr(struct expr_parse_ctx *ctx, const char *id,
+					  double val, int source_count, int aggr_nr)
+{
+	struct expr_id_data *data_ptr = NULL, *old_data = NULL;
+	char *old_key = NULL;
+	int ret;
+
+	data_ptr = malloc(sizeof(*data_ptr));
+	if (!data_ptr)
+		return -ENOMEM;
+	data_ptr->val.val = val;
+	data_ptr->val.source_count = source_count;
+	data_ptr->val.aggr_nr = aggr_nr;
+	data_ptr->kind = EXPR_ID_DATA__VALUE;
+
+	ret = hashmap__set(ctx->ids, id, data_ptr, &old_key, &old_data);
+	if (ret) {
+		free(data_ptr);
+	} else if (old_data) {
+		data_ptr->val.val += old_data->val.val;
+		data_ptr->val.source_count += old_data->val.source_count;
+		data_ptr->val.aggr_nr += old_data->val.aggr_nr;
+	}
+	free(old_key);
+	free(old_data);
+	return ret;
+}
+
+/* Caller must make sure id is allocated */
+int expr__add_id_val_source_count(struct expr_parse_ctx *ctx, const char *id,
+				  double val, int source_count)
+{
+	return expr__add_id_val_source_count_aggr_nr(ctx, id, val, source_count, 1);
+}
+
+int expr__add_ref(struct expr_parse_ctx *ctx, struct metric_ref *ref)
+{
+	struct expr_id_data *data_ptr = NULL, *old_data = NULL;
+	char *old_key = NULL;
+	char *name;
+	int ret;
+
+	data_ptr = zalloc(sizeof(*data_ptr));
+	if (!data_ptr)
+		return -ENOMEM;
+
+	name = strdup(ref->metric_name);
+	if (!name) {
+		free(data_ptr);
+		return -ENOMEM;
+	}
+
+	/*
+	 * Intentionally passing just const char pointers,
+	 * originally from 'struct pmu_event' object.
+	 * We don't need to change them, so there's no
+	 * need to create our own copy.
+	 */
+	data_ptr->ref.metric_name = ref->metric_name;
+	data_ptr->ref.metric_expr = ref->metric_expr;
+	data_ptr->kind = EXPR_ID_DATA__REF;
+
+	ret = hashmap__set(ctx->ids, name, data_ptr, &old_key, &old_data);
+	if (ret)
+		free(data_ptr);
+
+	pr_debug2("adding ref metric %s: %s\n",
+		  ref->metric_name, ref->metric_expr);
+
+	free(old_key);
+	free(old_data);
+	return ret;
+}
+
+int expr__get_id(struct expr_parse_ctx *ctx, const char *id,
+		 struct expr_id_data **data)
+{
+	if (!ctx || !id)
+		return -1;
+	return hashmap__find(ctx->ids, id, data) ? 0 : -1;
+}
+
+bool expr__subset_of_ids(struct expr_parse_ctx *haystack,
+			 struct expr_parse_ctx *needles)
+{
+	struct hashmap_entry *cur;
+	size_t bkt;
+	struct expr_id_data *data;
+
+	hashmap__for_each_entry(needles->ids, cur, bkt) {
+		if (expr__get_id(haystack, cur->pkey, &data))
+			return false;
+	}
+	return true;
+}
+
+
+int expr__resolve_id(struct expr_parse_ctx *ctx, const char *id,
+		     struct expr_id_data **datap)
+{
+	struct expr_id_data *data;
+
+	if (expr__get_id(ctx, id, datap) || !*datap) {
+		pr_debug("%s not found\n", id);
+		return -1;
+	}
+
+	data = *datap;
+
+	switch (data->kind) {
+	case EXPR_ID_DATA__VALUE:
+		pr_debug2("lookup(%s): val %f\n", id, data->val.val);
+		break;
+	case EXPR_ID_DATA__REF:
+		pr_debug2("lookup(%s): ref metric name %s\n", id,
+			data->ref.metric_name);
+		pr_debug("processing metric: %s ENTRY\n", id);
+		data->kind = EXPR_ID_DATA__REF_VALUE;
+		if (expr__parse(&data->ref.val, ctx, data->ref.metric_expr)) {
+			pr_debug("%s failed to count\n", id);
+			return -1;
+		}
+		pr_debug("processing metric: %s EXIT: %f\n", id, data->ref.val);
+		break;
+	case EXPR_ID_DATA__REF_VALUE:
+		pr_debug2("lookup(%s): ref val %f metric name %s\n", id,
+			data->ref.val, data->ref.metric_name);
+		break;
+	default:
+		assert(0);  /* Unreachable. */
+	}
+
+	return 0;
+}
+
+void expr__del_id(struct expr_parse_ctx *ctx, const char *id)
+{
+	struct expr_id_data *old_val = NULL;
+	char *old_key = NULL;
+
+	hashmap__delete(ctx->ids, id, &old_key, &old_val);
+	free(old_key);
+	free(old_val);
+}
+
+struct expr_parse_ctx *expr__ctx_new(void)
+{
+	struct expr_parse_ctx *ctx;
+
+	ctx = calloc(1, sizeof(struct expr_parse_ctx));
+	if (!ctx)
+		return NULL;
+
+	ctx->ids = hashmap__new(key_hash, key_equal, NULL);
+	if (IS_ERR(ctx->ids)) {
+		free(ctx);
+		return NULL;
+	}
+
+	return ctx;
+}
+
+void expr__ctx_clear(struct expr_parse_ctx *ctx)
+{
+	struct hashmap_entry *cur;
+	size_t bkt;
+
+	hashmap__for_each_entry(ctx->ids, cur, bkt) {
+		zfree(&cur->pkey);
+		zfree(&cur->pvalue);
+	}
+	hashmap__clear(ctx->ids);
+}
+
+void expr__ctx_free(struct expr_parse_ctx *ctx)
+{
+	struct hashmap_entry *cur;
+	size_t bkt;
+
+	if (!ctx)
+		return;
+
+	zfree(&ctx->sctx.user_requested_cpu_list);
+	hashmap__for_each_entry(ctx->ids, cur, bkt) {
+		zfree(&cur->pkey);
+		zfree(&cur->pvalue);
+	}
+	hashmap__free(ctx->ids);
+	free(ctx);
+}
+
+static int
+__expr__parse(double *val, struct expr_parse_ctx *ctx, const char *expr,
+	      bool compute_ids)
+{
+	YY_BUFFER_STATE buffer;
+	void *scanner;
+	int ret;
+
+	pr_debug2("parsing metric: %s\n", expr);
+
+	ret = expr_lex_init_extra(&ctx->sctx, &scanner);
+	if (ret)
+		return ret;
+
+	buffer = expr__scan_string(expr, scanner);
+
+#ifdef PARSER_DEBUG
+	expr_debug = 1;
+	expr_set_debug(1, scanner);
+#endif
+
+	ret = expr_parse(val, ctx, compute_ids, scanner);
+
+	expr__flush_buffer(buffer, scanner);
+	expr__delete_buffer(buffer, scanner);
+	expr_lex_destroy(scanner);
+	return ret;
+}
+
+int expr__parse(double *final_val, struct expr_parse_ctx *ctx,
+		const char *expr)
+{
+	return __expr__parse(final_val, ctx, expr, /*compute_ids=*/false) ? -1 : 0;
+}
+
+int expr__find_ids(const char *expr, const char *one,
+		   struct expr_parse_ctx *ctx)
+{
+	int ret = __expr__parse(NULL, ctx, expr, /*compute_ids=*/true);
+
+	if (one)
+		expr__del_id(ctx, one);
+
+	/* A positive value means syntax error, convert to -EINVAL */
+	return ret > 0 ? -EINVAL : ret;
+}
+
+double expr_id_data__value(const struct expr_id_data *data)
+{
+	if (data->kind == EXPR_ID_DATA__VALUE)
+		return data->val.val;
+	assert(data->kind == EXPR_ID_DATA__REF_VALUE);
+	return data->ref.val;
+}
+
+double expr_id_data__source_count(const struct expr_id_data *data)
+{
+	if (data->kind == EXPR_ID_DATA__VALUE)
+		return data->val.source_count;
+	return 1.0;
+}
+
+double expr_id_data__aggr_nr(const struct expr_id_data *data)
+{
+	if (data->kind == EXPR_ID_DATA__VALUE)
+		return data->val.aggr_nr;
+	return 1.0;
+}
+
+double expr__get_literal(const char *literal, const struct expr_scanner_ctx *ctx)
+{
+	double result = NAN;
+	enum tool_pmu_event ev = tool_pmu__str_to_event(literal + 1);
+
+	if (ev != TOOL_PMU__EVENT_NONE) {
+		u64 count;
+
+		if (tool_pmu__read_event(ev, /*evsel=*/NULL,
+					 ctx->system_wide, ctx->user_requested_cpu_list,
+					 &count))
+			result = count;
+		else
+			pr_err("Failure to read '%s'\n", literal);
+	} else {
+		pr_err("Unrecognized literal '%s'\n", literal);
+	}
+
+	pr_debug2("literal: %s = %f\n", literal, result);
+	return result;
+}
+
+/* Does the event 'id' parse? Determine via ctx->ids if possible. */
+double expr__has_event(const struct expr_parse_ctx *ctx, bool compute_ids, const char *id)
+{
+	struct evlist *tmp;
+	double ret;
+
+	if (hashmap__find(ctx->ids, id, /*value=*/NULL))
+		return 1.0;
+
+	if (!compute_ids)
+		return 0.0;
+
+	tmp = evlist__new();
+	if (!tmp)
+		return NAN;
+
+	if (strchr(id, '@')) {
+		char *tmp_id, *p;
+
+		tmp_id = strdup(id);
+		if (!tmp_id) {
+			ret = NAN;
+			goto out;
+		}
+		p = strchr(tmp_id, '@');
+		*p = '/';
+		p = strrchr(tmp_id, '@');
+		*p = '/';
+		ret = parse_event(tmp, tmp_id) ? 0 : 1;
+		free(tmp_id);
+	} else {
+		ret = parse_event(tmp, id) ? 0 : 1;
+	}
+out:
+	evlist__put(tmp);
+	return ret;
+}
+
+double expr__strcmp_cpuid_str(const struct expr_parse_ctx *ctx __maybe_unused,
+		       bool compute_ids __maybe_unused, const char *test_id)
+{
+	double ret;
+	struct perf_cpu cpu = {-1};
+	char *cpuid = get_cpuid_allow_env_override(cpu);
+
+	if (!cpuid)
+		return NAN;
+
+	ret = !strcmp_cpuid_str(test_id, cpuid);
+
+	free(cpuid);
+	return ret;
+}