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, 647 insertions, 0 deletions

diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
new file mode 100644
index 000000000..b531b1f0c
--- /dev/null
+++ b/tools/perf/util/parse-events.y
@@ -0,0 +1,647 @@
+%define api.pure full
+%parse-param {void *_parse_state}
+%parse-param {void *scanner}
+%lex-param {void* scanner}
+%locations
+
+%{
+
+#ifndef NDEBUG
+#define YYDEBUG 1
+#endif
+
+#include <errno.h>
+#include <linux/compiler.h>
+#include <linux/types.h>
+#include "pmu.h"
+#include "pmus.h"
+#include "evsel.h"
+#include "parse-events.h"
+#include "parse-events-bison.h"
+
+int parse_events_lex(YYSTYPE * yylval_param, YYLTYPE * yylloc_param , void *yyscanner);
+void parse_events_error(YYLTYPE *loc, void *parse_state, void *scanner, char const *msg);
+
+#define PE_ABORT(val) \
+do { \
+	if (val == -ENOMEM) \
+		YYNOMEM; \
+	YYABORT; \
+} while (0)
+
+static struct list_head* alloc_list(void)
+{
+	struct list_head *list;
+
+	list = malloc(sizeof(*list));
+	if (!list)
+		return NULL;
+
+	INIT_LIST_HEAD(list);
+	return list;
+}
+
+static void free_list_evsel(struct list_head* list_evsel)
+{
+	struct evsel *evsel, *tmp;
+
+	list_for_each_entry_safe(evsel, tmp, list_evsel, core.node) {
+		list_del_init(&evsel->core.node);
+		evsel__put(evsel);
+	}
+	free(list_evsel);
+}
+
+%}
+
+%token PE_START_EVENTS PE_START_TERMS
+%token PE_VALUE PE_TERM
+%token PE_EVENT_NAME
+%token PE_RAW PE_NAME
+%token PE_MODIFIER_EVENT PE_MODIFIER_BP PE_BP_COLON PE_BP_SLASH
+%token PE_PREFIX_MEM
+%token PE_ERROR
+%token PE_DRV_CFG_TERM
+%type <num> PE_VALUE
+%type <mod> PE_MODIFIER_EVENT
+%type <term_type> PE_TERM
+%type <str> PE_RAW
+%type <str> PE_NAME
+%type <str> PE_MODIFIER_BP
+%type <str> PE_EVENT_NAME
+%type <str> PE_DRV_CFG_TERM
+%type <str> name_or_raw
+%destructor { free ($$); } <str>
+%type <term> event_term
+%destructor { parse_events_term__delete ($$); } <term>
+%type <list_terms> event_config
+%type <list_terms> opt_event_config
+%type <list_terms> opt_pmu_config
+%destructor { parse_events_terms__delete ($$); } <list_terms>
+%type <list_evsel> event_pmu
+%type <list_evsel> event_legacy_mem
+%type <list_evsel> event_legacy_tracepoint
+%type <list_evsel> event_legacy_numeric
+%type <list_evsel> event_legacy_raw
+%type <list_evsel> event_def
+%type <list_evsel> event_mod
+%type <list_evsel> event_name
+%type <list_evsel> event
+%type <list_evsel> events
+%type <list_evsel> group_def
+%type <list_evsel> group
+%type <list_evsel> groups
+%destructor { free_list_evsel ($$); } <list_evsel>
+%type <tracepoint_name> tracepoint_name
+%destructor { free ($$.sys); free ($$.event); } <tracepoint_name>
+
+%union
+{
+	char *str;
+	u64 num;
+	struct parse_events_modifier mod;
+	enum parse_events__term_type term_type;
+	struct list_head *list_evsel;
+	struct parse_events_terms *list_terms;
+	struct parse_events_term *term;
+	struct tracepoint_name {
+		char *sys;
+		char *event;
+	} tracepoint_name;
+}
+%%
+
+ /*
+  * Entry points. We are either parsing events or terminals. Just terminal
+  * parsing is used for parsing events in sysfs.
+  */
+start:
+PE_START_EVENTS start_events
+|
+PE_START_TERMS  start_terms
+
+start_events: groups
+{
+	/* Take the parsed events, groups.. and place into parse_state. */
+	struct list_head *groups  = $1;
+	struct parse_events_state *parse_state = _parse_state;
+
+	list_splice_tail(groups, &parse_state->list);
+	free(groups);
+}
+
+groups: /* A list of groups or events. */
+groups ',' group
+{
+	/* Merge group into the list of events/groups. */
+	struct list_head *groups  = $1;
+	struct list_head *group  = $3;
+
+	list_splice_tail(group, groups);
+	free(group);
+	$$ = groups;
+}
+|
+groups ',' event
+{
+	/* Merge event into the list of events/groups. */
+	struct list_head *groups  = $1;
+	struct list_head *event = $3;
+
+
+	list_splice_tail(event, groups);
+	free(event);
+	$$ = groups;
+}
+|
+group
+|
+event
+
+group:
+group_def ':' PE_MODIFIER_EVENT
+{
+	/* Apply the modifier to the events in the group_def. */
+	struct list_head *list = $1;
+	int err;
+
+	err = parse_events__modifier_group(_parse_state, &@3, list, $3);
+	if (err)
+		YYABORT;
+	$$ = list;
+}
+|
+group_def
+
+group_def:
+PE_NAME '{' events '}'
+{
+	struct list_head *list = $3;
+
+	/*
+	 * Set the first entry of list to be the leader. Set the group name on
+	 * the leader to $1 taking ownership.
+	 */
+	parse_events__set_leader($1, list);
+	$$ = list;
+}
+|
+'{' events '}'
+{
+	struct list_head *list = $2;
+
+	/* Set the first entry of list to be the leader clearing the group name. */
+	parse_events__set_leader(NULL, list);
+	$$ = list;
+}
+
+events:
+events ',' event
+{
+	struct list_head *events  = $1;
+	struct list_head *event = $3;
+
+	list_splice_tail(event, events);
+	free(event);
+	$$ = events;
+}
+|
+event
+
+event: event_mod
+
+event_mod:
+event_name PE_MODIFIER_EVENT
+{
+	struct list_head *list = $1;
+	int err;
+
+	/*
+	 * Apply modifier on all events added by single event definition
+	 * (there could be more events added for multiple tracepoint
+	 * definitions via '*?'.
+	 */
+	err = parse_events__modifier_event(_parse_state, &@2, list, $2);
+	if (err)
+		YYABORT;
+	$$ = list;
+}
+|
+event_name
+
+event_name:
+PE_EVENT_NAME event_def
+{
+	/*
+	 * When an event is parsed the text is rewound and the entire text of
+	 * the event is set to the str of PE_EVENT_NAME token matched here. If
+	 * no name was on an event via a term, set the name to the entire text
+	 * taking ownership of the allocation.
+	 */
+	int err = parse_events__set_default_name($2, $1);
+
+	if (err) {
+		free_list_evsel($2);
+		YYNOMEM;
+	}
+	$$ = $2;
+}
+|
+event_def
+
+event_def: event_pmu |
+	   event_legacy_mem sep_dc |
+	   event_legacy_tracepoint sep_dc |
+	   event_legacy_numeric sep_dc |
+	   event_legacy_raw sep_dc
+
+event_pmu:
+PE_NAME opt_pmu_config
+{
+	/* List of created evsels. */
+	struct list_head *list = NULL;
+	int err = parse_events_multi_pmu_add_or_add_pmu(_parse_state, $1, $2, &list, &@1);
+
+	parse_events_terms__delete($2);
+	free($1);
+	if (err)
+		PE_ABORT(err);
+	$$ = list;
+}
+|
+PE_NAME sep_dc
+{
+	struct list_head *list;
+	int err;
+
+	err = parse_events_multi_pmu_add(_parse_state, $1, /*const_parsed_terms*/NULL, &list, &@1);
+	if (err < 0) {
+		struct parse_events_state *parse_state = _parse_state;
+		struct parse_events_error *error = parse_state->error;
+		char *help;
+
+		if (asprintf(&help, "Unable to find event on a PMU of '%s'", $1) < 0)
+			help = NULL;
+		parse_events_error__handle(error, @1.first_column, strdup("Bad event name"), help);
+		free($1);
+		PE_ABORT(err);
+	}
+	free($1);
+	$$ = list;
+}
+
+event_legacy_mem:
+PE_PREFIX_MEM PE_VALUE PE_BP_SLASH PE_VALUE PE_BP_COLON PE_MODIFIER_BP opt_event_config
+{
+	struct list_head *list;
+	int err;
+
+	list = alloc_list();
+	if (!list)
+		YYNOMEM;
+
+	err = parse_events_add_breakpoint(_parse_state, list,
+					  $2, $6, $4, $7);
+	parse_events_terms__delete($7);
+	free($6);
+	if (err) {
+		free(list);
+		PE_ABORT(err);
+	}
+	$$ = list;
+}
+|
+PE_PREFIX_MEM PE_VALUE PE_BP_SLASH PE_VALUE opt_event_config
+{
+	struct list_head *list;
+	int err;
+
+	list = alloc_list();
+	if (!list)
+		YYNOMEM;
+
+	err = parse_events_add_breakpoint(_parse_state, list,
+					  $2, NULL, $4, $5);
+	parse_events_terms__delete($5);
+	if (err) {
+		free(list);
+		PE_ABORT(err);
+	}
+	$$ = list;
+}
+|
+PE_PREFIX_MEM PE_VALUE PE_BP_COLON PE_MODIFIER_BP opt_event_config
+{
+	struct list_head *list;
+	int err;
+
+	list = alloc_list();
+	if (!list)
+		YYNOMEM;
+
+	err = parse_events_add_breakpoint(_parse_state, list,
+					  $2, $4, 0, $5);
+	parse_events_terms__delete($5);
+	free($4);
+	if (err) {
+		free(list);
+		PE_ABORT(err);
+	}
+	$$ = list;
+}
+|
+PE_PREFIX_MEM PE_VALUE opt_event_config
+{
+	struct list_head *list;
+	int err;
+
+	list = alloc_list();
+	if (!list)
+		YYNOMEM;
+	err = parse_events_add_breakpoint(_parse_state, list,
+					  $2, NULL, 0, $3);
+	parse_events_terms__delete($3);
+	if (err) {
+		free(list);
+		PE_ABORT(err);
+	}
+	$$ = list;
+}
+
+event_legacy_tracepoint:
+tracepoint_name opt_event_config
+{
+	struct parse_events_state *parse_state = _parse_state;
+	struct parse_events_error *error = parse_state->error;
+	struct list_head *list;
+	int err;
+
+	list = alloc_list();
+	if (!list)
+		YYNOMEM;
+
+	err = parse_events_add_tracepoint(parse_state, list, $1.sys, $1.event,
+					error, $2, &@1);
+
+	parse_events_terms__delete($2);
+	free($1.sys);
+	free($1.event);
+	if (err) {
+		free(list);
+		PE_ABORT(err);
+	}
+	$$ = list;
+}
+
+tracepoint_name:
+PE_NAME ':' PE_NAME
+{
+	struct tracepoint_name tracepoint = {$1, $3};
+
+	$$ = tracepoint;
+}
+
+event_legacy_numeric:
+PE_VALUE ':' PE_VALUE opt_event_config
+{
+	struct list_head *list;
+	int err;
+
+	list = alloc_list();
+	if (!list)
+		YYNOMEM;
+	err = parse_events_add_numeric(_parse_state, list, (u32)$1, $3, $4,
+				       /*wildcard=*/false);
+	parse_events_terms__delete($4);
+	if (err) {
+		free(list);
+		PE_ABORT(err);
+	}
+	$$ = list;
+}
+
+event_legacy_raw:
+PE_RAW opt_event_config
+{
+	struct list_head *list;
+	int err;
+	u64 num;
+
+	list = alloc_list();
+	if (!list)
+		YYNOMEM;
+	errno = 0;
+	num = strtoull($1 + 1, NULL, 16);
+	/* Given the lexer will only give [a-fA-F0-9]+ a failure here should be impossible. */
+	if (errno)
+		YYABORT;
+	free($1);
+	err = parse_events_add_numeric(_parse_state, list, PERF_TYPE_RAW, num, $2,
+				       /*wildcard=*/false);
+	parse_events_terms__delete($2);
+	if (err) {
+		free(list);
+		PE_ABORT(err);
+	}
+	$$ = list;
+}
+
+opt_event_config:
+'/' event_config '/'
+{
+	$$ = $2;
+}
+|
+'/' '/'
+{
+	$$ = NULL;
+}
+|
+{
+	$$ = NULL;
+}
+
+opt_pmu_config:
+'/' event_config '/'
+{
+	$$ = $2;
+}
+|
+'/' '/'
+{
+	$$ = NULL;
+}
+
+start_terms: event_config
+{
+	struct parse_events_state *parse_state = _parse_state;
+	if (parse_state->terms) {
+		parse_events_terms__delete ($1);
+		YYABORT;
+	}
+	parse_state->terms = $1;
+}
+
+event_config:
+event_config ',' event_term
+{
+	struct parse_events_terms *head = $1;
+	struct parse_events_term *term = $3;
+
+	if (!head) {
+		parse_events_term__delete(term);
+		YYABORT;
+	}
+	list_add_tail(&term->list, &head->terms);
+	$$ = $1;
+}
+|
+event_term
+{
+	struct parse_events_terms *head = malloc(sizeof(*head));
+	struct parse_events_term *term = $1;
+
+	if (!head)
+		YYNOMEM;
+	parse_events_terms__init(head);
+	list_add_tail(&term->list, &head->terms);
+	$$ = head;
+}
+
+name_or_raw: PE_RAW | PE_NAME
+
+event_term:
+PE_RAW
+{
+	struct parse_events_term *term;
+	int err = parse_events_term__str(&term, PARSE_EVENTS__TERM_TYPE_RAW,
+					 strdup("raw"), $1, &@1, &@1);
+
+	if (err) {
+		free($1);
+		PE_ABORT(err);
+	}
+	$$ = term;
+}
+|
+name_or_raw '=' name_or_raw
+{
+	struct parse_events_term *term;
+	int err = parse_events_term__str(&term, PARSE_EVENTS__TERM_TYPE_USER, $1, $3, &@1, &@3);
+
+	if (err) {
+		free($1);
+		free($3);
+		PE_ABORT(err);
+	}
+	$$ = term;
+}
+|
+name_or_raw '=' PE_VALUE
+{
+	struct parse_events_term *term;
+	int err = parse_events_term__num(&term, PARSE_EVENTS__TERM_TYPE_USER,
+					 $1, $3, /*novalue=*/false, &@1, &@3);
+
+	if (err) {
+		free($1);
+		PE_ABORT(err);
+	}
+	$$ = term;
+}
+|
+PE_NAME
+{
+	struct parse_events_term *term;
+	int err = parse_events_term__num(&term, PARSE_EVENTS__TERM_TYPE_USER,
+					 $1, /*num=*/1, /*novalue=*/true, &@1, /*loc_val=*/NULL);
+
+	if (err) {
+		free($1);
+		PE_ABORT(err);
+	}
+	$$ = term;
+}
+|
+PE_TERM '=' name_or_raw
+{
+	struct parse_events_term *term;
+	int err = parse_events_term__str(&term, $1, /*config=*/NULL, $3, &@1, &@3);
+
+	if (err) {
+		free($3);
+		PE_ABORT(err);
+	}
+	$$ = term;
+}
+|
+PE_TERM '=' PE_TERM
+{
+	struct parse_events_term *term;
+	int err = parse_events_term__term(&term, $1, $3, &@1, &@3);
+
+	if (err)
+		PE_ABORT(err);
+
+	$$ = term;
+}
+|
+PE_TERM '=' PE_VALUE
+{
+	struct parse_events_term *term;
+	int err = parse_events_term__num(&term, $1,
+					 /*config=*/NULL, $3, /*novalue=*/false,
+					 &@1, &@3);
+
+	if (err)
+		PE_ABORT(err);
+
+	$$ = term;
+}
+|
+PE_TERM
+{
+	struct parse_events_term *term;
+	int err = parse_events_term__num(&term, $1,
+					 /*config=*/NULL, /*num=*/1, /*novalue=*/true,
+					 &@1, /*loc_val=*/NULL);
+
+	if (err)
+		PE_ABORT(err);
+
+	$$ = term;
+}
+|
+PE_DRV_CFG_TERM
+{
+	struct parse_events_term *term;
+	char *config = strdup($1);
+	int err;
+
+	if (!config)
+		YYNOMEM;
+	err = parse_events_term__str(&term, PARSE_EVENTS__TERM_TYPE_DRV_CFG, config, $1, &@1, NULL);
+	if (err) {
+		free($1);
+		free(config);
+		PE_ABORT(err);
+	}
+	$$ = term;
+}
+
+sep_dc: ':' |
+
+%%
+
+void parse_events_error(YYLTYPE *loc, void *_parse_state,
+			void *scanner __maybe_unused,
+			char const *msg __maybe_unused)
+{
+	struct parse_events_state *parse_state = _parse_state;
+
+	if (!parse_state->error || !list_empty(&parse_state->error->list))
+		return;
+
+	parse_events_error__handle(parse_state->error, loc->last_column,
+				   strdup("Unrecognized input"), NULL);
+}