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, 407 insertions, 0 deletions

diff --git a/tools/perf/util/trace-event-scripting.c b/tools/perf/util/trace-event-scripting.c
new file mode 100644
index 000000000..dc584ac31
--- /dev/null
+++ b/tools/perf/util/trace-event-scripting.c
@@ -0,0 +1,407 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * trace-event-scripting.  Scripting engine common and initialization code.
+ *
+ * Copyright (C) 2009-2010 Tom Zanussi <tzanussi@gmail.com>
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#ifdef HAVE_LIBTRACEEVENT
+#include <event-parse.h>
+#endif
+
+#include "debug.h"
+#include "event.h"
+#include "trace-event.h"
+#include "evsel.h"
+#include <linux/perf_event.h>
+#include <linux/zalloc.h>
+#include "util/sample.h"
+
+unsigned int scripting_max_stack = PERF_MAX_STACK_DEPTH;
+
+struct scripting_context *scripting_context;
+
+struct script_spec {
+	struct list_head	node;
+	struct scripting_ops	*ops;
+	char			spec[];
+};
+
+static LIST_HEAD(script_specs);
+
+static struct script_spec *script_spec__new(const char *spec,
+					    struct scripting_ops *ops)
+{
+	struct script_spec *s = malloc(sizeof(*s) + strlen(spec) + 1);
+
+	if (s != NULL) {
+		strcpy(s->spec, spec);
+		s->ops = ops;
+	}
+
+	return s;
+}
+
+static void script_spec__add(struct script_spec *s)
+{
+	list_add_tail(&s->node, &script_specs);
+}
+
+static struct script_spec *script_spec__find(const char *spec)
+{
+	struct script_spec *s;
+
+	list_for_each_entry(s, &script_specs, node)
+		if (strcasecmp(s->spec, spec) == 0)
+			return s;
+	return NULL;
+}
+
+static int script_spec_register(const char *spec, struct scripting_ops *ops)
+{
+	struct script_spec *s;
+
+	s = script_spec__find(spec);
+	if (s)
+		return -1;
+
+	s = script_spec__new(spec, ops);
+	if (!s)
+		return -1;
+
+	script_spec__add(s);
+	return 0;
+}
+
+struct scripting_ops *script_spec__lookup(const char *spec)
+{
+	struct script_spec *s = script_spec__find(spec);
+
+	if (!s)
+		return NULL;
+
+	return s->ops;
+}
+
+int script_spec__for_each(int (*cb)(struct scripting_ops *ops, const char *spec))
+{
+	struct script_spec *s;
+	int ret = 0;
+
+	list_for_each_entry(s, &script_specs, node) {
+		ret = cb(s->ops, s->spec);
+		if (ret)
+			break;
+	}
+	return ret;
+}
+
+void scripting_context__update(struct scripting_context *c,
+			       union perf_event *event,
+			       struct perf_sample *sample,
+			       struct addr_location *al,
+			       struct addr_location *addr_al)
+{
+#ifdef HAVE_LIBTRACEEVENT
+	const struct tep_event *tp_format = evsel__tp_format(sample->evsel);
+
+	c->pevent = tp_format ? tp_format->tep : NULL;
+#else
+	c->pevent = NULL;
+#endif
+	c->event_data = sample->raw_data;
+	c->event = event;
+	c->sample = sample;
+	c->al = al;
+	c->addr_al = addr_al;
+}
+
+static int flush_script_unsupported(void)
+{
+	return 0;
+}
+
+static int stop_script_unsupported(void)
+{
+	return 0;
+}
+
+static void process_event_unsupported(union perf_event *event __maybe_unused,
+				      struct perf_sample *sample __maybe_unused,
+				      struct addr_location *al __maybe_unused,
+				      struct addr_location *addr_al __maybe_unused)
+{
+}
+
+static void print_python_unsupported_msg(void)
+{
+	fprintf(stderr, "Python scripting not supported."
+		"  Install libpython and rebuild perf to enable it.\n"
+		"For example:\n  # apt-get install python-dev (ubuntu)"
+		"\n  # yum install python-devel (Fedora)"
+		"\n  etc.\n");
+}
+
+static int python_start_script_unsupported(const char *script __maybe_unused,
+					   int argc __maybe_unused,
+					   const char **argv __maybe_unused,
+					   struct perf_session *session __maybe_unused)
+{
+	print_python_unsupported_msg();
+
+	return -1;
+}
+
+static int python_generate_script_unsupported(struct tep_handle *pevent
+					      __maybe_unused,
+					      const char *outfile
+					      __maybe_unused)
+{
+	print_python_unsupported_msg();
+
+	return -1;
+}
+
+struct scripting_ops python_scripting_unsupported_ops = {
+	.name = "Python",
+	.dirname = "python",
+	.start_script = python_start_script_unsupported,
+	.flush_script = flush_script_unsupported,
+	.stop_script = stop_script_unsupported,
+	.process_event = process_event_unsupported,
+	.generate_script = python_generate_script_unsupported,
+};
+
+static void register_python_scripting(struct scripting_ops *scripting_ops)
+{
+	if (scripting_context == NULL)
+		scripting_context = malloc(sizeof(*scripting_context));
+
+       if (scripting_context == NULL ||
+	   script_spec_register("Python", scripting_ops) ||
+	   script_spec_register("py", scripting_ops)) {
+		pr_err("Error registering Python script extension: disabling it\n");
+		zfree(&scripting_context);
+	}
+}
+
+#ifndef HAVE_LIBPYTHON_SUPPORT
+void setup_python_scripting(void)
+{
+	register_python_scripting(&python_scripting_unsupported_ops);
+}
+#else
+extern struct scripting_ops python_scripting_ops;
+
+void setup_python_scripting(void)
+{
+	register_python_scripting(&python_scripting_ops);
+}
+#endif
+
+#ifdef HAVE_LIBTRACEEVENT
+static void print_perl_unsupported_msg(void)
+{
+	fprintf(stderr, "Perl scripting not supported."
+		"  Install libperl and rebuild perf to enable it.\n"
+		"For example:\n  # apt-get install libperl-dev (ubuntu)"
+		"\n  # yum install 'perl(ExtUtils::Embed)' (Fedora)"
+		"\n  etc.\n");
+}
+
+static int perl_start_script_unsupported(const char *script __maybe_unused,
+					 int argc __maybe_unused,
+					 const char **argv __maybe_unused,
+					 struct perf_session *session __maybe_unused)
+{
+	print_perl_unsupported_msg();
+
+	return -1;
+}
+
+static int perl_generate_script_unsupported(struct tep_handle *pevent
+					    __maybe_unused,
+					    const char *outfile __maybe_unused)
+{
+	print_perl_unsupported_msg();
+
+	return -1;
+}
+
+struct scripting_ops perl_scripting_unsupported_ops = {
+	.name = "Perl",
+	.dirname = "perl",
+	.start_script = perl_start_script_unsupported,
+	.flush_script = flush_script_unsupported,
+	.stop_script = stop_script_unsupported,
+	.process_event = process_event_unsupported,
+	.generate_script = perl_generate_script_unsupported,
+};
+
+static void register_perl_scripting(struct scripting_ops *scripting_ops)
+{
+	if (scripting_context == NULL)
+		scripting_context = malloc(sizeof(*scripting_context));
+
+       if (scripting_context == NULL ||
+	   script_spec_register("Perl", scripting_ops) ||
+	   script_spec_register("pl", scripting_ops)) {
+		pr_err("Error registering Perl script extension: disabling it\n");
+		zfree(&scripting_context);
+	}
+}
+
+#ifndef HAVE_LIBPERL_SUPPORT
+void setup_perl_scripting(void)
+{
+	register_perl_scripting(&perl_scripting_unsupported_ops);
+}
+#else
+extern struct scripting_ops perl_scripting_ops;
+
+void setup_perl_scripting(void)
+{
+	register_perl_scripting(&perl_scripting_ops);
+}
+#endif
+#endif
+
+static const struct {
+	u32 flags;
+	const char *name;
+} sample_flags[] = {
+	{PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_CALL, "call"},
+	{PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_RETURN, "return"},
+	{PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_CONDITIONAL, "jcc"},
+	{PERF_IP_FLAG_BRANCH, "jmp"},
+	{PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_CALL | PERF_IP_FLAG_INTERRUPT, "int"},
+	{PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_RETURN | PERF_IP_FLAG_INTERRUPT, "iret"},
+	{PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_CALL | PERF_IP_FLAG_SYSCALLRET, "syscall"},
+	{PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_RETURN | PERF_IP_FLAG_SYSCALLRET, "sysret"},
+	{PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_ASYNC, "async"},
+	{PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_CALL | PERF_IP_FLAG_ASYNC |	PERF_IP_FLAG_INTERRUPT,
+	 "hw int"},
+	{PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_TX_ABORT, "tx abrt"},
+	{PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_TRACE_BEGIN, "tr strt"},
+	{PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_TRACE_END, "tr end"},
+	{PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_CALL | PERF_IP_FLAG_VMENTRY, "vmentry"},
+	{PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_CALL | PERF_IP_FLAG_VMEXIT, "vmexit"},
+	{0, NULL}
+};
+
+static const struct {
+	u32 flags;
+	const char *name;
+} branch_events[] = {
+	{PERF_IP_FLAG_BRANCH_MISS, "miss"},
+	{PERF_IP_FLAG_NOT_TAKEN, "not_taken"},
+	{0, NULL}
+};
+
+static int sample_flags_to_name(u32 flags, char *str, size_t size)
+{
+	int i;
+	const char *prefix;
+	int pos = 0, ret, ev_idx = 0;
+	u32 xf = flags & PERF_ADDITIONAL_STATE_MASK;
+	u32 types, events;
+	char xs[16] = { 0 };
+
+	/* Clear additional state bits */
+	flags &= ~PERF_ADDITIONAL_STATE_MASK;
+
+	if (flags & PERF_IP_FLAG_TRACE_BEGIN)
+		prefix = "tr strt ";
+	else if (flags & PERF_IP_FLAG_TRACE_END)
+		prefix = "tr end  ";
+	else
+		prefix = "";
+
+	ret = snprintf(str + pos, size - pos, "%s", prefix);
+	if (ret < 0)
+		return ret;
+	pos += ret;
+
+	flags &= ~(PERF_IP_FLAG_TRACE_BEGIN | PERF_IP_FLAG_TRACE_END);
+
+	types = flags & ~PERF_IP_FLAG_BRANCH_EVENT_MASK;
+	for (i = 0; sample_flags[i].name; i++) {
+		if (sample_flags[i].flags != types)
+			continue;
+
+		ret = snprintf(str + pos, size - pos, "%s", sample_flags[i].name);
+		if (ret < 0)
+			return ret;
+		pos += ret;
+		break;
+	}
+
+	events = flags & PERF_IP_FLAG_BRANCH_EVENT_MASK;
+	for (i = 0; branch_events[i].name; i++) {
+		if (!(branch_events[i].flags & events))
+			continue;
+
+		ret = snprintf(str + pos, size - pos, !ev_idx ? "/%s" : ",%s",
+			       branch_events[i].name);
+		if (ret < 0)
+			return ret;
+		pos += ret;
+		ev_idx++;
+	}
+
+	/* Add an end character '/' for events */
+	if (ev_idx) {
+		ret = snprintf(str + pos, size - pos, "/");
+		if (ret < 0)
+			return ret;
+		pos += ret;
+	}
+
+	if (!xf)
+		return pos;
+
+	snprintf(xs, sizeof(xs), "(%s%s%s)",
+		 flags & PERF_IP_FLAG_IN_TX ? "x" : "",
+		 flags & PERF_IP_FLAG_INTR_DISABLE ? "D" : "",
+		 flags & PERF_IP_FLAG_INTR_TOGGLE ? "t" : "");
+
+	/* Right align the string if its length is less than the limit */
+	if ((pos + strlen(xs)) < SAMPLE_FLAGS_STR_ALIGNED_SIZE)
+		ret = snprintf(str + pos, size - pos, "%*s",
+			       (int)(SAMPLE_FLAGS_STR_ALIGNED_SIZE - ret), xs);
+	else
+		ret = snprintf(str + pos, size - pos, " %s", xs);
+	if (ret < 0)
+		return ret;
+
+	return pos + ret;
+}
+
+int perf_sample__sprintf_flags(u32 flags, char *str, size_t sz)
+{
+	const char *chars = PERF_IP_FLAG_CHARS;
+	const size_t n = strlen(PERF_IP_FLAG_CHARS);
+	size_t i, pos = 0;
+	int ret;
+
+	ret = sample_flags_to_name(flags, str, sz);
+	if (ret > 0)
+		return ret;
+
+	for (i = 0; i < n; i++, flags >>= 1) {
+		if ((flags & 1) && pos < sz)
+			str[pos++] = chars[i];
+	}
+	for (; i < 32; i++, flags >>= 1) {
+		if ((flags & 1) && pos < sz)
+			str[pos++] = '?';
+	}
+	if (pos < sz)
+		str[pos] = 0;
+
+	return pos;
+}