[for-next][PATCH 00/13] tracing: Updates for 5.17

[for-next][PATCH 00/13] tracing: Updates for 5.17

[Steven Rostedt]

  git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
for-next

Head SHA1: a6ed2aee54644cfa2d04ca86308767f5c3a087e8


Colin Ian King (1):
      tracing: Fix spelling mistake "aritmethic" -> "arithmetic"

Masami Hiramatsu (5):
      tracing: Support __rel_loc relative dynamic data location attribute
      tracing: Add '__rel_loc' using trace event macros
      samples/trace_event: Add '__rel_loc' using sample event
      libtraceevent: Add __rel_loc relative location attribute support
      tools/perf: Add '__rel_loc' event field parsing support

Qiujun Huang (1):
      tracing: Fix synth_event_add_val() kernel-doc comment

Steven Rostedt (VMware) (5):
      tracing: Use __this_cpu_read() in trace_event_buffer_lock_reserver()
      tracing: Disable preemption when using the filter buffer
      tracing: Have eprobes use filtering logic of trace events
      tracing/kprobes: Do not open code event reserve logic
      tracing/uprobes: Use trace_event_buffer_reserve() helper

Uladzislau Rezki (Sony) (1):
      tracing: Switch to kvfree_rcu() API

----
 include/linux/trace_events.h                       |   1 +
 include/trace/bpf_probe.h                          |  16 +++
 include/trace/perf.h                               |  16 +++
 include/trace/trace_events.h                       | 120 ++++++++++++++++++++-
 kernel/trace/trace.c                               |  61 ++++++-----
 kernel/trace/trace.h                               |   8 +-
 kernel/trace/trace_eprobe.c                        |  16 +--
 kernel/trace/trace_events_filter.c                 |  32 +++++-
 kernel/trace/trace_events_hist.c                   |  21 +++-
 kernel/trace/trace_events_inject.c                 |  11 +-
 kernel/trace/trace_events_synth.c                  |   2 +-
 kernel/trace/trace_kprobe.c                        |  25 ++---
 kernel/trace/trace_osnoise.c                       |   3 +-
 kernel/trace/trace_probe.c                         |   3 +-
 kernel/trace/trace_uprobe.c                        |  11 +-
 samples/trace_events/trace-events-sample.c         |   3 +
 samples/trace_events/trace-events-sample.h         |  33 ++++++
 tools/lib/traceevent/event-parse.c                 |  59 ++++++----
 tools/lib/traceevent/event-parse.h                 |   5 +-
 tools/lib/traceevent/parse-filter.c                |   5 +-
 tools/perf/builtin-trace.c                         |   2 +
 tools/perf/util/data-convert-bt.c                  |   2 +
 tools/perf/util/evsel.c                            |   2 +
 tools/perf/util/python.c                           |   2 +
 .../perf/util/scripting-engines/trace-event-perl.c |   2 +
 .../util/scripting-engines/trace-event-python.c    |   2 +
 tools/perf/util/sort.c                             |   2 +
 27 files changed, 366 insertions(+), 99 deletions(-)

[for-next][PATCH 01/13] tracing: Fix spelling mistake "aritmethic" -> "arithmetic"

[Steven Rostedt]

From: Colin Ian King <colin.i.king@googlemail.com>

There is a spelling mistake in the tracing mini-HOWTO text. Fix it.

Link: https://lkml.kernel.org/r/20211108201513.42876-1-colin.i.king@gmail.com

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/trace/trace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 88de94da596b..4821fe6a40a5 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -5635,7 +5635,7 @@ static const char readme_msg[] =
 	"\t        - a numeric literal: e.g. ms_per_sec=1000,\n"
 	"\t        - an arithmetic expression: e.g. time_secs=current_timestamp/1000\n"
 	"\n"
-	"\t    hist trigger aritmethic expressions support addition(+), subtraction(-),\n"
+	"\t    hist trigger arithmetic expressions support addition(+), subtraction(-),\n"
 	"\t    multiplication(*) and division(/) operators. An operand can be either a\n"
 	"\t    variable reference, field or numeric literal.\n"
 	"\n"
-- 
2.33.0

[for-next][PATCH 02/13] tracing: Support __rel_loc relative dynamic data location attribute

[Steven Rostedt]

From: Masami Hiramatsu <mhiramat@kernel.org>

Add '__rel_loc' new dynamic data location attribute which encodes
the data location from the next to the field itself.

The '__data_loc' is used for encoding the dynamic data location on
the trace event record. But '__data_loc' is not useful if the writer
doesn't know the event header (e.g. user event), because it records
the dynamic data offset from the entry of the record, not the field
itself.

This new '__rel_loc' attribute encodes the data location relatively
from the next of the field. For example, when there is a record like
below (the number in the parentheses is the size of fields)

 |header(N)|common(M)|fields(K)|__data_loc(4)|fields(L)|data(G)|

In this case, '__data_loc' field will be

 __data_loc = (G << 16) | (N+M+K+4+L)

If '__rel_loc' is used, this will be

 |header(N)|common(M)|fields(K)|__rel_loc(4)|fields(L)|data(G)|

where

 __rel_loc = (G << 16) | (L)

This case shows L bytes after the '__rel_loc' attribute  field,
if there is no fields after the __rel_loc field, L must be 0.

This is relatively easy (and no need to consider the kernel header
change) when the event data fields are composed by user who doesn't
know header and common fields.

Link: https://lkml.kernel.org/r/163757341258.510314.4214431827833229956.stgit@devnote2

Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 include/linux/trace_events.h       |  1 +
 kernel/trace/trace.h               |  1 +
 kernel/trace/trace_events_filter.c | 32 ++++++++++++++++++++++++++++--
 kernel/trace/trace_events_hist.c   | 21 ++++++++++++++++++--
 kernel/trace/trace_events_inject.c | 11 ++++++++--
 5 files changed, 60 insertions(+), 6 deletions(-)

diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index 2d167ac3452c..3900404aa063 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -782,6 +782,7 @@ enum {
 	FILTER_OTHER = 0,
 	FILTER_STATIC_STRING,
 	FILTER_DYN_STRING,
+	FILTER_RDYN_STRING,
 	FILTER_PTR_STRING,
 	FILTER_TRACE_FN,
 	FILTER_COMM,
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 38715aa6cfdf..5db2bec8ca7e 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1465,6 +1465,7 @@ struct filter_pred {
 static inline bool is_string_field(struct ftrace_event_field *field)
 {
 	return field->filter_type == FILTER_DYN_STRING ||
+	       field->filter_type == FILTER_RDYN_STRING ||
 	       field->filter_type == FILTER_STATIC_STRING ||
 	       field->filter_type == FILTER_PTR_STRING ||
 	       field->filter_type == FILTER_COMM;
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index c9124038b140..996920ed1812 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -706,6 +706,29 @@ static int filter_pred_strloc(struct filter_pred *pred, void *event)
 	return match;
 }
 
+/*
+ * Filter predicate for relative dynamic sized arrays of characters.
+ * These are implemented through a list of strings at the end
+ * of the entry as same as dynamic string.
+ * The difference is that the relative one records the location offset
+ * from the field itself, not the event entry.
+ */
+static int filter_pred_strrelloc(struct filter_pred *pred, void *event)
+{
+	u32 *item = (u32 *)(event + pred->offset);
+	u32 str_item = *item;
+	int str_loc = str_item & 0xffff;
+	int str_len = str_item >> 16;
+	char *addr = (char *)(&item[1]) + str_loc;
+	int cmp, match;
+
+	cmp = pred->regex.match(addr, &pred->regex, str_len);
+
+	match = cmp ^ pred->not;
+
+	return match;
+}
+
 /* Filter predicate for CPUs. */
 static int filter_pred_cpu(struct filter_pred *pred, void *event)
 {
@@ -756,7 +779,7 @@ static int filter_pred_none(struct filter_pred *pred, void *event)
  *
  * Note:
  * - @str might not be NULL-terminated if it's of type DYN_STRING
- *   or STATIC_STRING, unless @len is zero.
+ *   RDYN_STRING, or STATIC_STRING, unless @len is zero.
  */
 
 static int regex_match_full(char *str, struct regex *r, int len)
@@ -1083,6 +1106,9 @@ int filter_assign_type(const char *type)
 	if (strstr(type, "__data_loc") && strstr(type, "char"))
 		return FILTER_DYN_STRING;
 
+	if (strstr(type, "__rel_loc") && strstr(type, "char"))
+		return FILTER_RDYN_STRING;
+
 	if (strchr(type, '[') && strstr(type, "char"))
 		return FILTER_STATIC_STRING;
 
@@ -1318,8 +1344,10 @@ static int parse_pred(const char *str, void *data,
 			pred->fn = filter_pred_string;
 			pred->regex.field_len = field->size;
 
-		} else if (field->filter_type == FILTER_DYN_STRING)
+		} else if (field->filter_type == FILTER_DYN_STRING) {
 			pred->fn = filter_pred_strloc;
+		} else if (field->filter_type == FILTER_RDYN_STRING)
+			pred->fn = filter_pred_strrelloc;
 		else
 			pred->fn = filter_pred_pchar;
 		/* go past the last quote */
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 319f9c8ca7e7..9b8da439149c 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -217,6 +217,20 @@ static u64 hist_field_dynstring(struct hist_field *hist_field,
 	return (u64)(unsigned long)addr;
 }
 
+static u64 hist_field_reldynstring(struct hist_field *hist_field,
+				   struct tracing_map_elt *elt,
+				   struct trace_buffer *buffer,
+				   struct ring_buffer_event *rbe,
+				   void *event)
+{
+	u32 *item = event + hist_field->field->offset;
+	u32 str_item = *item;
+	int str_loc = str_item & 0xffff;
+	char *addr = (char *)&item[1] + str_loc;
+
+	return (u64)(unsigned long)addr;
+}
+
 static u64 hist_field_pstring(struct hist_field *hist_field,
 			      struct tracing_map_elt *elt,
 			      struct trace_buffer *buffer,
@@ -1956,8 +1970,10 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,
 		if (field->filter_type == FILTER_STATIC_STRING) {
 			hist_field->fn = hist_field_string;
 			hist_field->size = field->size;
-		} else if (field->filter_type == FILTER_DYN_STRING)
+		} else if (field->filter_type == FILTER_DYN_STRING) {
 			hist_field->fn = hist_field_dynstring;
+		} else if (field->filter_type == FILTER_RDYN_STRING)
+			hist_field->fn = hist_field_reldynstring;
 		else
 			hist_field->fn = hist_field_pstring;
 	} else {
@@ -4961,7 +4977,8 @@ static inline void add_to_key(char *compound_key, void *key,
 		struct ftrace_event_field *field;
 
 		field = key_field->field;
-		if (field->filter_type == FILTER_DYN_STRING)
+		if (field->filter_type == FILTER_DYN_STRING ||
+		    field->filter_type == FILTER_RDYN_STRING)
 			size = *(u32 *)(rec + field->offset) >> 16;
 		else if (field->filter_type == FILTER_STATIC_STRING)
 			size = field->size;
diff --git a/kernel/trace/trace_events_inject.c b/kernel/trace/trace_events_inject.c
index c188045c5f97..d6b4935a78c0 100644
--- a/kernel/trace/trace_events_inject.c
+++ b/kernel/trace/trace_events_inject.c
@@ -168,10 +168,14 @@ static void *trace_alloc_entry(struct trace_event_call *call, int *size)
 			continue;
 		if (field->filter_type == FILTER_STATIC_STRING)
 			continue;
-		if (field->filter_type == FILTER_DYN_STRING) {
+		if (field->filter_type == FILTER_DYN_STRING ||
+		    field->filter_type == FILTER_RDYN_STRING) {
 			u32 *str_item;
 			int str_loc = entry_size & 0xffff;
 
+			if (field->filter_type == FILTER_RDYN_STRING)
+				str_loc -= field->offset + field->size;
+
 			str_item = (u32 *)(entry + field->offset);
 			*str_item = str_loc; /* string length is 0. */
 		} else {
@@ -214,7 +218,8 @@ static int parse_entry(char *str, struct trace_event_call *call, void **pentry)
 
 			if (field->filter_type == FILTER_STATIC_STRING) {
 				strlcpy(entry + field->offset, addr, field->size);
-			} else if (field->filter_type == FILTER_DYN_STRING) {
+			} else if (field->filter_type == FILTER_DYN_STRING ||
+				   field->filter_type == FILTER_RDYN_STRING) {
 				int str_len = strlen(addr) + 1;
 				int str_loc = entry_size & 0xffff;
 				u32 *str_item;
@@ -229,6 +234,8 @@ static int parse_entry(char *str, struct trace_event_call *call, void **pentry)
 
 				strlcpy(entry + (entry_size - str_len), addr, str_len);
 				str_item = (u32 *)(entry + field->offset);
+				if (field->filter_type == FILTER_RDYN_STRING)
+					str_loc -= field->offset + field->size;
 				*str_item = (str_len << 16) | str_loc;
 			} else {
 				char **paddr;
-- 
2.33.0

[for-next][PATCH 03/13] tracing: Add __rel_loc using trace event macros

[Steven Rostedt]

From: Masami Hiramatsu <mhiramat@kernel.org>

Add '__rel_loc' using trace event macros. These macros are usually
not used in the kernel, except for testing purpose.
This also add "rel_" variant of macros for dynamic_array string,
and bitmask.

Link: https://lkml.kernel.org/r/163757342119.510314.816029622439099016.stgit@devnote2

Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 include/trace/bpf_probe.h    |  16 +++++
 include/trace/perf.h         |  16 +++++
 include/trace/trace_events.h | 120 ++++++++++++++++++++++++++++++++++-
 kernel/trace/trace.h         |   3 +
 4 files changed, 153 insertions(+), 2 deletions(-)

diff --git a/include/trace/bpf_probe.h b/include/trace/bpf_probe.h
index a8e97f84b652..7660a7846586 100644
--- a/include/trace/bpf_probe.h
+++ b/include/trace/bpf_probe.h
@@ -21,6 +21,22 @@
 #undef __get_bitmask
 #define __get_bitmask(field) (char *)__get_dynamic_array(field)
 
+#undef __get_rel_dynamic_array
+#define __get_rel_dynamic_array(field)	\
+		((void *)(&__entry->__rel_loc_##field) +	\
+		 sizeof(__entry->__rel_loc_##field) +		\
+		 (__entry->__rel_loc_##field & 0xffff))
+
+#undef __get_rel_dynamic_array_len
+#define __get_rel_dynamic_array_len(field)	\
+		((__entry->__rel_loc_##field >> 16) & 0xffff)
+
+#undef __get_rel_str
+#define __get_rel_str(field) ((char *)__get_rel_dynamic_array(field))
+
+#undef __get_rel_bitmask
+#define __get_rel_bitmask(field) (char *)__get_rel_dynamic_array(field)
+
 #undef __perf_count
 #define __perf_count(c)	(c)
 
diff --git a/include/trace/perf.h b/include/trace/perf.h
index dbc6c74defc3..ea4405de175a 100644
--- a/include/trace/perf.h
+++ b/include/trace/perf.h
@@ -21,6 +21,22 @@
 #undef __get_bitmask
 #define __get_bitmask(field) (char *)__get_dynamic_array(field)
 
+#undef __get_rel_dynamic_array
+#define __get_rel_dynamic_array(field)	\
+		((void *)(&__entry->__rel_loc_##field) +	\
+		 sizeof(__entry->__rel_loc_##field) +		\
+		 (__entry->__rel_loc_##field & 0xffff))
+
+#undef __get_rel_dynamic_array_len
+#define __get_rel_dynamic_array_len(field)	\
+		((__entry->__rel_loc_##field >> 16) & 0xffff)
+
+#undef __get_rel_str
+#define __get_rel_str(field) ((char *)__get_rel_dynamic_array(field))
+
+#undef __get_rel_bitmask
+#define __get_rel_bitmask(field) (char *)__get_rel_dynamic_array(field)
+
 #undef __perf_count
 #define __perf_count(c)	(__count = (c))
 
diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
index 08810a463880..8c6f7c433518 100644
--- a/include/trace/trace_events.h
+++ b/include/trace/trace_events.h
@@ -108,6 +108,18 @@ TRACE_MAKE_SYSTEM_STR();
 #undef __bitmask
 #define __bitmask(item, nr_bits) __dynamic_array(char, item, -1)
 
+#undef __rel_dynamic_array
+#define __rel_dynamic_array(type, item, len) u32 __rel_loc_##item;
+
+#undef __rel_string
+#define __rel_string(item, src) __rel_dynamic_array(char, item, -1)
+
+#undef __rel_string_len
+#define __rel_string_len(item, src, len) __rel_dynamic_array(char, item, -1)
+
+#undef __rel_bitmask
+#define __rel_bitmask(item, nr_bits) __rel_dynamic_array(char, item, -1)
+
 #undef TP_STRUCT__entry
 #define TP_STRUCT__entry(args...) args
 
@@ -200,11 +212,23 @@ TRACE_MAKE_SYSTEM_STR();
 #undef __string
 #define __string(item, src) __dynamic_array(char, item, -1)
 
+#undef __bitmask
+#define __bitmask(item, nr_bits) __dynamic_array(unsigned long, item, -1)
+
 #undef __string_len
 #define __string_len(item, src, len) __dynamic_array(char, item, -1)
 
-#undef __bitmask
-#define __bitmask(item, nr_bits) __dynamic_array(unsigned long, item, -1)
+#undef __rel_dynamic_array
+#define __rel_dynamic_array(type, item, len)	u32 item;
+
+#undef __rel_string
+#define __rel_string(item, src) __rel_dynamic_array(char, item, -1)
+
+#undef __rel_string_len
+#define __rel_string_len(item, src, len) __rel_dynamic_array(char, item, -1)
+
+#undef __rel_bitmask
+#define __rel_bitmask(item, nr_bits) __rel_dynamic_array(unsigned long, item, -1)
 
 #undef DECLARE_EVENT_CLASS
 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)	\
@@ -293,6 +317,19 @@ TRACE_MAKE_SYSTEM_STR();
 #undef __get_str
 #define __get_str(field) ((char *)__get_dynamic_array(field))
 
+#undef __get_rel_dynamic_array
+#define __get_rel_dynamic_array(field)	\
+		((void *)(&__entry->__rel_loc_##field) +	\
+		 sizeof(__entry->__rel_loc_##field) +		\
+		 (__entry->__rel_loc_##field & 0xffff))
+
+#undef __get_rel_dynamic_array_len
+#define __get_rel_dynamic_array_len(field)	\
+		((__entry->__rel_loc_##field >> 16) & 0xffff)
+
+#undef __get_rel_str
+#define __get_rel_str(field) ((char *)__get_rel_dynamic_array(field))
+
 #undef __get_bitmask
 #define __get_bitmask(field)						\
 	({								\
@@ -302,6 +339,15 @@ TRACE_MAKE_SYSTEM_STR();
 		trace_print_bitmask_seq(p, __bitmask, __bitmask_size);	\
 	})
 
+#undef __get_rel_bitmask
+#define __get_rel_bitmask(field)						\
+	({								\
+		void *__bitmask = __get_rel_dynamic_array(field);		\
+		unsigned int __bitmask_size;				\
+		__bitmask_size = __get_rel_dynamic_array_len(field);	\
+		trace_print_bitmask_seq(p, __bitmask, __bitmask_size);	\
+	})
+
 #undef __print_flags
 #define __print_flags(flag, delim, flag_array...)			\
 	({								\
@@ -471,6 +517,21 @@ static struct trace_event_functions trace_event_type_funcs_##call = {	\
 #undef __bitmask
 #define __bitmask(item, nr_bits) __dynamic_array(unsigned long, item, -1)
 
+#undef __rel_dynamic_array
+#define __rel_dynamic_array(_type, _item, _len) {			\
+	.type = "__rel_loc " #_type "[]", .name = #_item,		\
+	.size = 4, .align = 4,						\
+	.is_signed = is_signed_type(_type), .filter_type = FILTER_OTHER },
+
+#undef __rel_string
+#define __rel_string(item, src) __rel_dynamic_array(char, item, -1)
+
+#undef __rel_string_len
+#define __rel_string_len(item, src, len) __rel_dynamic_array(char, item, -1)
+
+#undef __rel_bitmask
+#define __rel_bitmask(item, nr_bits) __rel_dynamic_array(unsigned long, item, -1)
+
 #undef DECLARE_EVENT_CLASS
 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, func, print)	\
 static struct trace_event_fields trace_event_fields_##call[] = {	\
@@ -519,6 +580,22 @@ static struct trace_event_fields trace_event_fields_##call[] = {	\
 #undef __string_len
 #define __string_len(item, src, len) __dynamic_array(char, item, (len) + 1)
 
+#undef __rel_dynamic_array
+#define __rel_dynamic_array(type, item, len)				\
+	__item_length = (len) * sizeof(type);				\
+	__data_offsets->item = __data_size +				\
+			       offsetof(typeof(*entry), __data) -	\
+			       offsetof(typeof(*entry), __rel_loc_##item) -	\
+			       sizeof(u32);				\
+	__data_offsets->item |= __item_length << 16;			\
+	__data_size += __item_length;
+
+#undef __rel_string
+#define __rel_string(item, src) __rel_dynamic_array(char, item,			\
+		    strlen((src) ? (const char *)(src) : "(null)") + 1)
+
+#undef __rel_string_len
+#define __rel_string_len(item, src, len) __rel_dynamic_array(char, item, (len) + 1)
 /*
  * __bitmask_size_in_bytes_raw is the number of bytes needed to hold
  * num_possible_cpus().
@@ -542,6 +619,10 @@ static struct trace_event_fields trace_event_fields_##call[] = {	\
 #define __bitmask(item, nr_bits) __dynamic_array(unsigned long, item,	\
 					 __bitmask_size_in_longs(nr_bits))
 
+#undef __rel_bitmask
+#define __rel_bitmask(item, nr_bits) __rel_dynamic_array(unsigned long, item,	\
+					 __bitmask_size_in_longs(nr_bits))
+
 #undef DECLARE_EVENT_CLASS
 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)	\
 static inline notrace int trace_event_get_offsets_##call(		\
@@ -706,6 +787,37 @@ static inline notrace int trace_event_get_offsets_##call(		\
 #define __assign_bitmask(dst, src, nr_bits)					\
 	memcpy(__get_bitmask(dst), (src), __bitmask_size_in_bytes(nr_bits))
 
+#undef __rel_dynamic_array
+#define __rel_dynamic_array(type, item, len)				\
+	__entry->__rel_loc_##item = __data_offsets.item;
+
+#undef __rel_string
+#define __rel_string(item, src) __rel_dynamic_array(char, item, -1)
+
+#undef __rel_string_len
+#define __rel_string_len(item, src, len) __rel_dynamic_array(char, item, -1)
+
+#undef __assign_rel_str
+#define __assign_rel_str(dst, src)					\
+	strcpy(__get_rel_str(dst), (src) ? (const char *)(src) : "(null)");
+
+#undef __assign_rel_str_len
+#define __assign_rel_str_len(dst, src, len)				\
+	do {								\
+		memcpy(__get_rel_str(dst), (src), (len));		\
+		__get_rel_str(dst)[len] = '\0';				\
+	} while (0)
+
+#undef __rel_bitmask
+#define __rel_bitmask(item, nr_bits) __rel_dynamic_array(unsigned long, item, -1)
+
+#undef __get_rel_bitmask
+#define __get_rel_bitmask(field) (char *)__get_rel_dynamic_array(field)
+
+#undef __assign_rel_bitmask
+#define __assign_rel_bitmask(dst, src, nr_bits)					\
+	memcpy(__get_rel_bitmask(dst), (src), __bitmask_size_in_bytes(nr_bits))
+
 #undef TP_fast_assign
 #define TP_fast_assign(args...) args
 
@@ -770,6 +882,10 @@ static inline void ftrace_test_probe_##call(void)			\
 #undef __get_dynamic_array_len
 #undef __get_str
 #undef __get_bitmask
+#undef __get_rel_dynamic_array
+#undef __get_rel_dynamic_array_len
+#undef __get_rel_str
+#undef __get_rel_bitmask
 #undef __print_array
 #undef __print_hex_dump
 
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 5db2bec8ca7e..7162157b970b 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -83,6 +83,9 @@ enum trace_type {
 #undef __dynamic_array
 #define __dynamic_array(type, item)	type	item[];
 
+#undef __rel_dynamic_array
+#define __rel_dynamic_array(type, item)	type	item[];
+
 #undef F_STRUCT
 #define F_STRUCT(args...)		args
 
-- 
2.33.0

[for-next][PATCH 04/13] samples/trace_event: Add __rel_loc using sample event

[Steven Rostedt]

From: Masami Hiramatsu <mhiramat@kernel.org>

Add '__rel_loc' using sample event for testing.
User can use this for testing purpose. There is
no reason to use this macro from the kernel.

Link: https://lkml.kernel.org/r/163757343050.510314.2876529802471645178.stgit@devnote2

Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 samples/trace_events/trace-events-sample.c |  3 ++
 samples/trace_events/trace-events-sample.h | 33 ++++++++++++++++++++++
 2 files changed, 36 insertions(+)

diff --git a/samples/trace_events/trace-events-sample.c b/samples/trace_events/trace-events-sample.c
index 1a72b7d95cdc..4d34dc0b0fee 100644
--- a/samples/trace_events/trace-events-sample.c
+++ b/samples/trace_events/trace-events-sample.c
@@ -21,6 +21,7 @@ static const char *random_strings[] = {
 
 static void simple_thread_func(int cnt)
 {
+	unsigned long bitmask[1] = {0xdeadbeefUL};
 	int array[6];
 	int len = cnt % 5;
 	int i;
@@ -43,6 +44,8 @@ static void simple_thread_func(int cnt)
 	trace_foo_with_template_cond("prints other times", cnt);
 
 	trace_foo_with_template_print("I have to be different", cnt);
+
+	trace_foo_rel_loc("Hello __rel_loc", cnt, bitmask);
 }
 
 static int simple_thread(void *arg)
diff --git a/samples/trace_events/trace-events-sample.h b/samples/trace_events/trace-events-sample.h
index e61471ab7d14..5ab74fc9a2df 100644
--- a/samples/trace_events/trace-events-sample.h
+++ b/samples/trace_events/trace-events-sample.h
@@ -506,6 +506,39 @@ DEFINE_EVENT_PRINT(foo_template, foo_with_template_print,
 	TP_ARGS(foo, bar),
 	TP_printk("bar %s %d", __get_str(foo), __entry->bar));
 
+/*
+ * There are yet another __rel_loc dynamic data attribute. If you
+ * use __rel_dynamic_array() and __rel_string() etc. macros, you
+ * can use this attribute. There is no difference from the viewpoint
+ * of functionality with/without 'rel' but the encoding is a bit
+ * different. This is expected to be used with user-space event,
+ * there is no reason that the kernel event use this, but only for
+ * testing.
+ */
+
+TRACE_EVENT(foo_rel_loc,
+
+	TP_PROTO(const char *foo, int bar, unsigned long *mask),
+
+	TP_ARGS(foo, bar, mask),
+
+	TP_STRUCT__entry(
+		__rel_string(	foo,	foo	)
+		__field(	int,	bar	)
+		__rel_bitmask(	bitmask,
+			BITS_PER_BYTE * sizeof(unsigned long)	)
+	),
+
+	TP_fast_assign(
+		__assign_rel_str(foo, foo);
+		__entry->bar = bar;
+		__assign_rel_bitmask(bitmask, mask,
+			BITS_PER_BYTE * sizeof(unsigned long));
+	),
+
+	TP_printk("foo_rel_loc %s, %d, %s", __get_rel_str(foo), __entry->bar,
+		  __get_rel_bitmask(bitmask))
+);
 #endif
 
 /***** NOTICE! The #if protection ends here. *****/
-- 
2.33.0

[for-next][PATCH 05/13] libtraceevent: Add __rel_loc relative location attribute support

[Steven Rostedt]

From: Masami Hiramatsu <mhiramat@kernel.org>

Add '__rel_loc' new dynamic data location attribute which encodes
the data location from the next to the field itself. This is similar
to the '__data_loc' but the location offset is not from the event
entry but from the next of the field.

This patch adds '__rel_loc' decoding support in the libtraceevent.

Link: https://lkml.kernel.org/r/163757343994.510314.13241077597729303802.stgit@devnote2

Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 tools/lib/traceevent/event-parse.c  | 59 +++++++++++++++++++----------
 tools/lib/traceevent/event-parse.h  |  5 ++-
 tools/lib/traceevent/parse-filter.c |  5 ++-
 3 files changed, 47 insertions(+), 22 deletions(-)

diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index fe58843d047c..8e24c4c78c7f 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -1367,6 +1367,14 @@ static int field_is_dynamic(struct tep_format_field *field)
 	return 0;
 }
 
+static int field_is_relative_dynamic(struct tep_format_field *field)
+{
+	if (strncmp(field->type, "__rel_loc", 9) == 0)
+		return 1;
+
+	return 0;
+}
+
 static int field_is_long(struct tep_format_field *field)
 {
 	/* includes long long */
@@ -1622,6 +1630,8 @@ static int event_read_fields(struct tep_event *event, struct tep_format_field **
 			field->flags |= TEP_FIELD_IS_STRING;
 		if (field_is_dynamic(field))
 			field->flags |= TEP_FIELD_IS_DYNAMIC;
+		if (field_is_relative_dynamic(field))
+			field->flags |= TEP_FIELD_IS_DYNAMIC | TEP_FIELD_IS_RELATIVE;
 		if (field_is_long(field))
 			field->flags |= TEP_FIELD_IS_LONG;
 
@@ -2928,7 +2938,7 @@ process_str(struct tep_event *event __maybe_unused, struct tep_print_arg *arg,
 
 	arg->type = TEP_PRINT_STRING;
 	arg->string.string = token;
-	arg->string.offset = -1;
+	arg->string.field = NULL;
 
 	if (read_expected(TEP_EVENT_DELIM, ")") < 0)
 		goto out_err;
@@ -2957,7 +2967,7 @@ process_bitmask(struct tep_event *event __maybe_unused, struct tep_print_arg *ar
 
 	arg->type = TEP_PRINT_BITMASK;
 	arg->bitmask.bitmask = token;
-	arg->bitmask.offset = -1;
+	arg->bitmask.field = NULL;
 
 	if (read_expected(TEP_EVENT_DELIM, ")") < 0)
 		goto out_err;
@@ -3123,19 +3133,23 @@ process_function(struct tep_event *event, struct tep_print_arg *arg,
 		free_token(token);
 		return process_int_array(event, arg, tok);
 	}
-	if (strcmp(token, "__get_str") == 0) {
+	if (strcmp(token, "__get_str") == 0 ||
+	    strcmp(token, "__get_rel_str") == 0) {
 		free_token(token);
 		return process_str(event, arg, tok);
 	}
-	if (strcmp(token, "__get_bitmask") == 0) {
+	if (strcmp(token, "__get_bitmask") == 0 ||
+	    strcmp(token, "__get_rel_bitmask") == 0) {
 		free_token(token);
 		return process_bitmask(event, arg, tok);
 	}
-	if (strcmp(token, "__get_dynamic_array") == 0) {
+	if (strcmp(token, "__get_dynamic_array") == 0 ||
+	    strcmp(token, "__get_rel_dynamic_array") == 0) {
 		free_token(token);
 		return process_dynamic_array(event, arg, tok);
 	}
-	if (strcmp(token, "__get_dynamic_array_len") == 0) {
+	if (strcmp(token, "__get_dynamic_array_len") == 0 ||
+	    strcmp(token, "__get_rel_dynamic_array_len") == 0) {
 		free_token(token);
 		return process_dynamic_array_len(event, arg, tok);
 	}
@@ -4163,14 +4177,16 @@ static void print_str_arg(struct trace_seq *s, void *data, int size,
 	case TEP_PRINT_STRING: {
 		int str_offset;
 
-		if (arg->string.offset == -1) {
-			struct tep_format_field *f;
+		if (!arg->string.field)
+			arg->string.field = tep_find_any_field(event, arg->string.string);
+		if (!arg->string.field)
+			break;
 
-			f = tep_find_any_field(event, arg->string.string);
-			arg->string.offset = f->offset;
-		}
-		str_offset = data2host4(tep, *(unsigned int *)(data + arg->string.offset));
+		str_offset = data2host4(tep,
+				*(unsigned int *)(data + arg->string.field->offset));
 		str_offset &= 0xffff;
+		if (arg->string.field->flags & TEP_FIELD_IS_RELATIVE)
+			str_offset += arg->string.field->offset + arg->string.field->size;
 		print_str_to_seq(s, format, len_arg, ((char *)data) + str_offset);
 		break;
 	}
@@ -4181,15 +4197,16 @@ static void print_str_arg(struct trace_seq *s, void *data, int size,
 		int bitmask_offset;
 		int bitmask_size;
 
-		if (arg->bitmask.offset == -1) {
-			struct tep_format_field *f;
-
-			f = tep_find_any_field(event, arg->bitmask.bitmask);
-			arg->bitmask.offset = f->offset;
-		}
-		bitmask_offset = data2host4(tep, *(unsigned int *)(data + arg->bitmask.offset));
+		if (!arg->bitmask.field)
+			arg->bitmask.field = tep_find_any_field(event, arg->bitmask.bitmask);
+		if (!arg->bitmask.field)
+			break;
+		bitmask_offset = data2host4(tep,
+				*(unsigned int *)(data + arg->bitmask.field->offset));
 		bitmask_size = bitmask_offset >> 16;
 		bitmask_offset &= 0xffff;
+		if (arg->bitmask.field->flags & TEP_FIELD_IS_RELATIVE)
+			bitmask_offset += arg->bitmask.field->offset + arg->bitmask.field->size;
 		print_bitmask_to_seq(tep, s, format, len_arg,
 				     data + bitmask_offset, bitmask_size);
 		break;
@@ -5109,6 +5126,8 @@ void tep_print_field(struct trace_seq *s, void *data,
 			offset = val;
 			len = offset >> 16;
 			offset &= 0xffff;
+			if (field->flags & TEP_FIELD_IS_RELATIVE)
+				offset += field->offset + field->size;
 		}
 		if (field->flags & TEP_FIELD_IS_STRING &&
 		    is_printable_array(data + offset, len)) {
@@ -6987,6 +7006,8 @@ void *tep_get_field_raw(struct trace_seq *s, struct tep_event *event,
 					 data + offset, field->size);
 		*len = offset >> 16;
 		offset &= 0xffff;
+		if (field->flags & TEP_FIELD_IS_RELATIVE)
+			offset += field->offset + field->size;
 	} else
 		*len = field->size;
 
diff --git a/tools/lib/traceevent/event-parse.h b/tools/lib/traceevent/event-parse.h
index a67ad9a5b835..41d4f9f6a843 100644
--- a/tools/lib/traceevent/event-parse.h
+++ b/tools/lib/traceevent/event-parse.h
@@ -125,6 +125,7 @@ enum tep_format_flags {
 	TEP_FIELD_IS_LONG	= 32,
 	TEP_FIELD_IS_FLAG	= 64,
 	TEP_FIELD_IS_SYMBOLIC	= 128,
+	TEP_FIELD_IS_RELATIVE	= 256,
 };
 
 struct tep_format_field {
@@ -153,12 +154,12 @@ struct tep_print_arg_atom {
 
 struct tep_print_arg_string {
 	char			*string;
-	int			offset;
+	struct tep_format_field *field;
 };
 
 struct tep_print_arg_bitmask {
 	char			*bitmask;
-	int			offset;
+	struct tep_format_field *field;
 };
 
 struct tep_print_arg_field {
diff --git a/tools/lib/traceevent/parse-filter.c b/tools/lib/traceevent/parse-filter.c
index 368826bb5a57..5df177070d53 100644
--- a/tools/lib/traceevent/parse-filter.c
+++ b/tools/lib/traceevent/parse-filter.c
@@ -1712,8 +1712,11 @@ static const char *get_field_str(struct tep_filter_arg *arg, struct tep_record *
 
 		if (arg->str.field->flags & TEP_FIELD_IS_DYNAMIC) {
 			addr = *(unsigned int *)val;
-			val = record->data + (addr & 0xffff);
 			size = addr >> 16;
+			addr &= 0xffff;
+			if (arg->str.field->flags & TEP_FIELD_IS_RELATIVE)
+				addr += arg->str.field->offset + arg->str.field->size;
+			val = record->data + addr;
 		}
 
 		/*
-- 
2.33.0

[for-next][PATCH 06/13] tools/perf: Add __rel_loc event field parsing support

[Steven Rostedt]

From: Masami Hiramatsu <mhiramat@kernel.org>

Add new '__rel_loc' dynamic data location attribute support.
This type attribute is similar to the '__data_loc' but records the
offset from the field itself.
The libtraceevent adds TEP_FIELD_IS_RELATIVE to the
'tep_format_field::flags' with TEP_FIELD_IS_DYNAMIC for'__rel_loc'.

Link: https://lkml.kernel.org/r/163757344810.510314.12449413842136229871.stgit@devnote2

Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 tools/perf/builtin-trace.c                             | 2 ++
 tools/perf/util/data-convert-bt.c                      | 2 ++
 tools/perf/util/evsel.c                                | 2 ++
 tools/perf/util/python.c                               | 2 ++
 tools/perf/util/scripting-engines/trace-event-perl.c   | 2 ++
 tools/perf/util/scripting-engines/trace-event-python.c | 2 ++
 tools/perf/util/sort.c                                 | 2 ++
 7 files changed, 14 insertions(+)

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 0b52e08e558e..ea517762cb0c 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -2726,6 +2726,8 @@ static size_t trace__fprintf_tp_fields(struct trace *trace, struct evsel *evsel,
 				offset = format_field__intval(field, sample, evsel->needs_swap);
 				syscall_arg.len = offset >> 16;
 				offset &= 0xffff;
+				if (field->flags & TEP_FIELD_IS_RELATIVE)
+					offset += field->offset + field->size;
 			}
 
 			val = (uintptr_t)(sample->raw_data + offset);
diff --git a/tools/perf/util/data-convert-bt.c b/tools/perf/util/data-convert-bt.c
index 8f7705bbc2da..9e0aee276df8 100644
--- a/tools/perf/util/data-convert-bt.c
+++ b/tools/perf/util/data-convert-bt.c
@@ -318,6 +318,8 @@ static int add_tracepoint_field_value(struct ctf_writer *cw,
 		offset = tmp_val;
 		len = offset >> 16;
 		offset &= 0xffff;
+		if (flags & TEP_FIELD_IS_RELATIVE)
+			offset += fmtf->offset + fmtf->size;
 	}
 
 	if (flags & TEP_FIELD_IS_ARRAY) {
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index ac0127be0459..f29d37004f55 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2706,6 +2706,8 @@ void *evsel__rawptr(struct evsel *evsel, struct perf_sample *sample, const char
 	if (field->flags & TEP_FIELD_IS_DYNAMIC) {
 		offset = *(int *)(sample->raw_data + field->offset);
 		offset &= 0xffff;
+		if (field->flags & TEP_FIELD_IS_RELATIVE)
+			offset += field->offset + field->size;
 	}
 
 	return sample->raw_data + offset;
diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c
index 563a9ba8954f..3e7538db9107 100644
--- a/tools/perf/util/python.c
+++ b/tools/perf/util/python.c
@@ -428,6 +428,8 @@ tracepoint_field(struct pyrf_event *pe, struct tep_format_field *field)
 			offset  = val;
 			len     = offset >> 16;
 			offset &= 0xffff;
+			if (field->flags & TEP_FIELD_IS_RELATIVE)
+				offset += field->offset + field->size;
 		}
 		if (field->flags & TEP_FIELD_IS_STRING &&
 		    is_printable_array(data + offset, len)) {
diff --git a/tools/perf/util/scripting-engines/trace-event-perl.c b/tools/perf/util/scripting-engines/trace-event-perl.c
index 32a721b3e9a5..a5d945415bbc 100644
--- a/tools/perf/util/scripting-engines/trace-event-perl.c
+++ b/tools/perf/util/scripting-engines/trace-event-perl.c
@@ -392,6 +392,8 @@ static void perl_process_tracepoint(struct perf_sample *sample,
 			if (field->flags & TEP_FIELD_IS_DYNAMIC) {
 				offset = *(int *)(data + field->offset);
 				offset &= 0xffff;
+				if (field->flags & TEP_FIELD_IS_RELATIVE)
+					offset += field->offset + field->size;
 			} else
 				offset = field->offset;
 			XPUSHs(sv_2mortal(newSVpv((char *)data + offset, 0)));
diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c
index c0c010350bc2..d1f1501ce7fc 100644
--- a/tools/perf/util/scripting-engines/trace-event-python.c
+++ b/tools/perf/util/scripting-engines/trace-event-python.c
@@ -942,6 +942,8 @@ static void python_process_tracepoint(struct perf_sample *sample,
 				offset  = val;
 				len     = offset >> 16;
 				offset &= 0xffff;
+				if (field->flags & TEP_FIELD_IS_RELATIVE)
+					offset += field->offset + field->size;
 			}
 			if (field->flags & TEP_FIELD_IS_STRING &&
 			    is_printable_array(data + offset, len)) {
diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c
index a111065b484e..d9a106f0edb2 100644
--- a/tools/perf/util/sort.c
+++ b/tools/perf/util/sort.c
@@ -2365,6 +2365,8 @@ static int64_t __sort__hde_cmp(struct perf_hpp_fmt *fmt,
 		tep_read_number_field(field, a->raw_data, &dyn);
 		offset = dyn & 0xffff;
 		size = (dyn >> 16) & 0xffff;
+		if (field->flags & TEP_FIELD_IS_RELATIVE)
+			offset += field->offset + field->size;
 
 		/* record max width for output */
 		if (size > hde->dynamic_len)
-- 
2.33.0

[for-next][PATCH 07/13] tracing: Use __this_cpu_read() in trace_event_buffer_lock_reserver()

[Steven Rostedt]

From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

The value read by this_cpu_read() is used later and its use is expected to
stay on the same CPU as being read. But this_cpu_read() does not warn if
it is called without preemption disabled, where as __this_cpu_read() will
check if preemption is disabled on CONFIG_DEBUG_PREEMPT

Currently all callers have preemption disabled, but there may be new
callers in the future that may not.

Link: https://lkml.kernel.org/r/20211130024318.698165354@goodmis.org

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/trace/trace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 4821fe6a40a5..2e87b7bf2ba7 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2746,7 +2746,7 @@ trace_event_buffer_lock_reserve(struct trace_buffer **current_rb,
 
 	if (!tr->no_filter_buffering_ref &&
 	    (trace_file->flags & (EVENT_FILE_FL_SOFT_DISABLED | EVENT_FILE_FL_FILTERED)) &&
-	    (entry = this_cpu_read(trace_buffered_event))) {
+	    (entry = __this_cpu_read(trace_buffered_event))) {
 		/*
 		 * Filtering is on, so try to use the per cpu buffer first.
 		 * This buffer will simulate a ring_buffer_event,
-- 
2.33.0

[for-next][PATCH 08/13] tracing: Disable preemption when using the filter buffer

[Steven Rostedt]

From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

In case trace_event_buffer_lock_reserve() is called with preemption
enabled, the algorithm that defines the usage of the per cpu filter buffer
may fail if the task schedules to another CPU after determining which
buffer it will use.

Disable preemption when using the filter buffer. And because that same
buffer must be used throughout the call, keep preemption disabled until
the filter buffer is released.

This will also keep the semantics between the use case of when the filter
buffer is used, and when the ring buffer itself is used, as that case also
disables preemption until the ring buffer is released.

Link: https://lkml.kernel.org/r/20211130024318.880190623@goodmis.org

[ Fixed warning of assignment in if statement
  Reported-by: kernel test robot <lkp@intel.com> ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/trace/trace.c | 59 +++++++++++++++++++++++++-------------------
 kernel/trace/trace.h |  4 ++-
 2 files changed, 36 insertions(+), 27 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 2e87b7bf2ba7..e3b8c906b7b4 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -980,6 +980,8 @@ __buffer_unlock_commit(struct trace_buffer *buffer, struct ring_buffer_event *ev
 		ring_buffer_write(buffer, event->array[0], &event->array[1]);
 		/* Release the temp buffer */
 		this_cpu_dec(trace_buffered_event_cnt);
+		/* ring_buffer_unlock_commit() enables preemption */
+		preempt_enable_notrace();
 	} else
 		ring_buffer_unlock_commit(buffer, event);
 }
@@ -2745,8 +2747,8 @@ trace_event_buffer_lock_reserve(struct trace_buffer **current_rb,
 	*current_rb = tr->array_buffer.buffer;
 
 	if (!tr->no_filter_buffering_ref &&
-	    (trace_file->flags & (EVENT_FILE_FL_SOFT_DISABLED | EVENT_FILE_FL_FILTERED)) &&
-	    (entry = __this_cpu_read(trace_buffered_event))) {
+	    (trace_file->flags & (EVENT_FILE_FL_SOFT_DISABLED | EVENT_FILE_FL_FILTERED))) {
+		preempt_disable_notrace();
 		/*
 		 * Filtering is on, so try to use the per cpu buffer first.
 		 * This buffer will simulate a ring_buffer_event,
@@ -2764,33 +2766,38 @@ trace_event_buffer_lock_reserve(struct trace_buffer **current_rb,
 		 * is still quicker than no copy on match, but having
 		 * to discard out of the ring buffer on a failed match.
 		 */
-		int max_len = PAGE_SIZE - struct_size(entry, array, 1);
+		if ((entry = __this_cpu_read(trace_buffered_event))) {
+			int max_len = PAGE_SIZE - struct_size(entry, array, 1);
 
-		val = this_cpu_inc_return(trace_buffered_event_cnt);
+			val = this_cpu_inc_return(trace_buffered_event_cnt);
 
-		/*
-		 * Preemption is disabled, but interrupts and NMIs
-		 * can still come in now. If that happens after
-		 * the above increment, then it will have to go
-		 * back to the old method of allocating the event
-		 * on the ring buffer, and if the filter fails, it
-		 * will have to call ring_buffer_discard_commit()
-		 * to remove it.
-		 *
-		 * Need to also check the unlikely case that the
-		 * length is bigger than the temp buffer size.
-		 * If that happens, then the reserve is pretty much
-		 * guaranteed to fail, as the ring buffer currently
-		 * only allows events less than a page. But that may
-		 * change in the future, so let the ring buffer reserve
-		 * handle the failure in that case.
-		 */
-		if (val == 1 && likely(len <= max_len)) {
-			trace_event_setup(entry, type, trace_ctx);
-			entry->array[0] = len;
-			return entry;
+			/*
+			 * Preemption is disabled, but interrupts and NMIs
+			 * can still come in now. If that happens after
+			 * the above increment, then it will have to go
+			 * back to the old method of allocating the event
+			 * on the ring buffer, and if the filter fails, it
+			 * will have to call ring_buffer_discard_commit()
+			 * to remove it.
+			 *
+			 * Need to also check the unlikely case that the
+			 * length is bigger than the temp buffer size.
+			 * If that happens, then the reserve is pretty much
+			 * guaranteed to fail, as the ring buffer currently
+			 * only allows events less than a page. But that may
+			 * change in the future, so let the ring buffer reserve
+			 * handle the failure in that case.
+			 */
+			if (val == 1 && likely(len <= max_len)) {
+				trace_event_setup(entry, type, trace_ctx);
+				entry->array[0] = len;
+				/* Return with preemption disabled */
+				return entry;
+			}
+			this_cpu_dec(trace_buffered_event_cnt);
 		}
-		this_cpu_dec(trace_buffered_event_cnt);
+		/* __trace_buffer_lock_reserve() disables preemption */
+		preempt_enable_notrace();
 	}
 
 	entry = __trace_buffer_lock_reserve(*current_rb, type, len,
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 7162157b970b..8bd1a815ce90 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1337,10 +1337,12 @@ __trace_event_discard_commit(struct trace_buffer *buffer,
 			     struct ring_buffer_event *event)
 {
 	if (this_cpu_read(trace_buffered_event) == event) {
-		/* Simply release the temp buffer */
+		/* Simply release the temp buffer and enable preemption */
 		this_cpu_dec(trace_buffered_event_cnt);
+		preempt_enable_notrace();
 		return;
 	}
+	/* ring_buffer_discard_commit() enables preemption */
 	ring_buffer_discard_commit(buffer, event);
 }
 
-- 
2.33.0

[for-next][PATCH 09/13] tracing: Have eprobes use filtering logic of trace events

[Steven Rostedt]

From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

The eprobes open code the reserving of the event on the ring buffer for
ftrace instead of using the ftrace event wrappers, which means that it
doesn't get affected by the filters, breaking the filtering logic on user
space.

Link: https://lkml.kernel.org/r/20211130024319.068451680@goodmis.org

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/trace/trace_eprobe.c | 16 +++++-----------
 1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index 928867f527e7..88487752d307 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -489,18 +489,12 @@ __eprobe_trace_func(struct eprobe_data *edata, void *rec)
 	if (trace_trigger_soft_disabled(edata->file))
 		return;
 
-	fbuffer.trace_ctx = tracing_gen_ctx();
-	fbuffer.trace_file = edata->file;
-
 	dsize = get_eprobe_size(&edata->ep->tp, rec);
-	fbuffer.regs = NULL;
-
-	fbuffer.event =
-		trace_event_buffer_lock_reserve(&fbuffer.buffer, edata->file,
-					call->event.type,
-					sizeof(*entry) + edata->ep->tp.size + dsize,
-					fbuffer.trace_ctx);
-	if (!fbuffer.event)
+
+	entry = trace_event_buffer_reserve(&fbuffer, edata->file,
+					   sizeof(*entry) + edata->ep->tp.size + dsize);
+
+	if (!entry)
 		return;
 
 	entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
-- 
2.33.0

[for-next][PATCH 10/13] tracing/kprobes: Do not open code event reserve logic

[Steven Rostedt]

From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

As kprobe events use trace_event_buffer_commit() to commit the event to
the ftrace ring buffer, for consistency, it should use
trace_event_buffer_reserve() to allocate it, as the two functions are
related.

Link: https://lkml.kernel.org/r/20211130024319.257430762@goodmis.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/trace/trace_kprobe.c | 25 +++++++------------------
 1 file changed, 7 insertions(+), 18 deletions(-)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 33272a7b6912..d10c01948e68 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1383,17 +1383,11 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
 	if (trace_trigger_soft_disabled(trace_file))
 		return;
 
-	fbuffer.trace_ctx = tracing_gen_ctx();
-	fbuffer.trace_file = trace_file;
-
 	dsize = __get_data_size(&tk->tp, regs);
 
-	fbuffer.event =
-		trace_event_buffer_lock_reserve(&fbuffer.buffer, trace_file,
-					call->event.type,
-					sizeof(*entry) + tk->tp.size + dsize,
-					fbuffer.trace_ctx);
-	if (!fbuffer.event)
+	entry = trace_event_buffer_reserve(&fbuffer, trace_file,
+					   sizeof(*entry) + tk->tp.size + dsize);
+	if (!entry)
 		return;
 
 	fbuffer.regs = regs;
@@ -1430,16 +1424,11 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
 	if (trace_trigger_soft_disabled(trace_file))
 		return;
 
-	fbuffer.trace_ctx = tracing_gen_ctx();
-	fbuffer.trace_file = trace_file;
-
 	dsize = __get_data_size(&tk->tp, regs);
-	fbuffer.event =
-		trace_event_buffer_lock_reserve(&fbuffer.buffer, trace_file,
-					call->event.type,
-					sizeof(*entry) + tk->tp.size + dsize,
-					fbuffer.trace_ctx);
-	if (!fbuffer.event)
+
+	entry = trace_event_buffer_reserve(&fbuffer, trace_file,
+					   sizeof(*entry) + tk->tp.size + dsize);
+	if (!entry)
 		return;
 
 	fbuffer.regs = regs;
-- 
2.33.0

[for-next][PATCH 11/13] tracing/uprobes: Use trace_event_buffer_reserve() helper

[Steven Rostedt]

From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

To be consistent with kprobes and eprobes, use
trace_event_buffer_reserver() and trace_event_buffer_commit(). This will
ensure that any updates to trace events will also be implemented on uprobe
events.

Link: https://lkml.kernel.org/r/20211206162440.69fbf96c@gandalf.local.home

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/trace/trace_uprobe.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index f5f0039d31e5..a4d5c624fe79 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -949,8 +949,7 @@ static void __uprobe_trace_func(struct trace_uprobe *tu,
 				struct trace_event_file *trace_file)
 {
 	struct uprobe_trace_entry_head *entry;
-	struct trace_buffer *buffer;
-	struct ring_buffer_event *event;
+	struct trace_event_buffer fbuffer;
 	void *data;
 	int size, esize;
 	struct trace_event_call *call = trace_probe_event_call(&tu->tp);
@@ -965,12 +964,10 @@ static void __uprobe_trace_func(struct trace_uprobe *tu,
 
 	esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
 	size = esize + tu->tp.size + dsize;
-	event = trace_event_buffer_lock_reserve(&buffer, trace_file,
-						call->event.type, size, 0);
-	if (!event)
+	entry = trace_event_buffer_reserve(&fbuffer, trace_file, size);
+	if (!entry)
 		return;
 
-	entry = ring_buffer_event_data(event);
 	if (is_ret_probe(tu)) {
 		entry->vaddr[0] = func;
 		entry->vaddr[1] = instruction_pointer(regs);
@@ -982,7 +979,7 @@ static void __uprobe_trace_func(struct trace_uprobe *tu,
 
 	memcpy(data, ucb->buf, tu->tp.size + dsize);
 
-	event_trigger_unlock_commit(trace_file, buffer, event, entry, 0);
+	trace_event_buffer_commit(&fbuffer);
 }
 
 /* uprobe handler */
-- 
2.33.0

[for-next][PATCH 12/13] tracing: Fix synth_event_add_val() kernel-doc comment

[Steven Rostedt]

From: Qiujun Huang <hqjagain@gmail.com>

It's named field here.

Link: https://lkml.kernel.org/r/20210516022410.64271-1-hqjagain@gmail.com

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/trace/trace_events_synth.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c
index 22db3ce95e74..98e002648994 100644
--- a/kernel/trace/trace_events_synth.c
+++ b/kernel/trace/trace_events_synth.c
@@ -1978,7 +1978,7 @@ EXPORT_SYMBOL_GPL(synth_event_add_next_val);
 /**
  * synth_event_add_val - Add a named field's value to an open synth trace
  * @field_name: The name of the synthetic event field value to set
- * @val: The value to set the next field to
+ * @val: The value to set the named field to
  * @trace_state: A pointer to object tracking the piecewise trace state
  *
  * Set the value of the named field in an event that's been opened by
-- 
2.33.0

[for-next][PATCH 13/13] tracing: Switch to kvfree_rcu() API

[Steven Rostedt]

From: "Uladzislau Rezki (Sony)" <urezki@gmail.com>

Instead of invoking a synchronize_rcu() to free a pointer
after a grace period we can directly make use of new API
that does the same but in more efficient way.

Link: https://lkml.kernel.org/r/20211124110308.2053-10-urezki@gmail.com

Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/trace/trace_osnoise.c | 3 +--
 kernel/trace/trace_probe.c   | 3 +--
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c
index 7520d43aed55..4719a848bf17 100644
--- a/kernel/trace/trace_osnoise.c
+++ b/kernel/trace/trace_osnoise.c
@@ -138,8 +138,7 @@ static void osnoise_unregister_instance(struct trace_array *tr)
 	if (!found)
 		return;
 
-	synchronize_rcu();
-	kfree(inst);
+	kvfree_rcu(inst);
 }
 
 /*
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 3ed2a3f37297..8a3822818bf8 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -1138,8 +1138,7 @@ int trace_probe_remove_file(struct trace_probe *tp,
 		return -ENOENT;
 
 	list_del_rcu(&link->list);
-	synchronize_rcu();
-	kfree(link);
+	kvfree_rcu(link);
 
 	if (list_empty(&tp->event->files))
 		trace_probe_clear_flag(tp, TP_FLAG_TRACE);
-- 
2.33.0