1 files changed, 157 insertions, 62 deletions

diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c
index 67592eed0be8..4554c458b78c 100644
--- a/kernel/trace/trace_events_synth.c
+++ b/kernel/trace/trace_events_synth.c
@@ -44,10 +44,12 @@ enum { ERRORS };
 
 static const char *err_text[] = { ERRORS };
 
+static DEFINE_MUTEX(lastcmd_mutex);
 static char *last_cmd;
 
 static int errpos(const char *str)
 {
+	guard(mutex)(&lastcmd_mutex);
 	if (!str || !last_cmd)
 		return 0;
 
@@ -59,13 +61,15 @@ static void last_cmd_set(const char *str)
 	if (!str)
 		return;
 
+	mutex_lock(&lastcmd_mutex);
 	kfree(last_cmd);
-
 	last_cmd = kstrdup(str, GFP_KERNEL);
+	mutex_unlock(&lastcmd_mutex);
 }
 
 static void synth_err(u8 err_type, u16 err_pos)
 {
+	guard(mutex)(&lastcmd_mutex);
 	if (!last_cmd)
 		return;
 
@@ -116,7 +120,7 @@ static bool synth_event_match(const char *system, const char *event,
 
 struct synth_trace_event {
 	struct trace_entry	ent;
-	u64			fields[];
+	union trace_synth_field	fields[];
 };
 
 static int synth_event_define_fields(struct trace_event_call *call)
@@ -173,6 +177,14 @@ static int synth_field_is_string(char *type)
 	return false;
 }
 
+static int synth_field_is_stack(char *type)
+{
+	if (strstr(type, "long[") != NULL)
+		return true;
+
+	return false;
+}
+
 static int synth_field_string_size(char *type)
 {
 	char buf[4], *end, *start;
@@ -195,7 +207,7 @@ static int synth_field_string_size(char *type)
 	if (len == 0)
 		return 0; /* variable-length string */
 
-	strncpy(buf, start, len);
+	memcpy(buf, start, len);
 	buf[len] = '\0';
 
 	err = kstrtouint(buf, 0, &size);
@@ -248,6 +260,8 @@ static int synth_field_size(char *type)
 		size = sizeof(gfp_t);
 	else if (synth_field_is_string(type))
 		size = synth_field_string_size(type);
+	else if (synth_field_is_stack(type))
+		size = 0;
 
 	return size;
 }
@@ -291,30 +305,32 @@ static const char *synth_field_fmt(char *type)
 	else if (strcmp(type, "gfp_t") == 0)
 		fmt = "%x";
 	else if (synth_field_is_string(type))
-		fmt = "%.*s";
+		fmt = "%s";
+	else if (synth_field_is_stack(type))
+		fmt = "%s";
 
 	return fmt;
 }
 
 static void print_synth_event_num_val(struct trace_seq *s,
 				      char *print_fmt, char *name,
-				      int size, u64 val, char *space)
+				      int size, union trace_synth_field *val, char *space)
 {
 	switch (size) {
 	case 1:
-		trace_seq_printf(s, print_fmt, name, (u8)val, space);
+		trace_seq_printf(s, print_fmt, name, val->as_u8, space);
 		break;
 
 	case 2:
-		trace_seq_printf(s, print_fmt, name, (u16)val, space);
+		trace_seq_printf(s, print_fmt, name, val->as_u16, space);
 		break;
 
 	case 4:
-		trace_seq_printf(s, print_fmt, name, (u32)val, space);
+		trace_seq_printf(s, print_fmt, name, val->as_u32, space);
 		break;
 
 	default:
-		trace_seq_printf(s, print_fmt, name, val, space);
+		trace_seq_printf(s, print_fmt, name, val->as_u64, space);
 		break;
 	}
 }
@@ -327,7 +343,7 @@ static enum print_line_t print_synth_event(struct trace_iterator *iter,
 	struct trace_seq *s = &iter->seq;
 	struct synth_trace_event *entry;
 	struct synth_event *se;
-	unsigned int i, n_u64;
+	unsigned int i, j, n_u64;
 	char print_fmt[32];
 	const char *fmt;
 
@@ -343,7 +359,7 @@ static enum print_line_t print_synth_event(struct trace_iterator *iter,
 		fmt = synth_field_fmt(se->fields[i]->type);
 
 		/* parameter types */
-		if (tr && tr->trace_flags & TRACE_ITER_VERBOSE)
+		if (tr && tr->trace_flags & TRACE_ITER(VERBOSE))
 			trace_seq_printf(s, "%s ", fmt);
 
 		snprintf(print_fmt, sizeof(print_fmt), "%%s=%s%%s", fmt);
@@ -351,26 +367,26 @@ static enum print_line_t print_synth_event(struct trace_iterator *iter,
 		/* parameter values */
 		if (se->fields[i]->is_string) {
 			if (se->fields[i]->is_dynamic) {
-				u32 offset, data_offset;
-				char *str_field;
-
-				offset = (u32)entry->fields[n_u64];
-				data_offset = offset & 0xffff;
-
-				str_field = (char *)entry + data_offset;
+				union trace_synth_field *data = &entry->fields[n_u64];
 
 				trace_seq_printf(s, print_fmt, se->fields[i]->name,
-						 STR_VAR_LEN_MAX,
-						 str_field,
+						 (char *)entry + data->as_dynamic.offset,
 						 i == se->n_fields - 1 ? "" : " ");
 				n_u64++;
 			} else {
 				trace_seq_printf(s, print_fmt, se->fields[i]->name,
-						 STR_VAR_LEN_MAX,
-						 (char *)&entry->fields[n_u64],
+						 (char *)&entry->fields[n_u64].as_u64,
 						 i == se->n_fields - 1 ? "" : " ");
 				n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
 			}
+		} else if (se->fields[i]->is_stack) {
+			union trace_synth_field *data = &entry->fields[n_u64];
+			unsigned long *p = (void *)entry + data->as_dynamic.offset;
+
+			trace_seq_printf(s, "%s=STACK:\n", se->fields[i]->name);
+			for (j = 1; j < data->as_dynamic.len / sizeof(long); j++)
+				trace_seq_printf(s, "=> %pS\n", (void *)p[j]);
+			n_u64++;
 		} else {
 			struct trace_print_flags __flags[] = {
 			    __def_gfpflag_names, {-1, NULL} };
@@ -379,13 +395,13 @@ static enum print_line_t print_synth_event(struct trace_iterator *iter,
 			print_synth_event_num_val(s, print_fmt,
 						  se->fields[i]->name,
 						  se->fields[i]->size,
-						  entry->fields[n_u64],
+						  &entry->fields[n_u64],
 						  space);
 
 			if (strcmp(se->fields[i]->type, "gfp_t") == 0) {
 				trace_seq_puts(s, " (");
 				trace_print_flags_seq(s, "|",
-						      entry->fields[n_u64],
+						      entry->fields[n_u64].as_u64,
 						      __flags);
 				trace_seq_putc(s, ')');
 			}
@@ -414,26 +430,21 @@ static unsigned int trace_string(struct synth_trace_event *entry,
 	int ret;
 
 	if (is_dynamic) {
-		u32 data_offset;
-
-		data_offset = offsetof(typeof(*entry), fields);
-		data_offset += event->n_u64 * sizeof(u64);
-		data_offset += data_size;
+		union trace_synth_field *data = &entry->fields[*n_u64];
 
-		len = kern_fetch_store_strlen((unsigned long)str_val);
+		len = fetch_store_strlen((unsigned long)str_val);
+		data->as_dynamic.offset = struct_size(entry, fields, event->n_u64) + data_size;
+		data->as_dynamic.len = len;
 
-		data_offset |= len << 16;
-		*(u32 *)&entry->fields[*n_u64] = data_offset;
-
-		ret = kern_fetch_store_string((unsigned long)str_val, &entry->fields[*n_u64], entry);
+		ret = fetch_store_string((unsigned long)str_val, &entry->fields[*n_u64], entry);
 
 		(*n_u64)++;
 	} else {
-		str_field = (char *)&entry->fields[*n_u64];
+		str_field = (char *)&entry->fields[*n_u64].as_u64;
 
 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
 		if ((unsigned long)str_val < TASK_SIZE)
-			ret = strncpy_from_user_nofault(str_field, str_val, STR_VAR_LEN_MAX);
+			ret = strncpy_from_user_nofault(str_field, (const void __user *)str_val, STR_VAR_LEN_MAX);
 		else
 #endif
 			ret = strncpy_from_kernel_nofault(str_field, str_val, STR_VAR_LEN_MAX);
@@ -447,6 +458,41 @@ static unsigned int trace_string(struct synth_trace_event *entry,
 	return len;
 }
 
+static unsigned int trace_stack(struct synth_trace_event *entry,
+				 struct synth_event *event,
+				 long *stack,
+				 unsigned int data_size,
+				 unsigned int *n_u64)
+{
+	union trace_synth_field *data = &entry->fields[*n_u64];
+	unsigned int len;
+	u32 data_offset;
+	void *data_loc;
+
+	data_offset = struct_size(entry, fields, event->n_u64);
+	data_offset += data_size;
+
+	for (len = 0; len < HIST_STACKTRACE_DEPTH; len++) {
+		if (!stack[len])
+			break;
+	}
+
+	len *= sizeof(long);
+
+	/* Find the dynamic section to copy the stack into. */
+	data_loc = (void *)entry + data_offset;
+	memcpy(data_loc, stack, len);
+
+	/* Fill in the field that holds the offset/len combo */
+
+	data->as_dynamic.offset = data_offset;
+	data->as_dynamic.len = len;
+
+	(*n_u64)++;
+
+	return len;
+}
+
 static notrace void trace_event_raw_event_synth(void *__data,
 						u64 *var_ref_vals,
 						unsigned int *var_ref_idx)
@@ -473,7 +519,13 @@ static notrace void trace_event_raw_event_synth(void *__data,
 		val_idx = var_ref_idx[field_pos];
 		str_val = (char *)(long)var_ref_vals[val_idx];
 
-		len = kern_fetch_store_strlen((unsigned long)str_val);
+		if (event->dynamic_fields[i]->is_stack) {
+			/* reserve one extra element for size */
+			len = *((unsigned long *)str_val) + 1;
+			len *= sizeof(unsigned long);
+		} else {
+			len = fetch_store_strlen((unsigned long)str_val);
+		}
 
 		fields_size += len;
 	}
@@ -483,12 +535,12 @@ static notrace void trace_event_raw_event_synth(void *__data,
 	 * is being performed within another event.
 	 */
 	buffer = trace_file->tr->array_buffer.buffer;
-	ring_buffer_nest_start(buffer);
+	guard(ring_buffer_nest)(buffer);
 
 	entry = trace_event_buffer_reserve(&fbuffer, trace_file,
 					   sizeof(*entry) + fields_size);
 	if (!entry)
-		goto out;
+		return;
 
 	for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
 		val_idx = var_ref_idx[i];
@@ -499,25 +551,31 @@ static notrace void trace_event_raw_event_synth(void *__data,
 					   event->fields[i]->is_dynamic,
 					   data_size, &n_u64);
 			data_size += len; /* only dynamic string increments */
+		} else if (event->fields[i]->is_stack) {
+			long *stack = (long *)(long)var_ref_vals[val_idx];
+
+			len = trace_stack(entry, event, stack,
+					   data_size, &n_u64);
+			data_size += len;
 		} else {
 			struct synth_field *field = event->fields[i];
 			u64 val = var_ref_vals[val_idx];
 
 			switch (field->size) {
 			case 1:
-				*(u8 *)&entry->fields[n_u64] = (u8)val;
+				entry->fields[n_u64].as_u8 = (u8)val;
 				break;
 
 			case 2:
-				*(u16 *)&entry->fields[n_u64] = (u16)val;
+				entry->fields[n_u64].as_u16 = (u16)val;
 				break;
 
 			case 4:
-				*(u32 *)&entry->fields[n_u64] = (u32)val;
+				entry->fields[n_u64].as_u32 = (u32)val;
 				break;
 
 			default:
-				entry->fields[n_u64] = val;
+				entry->fields[n_u64].as_u64 = val;
 				break;
 			}
 			n_u64++;
@@ -525,8 +583,6 @@ static notrace void trace_event_raw_event_synth(void *__data,
 	}
 
 	trace_event_buffer_commit(&fbuffer);
-out:
-	ring_buffer_nest_end(buffer);
 }
 
 static void free_synth_event_print_fmt(struct trace_event_call *call)
@@ -552,7 +608,7 @@ static int __set_synth_event_print_fmt(struct synth_event *event,
 		fmt = synth_field_fmt(event->fields[i]->type);
 		pos += snprintf(buf + pos, LEN_OR_ZERO, "%s=%s%s",
 				event->fields[i]->name, fmt,
-				i == event->n_fields - 1 ? "" : ", ");
+				i == event->n_fields - 1 ? "" : " ");
 	}
 	pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
 
@@ -561,6 +617,9 @@ static int __set_synth_event_print_fmt(struct synth_event *event,
 		    event->fields[i]->is_dynamic)
 			pos += snprintf(buf + pos, LEN_OR_ZERO,
 				", __get_str(%s)", event->fields[i]->name);
+		else if (event->fields[i]->is_stack)
+			pos += snprintf(buf + pos, LEN_OR_ZERO,
+				", __get_stacktrace(%s)", event->fields[i]->name);
 		else
 			pos += snprintf(buf + pos, LEN_OR_ZERO,
 					", REC->%s", event->fields[i]->name);
@@ -697,7 +756,8 @@ static struct synth_field *parse_synth_field(int argc, char **argv,
 		ret = -EINVAL;
 		goto free;
 	} else if (size == 0) {
-		if (synth_field_is_string(field->type)) {
+		if (synth_field_is_string(field->type) ||
+		    synth_field_is_stack(field->type)) {
 			char *type;
 
 			len = sizeof("__data_loc ") + strlen(field->type) + 1;
@@ -728,6 +788,8 @@ static struct synth_field *parse_synth_field(int argc, char **argv,
 
 	if (synth_field_is_string(field->type))
 		field->is_string = true;
+	else if (synth_field_is_stack(field->type))
+		field->is_stack = true;
 
 	field->is_signed = synth_field_signed(field->type);
  out:
@@ -786,6 +848,38 @@ static struct trace_event_fields synth_event_fields_array[] = {
 	{}
 };
 
+static int synth_event_reg(struct trace_event_call *call,
+		    enum trace_reg type, void *data)
+{
+	struct synth_event *event = container_of(call, struct synth_event, call);
+
+	switch (type) {
+#ifdef CONFIG_PERF_EVENTS
+	case TRACE_REG_PERF_REGISTER:
+#endif
+	case TRACE_REG_REGISTER:
+		if (!try_module_get(event->mod))
+			return -EBUSY;
+		break;
+	default:
+		break;
+	}
+
+	int ret = trace_event_reg(call, type, data);
+
+	switch (type) {
+#ifdef CONFIG_PERF_EVENTS
+	case TRACE_REG_PERF_UNREGISTER:
+#endif
+	case TRACE_REG_UNREGISTER:
+		module_put(event->mod);
+		break;
+	default:
+		break;
+	}
+	return ret;
+}
+
 static int register_synth_event(struct synth_event *event)
 {
 	struct trace_event_call *call = &event->call;
@@ -815,7 +909,7 @@ static int register_synth_event(struct synth_event *event)
 		goto out;
 	}
 	call->flags = TRACE_EVENT_FL_TRACEPOINT;
-	call->class->reg = trace_event_reg;
+	call->class->reg = synth_event_reg;
 	call->class->probe = trace_event_raw_event_synth;
 	call->data = event;
 	call->tp = event->tp;
@@ -1065,7 +1159,7 @@ EXPORT_SYMBOL_GPL(synth_event_add_fields);
  * @cmd: A pointer to the dynevent_cmd struct representing the new event
  * @name: The name of the synthetic event
  * @mod: The module creating the event, NULL if not created from a module
- * @args: Variable number of arg (pairs), one pair for each field
+ * @...: Variable number of arg (pairs), one pair for each field
  *
  * NOTE: Users normally won't want to call this function directly, but
  * rather use the synth_event_gen_cmd_start() wrapper, which
@@ -1137,6 +1231,7 @@ EXPORT_SYMBOL_GPL(__synth_event_gen_cmd_start);
  * synth_event_gen_cmd_array_start - Start synthetic event command from an array
  * @cmd: A pointer to the dynevent_cmd struct representing the new event
  * @name: The name of the synthetic event
+ * @mod: The module creating the event, NULL if not created from a module
  * @fields: An array of type/name field descriptions
  * @n_fields: The number of field descriptions contained in the fields array
  *
@@ -1622,7 +1717,7 @@ __synth_event_trace_end(struct synth_event_trace_state *trace_state)
  * synth_event_trace - Trace a synthetic event
  * @file: The trace_event_file representing the synthetic event
  * @n_vals: The number of values in vals
- * @args: Variable number of args containing the event values
+ * @...: Variable number of args containing the event values
  *
  * Trace a synthetic event using the values passed in the variable
  * argument list.
@@ -1697,19 +1792,19 @@ int synth_event_trace(struct trace_event_file *file, unsigned int n_vals, ...)
 
 			switch (field->size) {
 			case 1:
-				*(u8 *)&state.entry->fields[n_u64] = (u8)val;
+				state.entry->fields[n_u64].as_u8 = (u8)val;
 				break;
 
 			case 2:
-				*(u16 *)&state.entry->fields[n_u64] = (u16)val;
+				state.entry->fields[n_u64].as_u16 = (u16)val;
 				break;
 
 			case 4:
-				*(u32 *)&state.entry->fields[n_u64] = (u32)val;
+				state.entry->fields[n_u64].as_u32 = (u32)val;
 				break;
 
 			default:
-				state.entry->fields[n_u64] = val;
+				state.entry->fields[n_u64].as_u64 = val;
 				break;
 			}
 			n_u64++;
@@ -1790,19 +1885,19 @@ int synth_event_trace_array(struct trace_event_file *file, u64 *vals,
 
 			switch (field->size) {
 			case 1:
-				*(u8 *)&state.entry->fields[n_u64] = (u8)val;
+				state.entry->fields[n_u64].as_u8 = (u8)val;
 				break;
 
 			case 2:
-				*(u16 *)&state.entry->fields[n_u64] = (u16)val;
+				state.entry->fields[n_u64].as_u16 = (u16)val;
 				break;
 
 			case 4:
-				*(u32 *)&state.entry->fields[n_u64] = (u32)val;
+				state.entry->fields[n_u64].as_u32 = (u32)val;
 				break;
 
 			default:
-				state.entry->fields[n_u64] = val;
+				state.entry->fields[n_u64].as_u64 = val;
 				break;
 			}
 			n_u64++;
@@ -1937,19 +2032,19 @@ static int __synth_event_add_val(const char *field_name, u64 val,
 	} else {
 		switch (field->size) {
 		case 1:
-			*(u8 *)&trace_state->entry->fields[field->offset] = (u8)val;
+			trace_state->entry->fields[field->offset].as_u8 = (u8)val;
 			break;
 
 		case 2:
-			*(u16 *)&trace_state->entry->fields[field->offset] = (u16)val;
+			trace_state->entry->fields[field->offset].as_u16 = (u16)val;
 			break;
 
 		case 4:
-			*(u32 *)&trace_state->entry->fields[field->offset] = (u32)val;
+			trace_state->entry->fields[field->offset].as_u32 = (u32)val;
 			break;
 
 		default:
-			trace_state->entry->fields[field->offset] = val;
+			trace_state->entry->fields[field->offset].as_u64 = val;
 			break;
 		}
 	}