Commit d4d70463 authored by Tom Zanussi's avatar Tom Zanussi Committed by Steven Rostedt (VMware)
Browse files

tracing: Add synthetic event error logging 

Add support for synthetic event error logging, which entails adding a
logging function for it, a way to save the synthetic event command,
and a set of specific synthetic event parse error strings and
handling.

Link: https://lkml.kernel.org/r/ed099c66df13b40cfc633aaeb17f66c37a923066.1602598160.git.zanussi@kernel.org



[ <rostedt@goodmis.org>: wrote save_cmdstr() seq_buf implementation. ]
Tested-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: default avatarTom Zanussi <zanussi@kernel.org>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent 9bbb3329

kernel/trace/trace_events_synth.c

+90 −2
Original line number Diff line number Diff line
@@ -20,6 +20,48 @@ 


#include "trace_synth.h"



#undef ERRORS

#define ERRORS	\

	C(BAD_NAME,		"Illegal name"),		\

	C(CMD_INCOMPLETE,	"Incomplete command"),		\

	C(EVENT_EXISTS,		"Event already exists"),	\

	C(TOO_MANY_FIELDS,	"Too many fields"),		\

	C(INCOMPLETE_TYPE,	"Incomplete type"),		\

	C(INVALID_TYPE,		"Invalid type"),		\

	C(INVALID_FIELD,	"Invalid field"),		\

	C(CMD_TOO_LONG,		"Command too long"),



#undef C

#define C(a, b)		SYNTH_ERR_##a



enum { ERRORS };



#undef C

#define C(a, b)		b



static const char *err_text[] = { ERRORS };



static char last_cmd[MAX_FILTER_STR_VAL];



static int errpos(const char *str)

{

	return err_pos(last_cmd, str);

}



static void last_cmd_set(char *str)

{

	if (!str)

		return;



	strncpy(last_cmd, str, MAX_FILTER_STR_VAL - 1);

}



static void synth_err(u8 err_type, u8 err_pos)

{

	tracing_log_err(NULL, "synthetic_events", last_cmd, err_text,

			err_type, err_pos);

}



static int create_synth_event(int argc, const char **argv);

static int synth_event_show(struct seq_file *m, struct dyn_event *ev);

static int synth_event_release(struct dyn_event *ev);
@@ -545,8 +587,10 @@ static struct synth_field *parse_synth_field(int argc, const char **argv, 
		field_type++;



	if (!strcmp(field_type, "unsigned")) {

		if (argc < 3)

		if (argc < 3) {

			synth_err(SYNTH_ERR_INCOMPLETE_TYPE, errpos(field_type));

			return ERR_PTR(-EINVAL);

		}

		prefix = "unsigned ";

		field_type = argv[1];

		field_name = argv[2];
@@ -573,6 +617,7 @@ static struct synth_field *parse_synth_field(int argc, const char **argv, 
		goto free;

	}

	if (!is_good_name(field->name)) {

		synth_err(SYNTH_ERR_BAD_NAME, errpos(field_name));

		ret = -EINVAL;

		goto free;

	}
@@ -601,6 +646,7 @@ static struct synth_field *parse_synth_field(int argc, const char **argv, 


	size = synth_field_size(field->type);

	if (size < 0) {

		synth_err(SYNTH_ERR_INVALID_TYPE, errpos(field_type));

		ret = -EINVAL;

		goto free;

	} else if (size == 0) {
@@ -621,6 +667,7 @@ static struct synth_field *parse_synth_field(int argc, const char **argv, 
			field->is_dynamic = true;

			size = sizeof(u64);

		} else {

			synth_err(SYNTH_ERR_INVALID_TYPE, errpos(field_type));

			ret = -EINVAL;

			goto free;

		}
@@ -1098,12 +1145,47 @@ int synth_event_gen_cmd_array_start(struct dynevent_cmd *cmd, const char *name, 
}

EXPORT_SYMBOL_GPL(synth_event_gen_cmd_array_start);



static int save_cmdstr(int argc, const char *name, const char **argv)

{

	struct seq_buf s;

	char *buf;

	int i;



	buf = kzalloc(MAX_DYNEVENT_CMD_LEN, GFP_KERNEL);

	if (!buf)

		return -ENOMEM;



	seq_buf_init(&s, buf, MAX_DYNEVENT_CMD_LEN);



	seq_buf_puts(&s, name);



	for (i = 0; i < argc; i++) {

		seq_buf_putc(&s, ' ');

		seq_buf_puts(&s, argv[i]);

	}



	if (!seq_buf_buffer_left(&s)) {

		synth_err(SYNTH_ERR_CMD_TOO_LONG, 0);

		kfree(buf);

		return -EINVAL;

	}

	buf[s.len] = 0;

	last_cmd_set(buf);



	kfree(buf);

	return 0;

}



static int __create_synth_event(int argc, const char *name, const char **argv)

{

	struct synth_field *field, *fields[SYNTH_FIELDS_MAX];

	struct synth_event *event = NULL;

	int i, consumed = 0, n_fields = 0, ret = 0;



	ret = save_cmdstr(argc, name, argv);

	if (ret)

		return ret;



	/*

	 * Argument syntax:

	 *  - Add synthetic event: <event_name> field[;field] ...
@@ -1111,18 +1193,22 @@ static int __create_synth_event(int argc, const char *name, const char **argv) 
	 *      where 'field' = type field_name

	 */



	if (name[0] == '\0' || argc < 1)

	if (name[0] == '\0' || argc < 1) {

		synth_err(SYNTH_ERR_CMD_INCOMPLETE, 0);

		return -EINVAL;

	}



	mutex_lock(&event_mutex);



	if (!is_good_name(name)) {

		synth_err(SYNTH_ERR_BAD_NAME, errpos(name));

		ret = -EINVAL;

		goto out;

	}



	event = find_synth_event(name);

	if (event) {

		synth_err(SYNTH_ERR_EVENT_EXISTS, errpos(name));

		ret = -EEXIST;

		goto out;

	}
@@ -1131,6 +1217,7 @@ static int __create_synth_event(int argc, const char *name, const char **argv) 
		if (strcmp(argv[i], ";") == 0)

			continue;

		if (n_fields == SYNTH_FIELDS_MAX) {

			synth_err(SYNTH_ERR_TOO_MANY_FIELDS, 0);

			ret = -EINVAL;

			goto err;

		}
@@ -1145,6 +1232,7 @@ static int __create_synth_event(int argc, const char *name, const char **argv) 
	}



	if (i < argc && strcmp(argv[i], ";") != 0) {

		synth_err(SYNTH_ERR_INVALID_FIELD, errpos(argv[i]));

		ret = -EINVAL;

		goto err;

	}

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