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Message-Id: <cc39d3737ffa8b330c3d3754b062709dbc1c50f6.1608238451.git.zanussi@kernel.org>
Date: Thu, 17 Dec 2020 15:14:27 -0600
From: Tom Zanussi <zanussi@...nel.org>
To: rostedt@...dmis.org, axelrasmussen@...gle.com
Cc: mhiramat@...nel.org, linux-kernel@...r.kernel.org
Subject: [PATCH v4 2/5] tracing: Rework synthetic event command parsing
Now that command parsing has been delegated to the create functions
and we're no longer constrained by argv_split(), we can modify the
synthetic event command parser to better match the higher-level
structure of the synthetic event commands, which is basically an event
name followed by a set of semicolon-separated fields.
Since we're also now passed the raw command, we can also save it
directly and can get rid of save_cmdstr().
Signed-off-by: Tom Zanussi <zanussi@...nel.org>
---
kernel/trace/trace_events_synth.c | 184 +++++++++++++++---------------
1 file changed, 90 insertions(+), 94 deletions(-)
diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c
index b2588a5650c9..66ccbab3483b 100644
--- a/kernel/trace/trace_events_synth.c
+++ b/kernel/trace/trace_events_synth.c
@@ -48,7 +48,7 @@ static int errpos(const char *str)
return err_pos(last_cmd, str);
}
-static void last_cmd_set(char *str)
+static void last_cmd_set(const char *str)
{
if (!str)
return;
@@ -579,7 +579,7 @@ static void free_synth_field(struct synth_field *field)
kfree(field);
}
-static struct synth_field *parse_synth_field(int argc, const char **argv,
+static struct synth_field *parse_synth_field(int argc, char **argv,
int *consumed)
{
struct synth_field *field;
@@ -588,9 +588,6 @@ static struct synth_field *parse_synth_field(int argc, const char **argv,
struct seq_buf s;
ssize_t size;
- if (field_type[0] == ';')
- field_type++;
-
if (!strcmp(field_type, "unsigned")) {
if (argc < 3) {
synth_err(SYNTH_ERR_INCOMPLETE_TYPE, errpos(field_type));
@@ -605,6 +602,11 @@ static struct synth_field *parse_synth_field(int argc, const char **argv,
*consumed = 2;
}
+ if (!field_name) {
+ synth_err(SYNTH_ERR_INVALID_FIELD, errpos(field_type));
+ return ERR_PTR(-EINVAL);
+ }
+
field = kzalloc(sizeof(*field), GFP_KERNEL);
if (!field)
return ERR_PTR(-ENOMEM);
@@ -613,8 +615,6 @@ static struct synth_field *parse_synth_field(int argc, const char **argv,
array = strchr(field_name, '[');
if (array)
len -= strlen(array);
- else if (field_name[len - 1] == ';')
- len--;
field->name = kmemdup_nul(field_name, len, GFP_KERNEL);
if (!field->name)
@@ -626,8 +626,6 @@ static struct synth_field *parse_synth_field(int argc, const char **argv,
goto free;
}
- if (field_type[0] == ';')
- field_type++;
len = strlen(field_type) + 1;
if (array)
@@ -644,11 +642,8 @@ static struct synth_field *parse_synth_field(int argc, const char **argv,
if (prefix)
seq_buf_puts(&s, prefix);
seq_buf_puts(&s, field_type);
- if (array) {
+ if (array)
seq_buf_puts(&s, array);
- if (s.buffer[s.len - 1] == ';')
- s.len--;
- }
if (WARN_ON_ONCE(!seq_buf_buffer_left(&s)))
goto free;
@@ -656,7 +651,6 @@ 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) {
@@ -1160,46 +1154,12 @@ 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)
+static int __create_synth_event(const char *name, const char *raw_fields)
{
+ int i, argc, n_fields = 0, ret = 0, consumed;
struct synth_field *field, *fields[SYNTH_FIELDS_MAX];
+ char **argv, *field_str, *tmp_fields, *saved_fields = NULL;
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:
@@ -1208,13 +1168,14 @@ static int __create_synth_event(int argc, const char *name, const char **argv)
* where 'field' = type field_name
*/
- if (name[0] == '\0' || argc < 1) {
+ mutex_lock(&event_mutex);
+
+ if (name[0] == '\0') {
synth_err(SYNTH_ERR_CMD_INCOMPLETE, 0);
- return -EINVAL;
+ ret = -EINVAL;
+ goto out;
}
- mutex_lock(&event_mutex);
-
if (!is_good_name(name)) {
synth_err(SYNTH_ERR_BAD_NAME, errpos(name));
ret = -EINVAL;
@@ -1228,26 +1189,47 @@ static int __create_synth_event(int argc, const char *name, const char **argv)
goto out;
}
- for (i = 0; i < argc - 1; i++) {
- if (strcmp(argv[i], ";") == 0)
- continue;
+ tmp_fields = saved_fields = kstrdup(raw_fields, GFP_KERNEL);
+ if (!tmp_fields) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ while ((field_str = strsep(&tmp_fields, ";")) != NULL) {
if (n_fields == SYNTH_FIELDS_MAX) {
synth_err(SYNTH_ERR_TOO_MANY_FIELDS, 0);
ret = -EINVAL;
goto err;
}
- field = parse_synth_field(argc - i, &argv[i], &consumed);
+ argv = argv_split(GFP_KERNEL, field_str, &argc);
+ if (!argv) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ if (!argc)
+ continue;
+
+ field = parse_synth_field(argc, argv, &consumed);
if (IS_ERR(field)) {
+ argv_free(argv);
ret = PTR_ERR(field);
goto err;
}
+
+ argv_free(argv);
+
+ if (consumed < argc) {
+ ret = -EINVAL;
+ goto err;
+ }
+
fields[n_fields++] = field;
- i += consumed - 1;
}
- if (i < argc && strcmp(argv[i], ";") != 0) {
- synth_err(SYNTH_ERR_INVALID_FIELD, errpos(argv[i]));
+ if (n_fields == 0) {
+ synth_err(SYNTH_ERR_CMD_INCOMPLETE, 0);
ret = -EINVAL;
goto err;
}
@@ -1266,6 +1248,8 @@ static int __create_synth_event(int argc, const char *name, const char **argv)
out:
mutex_unlock(&event_mutex);
+ kfree(saved_fields);
+
return ret;
err:
for (i = 0; i < n_fields; i++)
@@ -1385,29 +1369,35 @@ EXPORT_SYMBOL_GPL(synth_event_delete);
static int create_or_delete_synth_event(const char *raw_command)
{
- char **argv, *name = NULL;
- int argc = 0, ret = 0;
+ char *name = NULL, *fields, *p;
+ int ret = 0;
- argv = argv_split(GFP_KERNEL, raw_command, &argc);
- if (!argv)
- return -ENOMEM;
+ raw_command = skip_spaces(raw_command);
+ if (raw_command[0] == '\0')
+ return ret;
- if (!argc)
- goto free;
+ last_cmd_set(raw_command);
- name = argv[0];
+ p = strpbrk(raw_command, " \t");
+ if (!p)
+ return -EINVAL;
+
+ name = kmemdup_nul(raw_command, p - raw_command, GFP_KERNEL);
+ if (!name)
+ return -ENOMEM;
+
+ fields = skip_spaces(p);
- /* trace_run_command() ensures argc != 0 */
if (name[0] == '!') {
ret = synth_event_delete(name + 1);
goto free;
}
- ret = __create_synth_event(argc - 1, name, (const char **)argv + 1);
+ ret = __create_synth_event(name, fields);
free:
- argv_free(argv);
+ kfree(name);
- return ret == -ECANCELED ? -EINVAL : ret;
+ return ret;
}
static int synth_event_run_command(struct dynevent_cmd *cmd)
@@ -1953,39 +1943,45 @@ EXPORT_SYMBOL_GPL(synth_event_trace_end);
static int create_synth_event(const char *raw_command)
{
- char **argv, *name;
- int len, argc = 0, ret = 0;
+ char *fields, *p;
+ const char *name;
+ int len, ret = 0;
- argv = argv_split(GFP_KERNEL, raw_command, &argc);
- if (!argv) {
- ret = -ENOMEM;
+ raw_command = skip_spaces(raw_command);
+ if (raw_command[0] == '\0')
return ret;
- }
- if (!argc)
- goto free;
+ last_cmd_set(raw_command);
- name = argv[0];
+ p = strpbrk(raw_command, " \t");
+ if (!p)
+ return -EINVAL;
- if (name[0] != 's' || name[1] != ':') {
- ret = -ECANCELED;
- goto free;
- }
+ fields = skip_spaces(p);
+
+ name = raw_command;
+
+ if (name[0] != 's' || name[1] != ':')
+ return -ECANCELED;
name += 2;
/* This interface accepts group name prefix */
if (strchr(name, '/')) {
len = str_has_prefix(name, SYNTH_SYSTEM "/");
- if (len == 0) {
- ret = -EINVAL;
- goto free;
- }
+ if (len == 0)
+ return -EINVAL;
name += len;
}
- ret = __create_synth_event(argc - 1, name, (const char **)argv + 1);
-free:
- argv_free(argv);
+ len = name - raw_command;
+
+ name = kmemdup_nul(raw_command + len, p - raw_command - len, GFP_KERNEL);
+ if (!name)
+ return -ENOMEM;
+
+ ret = __create_synth_event(name, fields);
+
+ kfree(name);
return ret;
}
--
2.17.1
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