[PATCH v4 3/5] tracing: Update synth command errors

From: Tom Zanussi
Date: Thu Dec 17 2020 - 16:15:47 EST


Since array types are handled differently, errors referencing them
also need to be handled differently. Add and use a new
INVALID_ARRAY_SPEC error. Also add INVALID_CMD and INVALID_DYN_CMD to
catch and display the correct form for badly-formed commands, which
can also be used in place of CMD_INCOMPLETE, which is removed, and
remove CMD_TOO_LONG, since it's no longer used.

Signed-off-by: Tom Zanussi <zanussi@xxxxxxxxxx>
---
kernel/trace/trace_events_synth.c | 71 +++++++++++++++++++++++++++----
1 file changed, 63 insertions(+), 8 deletions(-)

diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c
index 66ccbab3483b..2a9c8bf74bb2 100644
--- a/kernel/trace/trace_events_synth.c
+++ b/kernel/trace/trace_events_synth.c
@@ -23,13 +23,14 @@
#undef ERRORS
#define ERRORS \
C(BAD_NAME, "Illegal name"), \
- C(CMD_INCOMPLETE, "Incomplete command"), \
+ C(INVALID_CMD, "Command must be of the form: <name> field[;field] ..."),\
+ C(INVALID_DYN_CMD, "Command must be of the form: s or -:[synthetic/]<name> field[;field] ..."),\
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"),
+ C(INVALID_FIELD, "Invalid field"), \
+ C(INVALID_ARRAY_SPEC, "Invalid array specification"),

#undef C
#define C(a, b) SYNTH_ERR_##a
@@ -651,6 +652,10 @@ static struct synth_field *parse_synth_field(int argc, char **argv,

size = synth_field_size(field->type);
if (size < 0) {
+ if (array)
+ synth_err(SYNTH_ERR_INVALID_ARRAY_SPEC, errpos(field_name));
+ else
+ synth_err(SYNTH_ERR_INVALID_TYPE, errpos(field_type));
ret = -EINVAL;
goto free;
} else if (size == 0) {
@@ -1171,7 +1176,7 @@ static int __create_synth_event(const char *name, const char *raw_fields)
mutex_lock(&event_mutex);

if (name[0] == '\0') {
- synth_err(SYNTH_ERR_CMD_INCOMPLETE, 0);
+ synth_err(SYNTH_ERR_INVALID_CMD, 0);
ret = -EINVAL;
goto out;
}
@@ -1221,6 +1226,7 @@ static int __create_synth_event(const char *name, const char *raw_fields)
argv_free(argv);

if (consumed < argc) {
+ synth_err(SYNTH_ERR_INVALID_CMD, 0);
ret = -EINVAL;
goto err;
}
@@ -1229,7 +1235,7 @@ static int __create_synth_event(const char *name, const char *raw_fields)
}

if (n_fields == 0) {
- synth_err(SYNTH_ERR_CMD_INCOMPLETE, 0);
+ synth_err(SYNTH_ERR_INVALID_CMD, 0);
ret = -EINVAL;
goto err;
}
@@ -1367,6 +1373,37 @@ int synth_event_delete(const char *event_name)
}
EXPORT_SYMBOL_GPL(synth_event_delete);

+static int check_command(const char *raw_command)
+{
+ char **argv = NULL, *cmd, *saved_cmd, *name_and_field;
+ int argc, ret = 0;
+
+ cmd = saved_cmd = kstrdup(raw_command, GFP_KERNEL);
+ if (!cmd)
+ return -ENOMEM;
+
+ name_and_field = strsep(&cmd, ";");
+ if (!name_and_field) {
+ ret = -EINVAL;
+ goto free;
+ }
+
+ argv = argv_split(GFP_KERNEL, name_and_field, &argc);
+ if (!argv) {
+ ret = -ENOMEM;
+ goto free;
+ }
+
+ if (argc < 3)
+ ret = -EINVAL;
+free:
+ kfree(saved_cmd);
+ if (argv)
+ argv_free(argv);
+
+ return ret;
+}
+
static int create_or_delete_synth_event(const char *raw_command)
{
char *name = NULL, *fields, *p;
@@ -1378,9 +1415,17 @@ static int create_or_delete_synth_event(const char *raw_command)

last_cmd_set(raw_command);

+ ret = check_command(raw_command);
+ if (ret) {
+ synth_err(SYNTH_ERR_INVALID_CMD, 0);
+ return ret;
+ }
+
p = strpbrk(raw_command, " \t");
- if (!p)
+ if (!p) {
+ synth_err(SYNTH_ERR_INVALID_CMD, 0);
return -EINVAL;
+ }

name = kmemdup_nul(raw_command, p - raw_command, GFP_KERNEL);
if (!name)
@@ -1954,8 +1999,10 @@ static int create_synth_event(const char *raw_command)
last_cmd_set(raw_command);

p = strpbrk(raw_command, " \t");
- if (!p)
+ if (!p) {
+ synth_err(SYNTH_ERR_INVALID_CMD, 0);
return -EINVAL;
+ }

fields = skip_spaces(p);

@@ -1968,13 +2015,21 @@ static int create_synth_event(const char *raw_command)
/* This interface accepts group name prefix */
if (strchr(name, '/')) {
len = str_has_prefix(name, SYNTH_SYSTEM "/");
- if (len == 0)
+ if (len == 0) {
+ synth_err(SYNTH_ERR_INVALID_DYN_CMD, 0);
return -EINVAL;
+ }
name += len;
}

len = name - raw_command;

+ ret = check_command(raw_command + len);
+ if (ret) {
+ synth_err(SYNTH_ERR_INVALID_CMD, 0);
+ return ret;
+ }
+
name = kmemdup_nul(raw_command + len, p - raw_command - len, GFP_KERNEL);
if (!name)
return -ENOMEM;
--
2.17.1