With more event commands being implemented, it's been pointed out that
it would make sense to clean up the existing ones and make it easier
to implement new ones without copying a lot of boilerplate. The main
culprit here is the event_command.func() callback - the rest of the
event_command infrastructure has default implementations that work for
most implementations. The func() callback is a little different in
that every new command needs to customize parsing to some extent.
This patchset attempts to help clean that up and make it easier for
new users to deal with.
v7:
Missed a fixup in patch 6/6 to a data->ops->print() in the debug
code since I forgot to build with CONFIG_HIST_TRIGGERS_DEBUG.
Patches 1-5 remain the same.
v6:
Fixed warning for an uninitialized trigger_ops local in
event_trigger_parse() pointed out by Steve and the kernel test
robot. This was done by removing the need for the local by
removing the redundant trigger_ops params in [PATCH v6 3/6]
tracing: Remove ops param from event_command reg()/unreg()
callbacks.
Also added a follow-on patch to remove all the other instances of
redundant trigger_ops in [PATCH v6 6/6] tracing: Remove redundant
trigger_ops params
v5: Changed the parsing helper function example components param and
filter to reflect only the param and filter components, and added
param_and_filter which now appears in the functions.
Removed the check for a NULL *param following the strsep
separating the param from the filter in
event_trigger_separate_filter() because it will never be true due
to the previous check for NULL param_and_filter previously.
Changed the param name from trigger to param and updated the
function documentation in event_trigger_parse_num().
v4: Added two patches changing the names of event_command.func() and
event_trigger_ops.func() to make them reflect their functions.
Added back missing kfree(trigger_data) in event_trigger_callback().
Changed char *param to const char *param in
event_trigger_check_remove() and event_trigger_empty_param().
Changed event_trigger_separate_filter() to use separate param and
filter outparams, and changed the name of the param inparam to
param_and_filter to better reflect its contents and avoid the
clash with new param outparam. Changed all parse()
implementations to use this new scheme.
Fixed some typos and added more extensive comments with examples
explaining various things that were mentioned as causing confusion
and just in general tried to clarify things with respect to the
callbacks and parameters.
v3: broke up event_trigger_check() into smaller functions instead of
parameterizing it, and added function documentation.
v2: removed unused event_trigger_remove(). No change in functionality.
The following changes since commit a6ed2aee54644cfa2d04ca86308767f5c3a087e8:
tracing: Switch to kvfree_rcu() API (2021-12-06 17:53:50 -0500)
are available in the Git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/zanussi/linux-trace.git ftrace/cleanup-hist-func-v7
Tom Zanussi (6):
tracing: Change event_command func() to parse()
tracing: Change event_trigger_ops func() to trigger()
tracing: Remove ops param from event_command reg()/unreg() callbacks
tracing: Add helper functions to simplify event_command.parse()
callback handling
tracing: Have existing event_command.parse() implementations use
helpers
tracing: Remove redundant trigger_ops params
kernel/trace/trace.h | 81 ++--
kernel/trace/trace_eprobe.c | 30 +-
kernel/trace/trace_events_hist.c | 147 +++----
kernel/trace/trace_events_trigger.c | 626 +++++++++++++++++++---------
4 files changed, 566 insertions(+), 318 deletions(-)
--
2.17.1
The name of the func() callback on event_command is too generic and is
easily confused with other callbacks with that name, so change it to
something that reflects its actual purpose.
In this case, the main purpose of the callback is to parse an event
command, so call it parse() instead.
Signed-off-by: Tom Zanussi <[email protected]>
---
kernel/trace/trace.h | 19 +++++++++++-------
kernel/trace/trace_eprobe.c | 8 ++++----
kernel/trace/trace_events_hist.c | 26 ++++++++++++-------------
kernel/trace/trace_events_trigger.c | 30 ++++++++++++++---------------
4 files changed, 44 insertions(+), 39 deletions(-)
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 8bd1a815ce90..25bd5706ef0b 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1578,9 +1578,9 @@ extern int event_enable_trigger_print(struct seq_file *m,
struct event_trigger_data *data);
extern void event_enable_trigger_free(struct event_trigger_ops *ops,
struct event_trigger_data *data);
-extern int event_enable_trigger_func(struct event_command *cmd_ops,
- struct trace_event_file *file,
- char *glob, char *cmd, char *param);
+extern int event_enable_trigger_parse(struct event_command *cmd_ops,
+ struct trace_event_file *file,
+ char *glob, char *cmd, char *param);
extern int event_enable_register_trigger(char *glob,
struct event_trigger_ops *ops,
struct event_trigger_data *data,
@@ -1702,7 +1702,7 @@ struct event_trigger_ops {
* All the methods below, except for @set_filter() and @unreg_all(),
* must be implemented.
*
- * @func: The callback function responsible for parsing and
+ * @parse: The callback function responsible for parsing and
* registering the trigger written to the 'trigger' file by the
* user. It allocates the trigger instance and registers it with
* the appropriate trace event. It makes use of the other
@@ -1737,15 +1737,20 @@ struct event_trigger_ops {
*
* @get_trigger_ops: The callback function invoked to retrieve the
* event_trigger_ops implementation associated with the command.
+ * This callback function allows a single event_command to
+ * support multiple trigger implementations via different sets of
+ * event_trigger_ops, depending on the value of the @param
+ * string.
*/
struct event_command {
struct list_head list;
char *name;
enum event_trigger_type trigger_type;
int flags;
- int (*func)(struct event_command *cmd_ops,
- struct trace_event_file *file,
- char *glob, char *cmd, char *params);
+ int (*parse)(struct event_command *cmd_ops,
+ struct trace_event_file *file,
+ char *glob, char *cmd,
+ char *param_and_filter);
int (*reg)(char *glob,
struct event_trigger_ops *ops,
struct event_trigger_data *data,
diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index 88487752d307..84d5bfa34a99 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -549,9 +549,9 @@ static struct event_trigger_ops eprobe_trigger_ops = {
.free = eprobe_trigger_free,
};
-static int eprobe_trigger_cmd_func(struct event_command *cmd_ops,
- struct trace_event_file *file,
- char *glob, char *cmd, char *param)
+static int eprobe_trigger_cmd_parse(struct event_command *cmd_ops,
+ struct trace_event_file *file,
+ char *glob, char *cmd, char *param)
{
return -1;
}
@@ -580,7 +580,7 @@ static struct event_command event_trigger_cmd = {
.name = "eprobe",
.trigger_type = ETT_EVENT_EPROBE,
.flags = EVENT_CMD_FL_NEEDS_REC,
- .func = eprobe_trigger_cmd_func,
+ .parse = eprobe_trigger_cmd_parse,
.reg = eprobe_trigger_reg_func,
.unreg = eprobe_trigger_unreg_func,
.unreg_all = NULL,
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 9b8da439149c..89bbbbd3a3f5 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -2761,9 +2761,9 @@ static char *find_trigger_filter(struct hist_trigger_data *hist_data,
}
static struct event_command trigger_hist_cmd;
-static int event_hist_trigger_func(struct event_command *cmd_ops,
- struct trace_event_file *file,
- char *glob, char *cmd, char *param);
+static int event_hist_trigger_parse(struct event_command *cmd_ops,
+ struct trace_event_file *file,
+ char *glob, char *cmd, char *param);
static bool compatible_keys(struct hist_trigger_data *target_hist_data,
struct hist_trigger_data *hist_data,
@@ -2966,8 +2966,8 @@ create_field_var_hist(struct hist_trigger_data *target_hist_data,
var_hist->hist_data = hist_data;
/* Create the new histogram with our variable */
- ret = event_hist_trigger_func(&trigger_hist_cmd, file,
- "", "hist", cmd);
+ ret = event_hist_trigger_parse(&trigger_hist_cmd, file,
+ "", "hist", cmd);
if (ret) {
kfree(cmd);
kfree(var_hist->cmd);
@@ -5729,8 +5729,8 @@ static void unregister_field_var_hists(struct hist_trigger_data *hist_data)
for (i = 0; i < hist_data->n_field_var_hists; i++) {
file = hist_data->field_var_hists[i]->hist_data->event_file;
cmd = hist_data->field_var_hists[i]->cmd;
- ret = event_hist_trigger_func(&trigger_hist_cmd, file,
- "!hist", "hist", cmd);
+ ret = event_hist_trigger_parse(&trigger_hist_cmd, file,
+ "!hist", "hist", cmd);
WARN_ON_ONCE(ret < 0);
}
}
@@ -6146,9 +6146,9 @@ static void hist_unreg_all(struct trace_event_file *file)
}
}
-static int event_hist_trigger_func(struct event_command *cmd_ops,
- struct trace_event_file *file,
- char *glob, char *cmd, char *param)
+static int event_hist_trigger_parse(struct event_command *cmd_ops,
+ struct trace_event_file *file,
+ char *glob, char *cmd, char *param)
{
unsigned int hist_trigger_bits = TRACING_MAP_BITS_DEFAULT;
struct event_trigger_data *trigger_data;
@@ -6331,7 +6331,7 @@ static struct event_command trigger_hist_cmd = {
.name = "hist",
.trigger_type = ETT_EVENT_HIST,
.flags = EVENT_CMD_FL_NEEDS_REC,
- .func = event_hist_trigger_func,
+ .parse = event_hist_trigger_parse,
.reg = hist_register_trigger,
.unreg = hist_unregister_trigger,
.unreg_all = hist_unreg_all,
@@ -6446,7 +6446,7 @@ static void hist_enable_unreg_all(struct trace_event_file *file)
static struct event_command trigger_hist_enable_cmd = {
.name = ENABLE_HIST_STR,
.trigger_type = ETT_HIST_ENABLE,
- .func = event_enable_trigger_func,
+ .parse = event_enable_trigger_parse,
.reg = event_enable_register_trigger,
.unreg = event_enable_unregister_trigger,
.unreg_all = hist_enable_unreg_all,
@@ -6457,7 +6457,7 @@ static struct event_command trigger_hist_enable_cmd = {
static struct event_command trigger_hist_disable_cmd = {
.name = DISABLE_HIST_STR,
.trigger_type = ETT_HIST_ENABLE,
- .func = event_enable_trigger_func,
+ .parse = event_enable_trigger_parse,
.reg = event_enable_register_trigger,
.unreg = event_enable_unregister_trigger,
.unreg_all = hist_enable_unreg_all,
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 3d5c07239a2a..15aae07cbe61 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -245,7 +245,7 @@ int trigger_process_regex(struct trace_event_file *file, char *buff)
mutex_lock(&trigger_cmd_mutex);
list_for_each_entry(p, &trigger_commands, list) {
if (strcmp(p->name, command) == 0) {
- ret = p->func(p, file, buff, command, next);
+ ret = p->parse(p, file, buff, command, next);
goto out_unlock;
}
}
@@ -622,7 +622,7 @@ static void unregister_trigger(char *glob, struct event_trigger_ops *ops,
}
/**
- * event_trigger_callback - Generic event_command @func implementation
+ * event_trigger_parse - Generic event_command @parse implementation
* @cmd_ops: The command ops, used for trigger registration
* @file: The trace_event_file associated with the event
* @glob: The raw string used to register the trigger
@@ -632,15 +632,15 @@ static void unregister_trigger(char *glob, struct event_trigger_ops *ops,
* Common implementation for event command parsing and trigger
* instantiation.
*
- * Usually used directly as the @func method in event command
+ * Usually used directly as the @parse method in event command
* implementations.
*
* Return: 0 on success, errno otherwise
*/
static int
-event_trigger_callback(struct event_command *cmd_ops,
- struct trace_event_file *file,
- char *glob, char *cmd, char *param)
+event_trigger_parse(struct event_command *cmd_ops,
+ struct trace_event_file *file,
+ char *glob, char *cmd, char *param)
{
struct event_trigger_data *trigger_data;
struct event_trigger_ops *trigger_ops;
@@ -1069,7 +1069,7 @@ onoff_get_trigger_ops(char *cmd, char *param)
static struct event_command trigger_traceon_cmd = {
.name = "traceon",
.trigger_type = ETT_TRACE_ONOFF,
- .func = event_trigger_callback,
+ .parse = event_trigger_parse,
.reg = register_trigger,
.unreg = unregister_trigger,
.get_trigger_ops = onoff_get_trigger_ops,
@@ -1080,7 +1080,7 @@ static struct event_command trigger_traceoff_cmd = {
.name = "traceoff",
.trigger_type = ETT_TRACE_ONOFF,
.flags = EVENT_CMD_FL_POST_TRIGGER,
- .func = event_trigger_callback,
+ .parse = event_trigger_parse,
.reg = register_trigger,
.unreg = unregister_trigger,
.get_trigger_ops = onoff_get_trigger_ops,
@@ -1157,7 +1157,7 @@ snapshot_get_trigger_ops(char *cmd, char *param)
static struct event_command trigger_snapshot_cmd = {
.name = "snapshot",
.trigger_type = ETT_SNAPSHOT,
- .func = event_trigger_callback,
+ .parse = event_trigger_parse,
.reg = register_snapshot_trigger,
.unreg = unregister_trigger,
.get_trigger_ops = snapshot_get_trigger_ops,
@@ -1249,7 +1249,7 @@ static struct event_command trigger_stacktrace_cmd = {
.name = "stacktrace",
.trigger_type = ETT_STACKTRACE,
.flags = EVENT_CMD_FL_POST_TRIGGER,
- .func = event_trigger_callback,
+ .parse = event_trigger_parse,
.reg = register_trigger,
.unreg = unregister_trigger,
.get_trigger_ops = stacktrace_get_trigger_ops,
@@ -1380,9 +1380,9 @@ static struct event_trigger_ops event_disable_count_trigger_ops = {
.free = event_enable_trigger_free,
};
-int event_enable_trigger_func(struct event_command *cmd_ops,
- struct trace_event_file *file,
- char *glob, char *cmd, char *param)
+int event_enable_trigger_parse(struct event_command *cmd_ops,
+ struct trace_event_file *file,
+ char *glob, char *cmd, char *param)
{
struct trace_event_file *event_enable_file;
struct enable_trigger_data *enable_data;
@@ -1628,7 +1628,7 @@ event_enable_get_trigger_ops(char *cmd, char *param)
static struct event_command trigger_enable_cmd = {
.name = ENABLE_EVENT_STR,
.trigger_type = ETT_EVENT_ENABLE,
- .func = event_enable_trigger_func,
+ .parse = event_enable_trigger_parse,
.reg = event_enable_register_trigger,
.unreg = event_enable_unregister_trigger,
.get_trigger_ops = event_enable_get_trigger_ops,
@@ -1638,7 +1638,7 @@ static struct event_command trigger_enable_cmd = {
static struct event_command trigger_disable_cmd = {
.name = DISABLE_EVENT_STR,
.trigger_type = ETT_EVENT_ENABLE,
- .func = event_enable_trigger_func,
+ .parse = event_enable_trigger_parse,
.reg = event_enable_register_trigger,
.unreg = event_enable_unregister_trigger,
.get_trigger_ops = event_enable_get_trigger_ops,
--
2.17.1
The event_trigger_ops for an event_command are already accessible via
event_trigger_data.ops so remove the redundant ops from the callback.
Signed-off-by: Tom Zanussi <[email protected]>
---
kernel/trace/trace.h | 4 ----
kernel/trace/trace_eprobe.c | 12 ++++++------
kernel/trace/trace_events_hist.c | 10 +++++-----
kernel/trace/trace_events_trigger.c | 22 +++++++++-------------
4 files changed, 20 insertions(+), 28 deletions(-)
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 1a73659222d4..7d981af10b8f 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1582,11 +1582,9 @@ extern int event_enable_trigger_parse(struct event_command *cmd_ops,
struct trace_event_file *file,
char *glob, char *cmd, char *param);
extern int event_enable_register_trigger(char *glob,
- struct event_trigger_ops *ops,
struct event_trigger_data *data,
struct trace_event_file *file);
extern void event_enable_unregister_trigger(char *glob,
- struct event_trigger_ops *ops,
struct event_trigger_data *test,
struct trace_event_file *file);
extern void trigger_data_free(struct event_trigger_data *data);
@@ -1763,11 +1761,9 @@ struct event_command {
char *glob, char *cmd,
char *param_and_filter);
int (*reg)(char *glob,
- struct event_trigger_ops *ops,
struct event_trigger_data *data,
struct trace_event_file *file);
void (*unreg)(char *glob,
- struct event_trigger_ops *ops,
struct event_trigger_data *data,
struct trace_event_file *file);
void (*unreg_all)(struct trace_event_file *file);
diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index 6d363fd8a1e4..191db32dec46 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -556,16 +556,16 @@ static int eprobe_trigger_cmd_parse(struct event_command *cmd_ops,
return -1;
}
-static int eprobe_trigger_reg_func(char *glob, struct event_trigger_ops *ops,
- struct event_trigger_data *data,
- struct trace_event_file *file)
+static int eprobe_trigger_reg_func(char *glob,
+ struct event_trigger_data *data,
+ struct trace_event_file *file)
{
return -1;
}
-static void eprobe_trigger_unreg_func(char *glob, struct event_trigger_ops *ops,
- struct event_trigger_data *data,
- struct trace_event_file *file)
+static void eprobe_trigger_unreg_func(char *glob,
+ struct event_trigger_data *data,
+ struct trace_event_file *file)
{
}
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 229ce5c2dfd3..5e6a988a8a51 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -5910,7 +5910,7 @@ static bool hist_trigger_match(struct event_trigger_data *data,
return true;
}
-static int hist_register_trigger(char *glob, struct event_trigger_ops *ops,
+static int hist_register_trigger(char *glob,
struct event_trigger_data *data,
struct trace_event_file *file)
{
@@ -6062,7 +6062,7 @@ static bool hist_trigger_check_refs(struct event_trigger_data *data,
return false;
}
-static void hist_unregister_trigger(char *glob, struct event_trigger_ops *ops,
+static void hist_unregister_trigger(char *glob,
struct event_trigger_data *data,
struct trace_event_file *file)
{
@@ -6262,7 +6262,7 @@ static int event_hist_trigger_parse(struct event_command *cmd_ops,
goto out_free;
}
- cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
+ cmd_ops->unreg(glob+1, trigger_data, file);
se_name = trace_event_name(file->event_call);
se = find_synth_event(se_name);
if (se)
@@ -6271,7 +6271,7 @@ static int event_hist_trigger_parse(struct event_command *cmd_ops,
goto out_free;
}
- ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
+ ret = cmd_ops->reg(glob, trigger_data, file);
/*
* The above returns on success the # of triggers registered,
* but if it didn't register any it returns zero. Consider no
@@ -6314,7 +6314,7 @@ static int event_hist_trigger_parse(struct event_command *cmd_ops,
return ret;
out_unreg:
- cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
+ cmd_ops->unreg(glob+1, trigger_data, file);
out_free:
if (cmd_ops->set_filter)
cmd_ops->set_filter(NULL, trigger_data, NULL);
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 24aceeb50dc0..d40b857db572 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -540,7 +540,6 @@ void update_cond_flag(struct trace_event_file *file)
/**
* register_trigger - Generic event_command @reg implementation
* @glob: The raw string used to register the trigger
- * @ops: The trigger ops associated with the trigger
* @data: Trigger-specific data to associate with the trigger
* @file: The trace_event_file associated with the event
*
@@ -551,7 +550,7 @@ void update_cond_flag(struct trace_event_file *file)
*
* Return: 0 on success, errno otherwise
*/
-static int register_trigger(char *glob, struct event_trigger_ops *ops,
+static int register_trigger(char *glob,
struct event_trigger_data *data,
struct trace_event_file *file)
{
@@ -589,7 +588,6 @@ static int register_trigger(char *glob, struct event_trigger_ops *ops,
/**
* unregister_trigger - Generic event_command @unreg implementation
* @glob: The raw string used to register the trigger
- * @ops: The trigger ops associated with the trigger
* @test: Trigger-specific data used to find the trigger to remove
* @file: The trace_event_file associated with the event
*
@@ -598,7 +596,7 @@ static int register_trigger(char *glob, struct event_trigger_ops *ops,
* Usually used directly as the @unreg method in event command
* implementations.
*/
-static void unregister_trigger(char *glob, struct event_trigger_ops *ops,
+static void unregister_trigger(char *glob,
struct event_trigger_data *test,
struct trace_event_file *file)
{
@@ -673,7 +671,7 @@ event_trigger_parse(struct event_command *cmd_ops,
INIT_LIST_HEAD(&trigger_data->named_list);
if (glob[0] == '!') {
- cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
+ cmd_ops->unreg(glob+1, trigger_data, file);
kfree(trigger_data);
ret = 0;
goto out;
@@ -708,14 +706,14 @@ event_trigger_parse(struct event_command *cmd_ops,
out_reg:
/* Up the trigger_data count to make sure reg doesn't free it on failure */
event_trigger_init(trigger_ops, trigger_data);
- ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
+ ret = cmd_ops->reg(glob, trigger_data, file);
/*
* The above returns on success the # of functions enabled,
* but if it didn't find any functions it returns zero.
* Consider no functions a failure too.
*/
if (!ret) {
- cmd_ops->unreg(glob, trigger_ops, trigger_data, file);
+ cmd_ops->unreg(glob, trigger_data, file);
ret = -ENOENT;
} else if (ret > 0)
ret = 0;
@@ -1116,14 +1114,14 @@ snapshot_count_trigger(struct event_trigger_data *data,
}
static int
-register_snapshot_trigger(char *glob, struct event_trigger_ops *ops,
+register_snapshot_trigger(char *glob,
struct event_trigger_data *data,
struct trace_event_file *file)
{
if (tracing_alloc_snapshot_instance(file->tr) != 0)
return 0;
- return register_trigger(glob, ops, data, file);
+ return register_trigger(glob, data, file);
}
static int
@@ -1455,7 +1453,7 @@ int event_enable_trigger_parse(struct event_command *cmd_ops,
trigger_data->private_data = enable_data;
if (glob[0] == '!') {
- cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
+ cmd_ops->unreg(glob+1, trigger_data, file);
kfree(trigger_data);
kfree(enable_data);
ret = 0;
@@ -1502,7 +1500,7 @@ int event_enable_trigger_parse(struct event_command *cmd_ops,
ret = trace_event_enable_disable(event_enable_file, 1, 1);
if (ret < 0)
goto out_put;
- ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
+ ret = cmd_ops->reg(glob, trigger_data, file);
/*
* The above returns on success the # of functions enabled,
* but if it didn't find any functions it returns zero.
@@ -1532,7 +1530,6 @@ int event_enable_trigger_parse(struct event_command *cmd_ops,
}
int event_enable_register_trigger(char *glob,
- struct event_trigger_ops *ops,
struct event_trigger_data *data,
struct trace_event_file *file)
{
@@ -1574,7 +1571,6 @@ int event_enable_register_trigger(char *glob,
}
void event_enable_unregister_trigger(char *glob,
- struct event_trigger_ops *ops,
struct event_trigger_data *test,
struct trace_event_file *file)
{
--
2.17.1
Simplify the existing event_command.parse() implementations by having
them make use of the helper functions previously introduced.
Signed-off-by: Tom Zanussi <[email protected]>
---
kernel/trace/trace.h | 3 +-
kernel/trace/trace_eprobe.c | 3 +-
kernel/trace/trace_events_hist.c | 76 +++++------
kernel/trace/trace_events_trigger.c | 192 ++++++++--------------------
4 files changed, 86 insertions(+), 188 deletions(-)
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 23c16018bb4f..fd2334771bdc 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1580,7 +1580,8 @@ extern void event_enable_trigger_free(struct event_trigger_ops *ops,
struct event_trigger_data *data);
extern int event_enable_trigger_parse(struct event_command *cmd_ops,
struct trace_event_file *file,
- char *glob, char *cmd, char *param);
+ char *glob, char *cmd,
+ char *param_and_filter);
extern int event_enable_register_trigger(char *glob,
struct event_trigger_data *data,
struct trace_event_file *file);
diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index 191db32dec46..f5c8dc1a5b5f 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -551,7 +551,8 @@ static struct event_trigger_ops eprobe_trigger_ops = {
static int eprobe_trigger_cmd_parse(struct event_command *cmd_ops,
struct trace_event_file *file,
- char *glob, char *cmd, char *param)
+ char *glob, char *cmd,
+ char *param_and_filter)
{
return -1;
}
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 5e6a988a8a51..f9f7fd9ecc3d 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -2763,7 +2763,8 @@ static char *find_trigger_filter(struct hist_trigger_data *hist_data,
static struct event_command trigger_hist_cmd;
static int event_hist_trigger_parse(struct event_command *cmd_ops,
struct trace_event_file *file,
- char *glob, char *cmd, char *param);
+ char *glob, char *cmd,
+ char *param_and_filter);
static bool compatible_keys(struct hist_trigger_data *target_hist_data,
struct hist_trigger_data *hist_data,
@@ -6148,48 +6149,48 @@ static void hist_unreg_all(struct trace_event_file *file)
static int event_hist_trigger_parse(struct event_command *cmd_ops,
struct trace_event_file *file,
- char *glob, char *cmd, char *param)
+ char *glob, char *cmd,
+ char *param_and_filter)
{
unsigned int hist_trigger_bits = TRACING_MAP_BITS_DEFAULT;
struct event_trigger_data *trigger_data;
struct hist_trigger_attrs *attrs;
- struct event_trigger_ops *trigger_ops;
struct hist_trigger_data *hist_data;
+ char *param, *filter, *p, *start;
struct synth_event *se;
const char *se_name;
- bool remove = false;
- char *trigger, *p, *start;
+ int n_registered;
+ bool remove;
int ret = 0;
lockdep_assert_held(&event_mutex);
if (glob && strlen(glob)) {
hist_err_clear();
- last_cmd_set(file, param);
+ last_cmd_set(file, param_and_filter);
}
- if (!param)
- return -EINVAL;
+ remove = event_trigger_check_remove(glob);
- if (glob[0] == '!')
- remove = true;
+ if (event_trigger_empty_param(param_and_filter))
+ return -EINVAL;
/*
* separate the trigger from the filter (k:v [if filter])
* allowing for whitespace in the trigger
*/
- p = trigger = param;
+ p = param = param_and_filter;
do {
p = strstr(p, "if");
if (!p)
break;
- if (p == param)
+ if (p == param_and_filter)
return -EINVAL;
if (*(p - 1) != ' ' && *(p - 1) != '\t') {
p++;
continue;
}
- if (p >= param + strlen(param) - (sizeof("if") - 1) - 1)
+ if (p >= param_and_filter + strlen(param_and_filter) - (sizeof("if") - 1) - 1)
return -EINVAL;
if (*(p + sizeof("if") - 1) != ' ' && *(p + sizeof("if") - 1) != '\t') {
p++;
@@ -6199,24 +6200,24 @@ static int event_hist_trigger_parse(struct event_command *cmd_ops,
} while (p);
if (!p)
- param = NULL;
+ filter = NULL;
else {
*(p - 1) = '\0';
- param = strstrip(p);
- trigger = strstrip(trigger);
+ filter = strstrip(p);
+ param = strstrip(param);
}
/*
* To simplify arithmetic expression parsing, replace occurrences of
* '.sym-offset' modifier with '.symXoffset'
*/
- start = strstr(trigger, ".sym-offset");
+ start = strstr(param, ".sym-offset");
while (start) {
*(start + 4) = 'X';
start = strstr(start + 11, ".sym-offset");
}
- attrs = parse_hist_trigger_attrs(file->tr, trigger);
+ attrs = parse_hist_trigger_attrs(file->tr, param);
if (IS_ERR(attrs))
return PTR_ERR(attrs);
@@ -6229,29 +6230,15 @@ static int event_hist_trigger_parse(struct event_command *cmd_ops,
return PTR_ERR(hist_data);
}
- trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
-
- trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
+ trigger_data = event_trigger_alloc(cmd_ops, cmd, param, hist_data);
if (!trigger_data) {
ret = -ENOMEM;
goto out_free;
}
- trigger_data->count = -1;
- trigger_data->ops = trigger_ops;
- trigger_data->cmd_ops = cmd_ops;
-
- INIT_LIST_HEAD(&trigger_data->list);
- RCU_INIT_POINTER(trigger_data->filter, NULL);
-
- trigger_data->private_data = hist_data;
-
- /* if param is non-empty, it's supposed to be a filter */
- if (param && cmd_ops->set_filter) {
- ret = cmd_ops->set_filter(param, trigger_data, file);
- if (ret < 0)
- goto out_free;
- }
+ ret = event_trigger_set_filter(cmd_ops, file, filter, trigger_data);
+ if (ret < 0)
+ goto out_free;
if (remove) {
if (!have_hist_trigger_match(trigger_data, file))
@@ -6271,18 +6258,14 @@ static int event_hist_trigger_parse(struct event_command *cmd_ops,
goto out_free;
}
- ret = cmd_ops->reg(glob, trigger_data, file);
- /*
- * The above returns on success the # of triggers registered,
- * but if it didn't register any it returns zero. Consider no
- * triggers registered a failure too.
- */
- if (!ret) {
+ ret = event_trigger_register(cmd_ops, file, glob, cmd, param, trigger_data, &n_registered);
+ if (ret)
+ goto out_free;
+ if ((ret == 0) && (n_registered == 0)) {
if (!(attrs->pause || attrs->cont || attrs->clear))
ret = -ENOENT;
goto out_free;
- } else if (ret < 0)
- goto out_free;
+ }
if (get_named_trigger_data(trigger_data))
goto enable;
@@ -6316,8 +6299,7 @@ static int event_hist_trigger_parse(struct event_command *cmd_ops,
out_unreg:
cmd_ops->unreg(glob+1, trigger_data, file);
out_free:
- if (cmd_ops->set_filter)
- cmd_ops->set_filter(NULL, trigger_data, NULL);
+ event_trigger_reset_filter(cmd_ops, trigger_data);
remove_hist_vars(hist_data);
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index d00fee705f9c..2ab5837bc141 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -967,7 +967,7 @@ int event_trigger_register(struct event_command *cmd_ops,
* @file: The trace_event_file associated with the event
* @glob: The raw string used to register the trigger
* @cmd: The cmd portion of the string used to register the trigger
- * @param: The params portion of the string used to register the trigger
+ * @param_and_filter: The param and filter portion of the string used to register the trigger
*
* Common implementation for event command parsing and trigger
* instantiation.
@@ -980,94 +980,52 @@ int event_trigger_register(struct event_command *cmd_ops,
static int
event_trigger_parse(struct event_command *cmd_ops,
struct trace_event_file *file,
- char *glob, char *cmd, char *param)
+ char *glob, char *cmd, char *param_and_filter)
{
struct event_trigger_data *trigger_data;
- struct event_trigger_ops *trigger_ops;
- char *trigger = NULL;
- char *number;
+ char *param, *filter;
+ bool remove;
int ret;
- /* separate the trigger from the filter (t:n [if filter]) */
- if (param && isdigit(param[0])) {
- trigger = strsep(¶m, " \t");
- if (param) {
- param = skip_spaces(param);
- if (!*param)
- param = NULL;
- }
- }
+ remove = event_trigger_check_remove(glob);
- trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
+ ret = event_trigger_separate_filter(param_and_filter, ¶m, &filter, false);
+ if (ret)
+ return ret;
ret = -ENOMEM;
- trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
+ trigger_data = event_trigger_alloc(cmd_ops, cmd, param, file);
if (!trigger_data)
goto out;
- trigger_data->count = -1;
- trigger_data->ops = trigger_ops;
- trigger_data->cmd_ops = cmd_ops;
- trigger_data->private_data = file;
- INIT_LIST_HEAD(&trigger_data->list);
- INIT_LIST_HEAD(&trigger_data->named_list);
-
- if (glob[0] == '!') {
+ if (remove) {
cmd_ops->unreg(glob+1, trigger_data, file);
kfree(trigger_data);
ret = 0;
goto out;
}
- if (trigger) {
- number = strsep(&trigger, ":");
-
- ret = -EINVAL;
- if (!strlen(number))
- goto out_free;
-
- /*
- * We use the callback data field (which is a pointer)
- * as our counter.
- */
- ret = kstrtoul(number, 0, &trigger_data->count);
- if (ret)
- goto out_free;
- }
-
- if (!param) /* if param is non-empty, it's supposed to be a filter */
- goto out_reg;
-
- if (!cmd_ops->set_filter)
- goto out_reg;
+ ret = event_trigger_parse_num(param, trigger_data);
+ if (ret)
+ goto out_free;
- ret = cmd_ops->set_filter(param, trigger_data, file);
+ ret = event_trigger_set_filter(cmd_ops, file, filter, trigger_data);
if (ret < 0)
goto out_free;
- out_reg:
/* Up the trigger_data count to make sure reg doesn't free it on failure */
- event_trigger_init(trigger_ops, trigger_data);
- ret = cmd_ops->reg(glob, trigger_data, file);
- /*
- * The above returns on success the # of functions enabled,
- * but if it didn't find any functions it returns zero.
- * Consider no functions a failure too.
- */
- if (!ret) {
- cmd_ops->unreg(glob, trigger_data, file);
- ret = -ENOENT;
- } else if (ret > 0)
- ret = 0;
+ event_trigger_init(trigger_data->ops, trigger_data);
+
+ ret = event_trigger_register(cmd_ops, file, glob, cmd, param, trigger_data, NULL);
+ if (ret)
+ goto out_free;
/* Down the counter of trigger_data or free it if not used anymore */
- event_trigger_free(trigger_ops, trigger_data);
+ event_trigger_free(trigger_data->ops, trigger_data);
out:
return ret;
-
out_free:
- if (cmd_ops->set_filter)
- cmd_ops->set_filter(NULL, trigger_data, NULL);
+ event_trigger_reset_filter(cmd_ops, trigger_data);
kfree(trigger_data);
goto out;
}
@@ -1722,39 +1680,33 @@ static struct event_trigger_ops event_disable_count_trigger_ops = {
int event_enable_trigger_parse(struct event_command *cmd_ops,
struct trace_event_file *file,
- char *glob, char *cmd, char *param)
+ char *glob, char *cmd, char *param_and_filter)
{
struct trace_event_file *event_enable_file;
struct enable_trigger_data *enable_data;
struct event_trigger_data *trigger_data;
- struct event_trigger_ops *trigger_ops;
struct trace_array *tr = file->tr;
+ char *param, *filter;
+ bool enable, remove;
const char *system;
const char *event;
bool hist = false;
- char *trigger;
- char *number;
- bool enable;
int ret;
- if (!param)
- return -EINVAL;
+ remove = event_trigger_check_remove(glob);
- /* separate the trigger from the filter (s:e:n [if filter]) */
- trigger = strsep(¶m, " \t");
- if (!trigger)
+ if (event_trigger_empty_param(param_and_filter))
return -EINVAL;
- if (param) {
- param = skip_spaces(param);
- if (!*param)
- param = NULL;
- }
- system = strsep(&trigger, ":");
- if (!trigger)
+ ret = event_trigger_separate_filter(param_and_filter, ¶m, &filter, true);
+ if (ret)
+ return ret;
+
+ system = strsep(¶m, ":");
+ if (!param)
return -EINVAL;
- event = strsep(&trigger, ":");
+ event = strsep(¶m, ":");
ret = -EINVAL;
event_enable_file = find_event_file(tr, system, event);
@@ -1770,31 +1722,22 @@ int event_enable_trigger_parse(struct event_command *cmd_ops,
#else
enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
#endif
- trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
-
ret = -ENOMEM;
- trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
- if (!trigger_data)
- goto out;
-
enable_data = kzalloc(sizeof(*enable_data), GFP_KERNEL);
- if (!enable_data) {
- kfree(trigger_data);
+ if (!enable_data)
goto out;
- }
-
- trigger_data->count = -1;
- trigger_data->ops = trigger_ops;
- trigger_data->cmd_ops = cmd_ops;
- INIT_LIST_HEAD(&trigger_data->list);
- RCU_INIT_POINTER(trigger_data->filter, NULL);
enable_data->hist = hist;
enable_data->enable = enable;
enable_data->file = event_enable_file;
- trigger_data->private_data = enable_data;
- if (glob[0] == '!') {
+ trigger_data = event_trigger_alloc(cmd_ops, cmd, param, enable_data);
+ if (!trigger_data) {
+ kfree(enable_data);
+ goto out;
+ }
+
+ if (remove) {
cmd_ops->unreg(glob+1, trigger_data, file);
kfree(trigger_data);
kfree(enable_data);
@@ -1803,35 +1746,16 @@ int event_enable_trigger_parse(struct event_command *cmd_ops,
}
/* Up the trigger_data count to make sure nothing frees it on failure */
- event_trigger_init(trigger_ops, trigger_data);
-
- if (trigger) {
- number = strsep(&trigger, ":");
+ event_trigger_init(trigger_data->ops, trigger_data);
- ret = -EINVAL;
- if (!strlen(number))
- goto out_free;
-
- /*
- * We use the callback data field (which is a pointer)
- * as our counter.
- */
- ret = kstrtoul(number, 0, &trigger_data->count);
- if (ret)
- goto out_free;
- }
-
- if (!param) /* if param is non-empty, it's supposed to be a filter */
- goto out_reg;
-
- if (!cmd_ops->set_filter)
- goto out_reg;
+ ret = event_trigger_parse_num(param, trigger_data);
+ if (ret)
+ goto out_free;
- ret = cmd_ops->set_filter(param, trigger_data, file);
+ ret = event_trigger_set_filter(cmd_ops, file, filter, trigger_data);
if (ret < 0)
goto out_free;
- out_reg:
/* Don't let event modules unload while probe registered */
ret = trace_event_try_get_ref(event_enable_file->event_call);
if (!ret) {
@@ -1842,31 +1766,21 @@ int event_enable_trigger_parse(struct event_command *cmd_ops,
ret = trace_event_enable_disable(event_enable_file, 1, 1);
if (ret < 0)
goto out_put;
- ret = cmd_ops->reg(glob, trigger_data, file);
- /*
- * The above returns on success the # of functions enabled,
- * but if it didn't find any functions it returns zero.
- * Consider no functions a failure too.
- */
- if (!ret) {
- ret = -ENOENT;
- goto out_disable;
- } else if (ret < 0)
+
+ ret = event_trigger_register(cmd_ops, file, glob, cmd, param, trigger_data, NULL);
+ if (ret)
goto out_disable;
- /* Just return zero, not the number of enabled functions */
- ret = 0;
- event_trigger_free(trigger_ops, trigger_data);
+
+ event_trigger_free(trigger_data->ops, trigger_data);
out:
return ret;
-
out_disable:
trace_event_enable_disable(event_enable_file, 0, 1);
out_put:
trace_event_put_ref(event_enable_file->event_call);
out_free:
- if (cmd_ops->set_filter)
- cmd_ops->set_filter(NULL, trigger_data, NULL);
- event_trigger_free(trigger_ops, trigger_data);
+ event_trigger_reset_filter(cmd_ops, trigger_data);
+ event_trigger_free(trigger_data->ops, trigger_data);
kfree(enable_data);
goto out;
}
--
2.17.1
The event_command.parse() callback is responsible for parsing and
registering triggers. The existing command implementions for this
callback duplicate a lot of the same code, so to clean up and
consolidate those implementations, introduce a handful of helper
functions for implementors to use.
This also makes it easier for new commands to be implemented and
allows them to focus more on the customizations they provide rather
than obscuring and complicating it with boilerplate code.
Signed-off-by: Tom Zanussi <[email protected]>
---
kernel/trace/trace.h | 24 ++
kernel/trace/trace_events_trigger.c | 342 ++++++++++++++++++++++++++++
2 files changed, 366 insertions(+)
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 7d981af10b8f..23c16018bb4f 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1610,6 +1610,30 @@ get_named_trigger_data(struct event_trigger_data *data);
extern int register_event_command(struct event_command *cmd);
extern int unregister_event_command(struct event_command *cmd);
extern int register_trigger_hist_enable_disable_cmds(void);
+extern bool event_trigger_check_remove(const char *glob);
+extern bool event_trigger_empty_param(const char *param);
+extern int event_trigger_separate_filter(char *param_and_filter, char **param,
+ char **filter, bool param_required);
+extern struct event_trigger_data *
+event_trigger_alloc(struct event_command *cmd_ops,
+ char *cmd,
+ char *param,
+ void *private_data);
+extern int event_trigger_parse_num(char *trigger,
+ struct event_trigger_data *trigger_data);
+extern int event_trigger_set_filter(struct event_command *cmd_ops,
+ struct trace_event_file *file,
+ char *param,
+ struct event_trigger_data *trigger_data);
+extern void event_trigger_reset_filter(struct event_command *cmd_ops,
+ struct event_trigger_data *trigger_data);
+extern int event_trigger_register(struct event_command *cmd_ops,
+ struct trace_event_file *file,
+ char *glob,
+ char *cmd,
+ char *trigger,
+ struct event_trigger_data *trigger_data,
+ int *n_registered);
/**
* struct event_trigger_ops - callbacks for trace event triggers
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index d40b857db572..d00fee705f9c 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -619,6 +619,348 @@ static void unregister_trigger(char *glob,
data->ops->free(data->ops, data);
}
+/*
+ * Event trigger parsing helper functions.
+ *
+ * These functions help make it easier to write an event trigger
+ * parsing function i.e. the struct event_command.parse() callback
+ * function responsible for parsing and registering a trigger command
+ * written to the 'trigger' file.
+ *
+ * A trigger command (or just 'trigger' for short) takes the form:
+ * [trigger] [if filter]
+ *
+ * The struct event_command.parse() callback (and other struct
+ * event_command functions) refer to several components of a trigger
+ * command. Those same components are referenced by the event trigger
+ * parsing helper functions defined below. These components are:
+ *
+ * cmd - the trigger command name
+ * glob - the trigger command name optionally prefaced with '!'
+ * param_and_filter - text following cmd and ':'
+ * param - text following cmd and ':' and stripped of filter
+ * filter - the optional filter text following (and including) 'if'
+ *
+ * To illustrate the use of these componenents, here are some concrete
+ * examples. For the following triggers:
+ *
+ * echo 'traceon:5 if pid == 0' > trigger
+ * - 'traceon' is both cmd and glob
+ * - '5 if pid == 0' is the param_and_filter
+ * - '5' is the param
+ * - 'if pid == 0' is the filter
+ *
+ * echo 'enable_event:sys:event:n' > trigger
+ * - 'enable_event' is both cmd and glob
+ * - 'sys:event:n' is the param_and_filter
+ * - 'sys:event:n' is the param
+ * - there is no filter
+ *
+ * echo 'hist:keys=pid if prio > 50' > trigger
+ * - 'hist' is both cmd and glob
+ * - 'keys=pid if prio > 50' is the param_and_filter
+ * - 'keys=pid' is the param
+ * - 'if prio > 50' is the filter
+ *
+ * echo '!enable_event:sys:event:n' > trigger
+ * - 'enable_event' the cmd
+ * - '!enable_event' is the glob
+ * - 'sys:event:n' is the param_and_filter
+ * - 'sys:event:n' is the param
+ * - there is no filter
+ *
+ * echo 'traceoff' > trigger
+ * - 'traceoff' is both cmd and glob
+ * - there is no param_and_filter
+ * - there is no param
+ * - there is no filter
+ *
+ * There are a few different categories of event trigger covered by
+ * these helpers:
+ *
+ * - triggers that don't require a parameter e.g. traceon
+ * - triggers that do require a parameter e.g. enable_event and hist
+ * - triggers that though they may not require a param may support an
+ * optional 'n' param (n = number of times the trigger should fire)
+ * e.g.: traceon:5 or enable_event:sys:event:n
+ * - triggers that do not support an 'n' param e.g. hist
+ *
+ * These functions can be used or ignored as necessary - it all
+ * depends on the complexity of the trigger, and the granularity of
+ * the functions supported reflects the fact that some implementations
+ * may need to customize certain aspects of their implementations and
+ * won't need certain functions. For instance, the hist trigger
+ * implementation doesn't use event_trigger_separate_filter() because
+ * it has special requirements for handling the filter.
+ */
+
+/**
+ * event_trigger_check_remove - check whether an event trigger specifies remove
+ * @glob: The trigger command string, with optional remove(!) operator
+ *
+ * The event trigger callback implementations pass in 'glob' as a
+ * parameter. This is the command name either with or without a
+ * remove(!) operator. This function simply parses the glob and
+ * determines whether the command corresponds to a trigger removal or
+ * a trigger addition.
+ *
+ * Return: true if this is a remove command, false otherwise
+ */
+bool event_trigger_check_remove(const char *glob)
+{
+ return (glob && glob[0] == '!') ? true : false;
+}
+
+/**
+ * event_trigger_empty_param - check whether the param is empty
+ * @param: The trigger param string
+ *
+ * The event trigger callback implementations pass in 'param' as a
+ * parameter. This corresponds to the string following the command
+ * name minus the command name. This function can be called by a
+ * callback implementation for any command that requires a param; a
+ * callback that doesn't require a param can ignore it.
+ *
+ * Return: true if this is an empty param, false otherwise
+ */
+bool event_trigger_empty_param(const char *param)
+{
+ return !param;
+}
+
+/**
+ * event_trigger_separate_filter - separate an event trigger from a filter
+ * @param: The param string containing trigger and possibly filter
+ * @trigger: outparam, will be filled with a pointer to the trigger
+ * @filter: outparam, will be filled with a pointer to the filter
+ * @param_required: Specifies whether or not the param string is required
+ *
+ * Given a param string of the form '[trigger] [if filter]', this
+ * function separates the filter from the trigger and returns the
+ * trigger in *trigger and the filter in *filter. Either the *trigger
+ * or the *filter may be set to NULL by this function - if not set to
+ * NULL, they will contain strings corresponding to the trigger and
+ * filter.
+ *
+ * There are two cases that need to be handled with respect to the
+ * passed-in param: either the param is required, or it is not
+ * required. If @param_required is set, and there's no param, it will
+ * return -EINVAL. If @param_required is not set and there's a param
+ * that starts with a number, that corresponds to the case of a
+ * trigger with :n (n = number of times the trigger should fire) and
+ * the parsing continues normally; otherwise the function just returns
+ * and assumes param just contains a filter and there's nothing else
+ * to do.
+ *
+ * Return: 0 on success, errno otherwise
+ */
+int event_trigger_separate_filter(char *param_and_filter, char **param,
+ char **filter, bool param_required)
+{
+ int ret = 0;
+
+ *param = *filter = NULL;
+
+ if (!param_and_filter) {
+ if (param_required)
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /*
+ * Here we check for an optional param. The only legal
+ * optional param is :n, and if that's the case, continue
+ * below. Otherwise we assume what's left is a filter and
+ * return it as the filter string for the caller to deal with.
+ */
+ if (!param_required && param_and_filter && !isdigit(param_and_filter[0])) {
+ *filter = param_and_filter;
+ goto out;
+ }
+
+ /*
+ * Separate the param from the filter (param [if filter]).
+ * Here we have either an optional :n param or a required
+ * param and an optional filter.
+ */
+ *param = strsep(¶m_and_filter, " \t");
+
+ /*
+ * Here we have a filter, though it may be empty.
+ */
+ if (param_and_filter) {
+ *filter = skip_spaces(param_and_filter);
+ if (!**filter)
+ *filter = NULL;
+ }
+out:
+ return ret;
+}
+
+/**
+ * event_trigger_alloc - allocate and init event_trigger_data for a trigger
+ * @cmd_ops: The event_command operations for the trigger
+ * @cmd: The cmd string
+ * @param: The param string
+ * @private_data: User data to associate with the event trigger
+ *
+ * Allocate an event_trigger_data instance and initialize it. The
+ * @cmd_ops are used along with the @cmd and @param to get the
+ * trigger_ops to assign to the event_trigger_data. @private_data can
+ * also be passed in and associated with the event_trigger_data.
+ *
+ * Use event_trigger_free() to free an event_trigger_data object.
+ *
+ * Return: The trigger_data object success, NULL otherwise
+ */
+struct event_trigger_data *event_trigger_alloc(struct event_command *cmd_ops,
+ char *cmd,
+ char *param,
+ void *private_data)
+{
+ struct event_trigger_data *trigger_data;
+ struct event_trigger_ops *trigger_ops;
+
+ trigger_ops = cmd_ops->get_trigger_ops(cmd, param);
+
+ trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
+ if (!trigger_data)
+ return NULL;
+
+ trigger_data->count = -1;
+ trigger_data->ops = trigger_ops;
+ trigger_data->cmd_ops = cmd_ops;
+ trigger_data->private_data = private_data;
+
+ INIT_LIST_HEAD(&trigger_data->list);
+ INIT_LIST_HEAD(&trigger_data->named_list);
+ RCU_INIT_POINTER(trigger_data->filter, NULL);
+
+ return trigger_data;
+}
+
+/**
+ * event_trigger_parse_num - parse and return the number param for a trigger
+ * @param: The param string
+ * @trigger_data: The trigger_data for the trigger
+ *
+ * Parse the :n (n = number of times the trigger should fire) param
+ * and set the count variable in the trigger_data to the parsed count.
+ *
+ * Return: 0 on success, errno otherwise
+ */
+int event_trigger_parse_num(char *param,
+ struct event_trigger_data *trigger_data)
+{
+ char *number;
+ int ret = 0;
+
+ if (param) {
+ number = strsep(¶m, ":");
+
+ if (!strlen(number))
+ return -EINVAL;
+
+ /*
+ * We use the callback data field (which is a pointer)
+ * as our counter.
+ */
+ ret = kstrtoul(number, 0, &trigger_data->count);
+ }
+
+ return ret;
+}
+
+/**
+ * event_trigger_set_filter - set an event trigger's filter
+ * @cmd_ops: The event_command operations for the trigger
+ * @file: The event file for the trigger's event
+ * @param: The string containing the filter
+ * @trigger_data: The trigger_data for the trigger
+ *
+ * Set the filter for the trigger. If the filter is NULL, just return
+ * without error.
+ *
+ * Return: 0 on success, errno otherwise
+ */
+int event_trigger_set_filter(struct event_command *cmd_ops,
+ struct trace_event_file *file,
+ char *param,
+ struct event_trigger_data *trigger_data)
+{
+ if (param && cmd_ops->set_filter)
+ return cmd_ops->set_filter(param, trigger_data, file);
+
+ return 0;
+}
+
+/**
+ * event_trigger_reset_filter - reset an event trigger's filter
+ * @cmd_ops: The event_command operations for the trigger
+ * @trigger_data: The trigger_data for the trigger
+ *
+ * Reset the filter for the trigger to no filter.
+ */
+void event_trigger_reset_filter(struct event_command *cmd_ops,
+ struct event_trigger_data *trigger_data)
+{
+ if (cmd_ops->set_filter)
+ cmd_ops->set_filter(NULL, trigger_data, NULL);
+}
+
+/**
+ * event_trigger_register - register an event trigger
+ * @cmd_ops: The event_command operations for the trigger
+ * @file: The event file for the trigger's event
+ * @glob: The trigger command string, with optional remove(!) operator
+ * @cmd: The cmd string
+ * @param: The param string
+ * @trigger_data: The trigger_data for the trigger
+ * @n_registered: optional outparam, the number of triggers registered
+ *
+ * Register an event trigger. The @cmd_ops are used to call the
+ * cmd_ops->reg() function which actually does the registration. The
+ * cmd_ops->reg() function returns the number of triggers registered,
+ * which is assigned to n_registered, if n_registered is non-NULL.
+ *
+ * Return: 0 on success, errno otherwise
+ */
+int event_trigger_register(struct event_command *cmd_ops,
+ struct trace_event_file *file,
+ char *glob,
+ char *cmd,
+ char *param,
+ struct event_trigger_data *trigger_data,
+ int *n_registered)
+{
+ int ret;
+
+ if (n_registered)
+ *n_registered = 0;
+
+ ret = cmd_ops->reg(glob, trigger_data, file);
+ /*
+ * The above returns on success the # of functions enabled,
+ * but if it didn't find any functions it returns zero.
+ * Consider no functions a failure too.
+ */
+ if (!ret) {
+ cmd_ops->unreg(glob, trigger_data, file);
+ ret = -ENOENT;
+ } else if (ret > 0) {
+ if (n_registered)
+ *n_registered = ret;
+ /* Just return zero, not the number of enabled functions */
+ ret = 0;
+ }
+
+ return ret;
+}
+
+/*
+ * End event trigger parsing helper functions.
+ */
+
/**
* event_trigger_parse - Generic event_command @parse implementation
* @cmd_ops: The command ops, used for trigger registration
--
2.17.1
Since event_trigger_data contains the .ops trigger_ops field, there's
no reason to pass the trigger_ops separately. Remove it as a param
from functions whenever event_trigger_data is passed.
Signed-off-by: Tom Zanussi <[email protected]>
---
kernel/trace/trace.h | 14 +++------
kernel/trace/trace_eprobe.c | 7 ++---
kernel/trace/trace_events_hist.c | 29 ++++++++----------
kernel/trace/trace_events_trigger.c | 46 +++++++++++------------------
4 files changed, 36 insertions(+), 60 deletions(-)
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index fd2334771bdc..8072f57331dc 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1574,10 +1574,8 @@ struct enable_trigger_data {
};
extern int event_enable_trigger_print(struct seq_file *m,
- struct event_trigger_ops *ops,
- struct event_trigger_data *data);
-extern void event_enable_trigger_free(struct event_trigger_ops *ops,
struct event_trigger_data *data);
+extern void event_enable_trigger_free(struct event_trigger_data *data);
extern int event_enable_trigger_parse(struct event_command *cmd_ops,
struct trace_event_file *file,
char *glob, char *cmd,
@@ -1589,8 +1587,7 @@ extern void event_enable_unregister_trigger(char *glob,
struct event_trigger_data *test,
struct trace_event_file *file);
extern void trigger_data_free(struct event_trigger_data *data);
-extern int event_trigger_init(struct event_trigger_ops *ops,
- struct event_trigger_data *data);
+extern int event_trigger_init(struct event_trigger_data *data);
extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
int trigger_enable);
extern void update_cond_flag(struct trace_event_file *file);
@@ -1688,12 +1685,9 @@ struct event_trigger_ops {
struct trace_buffer *buffer,
void *rec,
struct ring_buffer_event *rbe);
- int (*init)(struct event_trigger_ops *ops,
- struct event_trigger_data *data);
- void (*free)(struct event_trigger_ops *ops,
- struct event_trigger_data *data);
+ int (*init)(struct event_trigger_data *data);
+ void (*free)(struct event_trigger_data *data);
int (*print)(struct seq_file *m,
- struct event_trigger_ops *ops,
struct event_trigger_data *data);
};
diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index f5c8dc1a5b5f..f8270214ee96 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -513,20 +513,17 @@ __eprobe_trace_func(struct eprobe_data *edata, void *rec)
* functions are just stubs to fulfill what is needed to use the trigger
* infrastructure.
*/
-static int eprobe_trigger_init(struct event_trigger_ops *ops,
- struct event_trigger_data *data)
+static int eprobe_trigger_init(struct event_trigger_data *data)
{
return 0;
}
-static void eprobe_trigger_free(struct event_trigger_ops *ops,
- struct event_trigger_data *data)
+static void eprobe_trigger_free(struct event_trigger_data *data)
{
}
static int eprobe_trigger_print(struct seq_file *m,
- struct event_trigger_ops *ops,
struct event_trigger_data *data)
{
/* Do not print eprobe event triggers */
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index f9f7fd9ecc3d..19d938e15dd4 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -5230,7 +5230,7 @@ static void hist_trigger_show(struct seq_file *m,
seq_puts(m, "\n\n");
seq_puts(m, "# event histogram\n#\n# trigger info: ");
- data->ops->print(m, data->ops, data);
+ data->ops->print(m, data);
seq_puts(m, "#\n\n");
hist_data = data->private_data;
@@ -5462,7 +5462,7 @@ static void hist_trigger_debug_show(struct seq_file *m,
seq_puts(m, "\n\n");
seq_puts(m, "# event histogram\n#\n# trigger info: ");
- data->ops->print(m, data->ops, data);
+ data->ops->print(m, data);
seq_puts(m, "#\n\n");
hist_data = data->private_data;
@@ -5599,7 +5599,6 @@ static void hist_field_print(struct seq_file *m, struct hist_field *hist_field)
}
static int event_hist_trigger_print(struct seq_file *m,
- struct event_trigger_ops *ops,
struct event_trigger_data *data)
{
struct hist_trigger_data *hist_data = data->private_data;
@@ -5707,8 +5706,7 @@ static int event_hist_trigger_print(struct seq_file *m,
return 0;
}
-static int event_hist_trigger_init(struct event_trigger_ops *ops,
- struct event_trigger_data *data)
+static int event_hist_trigger_init(struct event_trigger_data *data)
{
struct hist_trigger_data *hist_data = data->private_data;
@@ -5736,8 +5734,7 @@ static void unregister_field_var_hists(struct hist_trigger_data *hist_data)
}
}
-static void event_hist_trigger_free(struct event_trigger_ops *ops,
- struct event_trigger_data *data)
+static void event_hist_trigger_free(struct event_trigger_data *data)
{
struct hist_trigger_data *hist_data = data->private_data;
@@ -5766,25 +5763,23 @@ static struct event_trigger_ops event_hist_trigger_ops = {
.free = event_hist_trigger_free,
};
-static int event_hist_trigger_named_init(struct event_trigger_ops *ops,
- struct event_trigger_data *data)
+static int event_hist_trigger_named_init(struct event_trigger_data *data)
{
data->ref++;
save_named_trigger(data->named_data->name, data);
- event_hist_trigger_init(ops, data->named_data);
+ event_hist_trigger_init(data->named_data);
return 0;
}
-static void event_hist_trigger_named_free(struct event_trigger_ops *ops,
- struct event_trigger_data *data)
+static void event_hist_trigger_named_free(struct event_trigger_data *data)
{
if (WARN_ON_ONCE(data->ref <= 0))
return;
- event_hist_trigger_free(ops, data->named_data);
+ event_hist_trigger_free(data->named_data);
data->ref--;
if (!data->ref) {
@@ -5971,7 +5966,7 @@ static int hist_register_trigger(char *glob,
}
if (data->ops->init) {
- ret = data->ops->init(data->ops, data);
+ ret = data->ops->init(data);
if (ret < 0)
goto out;
}
@@ -6089,7 +6084,7 @@ static void hist_unregister_trigger(char *glob,
}
if (unregistered && test->ops->free)
- test->ops->free(test->ops, test);
+ test->ops->free(test);
if (hist_data->enable_timestamps) {
if (!hist_data->remove || unregistered)
@@ -6142,7 +6137,7 @@ static void hist_unreg_all(struct trace_event_file *file)
if (hist_data->enable_timestamps)
tracing_set_filter_buffering(file->tr, false);
if (test->ops->free)
- test->ops->free(test->ops, test);
+ test->ops->free(test);
}
}
}
@@ -6420,7 +6415,7 @@ static void hist_enable_unreg_all(struct trace_event_file *file)
update_cond_flag(file);
trace_event_trigger_enable_disable(file, 0);
if (test->ops->free)
- test->ops->free(test->ops, test);
+ test->ops->free(test);
}
}
}
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 2ab5837bc141..2a51db416cee 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -174,7 +174,7 @@ static int trigger_show(struct seq_file *m, void *v)
}
data = list_entry(v, struct event_trigger_data, list);
- data->ops->print(m, data->ops, data);
+ data->ops->print(m, data);
return 0;
}
@@ -418,7 +418,6 @@ event_trigger_print(const char *name, struct seq_file *m,
/**
* event_trigger_init - Generic event_trigger_ops @init implementation
- * @ops: The trigger ops associated with the trigger
* @data: Trigger-specific data
*
* Common implementation of event trigger initialization.
@@ -428,8 +427,7 @@ event_trigger_print(const char *name, struct seq_file *m,
*
* Return: 0 on success, errno otherwise
*/
-int event_trigger_init(struct event_trigger_ops *ops,
- struct event_trigger_data *data)
+int event_trigger_init(struct event_trigger_data *data)
{
data->ref++;
return 0;
@@ -437,7 +435,6 @@ int event_trigger_init(struct event_trigger_ops *ops,
/**
* event_trigger_free - Generic event_trigger_ops @free implementation
- * @ops: The trigger ops associated with the trigger
* @data: Trigger-specific data
*
* Common implementation of event trigger de-initialization.
@@ -446,8 +443,7 @@ int event_trigger_init(struct event_trigger_ops *ops,
* implementations.
*/
static void
-event_trigger_free(struct event_trigger_ops *ops,
- struct event_trigger_data *data)
+event_trigger_free(struct event_trigger_data *data)
{
if (WARN_ON_ONCE(data->ref <= 0))
return;
@@ -501,7 +497,7 @@ clear_event_triggers(struct trace_array *tr)
trace_event_trigger_enable_disable(file, 0);
list_del_rcu(&data->list);
if (data->ops->free)
- data->ops->free(data->ops, data);
+ data->ops->free(data);
}
}
}
@@ -567,7 +563,7 @@ static int register_trigger(char *glob,
}
if (data->ops->init) {
- ret = data->ops->init(data->ops, data);
+ ret = data->ops->init(data);
if (ret < 0)
goto out;
}
@@ -616,7 +612,7 @@ static void unregister_trigger(char *glob,
}
if (unregistered && data->ops->free)
- data->ops->free(data->ops, data);
+ data->ops->free(data);
}
/*
@@ -1014,14 +1010,14 @@ event_trigger_parse(struct event_command *cmd_ops,
goto out_free;
/* Up the trigger_data count to make sure reg doesn't free it on failure */
- event_trigger_init(trigger_data->ops, trigger_data);
+ event_trigger_init(trigger_data);
ret = event_trigger_register(cmd_ops, file, glob, cmd, param, trigger_data, NULL);
if (ret)
goto out_free;
/* Down the counter of trigger_data or free it if not used anymore */
- event_trigger_free(trigger_data->ops, trigger_data);
+ event_trigger_free(trigger_data);
out:
return ret;
out_free:
@@ -1305,16 +1301,14 @@ traceoff_count_trigger(struct event_trigger_data *data,
}
static int
-traceon_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
- struct event_trigger_data *data)
+traceon_trigger_print(struct seq_file *m, struct event_trigger_data *data)
{
return event_trigger_print("traceon", m, (void *)data->count,
data->filter_str);
}
static int
-traceoff_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
- struct event_trigger_data *data)
+traceoff_trigger_print(struct seq_file *m, struct event_trigger_data *data)
{
return event_trigger_print("traceoff", m, (void *)data->count,
data->filter_str);
@@ -1425,8 +1419,7 @@ register_snapshot_trigger(char *glob,
}
static int
-snapshot_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
- struct event_trigger_data *data)
+snapshot_trigger_print(struct seq_file *m, struct event_trigger_data *data)
{
return event_trigger_print("snapshot", m, (void *)data->count,
data->filter_str);
@@ -1516,8 +1509,7 @@ stacktrace_count_trigger(struct event_trigger_data *data,
}
static int
-stacktrace_trigger_print(struct seq_file *m, struct event_trigger_ops *ops,
- struct event_trigger_data *data)
+stacktrace_trigger_print(struct seq_file *m, struct event_trigger_data *data)
{
return event_trigger_print("stacktrace", m, (void *)data->count,
data->filter_str);
@@ -1607,7 +1599,6 @@ event_enable_count_trigger(struct event_trigger_data *data,
}
int event_enable_trigger_print(struct seq_file *m,
- struct event_trigger_ops *ops,
struct event_trigger_data *data)
{
struct enable_trigger_data *enable_data = data->private_data;
@@ -1632,8 +1623,7 @@ int event_enable_trigger_print(struct seq_file *m,
return 0;
}
-void event_enable_trigger_free(struct event_trigger_ops *ops,
- struct event_trigger_data *data)
+void event_enable_trigger_free(struct event_trigger_data *data)
{
struct enable_trigger_data *enable_data = data->private_data;
@@ -1746,7 +1736,7 @@ int event_enable_trigger_parse(struct event_command *cmd_ops,
}
/* Up the trigger_data count to make sure nothing frees it on failure */
- event_trigger_init(trigger_data->ops, trigger_data);
+ event_trigger_init(trigger_data);
ret = event_trigger_parse_num(param, trigger_data);
if (ret)
@@ -1771,7 +1761,7 @@ int event_enable_trigger_parse(struct event_command *cmd_ops,
if (ret)
goto out_disable;
- event_trigger_free(trigger_data->ops, trigger_data);
+ event_trigger_free(trigger_data);
out:
return ret;
out_disable:
@@ -1780,7 +1770,7 @@ int event_enable_trigger_parse(struct event_command *cmd_ops,
trace_event_put_ref(event_enable_file->event_call);
out_free:
event_trigger_reset_filter(cmd_ops, trigger_data);
- event_trigger_free(trigger_data->ops, trigger_data);
+ event_trigger_free(trigger_data);
kfree(enable_data);
goto out;
}
@@ -1808,7 +1798,7 @@ int event_enable_register_trigger(char *glob,
}
if (data->ops->init) {
- ret = data->ops->init(data->ops, data);
+ ret = data->ops->init(data);
if (ret < 0)
goto out;
}
@@ -1852,7 +1842,7 @@ void event_enable_unregister_trigger(char *glob,
}
if (unregistered && data->ops->free)
- data->ops->free(data->ops, data);
+ data->ops->free(data);
}
static struct event_trigger_ops *
--
2.17.1