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-rw-r--r--include/linux/ftrace_event.h9
-rw-r--r--include/trace/ftrace.h48
-rw-r--r--kernel/trace/trace.h5
-rw-r--r--kernel/trace/trace_events_filter.c12
-rw-r--r--kernel/trace/trace_events_trigger.c170
-rw-r--r--kernel/trace/trace_syscalls.c46
6 files changed, 263 insertions, 27 deletions
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 2f73c3988fc7..03d2db22ad0d 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -1,3 +1,4 @@
+
#ifndef _LINUX_FTRACE_EVENT_H
#define _LINUX_FTRACE_EVENT_H
@@ -265,6 +266,7 @@ enum {
FTRACE_EVENT_FL_SOFT_MODE_BIT,
FTRACE_EVENT_FL_SOFT_DISABLED_BIT,
FTRACE_EVENT_FL_TRIGGER_MODE_BIT,
+ FTRACE_EVENT_FL_TRIGGER_COND_BIT,
};
/*
@@ -277,6 +279,7 @@ enum {
* SOFT_DISABLED - When set, do not trace the event (even though its
* tracepoint may be enabled)
* TRIGGER_MODE - When set, invoke the triggers associated with the event
+ * TRIGGER_COND - When set, one or more triggers has an associated filter
*/
enum {
FTRACE_EVENT_FL_ENABLED = (1 << FTRACE_EVENT_FL_ENABLED_BIT),
@@ -286,6 +289,7 @@ enum {
FTRACE_EVENT_FL_SOFT_MODE = (1 << FTRACE_EVENT_FL_SOFT_MODE_BIT),
FTRACE_EVENT_FL_SOFT_DISABLED = (1 << FTRACE_EVENT_FL_SOFT_DISABLED_BIT),
FTRACE_EVENT_FL_TRIGGER_MODE = (1 << FTRACE_EVENT_FL_TRIGGER_MODE_BIT),
+ FTRACE_EVENT_FL_TRIGGER_COND = (1 << FTRACE_EVENT_FL_TRIGGER_COND_BIT),
};
struct ftrace_event_file {
@@ -361,7 +365,10 @@ extern int filter_check_discard(struct ftrace_event_file *file, void *rec,
extern int call_filter_check_discard(struct ftrace_event_call *call, void *rec,
struct ring_buffer *buffer,
struct ring_buffer_event *event);
-extern void event_triggers_call(struct ftrace_event_file *file);
+extern enum event_trigger_type event_triggers_call(struct ftrace_event_file *file,
+ void *rec);
+extern void event_triggers_post_call(struct ftrace_event_file *file,
+ enum event_trigger_type tt);
enum {
FILTER_OTHER = 0,
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 0a48bff964bd..0962968b8b37 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -418,6 +418,8 @@ static inline notrace int ftrace_get_offsets_##call( \
* struct ftrace_event_file *ftrace_file = __data;
* struct ftrace_event_call *event_call = ftrace_file->event_call;
* struct ftrace_data_offsets_<call> __maybe_unused __data_offsets;
+ * unsigned long eflags = ftrace_file->flags;
+ * enum event_trigger_type __tt = ETT_NONE;
* struct ring_buffer_event *event;
* struct ftrace_raw_<call> *entry; <-- defined in stage 1
* struct ring_buffer *buffer;
@@ -425,9 +427,12 @@ static inline notrace int ftrace_get_offsets_##call( \
* int __data_size;
* int pc;
*
- * if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT,
- * &ftrace_file->flags))
- * return;
+ * if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
+ * if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
+ * event_triggers_call(ftrace_file, NULL);
+ * if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
+ * return;
+ * }
*
* local_save_flags(irq_flags);
* pc = preempt_count();
@@ -445,8 +450,17 @@ static inline notrace int ftrace_get_offsets_##call( \
* { <assign>; } <-- Here we assign the entries by the __field and
* __array macros.
*
- * if (!filter_check_discard(ftrace_file, entry, buffer, event))
+ * if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
+ * __tt = event_triggers_call(ftrace_file, entry);
+ *
+ * if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT,
+ * &ftrace_file->flags))
+ * ring_buffer_discard_commit(buffer, event);
+ * else if (!filter_check_discard(ftrace_file, entry, buffer, event))
* trace_buffer_unlock_commit(buffer, event, irq_flags, pc);
+ *
+ * if (__tt)
+ * event_triggers_post_call(ftrace_file, __tt);
* }
*
* static struct trace_event ftrace_event_type_<call> = {
@@ -532,6 +546,8 @@ ftrace_raw_event_##call(void *__data, proto) \
struct ftrace_event_file *ftrace_file = __data; \
struct ftrace_event_call *event_call = ftrace_file->event_call; \
struct ftrace_data_offsets_##call __maybe_unused __data_offsets;\
+ unsigned long eflags = ftrace_file->flags; \
+ enum event_trigger_type __tt = ETT_NONE; \
struct ring_buffer_event *event; \
struct ftrace_raw_##call *entry; \
struct ring_buffer *buffer; \
@@ -539,13 +555,12 @@ ftrace_raw_event_##call(void *__data, proto) \
int __data_size; \
int pc; \
\
- if (test_bit(FTRACE_EVENT_FL_TRIGGER_MODE_BIT, \
- &ftrace_file->flags)) \
- event_triggers_call(ftrace_file); \
- \
- if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, \
- &ftrace_file->flags)) \
- return; \
+ if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) { \
+ if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE) \
+ event_triggers_call(ftrace_file, NULL); \
+ if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED) \
+ return; \
+ } \
\
local_save_flags(irq_flags); \
pc = preempt_count(); \
@@ -564,8 +579,17 @@ ftrace_raw_event_##call(void *__data, proto) \
\
{ assign; } \
\
- if (!filter_check_discard(ftrace_file, entry, buffer, event)) \
+ if (eflags & FTRACE_EVENT_FL_TRIGGER_COND) \
+ __tt = event_triggers_call(ftrace_file, entry); \
+ \
+ if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, \
+ &ftrace_file->flags)) \
+ ring_buffer_discard_commit(buffer, event); \
+ else if (!filter_check_discard(ftrace_file, entry, buffer, event)) \
trace_buffer_unlock_commit(buffer, event, irq_flags, pc); \
+ \
+ if (__tt) \
+ event_triggers_post_call(ftrace_file, __tt); \
}
/*
* The ftrace_test_probe is compiled out, it is only here as a build time check
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index ccbd8104cf99..433bfc5dd576 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1,3 +1,4 @@
+
#ifndef _LINUX_KERNEL_TRACE_H
#define _LINUX_KERNEL_TRACE_H
@@ -1020,6 +1021,10 @@ extern int apply_subsystem_event_filter(struct ftrace_subsystem_dir *dir,
extern void print_subsystem_event_filter(struct event_subsystem *system,
struct trace_seq *s);
extern int filter_assign_type(const char *type);
+extern int create_event_filter(struct ftrace_event_call *call,
+ char *filter_str, bool set_str,
+ struct event_filter **filterp);
+extern void free_event_filter(struct event_filter *filter);
struct ftrace_event_field *
trace_find_event_field(struct ftrace_event_call *call, char *name);
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 2468f56dc5db..8a8631926a07 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -799,6 +799,11 @@ static void __free_filter(struct event_filter *filter)
kfree(filter);
}
+void free_event_filter(struct event_filter *filter)
+{
+ __free_filter(filter);
+}
+
void destroy_call_preds(struct ftrace_event_call *call)
{
__free_filter(call->filter);
@@ -1938,6 +1943,13 @@ static int create_filter(struct ftrace_event_call *call,
return err;
}
+int create_event_filter(struct ftrace_event_call *call,
+ char *filter_str, bool set_str,
+ struct event_filter **filterp)
+{
+ return create_filter(call, filter_str, set_str, filterp);
+}
+
/**
* create_system_filter - create a filter for an event_subsystem
* @system: event_subsystem to create a filter for
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 45e48b109d51..f5b3f780fda4 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -31,6 +31,9 @@ static DEFINE_MUTEX(trigger_cmd_mutex);
static void
trigger_data_free(struct event_trigger_data *data)
{
+ if (data->cmd_ops->set_filter)
+ data->cmd_ops->set_filter(NULL, data, NULL);
+
synchronize_sched(); /* make sure current triggers exit before free */
kfree(data);
}
@@ -38,27 +41,78 @@ trigger_data_free(struct event_trigger_data *data)
/**
* event_triggers_call - Call triggers associated with a trace event
* @file: The ftrace_event_file associated with the event
+ * @rec: The trace entry for the event, NULL for unconditional invocation
*
* For each trigger associated with an event, invoke the trigger
- * function registered with the associated trigger command.
+ * function registered with the associated trigger command. If rec is
+ * non-NULL, it means that the trigger requires further processing and
+ * shouldn't be unconditionally invoked. If rec is non-NULL and the
+ * trigger has a filter associated with it, rec will checked against
+ * the filter and if the record matches the trigger will be invoked.
+ * If the trigger is a 'post_trigger', meaning it shouldn't be invoked
+ * in any case until the current event is written, the trigger
+ * function isn't invoked but the bit associated with the deferred
+ * trigger is set in the return value.
+ *
+ * Returns an enum event_trigger_type value containing a set bit for
+ * any trigger that should be deferred, ETT_NONE if nothing to defer.
*
* Called from tracepoint handlers (with rcu_read_lock_sched() held).
*
* Return: an enum event_trigger_type value containing a set bit for
* any trigger that should be deferred, ETT_NONE if nothing to defer.
*/
-void event_triggers_call(struct ftrace_event_file *file)
+enum event_trigger_type
+event_triggers_call(struct ftrace_event_file *file, void *rec)
{
struct event_trigger_data *data;
+ enum event_trigger_type tt = ETT_NONE;
if (list_empty(&file->triggers))
- return;
+ return tt;
- list_for_each_entry_rcu(data, &file->triggers, list)
+ list_for_each_entry_rcu(data, &file->triggers, list) {
+ if (!rec) {
+ data->ops->func(data);
+ continue;
+ }
+ if (data->filter && !filter_match_preds(data->filter, rec))
+ continue;
+ if (data->cmd_ops->post_trigger) {
+ tt |= data->cmd_ops->trigger_type;
+ continue;
+ }
data->ops->func(data);
+ }
+ return tt;
}
EXPORT_SYMBOL_GPL(event_triggers_call);
+/**
+ * event_triggers_post_call - Call 'post_triggers' for a trace event
+ * @file: The ftrace_event_file associated with the event
+ * @tt: enum event_trigger_type containing a set bit for each trigger to invoke
+ *
+ * For each trigger associated with an event, invoke the trigger
+ * function registered with the associated trigger command, if the
+ * corresponding bit is set in the tt enum passed into this function.
+ * See @event_triggers_call for details on how those bits are set.
+ *
+ * Called from tracepoint handlers (with rcu_read_lock_sched() held).
+ */
+void
+event_triggers_post_call(struct ftrace_event_file *file,
+ enum event_trigger_type tt)
+{
+ struct event_trigger_data *data;
+
+ list_for_each_entry_rcu(data, &file->triggers, list) {
+ if (data->cmd_ops->trigger_type & tt)
+ data->ops->func(data);
+ }
+}
+EXPORT_SYMBOL_GPL(event_triggers_post_call);
+
static void *trigger_next(struct seq_file *m, void *t, loff_t *pos)
{
struct ftrace_event_file *event_file = event_file_data(m->private);
@@ -403,6 +457,34 @@ clear_event_triggers(struct trace_array *tr)
}
/**
+ * update_cond_flag - Set or reset the TRIGGER_COND bit
+ * @file: The ftrace_event_file associated with the event
+ *
+ * If an event has triggers and any of those triggers has a filter or
+ * a post_trigger, trigger invocation needs to be deferred until after
+ * the current event has logged its data, and the event should have
+ * its TRIGGER_COND bit set, otherwise the TRIGGER_COND bit should be
+ * cleared.
+ */
+static void update_cond_flag(struct ftrace_event_file *file)
+{
+ struct event_trigger_data *data;
+ bool set_cond = false;
+
+ list_for_each_entry_rcu(data, &file->triggers, list) {
+ if (data->filter || data->cmd_ops->post_trigger) {
+ set_cond = true;
+ break;
+ }
+ }
+
+ if (set_cond)
+ set_bit(FTRACE_EVENT_FL_TRIGGER_COND_BIT, &file->flags);
+ else
+ clear_bit(FTRACE_EVENT_FL_TRIGGER_COND_BIT, &file->flags);
+}
+
+/**
* register_trigger - Generic event_command @reg implementation
* @glob: The raw string used to register the trigger
* @ops: The trigger ops associated with the trigger
@@ -443,6 +525,7 @@ static int register_trigger(char *glob, struct event_trigger_ops *ops,
list_del_rcu(&data->list);
ret--;
}
+ update_cond_flag(file);
out:
return ret;
}
@@ -470,6 +553,7 @@ static void unregister_trigger(char *glob, struct event_trigger_ops *ops,
if (data->cmd_ops->trigger_type == test->cmd_ops->trigger_type) {
unregistered = true;
list_del_rcu(&data->list);
+ update_cond_flag(file);
trace_event_trigger_enable_disable(file, 0);
break;
}
@@ -572,10 +656,78 @@ event_trigger_callback(struct event_command *cmd_ops,
return ret;
out_free:
+ if (cmd_ops->set_filter)
+ cmd_ops->set_filter(NULL, trigger_data, NULL);
kfree(trigger_data);
goto out;
}
+/**
+ * set_trigger_filter - Generic event_command @set_filter implementation
+ * @filter_str: The filter string for the trigger, NULL to remove filter
+ * @trigger_data: Trigger-specific data
+ * @file: The ftrace_event_file associated with the event
+ *
+ * Common implementation for event command filter parsing and filter
+ * instantiation.
+ *
+ * Usually used directly as the @set_filter method in event command
+ * implementations.
+ *
+ * Also used to remove a filter (if filter_str = NULL).
+ *
+ * Return: 0 on success, errno otherwise
+ */
+static int set_trigger_filter(char *filter_str,
+ struct event_trigger_data *trigger_data,
+ struct ftrace_event_file *file)
+{
+ struct event_trigger_data *data = trigger_data;
+ struct event_filter *filter = NULL, *tmp;
+ int ret = -EINVAL;
+ char *s;
+
+ if (!filter_str) /* clear the current filter */
+ goto assign;
+
+ s = strsep(&filter_str, " \t");
+
+ if (!strlen(s) || strcmp(s, "if") != 0)
+ goto out;
+
+ if (!filter_str)
+ goto out;
+
+ /* The filter is for the 'trigger' event, not the triggered event */
+ ret = create_event_filter(file->event_call, filter_str, false, &filter);
+ if (ret)
+ goto out;
+ assign:
+ tmp = data->filter;
+
+ rcu_assign_pointer(data->filter, filter);
+
+ if (tmp) {
+ /* Make sure the call is done with the filter */
+ synchronize_sched();
+ free_event_filter(tmp);
+ }
+
+ kfree(data->filter_str);
+ data->filter_str = NULL;
+
+ if (filter_str) {
+ data->filter_str = kstrdup(filter_str, GFP_KERNEL);
+ if (!data->filter_str) {
+ free_event_filter(data->filter);
+ data->filter = NULL;
+ ret = -ENOMEM;
+ }
+ }
+ out:
+ return ret;
+}
+
static void
traceon_trigger(struct event_trigger_data *data)
{
@@ -685,6 +837,7 @@ static struct event_command trigger_traceon_cmd = {
.reg = register_trigger,
.unreg = unregister_trigger,
.get_trigger_ops = onoff_get_trigger_ops,
+ .set_filter = set_trigger_filter,
};
static struct event_command trigger_traceoff_cmd = {
@@ -694,6 +847,7 @@ static struct event_command trigger_traceoff_cmd = {
.reg = register_trigger,
.unreg = unregister_trigger,
.get_trigger_ops = onoff_get_trigger_ops,
+ .set_filter = set_trigger_filter,
};
#ifdef CONFIG_TRACER_SNAPSHOT
@@ -765,6 +919,7 @@ static struct event_command trigger_snapshot_cmd = {
.reg = register_snapshot_trigger,
.unreg = unregister_trigger,
.get_trigger_ops = snapshot_get_trigger_ops,
+ .set_filter = set_trigger_filter,
};
static __init int register_trigger_snapshot_cmd(void)
@@ -843,6 +998,7 @@ static struct event_command trigger_stacktrace_cmd = {
.reg = register_trigger,
.unreg = unregister_trigger,
.get_trigger_ops = stacktrace_get_trigger_ops,
+ .set_filter = set_trigger_filter,
};
static __init int register_trigger_stacktrace_cmd(void)
@@ -1100,6 +1256,8 @@ event_enable_trigger_func(struct event_command *cmd_ops,
out_put:
module_put(event_enable_file->event_call->mod);
out_free:
+ if (cmd_ops->set_filter)
+ cmd_ops->set_filter(NULL, trigger_data, NULL);
kfree(trigger_data);
kfree(enable_data);
goto out;
@@ -1137,6 +1295,7 @@ static int event_enable_register_trigger(char *glob,
list_del_rcu(&data->list);
ret--;
}
+ update_cond_flag(file);
out:
return ret;
}
@@ -1157,6 +1316,7 @@ static void event_enable_unregister_trigger(char *glob,
(enable_data->file == test_enable_data->file)) {
unregistered = true;
list_del_rcu(&data->list);
+ update_cond_flag(file);
trace_event_trigger_enable_disable(file, 0);
break;
}
@@ -1191,6 +1351,7 @@ static struct event_command trigger_enable_cmd = {
.reg = event_enable_register_trigger,
.unreg = event_enable_unregister_trigger,
.get_trigger_ops = event_enable_get_trigger_ops,
+ .set_filter = set_trigger_filter,
};
static struct event_command trigger_disable_cmd = {
@@ -1200,6 +1361,7 @@ static struct event_command trigger_disable_cmd = {
.reg = event_enable_register_trigger,
.unreg = event_enable_unregister_trigger,
.get_trigger_ops = event_enable_get_trigger_ops,
+ .set_filter = set_trigger_filter,
};
static __init void unregister_trigger_enable_disable_cmds(void)
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 936ec3960335..fdd955f2f1aa 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -306,8 +306,10 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
struct syscall_trace_enter *entry;
struct syscall_metadata *sys_data;
struct ring_buffer_event *event;
+ enum event_trigger_type __tt = ETT_NONE;
struct ring_buffer *buffer;
unsigned long irq_flags;
+ unsigned long eflags;
int pc;
int syscall_nr;
int size;
@@ -321,10 +323,14 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
if (!ftrace_file)
return;
- if (test_bit(FTRACE_EVENT_FL_TRIGGER_MODE_BIT, &ftrace_file->flags))
- event_triggers_call(ftrace_file);
- if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
- return;
+ eflags = ftrace_file->flags;
+
+ if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
+ if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
+ event_triggers_call(ftrace_file, NULL);
+ if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
+ return;
+ }
sys_data = syscall_nr_to_meta(syscall_nr);
if (!sys_data)
@@ -345,9 +351,16 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
entry->nr = syscall_nr;
syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args);
- if (!filter_check_discard(ftrace_file, entry, buffer, event))
+ if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
+ __tt = event_triggers_call(ftrace_file, entry);
+
+ if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
+ ring_buffer_discard_commit(buffer, event);
+ else if (!filter_check_discard(ftrace_file, entry, buffer, event))
trace_current_buffer_unlock_commit(buffer, event,
irq_flags, pc);
+ if (__tt)
+ event_triggers_post_call(ftrace_file, __tt);
}
static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
@@ -357,8 +370,10 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
struct syscall_trace_exit *entry;
struct syscall_metadata *sys_data;
struct ring_buffer_event *event;
+ enum event_trigger_type __tt = ETT_NONE;
struct ring_buffer *buffer;
unsigned long irq_flags;
+ unsigned long eflags;
int pc;
int syscall_nr;
@@ -371,10 +386,14 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
if (!ftrace_file)
return;
- if (test_bit(FTRACE_EVENT_FL_TRIGGER_MODE_BIT, &ftrace_file->flags))
- event_triggers_call(ftrace_file);
- if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
- return;
+ eflags = ftrace_file->flags;
+
+ if (!(eflags & FTRACE_EVENT_FL_TRIGGER_COND)) {
+ if (eflags & FTRACE_EVENT_FL_TRIGGER_MODE)
+ event_triggers_call(ftrace_file, NULL);
+ if (eflags & FTRACE_EVENT_FL_SOFT_DISABLED)
+ return;
+ }
sys_data = syscall_nr_to_meta(syscall_nr);
if (!sys_data)
@@ -394,9 +413,16 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
entry->nr = syscall_nr;
entry->ret = syscall_get_return_value(current, regs);
- if (!filter_check_discard(ftrace_file, entry, buffer, event))
+ if (eflags & FTRACE_EVENT_FL_TRIGGER_COND)
+ __tt = event_triggers_call(ftrace_file, entry);
+
+ if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags))
+ ring_buffer_discard_commit(buffer, event);
+ else if (!filter_check_discard(ftrace_file, entry, buffer, event))
trace_current_buffer_unlock_commit(buffer, event,
irq_flags, pc);
+ if (__tt)
+ event_triggers_post_call(ftrace_file, __tt);
}
static int reg_event_syscall_enter(struct ftrace_event_file *file,

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