* FAILED: patch "[PATCH] tracing: Undo the registration when enabling the histogram" failed to apply to 6.6-stable tree
@ 2026-09-16 14:19 gregkh
2026-09-16 19:49 ` [PATCH 6.6.y 1/3] tracing: Constify struct event_trigger_ops Sasha Levin
0 siblings, 1 reply; 6+ messages in thread
From: gregkh @ 2026-09-16 14:19 UTC (permalink / raw)
To: donggeunyoo.kernel, rostedt, sashiko-bot; +Cc: stable
The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 92383cef66791a0c63a2f27755cadbdb2fbf270b
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026091601-uncurled-paddle-226d@gregkh' --subject-prefix 'PATCH 6.6.y' 'HEAD^..'
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 92383cef66791a0c63a2f27755cadbdb2fbf270b Mon Sep 17 00:00:00 2001
From: Donggeun Yoo <donggeunyoo.kernel@gmail.com>
Date: Mon, 7 Sep 2026 21:44:20 +0900
Subject: [PATCH] tracing: Undo the registration when enabling the histogram
trigger fails
Commit 6f86bdeab633 ("tracing: Fix bad hist from corrupting named_triggers
list") described how a trigger that is registered but not on file->triggers
ends up freed while still on the global named_triggers list, and moved the
registration down so that hist_trigger_enable() follows it immediately. One
path still gets there. hist_trigger_enable() adds the trigger and takes it
straight back out when the event cannot be enabled:
list_add_tail_rcu(&data->list, &file->triggers);
update_cond_flag(file);
if (trace_event_trigger_enable_disable(file, 1) < 0) {
list_del_rcu(&data->list);
update_cond_flag(file);
ret--;
}
so the list walk in hist_unregister_trigger() matches nothing, test stays
NULL, and the ->free() that would call del_named_trigger() is skipped.
out_unreg falls through to out_free, which frees the trigger anyway:
BUG: KASAN: slab-use-after-free in find_named_trigger+0xac/0xc0
Read of size 8 at addr ffff8880091d3160 by task init/1
find_named_trigger+0xac/0xc0
hist_register_trigger+0xc1/0xa00
event_hist_trigger_parse+0x3146/0x6af0
event_trigger_write+0xce/0x160
Freed by task 69:
kfree+0x154/0x420
trigger_kthread_fn+0xfd/0x160
Leave the trigger where hist_unregister_trigger() can find it and let that
undo the registration, which is the only code that knows all of what
cmd_ops->init() took: the named list entry, the hist_pad reference, the
reference on the trigger a named histogram is shared with, and the copied
cmd_ops. It also pairs the failed trace_event_trigger_enable_disable(),
whose sm_ref and buffered event reference are otherwise left behind.
Since ->free() releases trigger_data and, for a trigger that does not share
its histogram, hist_data with it, out_unreg can no longer fall through to
out_free. For a trigger that does share, hist_register_trigger() has
already destroyed the caller's hist_data, so the fall-through was reading
freed memory there as well.
Move the enable_timestamps check in hist_unregister_trigger() above the
->free() call for the same reason: hist_data does not outlive it once the
trigger being removed is the one that owns it.
Cc: stable@vger.kernel.org
Fixes: 067fe038e70f ("tracing: Add variable reference handling to hist triggers")
Reported-by: Sashiko AI <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/linux-trace-kernel/20260907092944.3950E1F00A3D@smtp.kernel.org/
Link: https://patch.msgid.link/20260907124420.607097-3-donggeunyoo.kernel@gmail.com
Signed-off-by: Donggeun Yoo <donggeunyoo.kernel@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 54c95f9bd0a3..53100287466f 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -6670,11 +6670,12 @@ static int hist_trigger_enable(struct event_trigger_data *data,
update_cond_flag(file);
- if (trace_event_trigger_enable_disable(file, 1) < 0) {
- list_del_rcu(&data->list);
- update_cond_flag(file);
+ /*
+ * On failure the caller undoes the registration, and
+ * hist_unregister_trigger() can only find the trigger here.
+ */
+ if (trace_event_trigger_enable_disable(file, 1) < 0)
ret--;
- }
return ret;
}
@@ -6752,13 +6753,13 @@ static void hist_unregister_trigger(char *glob,
}
}
- if (test && test->cmd_ops->free)
- test->cmd_ops->free(test);
-
if (hist_data->enable_timestamps) {
if (!hist_data->remove || test)
tracing_set_filter_buffering(file->tr, false);
}
+
+ if (test && test->cmd_ops->free)
+ test->cmd_ops->free(test);
}
static bool hist_file_check_refs(struct trace_event_file *file)
@@ -6963,6 +6964,8 @@ static int event_hist_trigger_parse(struct event_command *cmd_ops,
return ret;
out_unreg:
event_trigger_unregister(cmd_ops, file, glob+1, trigger_data);
+ /* The unregister frees trigger_data, skip out_free */
+ goto out;
out_free:
remove_hist_vars(hist_data);
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 6.6.y 2/3] tracing: Merge struct event_trigger_ops into struct event_command
2026-09-16 16:48 ` [PATCH 6.6.y 1/3] tracing: Constify struct event_trigger_ops Sasha Levin
@ 2026-09-16 16:48 ` Sasha Levin
0 siblings, 0 replies; 6+ messages in thread
From: Sasha Levin @ 2026-09-16 16:48 UTC (permalink / raw)
To: stable
Cc: Steven Rostedt, Masami Hiramatsu, Mark Rutland, Mathieu Desnoyers,
Andrew Morton, Tom Zanussi, Sasha Levin
From: Steven Rostedt <rostedt@goodmis.org>
[ Upstream commit b052d70f7c9c156409a70e65c10d83b5650e7e78 ]
Now that there's pretty much a one to one mapping between the struct
event_trigger_ops and struct event_command, there's no reason to have two
different structures. Merge the function pointers of event_trigger_ops
into event_command.
There's one exception in trace_events_hist.c for the
event_hist_trigger_named_ops. This has special logic for the init and free
function pointers for "named histograms". In this case, allocate the
cmd_ops of the event_trigger_data and set it to the proper init and free
functions, which are used to initialize and free the event_trigger_data
respectively. Have the free function and the init function (on failure)
free the cmd_ops of the data element.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://patch.msgid.link/20251125200932.446322765@kernel.org
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
[6.6 dependency adaptation]
The stable branch still selects separate counted trigger callbacks through
get_trigger_ops(), and lacks the upstream count_func/data_ops_trigger
refactoring. Merge the callbacks into event_command while retaining the
existing counted callbacks as count_trigger. Select them in the existing
trigger dispatch functions using EVENT_TRIGGER_FL_COUNT, preserving the
old parameter-based selection and count semantics without adding functions.
Remove the obsolete get_trigger_ops callbacks and event_trigger_ops tables,
including the eprobe selector left behind by the automatic merge.
For shared named histograms, retain the dependency's per-trigger copy of
cmd_ops and its specialized init/free callbacks. Mark the copy as owned by
the trigger and release it in trigger_data_free(), instead of adding frees
to named init/free. This covers normal teardown and parse error cleanup,
including clock validation failure before init after the target is applied.
Keep hist_register_trigger() in the form expected by 6ede78d0563a so that
its clock-before-registration change applies directly. The target itself
is not included in this dependency.
Stable-dep-of: 6ede78d0563a ("tracing: Set the trace clock before registering the histogram trigger")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/trace/trace.h | 120 ++++++---------
kernel/trace/trace_eprobe.c | 19 +--
kernel/trace/trace_events_hist.c | 117 +++++---------
kernel/trace/trace_events_trigger.c | 230 ++++++++--------------------
4 files changed, 157 insertions(+), 329 deletions(-)
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index cb3b9e3eabead..6c19b3eac7766 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1608,13 +1608,14 @@ extern void clear_event_triggers(struct trace_array *tr);
enum {
EVENT_TRIGGER_FL_PROBE = BIT(0),
+ EVENT_TRIGGER_FL_COUNT = BIT(1),
+ EVENT_TRIGGER_FL_CMD_ALLOC = BIT(2),
};
struct event_trigger_data {
unsigned long count;
int ref;
int flags;
- const struct event_trigger_ops *ops;
struct event_command *cmd_ops;
struct event_filter __rcu *filter;
char *filter_str;
@@ -1701,64 +1702,6 @@ extern void event_trigger_unregister(struct event_command *cmd_ops,
extern void event_file_get(struct trace_event_file *file);
extern void event_file_put(struct trace_event_file *file);
-/**
- * struct event_trigger_ops - callbacks for trace event triggers
- *
- * The methods in this structure provide per-event trigger hooks for
- * various trigger operations.
- *
- * The @init and @free methods are used during trigger setup and
- * teardown, typically called from an event_command's @parse()
- * function implementation.
- *
- * The @print method is used to print the trigger spec.
- *
- * The @trigger method is the function that actually implements the
- * trigger and is called in the context of the triggering event
- * whenever that event occurs.
- *
- * All the methods below, except for @init() and @free(), must be
- * implemented.
- *
- * @trigger: The trigger 'probe' function called when the triggering
- * event occurs. The data passed into this callback is the data
- * that was supplied to the event_command @reg() function that
- * registered the trigger (see struct event_command) along with
- * the trace record, rec.
- *
- * @init: An optional initialization function called for the trigger
- * when the trigger is registered (via the event_command reg()
- * function). This can be used to perform per-trigger
- * initialization such as incrementing a per-trigger reference
- * count, for instance. This is usually implemented by the
- * generic utility function @event_trigger_init() (see
- * trace_event_triggers.c).
- *
- * @free: An optional de-initialization function called for the
- * trigger when the trigger is unregistered (via the
- * event_command @reg() function). This can be used to perform
- * per-trigger de-initialization such as decrementing a
- * per-trigger reference count and freeing corresponding trigger
- * data, for instance. This is usually implemented by the
- * generic utility function @event_trigger_free() (see
- * trace_event_triggers.c).
- *
- * @print: The callback function invoked to have the trigger print
- * itself. This is usually implemented by a wrapper function
- * that calls the generic utility function @event_trigger_print()
- * (see trace_event_triggers.c).
- */
-struct event_trigger_ops {
- void (*trigger)(struct event_trigger_data *data,
- struct trace_buffer *buffer,
- void *rec,
- struct ring_buffer_event *rbe);
- int (*init)(struct event_trigger_data *data);
- void (*free)(struct event_trigger_data *data);
- int (*print)(struct seq_file *m,
- struct event_trigger_data *data);
-};
-
/**
* struct event_command - callbacks and data members for event commands
*
@@ -1808,7 +1751,7 @@ struct event_trigger_ops {
*
* @reg: Adds the trigger to the list of triggers associated with the
* event, and enables the event trigger itself, after
- * initializing it (via the event_trigger_ops @init() function).
+ * initializing it (via the event_command @init() function).
* This is also where commands can use the @trigger_type value to
* make the decision as to whether or not multiple instances of
* the trigger should be allowed. This is usually implemented by
@@ -1817,7 +1760,7 @@ struct event_trigger_ops {
*
* @unreg: Removes the trigger from the list of triggers associated
* with the event, and disables the event trigger itself, after
- * initializing it (via the event_trigger_ops @free() function).
+ * initializing it (via the event_command @free() function).
* This is usually implemented by the generic utility function
* @unregister_trigger() (see trace_event_triggers.c).
*
@@ -1831,12 +1774,40 @@ struct event_trigger_ops {
* ignored. This is usually implemented by the generic utility
* function @set_trigger_filter() (see trace_event_triggers.c).
*
- * @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.
+ * All the methods below, except for @count_trigger(), @init() and
+ * @free(), must be implemented.
+ *
+ * @trigger: The trigger 'probe' function called when the triggering
+ * event occurs. The data passed into this callback is the data
+ * that was supplied to the event_command @reg() function that
+ * registered the trigger (see struct event_command) along with
+ * the trace record, rec.
+ *
+ * @count_trigger: If defined and a numeric parameter is passed to the
+ * trigger, this function is called instead of @trigger. It handles
+ * the count and invokes the trigger when appropriate.
+ *
+ * @init: An optional initialization function called for the trigger
+ * when the trigger is registered (via the event_command reg()
+ * function). This can be used to perform per-trigger
+ * initialization such as incrementing a per-trigger reference
+ * count, for instance. This is usually implemented by the
+ * generic utility function @event_trigger_init() (see
+ * trace_event_triggers.c).
+ *
+ * @free: An optional de-initialization function called for the
+ * trigger when the trigger is unregistered (via the
+ * event_command @reg() function). This can be used to perform
+ * per-trigger de-initialization such as decrementing a
+ * per-trigger reference count and freeing corresponding trigger
+ * data, for instance. This is usually implemented by the
+ * generic utility function @event_trigger_free() (see
+ * trace_event_triggers.c).
+ *
+ * @print: The callback function invoked to have the trigger print
+ * itself. This is usually implemented by a wrapper function
+ * that calls the generic utility function @event_trigger_print()
+ * (see trace_event_triggers.c).
*/
struct event_command {
struct list_head list;
@@ -1857,7 +1828,18 @@ struct event_command {
int (*set_filter)(char *filter_str,
struct event_trigger_data *data,
struct trace_event_file *file);
- const struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
+ void (*trigger)(struct event_trigger_data *data,
+ struct trace_buffer *buffer,
+ void *rec,
+ struct ring_buffer_event *rbe);
+ void (*count_trigger)(struct event_trigger_data *data,
+ struct trace_buffer *buffer,
+ void *rec,
+ struct ring_buffer_event *rbe);
+ int (*init)(struct event_trigger_data *data);
+ void (*free)(struct event_trigger_data *data);
+ int (*print)(struct seq_file *m,
+ struct event_trigger_data *data);
};
/**
@@ -1878,7 +1860,7 @@ struct event_command {
* either committed or discarded. At that point, if any commands
* have deferred their triggers, those commands are finally
* invoked following the close of the current event. In other
- * words, if the event_trigger_ops @func() probe implementation
+ * words, if the event_command @func() probe implementation
* itself logs to the trace buffer, this flag should be set,
* otherwise it can be left unspecified.
*
diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index c7763d67741cc..f35b6055aaec8 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -479,13 +479,6 @@ static void eprobe_trigger_func(struct event_trigger_data *data,
__eprobe_trace_func(edata, rec);
}
-static const struct event_trigger_ops eprobe_trigger_ops = {
- .trigger = eprobe_trigger_func,
- .print = eprobe_trigger_print,
- .init = eprobe_trigger_init,
- .free = eprobe_trigger_free,
-};
-
static int eprobe_trigger_cmd_parse(struct event_command *cmd_ops,
struct trace_event_file *file,
char *glob, char *cmd,
@@ -508,12 +501,6 @@ static void eprobe_trigger_unreg_func(char *glob,
}
-static const struct event_trigger_ops *eprobe_trigger_get_ops(char *cmd,
- char *param)
-{
- return &eprobe_trigger_ops;
-}
-
static struct event_command event_trigger_cmd = {
.name = "eprobe",
.trigger_type = ETT_EVENT_EPROBE,
@@ -522,8 +509,11 @@ static struct event_command event_trigger_cmd = {
.reg = eprobe_trigger_reg_func,
.unreg = eprobe_trigger_unreg_func,
.unreg_all = NULL,
- .get_trigger_ops = eprobe_trigger_get_ops,
.set_filter = NULL,
+ .trigger = eprobe_trigger_func,
+ .print = eprobe_trigger_print,
+ .init = eprobe_trigger_init,
+ .free = eprobe_trigger_free,
};
static struct event_trigger_data *
@@ -543,7 +533,6 @@ new_eprobe_trigger(struct trace_eprobe *ep, struct trace_event_file *file)
trigger->flags = EVENT_TRIGGER_FL_PROBE;
trigger->count = -1;
- trigger->ops = &eprobe_trigger_ops;
/*
* EVENT PROBE triggers are not registered as commands with
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index ae70e3007fe10..08e1027a16b0a 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -5704,7 +5704,7 @@ 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);
+ data->cmd_ops->print(m, data);
seq_puts(m, "#\n\n");
hist_data = data->private_data;
@@ -6026,7 +6026,7 @@ 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);
+ data->cmd_ops->print(m, data);
seq_puts(m, "#\n\n");
hist_data = data->private_data;
@@ -6334,13 +6334,6 @@ static void event_hist_trigger_free(struct event_trigger_data *data)
free_hist_pad();
}
-static const struct event_trigger_ops event_hist_trigger_ops = {
- .trigger = event_hist_trigger,
- .print = event_hist_trigger_print,
- .init = event_hist_trigger_init,
- .free = event_hist_trigger_free,
-};
-
static int event_hist_trigger_named_init(struct event_trigger_data *data)
{
data->ref++;
@@ -6364,19 +6357,6 @@ static void event_hist_trigger_named_free(struct event_trigger_data *data)
}
}
-static const struct event_trigger_ops event_hist_trigger_named_ops = {
- .trigger = event_hist_trigger,
- .print = event_hist_trigger_print,
- .init = event_hist_trigger_named_init,
- .free = event_hist_trigger_named_free,
-};
-
-static const struct event_trigger_ops *event_hist_get_trigger_ops(char *cmd,
- char *param)
-{
- return &event_hist_trigger_ops;
-}
-
static void hist_clear(struct event_trigger_data *data)
{
struct hist_trigger_data *hist_data = data->private_data;
@@ -6570,13 +6550,25 @@ static int hist_register_trigger(char *glob,
data->paused = true;
if (named_data) {
+ struct event_command *cmd_ops;
+
data->private_data = named_data->private_data;
set_named_trigger_data(data, named_data);
- data->ops = &event_hist_trigger_named_ops;
+ /* Copy the command ops and update some of the functions */
+ cmd_ops = kmalloc(sizeof(*cmd_ops), GFP_KERNEL);
+ if (!cmd_ops) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ *cmd_ops = *data->cmd_ops;
+ cmd_ops->init = event_hist_trigger_named_init;
+ cmd_ops->free = event_hist_trigger_named_free;
+ data->flags |= EVENT_TRIGGER_FL_CMD_ALLOC;
+ data->cmd_ops = cmd_ops;
}
- if (data->ops->init) {
- ret = data->ops->init(data);
+ if (data->cmd_ops->init) {
+ ret = data->cmd_ops->init(data);
if (ret < 0)
goto out;
}
@@ -6692,8 +6684,8 @@ static void hist_unregister_trigger(char *glob,
}
}
- if (test && test->ops->free)
- test->ops->free(test);
+ if (test && test->cmd_ops->free)
+ test->cmd_ops->free(test);
if (hist_data->enable_timestamps) {
if (!hist_data->remove || test)
@@ -6745,8 +6737,8 @@ static void hist_unreg_all(struct trace_event_file *file)
update_cond_flag(file);
if (hist_data->enable_timestamps)
tracing_set_filter_buffering(file->tr, false);
- if (test->ops->free)
- test->ops->free(test);
+ if (test->cmd_ops->free)
+ test->cmd_ops->free(test);
}
}
}
@@ -6922,8 +6914,11 @@ static struct event_command trigger_hist_cmd = {
.reg = hist_register_trigger,
.unreg = hist_unregister_trigger,
.unreg_all = hist_unreg_all,
- .get_trigger_ops = event_hist_get_trigger_ops,
.set_filter = set_trigger_filter,
+ .trigger = event_hist_trigger,
+ .print = event_hist_trigger_print,
+ .init = event_hist_trigger_init,
+ .free = event_hist_trigger_free,
};
__init int register_trigger_hist_cmd(void)
@@ -6969,52 +6964,6 @@ hist_enable_count_trigger(struct event_trigger_data *data,
hist_enable_trigger(data, buffer, rec, event);
}
-static const struct event_trigger_ops hist_enable_trigger_ops = {
- .trigger = hist_enable_trigger,
- .print = event_enable_trigger_print,
- .init = event_trigger_init,
- .free = event_enable_trigger_free,
-};
-
-static const struct event_trigger_ops hist_enable_count_trigger_ops = {
- .trigger = hist_enable_count_trigger,
- .print = event_enable_trigger_print,
- .init = event_trigger_init,
- .free = event_enable_trigger_free,
-};
-
-static const struct event_trigger_ops hist_disable_trigger_ops = {
- .trigger = hist_enable_trigger,
- .print = event_enable_trigger_print,
- .init = event_trigger_init,
- .free = event_enable_trigger_free,
-};
-
-static const struct event_trigger_ops hist_disable_count_trigger_ops = {
- .trigger = hist_enable_count_trigger,
- .print = event_enable_trigger_print,
- .init = event_trigger_init,
- .free = event_enable_trigger_free,
-};
-
-static const struct event_trigger_ops *
-hist_enable_get_trigger_ops(char *cmd, char *param)
-{
- const struct event_trigger_ops *ops;
- bool enable;
-
- enable = (strcmp(cmd, ENABLE_HIST_STR) == 0);
-
- if (enable)
- ops = param ? &hist_enable_count_trigger_ops :
- &hist_enable_trigger_ops;
- else
- ops = param ? &hist_disable_count_trigger_ops :
- &hist_disable_trigger_ops;
-
- return ops;
-}
-
static void hist_enable_unreg_all(struct trace_event_file *file)
{
struct event_trigger_data *test, *n;
@@ -7024,8 +6973,8 @@ static void hist_enable_unreg_all(struct trace_event_file *file)
list_del_rcu(&test->list);
update_cond_flag(file);
trace_event_trigger_enable_disable(file, 0);
- if (test->ops->free)
- test->ops->free(test);
+ if (test->cmd_ops->free)
+ test->cmd_ops->free(test);
}
}
}
@@ -7037,8 +6986,12 @@ static struct event_command trigger_hist_enable_cmd = {
.reg = event_enable_register_trigger,
.unreg = event_enable_unregister_trigger,
.unreg_all = hist_enable_unreg_all,
- .get_trigger_ops = hist_enable_get_trigger_ops,
.set_filter = set_trigger_filter,
+ .trigger = hist_enable_trigger,
+ .count_trigger = hist_enable_count_trigger,
+ .print = event_enable_trigger_print,
+ .init = event_trigger_init,
+ .free = event_enable_trigger_free,
};
static struct event_command trigger_hist_disable_cmd = {
@@ -7048,8 +7001,12 @@ static struct event_command trigger_hist_disable_cmd = {
.reg = event_enable_register_trigger,
.unreg = event_enable_unregister_trigger,
.unreg_all = hist_enable_unreg_all,
- .get_trigger_ops = hist_enable_get_trigger_ops,
.set_filter = set_trigger_filter,
+ .trigger = hist_enable_trigger,
+ .count_trigger = hist_enable_count_trigger,
+ .print = event_enable_trigger_print,
+ .init = event_trigger_init,
+ .free = event_enable_trigger_free,
};
static __init void unregister_trigger_hist_enable_disable_cmds(void)
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 48db99b7d61cb..de0e2075d3627 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -28,6 +28,8 @@ void trigger_data_free(struct event_trigger_data *data)
/* make sure current triggers exit before free */
tracepoint_synchronize_unregister();
+ if (data->flags & EVENT_TRIGGER_FL_CMD_ALLOC)
+ kfree(data->cmd_ops);
kfree(data);
}
@@ -73,7 +75,10 @@ event_triggers_call(struct trace_event_file *file,
if (data->paused)
continue;
if (!rec) {
- data->ops->trigger(data, buffer, rec, event);
+ if (data->flags & EVENT_TRIGGER_FL_COUNT)
+ data->cmd_ops->count_trigger(data, buffer, rec, event);
+ else
+ data->cmd_ops->trigger(data, buffer, rec, event);
continue;
}
filter = rcu_dereference_sched(data->filter);
@@ -83,7 +88,10 @@ event_triggers_call(struct trace_event_file *file,
tt |= data->cmd_ops->trigger_type;
continue;
}
- data->ops->trigger(data, buffer, rec, event);
+ if (data->flags & EVENT_TRIGGER_FL_COUNT)
+ data->cmd_ops->count_trigger(data, buffer, rec, event);
+ else
+ data->cmd_ops->trigger(data, buffer, rec, event);
}
return tt;
}
@@ -124,8 +132,12 @@ event_triggers_post_call(struct trace_event_file *file,
list_for_each_entry_rcu(data, &file->triggers, list) {
if (data->paused)
continue;
- if (data->cmd_ops->trigger_type & tt)
- data->ops->trigger(data, NULL, NULL, NULL);
+ if (data->cmd_ops->trigger_type & tt) {
+ if (data->flags & EVENT_TRIGGER_FL_COUNT)
+ data->cmd_ops->count_trigger(data, NULL, NULL, NULL);
+ else
+ data->cmd_ops->trigger(data, NULL, NULL, NULL);
+ }
}
}
EXPORT_SYMBOL_GPL(event_triggers_post_call);
@@ -194,7 +206,7 @@ static int trigger_show(struct seq_file *m, void *v)
}
data = list_entry(v, struct event_trigger_data, list);
- data->ops->print(m, data);
+ data->cmd_ops->print(m, data);
return 0;
}
@@ -402,7 +414,7 @@ __init int unregister_event_command(struct event_command *cmd)
}
/**
- * event_trigger_print - Generic event_trigger_ops @print implementation
+ * event_trigger_print - Generic event_command @print implementation
* @name: The name of the event trigger
* @m: The seq_file being printed to
* @data: Trigger-specific data
@@ -437,7 +449,7 @@ event_trigger_print(const char *name, struct seq_file *m,
}
/**
- * event_trigger_init - Generic event_trigger_ops @init implementation
+ * event_trigger_init - Generic event_command @init implementation
* @data: Trigger-specific data
*
* Common implementation of event trigger initialization.
@@ -454,7 +466,7 @@ int event_trigger_init(struct event_trigger_data *data)
}
/**
- * event_trigger_free - Generic event_trigger_ops @free implementation
+ * event_trigger_free - Generic event_command @free implementation
* @data: Trigger-specific data
*
* Common implementation of event trigger de-initialization.
@@ -516,8 +528,8 @@ clear_event_triggers(struct trace_array *tr)
list_for_each_entry_safe(data, n, &file->triggers, list) {
trace_event_trigger_enable_disable(file, 0);
list_del_rcu(&data->list);
- if (data->ops->free)
- data->ops->free(data);
+ if (data->cmd_ops->free)
+ data->cmd_ops->free(data);
}
}
}
@@ -582,8 +594,8 @@ static int register_trigger(char *glob,
}
}
- if (data->ops->init) {
- ret = data->ops->init(data);
+ if (data->cmd_ops->init) {
+ ret = data->cmd_ops->init(data);
if (ret < 0)
goto out;
}
@@ -629,8 +641,8 @@ static void unregister_trigger(char *glob,
}
}
- if (data && data->ops->free)
- data->ops->free(data);
+ if (data && data->cmd_ops->free)
+ data->cmd_ops->free(data);
}
/*
@@ -819,9 +831,9 @@ int event_trigger_separate_filter(char *param_and_filter, char **param,
* @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.
+ * @cmd_ops provide the callbacks for the event_trigger_data. @param
+ * selects the counted callback when the command supports one.
+ * @private_data can also be associated with the event_trigger_data.
*
* Use trigger_data_free() to free an event_trigger_data object.
*
@@ -833,18 +845,16 @@ struct event_trigger_data *trigger_data_alloc(struct event_command *cmd_ops,
void *private_data)
{
struct event_trigger_data *trigger_data;
- const 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;
+ if (param && cmd_ops->count_trigger)
+ trigger_data->flags |= EVENT_TRIGGER_FL_COUNT;
INIT_LIST_HEAD(&trigger_data->list);
INIT_LIST_HEAD(&trigger_data->named_list);
@@ -1375,58 +1385,18 @@ traceoff_trigger_print(struct seq_file *m, struct event_trigger_data *data)
data->filter_str);
}
-static const struct event_trigger_ops traceon_trigger_ops = {
- .trigger = traceon_trigger,
- .print = traceon_trigger_print,
- .init = event_trigger_init,
- .free = event_trigger_free,
-};
-
-static const struct event_trigger_ops traceon_count_trigger_ops = {
- .trigger = traceon_count_trigger,
- .print = traceon_trigger_print,
- .init = event_trigger_init,
- .free = event_trigger_free,
-};
-
-static const struct event_trigger_ops traceoff_trigger_ops = {
- .trigger = traceoff_trigger,
- .print = traceoff_trigger_print,
- .init = event_trigger_init,
- .free = event_trigger_free,
-};
-
-static const struct event_trigger_ops traceoff_count_trigger_ops = {
- .trigger = traceoff_count_trigger,
- .print = traceoff_trigger_print,
- .init = event_trigger_init,
- .free = event_trigger_free,
-};
-
-static const struct event_trigger_ops *
-onoff_get_trigger_ops(char *cmd, char *param)
-{
- const struct event_trigger_ops *ops;
-
- /* we register both traceon and traceoff to this callback */
- if (strcmp(cmd, "traceon") == 0)
- ops = param ? &traceon_count_trigger_ops :
- &traceon_trigger_ops;
- else
- ops = param ? &traceoff_count_trigger_ops :
- &traceoff_trigger_ops;
-
- return ops;
-}
-
static struct event_command trigger_traceon_cmd = {
.name = "traceon",
.trigger_type = ETT_TRACE_ONOFF,
.parse = event_trigger_parse,
.reg = register_trigger,
.unreg = unregister_trigger,
- .get_trigger_ops = onoff_get_trigger_ops,
.set_filter = set_trigger_filter,
+ .trigger = traceon_trigger,
+ .count_trigger = traceon_count_trigger,
+ .print = traceon_trigger_print,
+ .init = event_trigger_init,
+ .free = event_trigger_free,
};
static struct event_command trigger_traceoff_cmd = {
@@ -1436,8 +1406,12 @@ static struct event_command trigger_traceoff_cmd = {
.parse = event_trigger_parse,
.reg = register_trigger,
.unreg = unregister_trigger,
- .get_trigger_ops = onoff_get_trigger_ops,
.set_filter = set_trigger_filter,
+ .trigger = traceoff_trigger,
+ .count_trigger = traceoff_count_trigger,
+ .print = traceoff_trigger_print,
+ .init = event_trigger_init,
+ .free = event_trigger_free,
};
#ifdef CONFIG_TRACER_SNAPSHOT
@@ -1488,34 +1462,18 @@ snapshot_trigger_print(struct seq_file *m, struct event_trigger_data *data)
data->filter_str);
}
-static const struct event_trigger_ops snapshot_trigger_ops = {
- .trigger = snapshot_trigger,
- .print = snapshot_trigger_print,
- .init = event_trigger_init,
- .free = event_trigger_free,
-};
-
-static const struct event_trigger_ops snapshot_count_trigger_ops = {
- .trigger = snapshot_count_trigger,
- .print = snapshot_trigger_print,
- .init = event_trigger_init,
- .free = event_trigger_free,
-};
-
-static const struct event_trigger_ops *
-snapshot_get_trigger_ops(char *cmd, char *param)
-{
- return param ? &snapshot_count_trigger_ops : &snapshot_trigger_ops;
-}
-
static struct event_command trigger_snapshot_cmd = {
.name = "snapshot",
.trigger_type = ETT_SNAPSHOT,
.parse = event_trigger_parse,
.reg = register_snapshot_trigger,
.unreg = unregister_trigger,
- .get_trigger_ops = snapshot_get_trigger_ops,
.set_filter = set_trigger_filter,
+ .trigger = snapshot_trigger,
+ .count_trigger = snapshot_count_trigger,
+ .print = snapshot_trigger_print,
+ .init = event_trigger_init,
+ .free = event_trigger_free,
};
static __init int register_trigger_snapshot_cmd(void)
@@ -1583,26 +1541,6 @@ stacktrace_trigger_print(struct seq_file *m, struct event_trigger_data *data)
data->filter_str);
}
-static const struct event_trigger_ops stacktrace_trigger_ops = {
- .trigger = stacktrace_trigger,
- .print = stacktrace_trigger_print,
- .init = event_trigger_init,
- .free = event_trigger_free,
-};
-
-static const struct event_trigger_ops stacktrace_count_trigger_ops = {
- .trigger = stacktrace_count_trigger,
- .print = stacktrace_trigger_print,
- .init = event_trigger_init,
- .free = event_trigger_free,
-};
-
-static const struct event_trigger_ops *
-stacktrace_get_trigger_ops(char *cmd, char *param)
-{
- return param ? &stacktrace_count_trigger_ops : &stacktrace_trigger_ops;
-}
-
static struct event_command trigger_stacktrace_cmd = {
.name = "stacktrace",
.trigger_type = ETT_STACKTRACE,
@@ -1610,8 +1548,12 @@ static struct event_command trigger_stacktrace_cmd = {
.parse = event_trigger_parse,
.reg = register_trigger,
.unreg = unregister_trigger,
- .get_trigger_ops = stacktrace_get_trigger_ops,
.set_filter = set_trigger_filter,
+ .trigger = stacktrace_trigger,
+ .count_trigger = stacktrace_count_trigger,
+ .print = stacktrace_trigger_print,
+ .init = event_trigger_init,
+ .free = event_trigger_free,
};
static __init int register_trigger_stacktrace_cmd(void)
@@ -1708,34 +1650,6 @@ void event_enable_trigger_free(struct event_trigger_data *data)
}
}
-static const struct event_trigger_ops event_enable_trigger_ops = {
- .trigger = event_enable_trigger,
- .print = event_enable_trigger_print,
- .init = event_trigger_init,
- .free = event_enable_trigger_free,
-};
-
-static const struct event_trigger_ops event_enable_count_trigger_ops = {
- .trigger = event_enable_count_trigger,
- .print = event_enable_trigger_print,
- .init = event_trigger_init,
- .free = event_enable_trigger_free,
-};
-
-static const struct event_trigger_ops event_disable_trigger_ops = {
- .trigger = event_enable_trigger,
- .print = event_enable_trigger_print,
- .init = event_trigger_init,
- .free = event_enable_trigger_free,
-};
-
-static const struct event_trigger_ops event_disable_count_trigger_ops = {
- .trigger = event_enable_count_trigger,
- .print = event_enable_trigger_print,
- .init = event_trigger_init,
- .free = event_enable_trigger_free,
-};
-
int event_enable_trigger_parse(struct event_command *cmd_ops,
struct trace_event_file *file,
char *glob, char *cmd, char *param_and_filter)
@@ -1867,8 +1781,8 @@ int event_enable_register_trigger(char *glob,
}
}
- if (data->ops->init) {
- ret = data->ops->init(data);
+ if (data->cmd_ops->init) {
+ ret = data->cmd_ops->init(data);
if (ret < 0)
goto out;
}
@@ -1909,30 +1823,8 @@ void event_enable_unregister_trigger(char *glob,
}
}
- if (data && data->ops->free)
- data->ops->free(data);
-}
-
-static const struct event_trigger_ops *
-event_enable_get_trigger_ops(char *cmd, char *param)
-{
- const struct event_trigger_ops *ops;
- bool enable;
-
-#ifdef CONFIG_HIST_TRIGGERS
- enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
- (strcmp(cmd, ENABLE_HIST_STR) == 0));
-#else
- enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
-#endif
- if (enable)
- ops = param ? &event_enable_count_trigger_ops :
- &event_enable_trigger_ops;
- else
- ops = param ? &event_disable_count_trigger_ops :
- &event_disable_trigger_ops;
-
- return ops;
+ if (data && data->cmd_ops->free)
+ data->cmd_ops->free(data);
}
static struct event_command trigger_enable_cmd = {
@@ -1941,8 +1833,12 @@ static struct event_command trigger_enable_cmd = {
.parse = event_enable_trigger_parse,
.reg = event_enable_register_trigger,
.unreg = event_enable_unregister_trigger,
- .get_trigger_ops = event_enable_get_trigger_ops,
.set_filter = set_trigger_filter,
+ .trigger = event_enable_trigger,
+ .count_trigger = event_enable_count_trigger,
+ .print = event_enable_trigger_print,
+ .init = event_trigger_init,
+ .free = event_enable_trigger_free,
};
static struct event_command trigger_disable_cmd = {
@@ -1951,8 +1847,12 @@ static struct event_command trigger_disable_cmd = {
.parse = event_enable_trigger_parse,
.reg = event_enable_register_trigger,
.unreg = event_enable_unregister_trigger,
- .get_trigger_ops = event_enable_get_trigger_ops,
.set_filter = set_trigger_filter,
+ .trigger = event_enable_trigger,
+ .count_trigger = event_enable_count_trigger,
+ .print = event_enable_trigger_print,
+ .init = event_trigger_init,
+ .free = event_enable_trigger_free,
};
static __init void unregister_trigger_enable_disable_cmds(void)
--
2.53.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 6.6.y 2/3] tracing: Merge struct event_trigger_ops into struct event_command
2026-09-16 19:44 ` [PATCH 6.6.y 1/3] tracing: Constify struct event_trigger_ops Sasha Levin
@ 2026-09-16 19:44 ` Sasha Levin
0 siblings, 0 replies; 6+ messages in thread
From: Sasha Levin @ 2026-09-16 19:44 UTC (permalink / raw)
To: stable
Cc: Steven Rostedt, Masami Hiramatsu, Mark Rutland, Mathieu Desnoyers,
Andrew Morton, Tom Zanussi, Sasha Levin
From: Steven Rostedt <rostedt@goodmis.org>
[ Upstream commit b052d70f7c9c156409a70e65c10d83b5650e7e78 ]
Now that there's pretty much a one to one mapping between the struct
event_trigger_ops and struct event_command, there's no reason to have two
different structures. Merge the function pointers of event_trigger_ops
into event_command.
There's one exception in trace_events_hist.c for the
event_hist_trigger_named_ops. This has special logic for the init and free
function pointers for "named histograms". In this case, allocate the
cmd_ops of the event_trigger_data and set it to the proper init and free
functions, which are used to initialize and free the event_trigger_data
respectively. Have the free function and the init function (on failure)
free the cmd_ops of the data element.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://patch.msgid.link/20251125200932.446322765@kernel.org
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Stable backport note: Linux 6.6 still uses get_trigger_ops() to select
separate counted and uncounted trigger implementations. Limit this
preparatory merge to the init/free lifecycle callbacks and retain the
existing trigger/print dispatch in event_trigger_ops. Move every lifecycle
initializer and caller to event_command, including eprobes and histogram
enable/disable commands.
Keep the upstream allocation, initialization-failure cleanup, and teardown
of private command operations for named histograms. This supplies the
context needed by commit 0fe23b8eaba0 ("tracing: Take the reference before
publishing the named histogram trigger") without importing the missing
counting and unregister refactors or adding any functions.
Stable-dep-of: 0fe23b8eaba0 ("tracing: Take the reference before publishing the named histogram trigger")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/trace/trace.h | 49 ++++++++++------------
kernel/trace/trace_eprobe.c | 4 +-
kernel/trace/trace_events_hist.c | 65 +++++++++++++++++------------
kernel/trace/trace_events_trigger.c | 60 +++++++++++---------------
4 files changed, 86 insertions(+), 92 deletions(-)
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index cb3b9e3eabead..718cdf94f1600 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1707,18 +1707,13 @@ extern void event_file_put(struct trace_event_file *file);
* The methods in this structure provide per-event trigger hooks for
* various trigger operations.
*
- * The @init and @free methods are used during trigger setup and
- * teardown, typically called from an event_command's @parse()
- * function implementation.
- *
* The @print method is used to print the trigger spec.
*
* The @trigger method is the function that actually implements the
* trigger and is called in the context of the triggering event
* whenever that event occurs.
*
- * All the methods below, except for @init() and @free(), must be
- * implemented.
+ * All the methods below must be implemented.
*
* @trigger: The trigger 'probe' function called when the triggering
* event occurs. The data passed into this callback is the data
@@ -1726,23 +1721,6 @@ extern void event_file_put(struct trace_event_file *file);
* registered the trigger (see struct event_command) along with
* the trace record, rec.
*
- * @init: An optional initialization function called for the trigger
- * when the trigger is registered (via the event_command reg()
- * function). This can be used to perform per-trigger
- * initialization such as incrementing a per-trigger reference
- * count, for instance. This is usually implemented by the
- * generic utility function @event_trigger_init() (see
- * trace_event_triggers.c).
- *
- * @free: An optional de-initialization function called for the
- * trigger when the trigger is unregistered (via the
- * event_command @reg() function). This can be used to perform
- * per-trigger de-initialization such as decrementing a
- * per-trigger reference count and freeing corresponding trigger
- * data, for instance. This is usually implemented by the
- * generic utility function @event_trigger_free() (see
- * trace_event_triggers.c).
- *
* @print: The callback function invoked to have the trigger print
* itself. This is usually implemented by a wrapper function
* that calls the generic utility function @event_trigger_print()
@@ -1753,8 +1731,6 @@ struct event_trigger_ops {
struct trace_buffer *buffer,
void *rec,
struct ring_buffer_event *rbe);
- int (*init)(struct event_trigger_data *data);
- void (*free)(struct event_trigger_data *data);
int (*print)(struct seq_file *m,
struct event_trigger_data *data);
};
@@ -1808,7 +1784,7 @@ struct event_trigger_ops {
*
* @reg: Adds the trigger to the list of triggers associated with the
* event, and enables the event trigger itself, after
- * initializing it (via the event_trigger_ops @init() function).
+ * initializing it (via the event_command @init() function).
* This is also where commands can use the @trigger_type value to
* make the decision as to whether or not multiple instances of
* the trigger should be allowed. This is usually implemented by
@@ -1817,7 +1793,7 @@ struct event_trigger_ops {
*
* @unreg: Removes the trigger from the list of triggers associated
* with the event, and disables the event trigger itself, after
- * initializing it (via the event_trigger_ops @free() function).
+ * initializing it (via the event_command @free() function).
* This is usually implemented by the generic utility function
* @unregister_trigger() (see trace_event_triggers.c).
*
@@ -1837,6 +1813,23 @@ struct event_trigger_ops {
* support multiple trigger implementations via different sets of
* event_trigger_ops, depending on the value of the @param
* string.
+ *
+ * @init: An optional initialization function called for the trigger
+ * when the trigger is registered (via the event_command reg()
+ * function). This can be used to perform per-trigger
+ * initialization such as incrementing a per-trigger reference
+ * count, for instance. This is usually implemented by the
+ * generic utility function @event_trigger_init() (see
+ * trace_event_triggers.c).
+ *
+ * @free: An optional de-initialization function called for the
+ * trigger when the trigger is unregistered (via the
+ * event_command @reg() function). This can be used to perform
+ * per-trigger de-initialization such as decrementing a
+ * per-trigger reference count and freeing corresponding trigger
+ * data, for instance. This is usually implemented by the
+ * generic utility function @event_trigger_free() (see
+ * trace_event_triggers.c).
*/
struct event_command {
struct list_head list;
@@ -1858,6 +1851,8 @@ struct event_command {
struct event_trigger_data *data,
struct trace_event_file *file);
const struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
+ int (*init)(struct event_trigger_data *data);
+ void (*free)(struct event_trigger_data *data);
};
/**
diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index c7763d67741cc..1f5668a2c6423 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -482,8 +482,6 @@ static void eprobe_trigger_func(struct event_trigger_data *data,
static const struct event_trigger_ops eprobe_trigger_ops = {
.trigger = eprobe_trigger_func,
.print = eprobe_trigger_print,
- .init = eprobe_trigger_init,
- .free = eprobe_trigger_free,
};
static int eprobe_trigger_cmd_parse(struct event_command *cmd_ops,
@@ -524,6 +522,8 @@ static struct event_command event_trigger_cmd = {
.unreg_all = NULL,
.get_trigger_ops = eprobe_trigger_get_ops,
.set_filter = NULL,
+ .init = eprobe_trigger_init,
+ .free = eprobe_trigger_free,
};
static struct event_trigger_data *
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index ae70e3007fe10..516a610dce8da 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -6337,17 +6337,23 @@ static void event_hist_trigger_free(struct event_trigger_data *data)
static const struct event_trigger_ops event_hist_trigger_ops = {
.trigger = event_hist_trigger,
.print = event_hist_trigger_print,
- .init = event_hist_trigger_init,
- .free = event_hist_trigger_free,
};
static int event_hist_trigger_named_init(struct event_trigger_data *data)
{
+ int ret;
+
data->ref++;
save_named_trigger(data->named_data->name, data);
- return event_hist_trigger_init(data->named_data);
+ ret = event_hist_trigger_init(data->named_data);
+ if (ret < 0) {
+ kfree(data->cmd_ops);
+ data->cmd_ops = &trigger_hist_cmd;
+ }
+
+ return ret;
}
static void event_hist_trigger_named_free(struct event_trigger_data *data)
@@ -6359,18 +6365,14 @@ static void event_hist_trigger_named_free(struct event_trigger_data *data)
data->ref--;
if (!data->ref) {
+ struct event_command *cmd_ops = data->cmd_ops;
+
del_named_trigger(data);
trigger_data_free(data);
+ kfree(cmd_ops);
}
}
-static const struct event_trigger_ops event_hist_trigger_named_ops = {
- .trigger = event_hist_trigger,
- .print = event_hist_trigger_print,
- .init = event_hist_trigger_named_init,
- .free = event_hist_trigger_named_free,
-};
-
static const struct event_trigger_ops *event_hist_get_trigger_ops(char *cmd,
char *param)
{
@@ -6570,13 +6572,24 @@ static int hist_register_trigger(char *glob,
data->paused = true;
if (named_data) {
+ struct event_command *cmd_ops;
+
data->private_data = named_data->private_data;
set_named_trigger_data(data, named_data);
- data->ops = &event_hist_trigger_named_ops;
+ /* Copy the command ops and update some of the functions */
+ cmd_ops = kmalloc(sizeof(*cmd_ops), GFP_KERNEL);
+ if (!cmd_ops) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ *cmd_ops = *data->cmd_ops;
+ cmd_ops->init = event_hist_trigger_named_init;
+ cmd_ops->free = event_hist_trigger_named_free;
+ data->cmd_ops = cmd_ops;
}
- if (data->ops->init) {
- ret = data->ops->init(data);
+ if (data->cmd_ops->init) {
+ ret = data->cmd_ops->init(data);
if (ret < 0)
goto out;
}
@@ -6692,8 +6705,8 @@ static void hist_unregister_trigger(char *glob,
}
}
- if (test && test->ops->free)
- test->ops->free(test);
+ if (test && test->cmd_ops->free)
+ test->cmd_ops->free(test);
if (hist_data->enable_timestamps) {
if (!hist_data->remove || test)
@@ -6745,8 +6758,8 @@ static void hist_unreg_all(struct trace_event_file *file)
update_cond_flag(file);
if (hist_data->enable_timestamps)
tracing_set_filter_buffering(file->tr, false);
- if (test->ops->free)
- test->ops->free(test);
+ if (test->cmd_ops->free)
+ test->cmd_ops->free(test);
}
}
}
@@ -6924,6 +6937,8 @@ static struct event_command trigger_hist_cmd = {
.unreg_all = hist_unreg_all,
.get_trigger_ops = event_hist_get_trigger_ops,
.set_filter = set_trigger_filter,
+ .init = event_hist_trigger_init,
+ .free = event_hist_trigger_free,
};
__init int register_trigger_hist_cmd(void)
@@ -6972,29 +6987,21 @@ hist_enable_count_trigger(struct event_trigger_data *data,
static const struct event_trigger_ops hist_enable_trigger_ops = {
.trigger = hist_enable_trigger,
.print = event_enable_trigger_print,
- .init = event_trigger_init,
- .free = event_enable_trigger_free,
};
static const struct event_trigger_ops hist_enable_count_trigger_ops = {
.trigger = hist_enable_count_trigger,
.print = event_enable_trigger_print,
- .init = event_trigger_init,
- .free = event_enable_trigger_free,
};
static const struct event_trigger_ops hist_disable_trigger_ops = {
.trigger = hist_enable_trigger,
.print = event_enable_trigger_print,
- .init = event_trigger_init,
- .free = event_enable_trigger_free,
};
static const struct event_trigger_ops hist_disable_count_trigger_ops = {
.trigger = hist_enable_count_trigger,
.print = event_enable_trigger_print,
- .init = event_trigger_init,
- .free = event_enable_trigger_free,
};
static const struct event_trigger_ops *
@@ -7024,8 +7031,8 @@ static void hist_enable_unreg_all(struct trace_event_file *file)
list_del_rcu(&test->list);
update_cond_flag(file);
trace_event_trigger_enable_disable(file, 0);
- if (test->ops->free)
- test->ops->free(test);
+ if (test->cmd_ops->free)
+ test->cmd_ops->free(test);
}
}
}
@@ -7039,6 +7046,8 @@ static struct event_command trigger_hist_enable_cmd = {
.unreg_all = hist_enable_unreg_all,
.get_trigger_ops = hist_enable_get_trigger_ops,
.set_filter = set_trigger_filter,
+ .init = event_trigger_init,
+ .free = event_enable_trigger_free,
};
static struct event_command trigger_hist_disable_cmd = {
@@ -7050,6 +7059,8 @@ static struct event_command trigger_hist_disable_cmd = {
.unreg_all = hist_enable_unreg_all,
.get_trigger_ops = hist_enable_get_trigger_ops,
.set_filter = set_trigger_filter,
+ .init = event_trigger_init,
+ .free = event_enable_trigger_free,
};
static __init void unregister_trigger_hist_enable_disable_cmds(void)
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 48db99b7d61cb..c517515d9f859 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -437,7 +437,7 @@ event_trigger_print(const char *name, struct seq_file *m,
}
/**
- * event_trigger_init - Generic event_trigger_ops @init implementation
+ * event_trigger_init - Generic event_command @init implementation
* @data: Trigger-specific data
*
* Common implementation of event trigger initialization.
@@ -454,7 +454,7 @@ int event_trigger_init(struct event_trigger_data *data)
}
/**
- * event_trigger_free - Generic event_trigger_ops @free implementation
+ * event_trigger_free - Generic event_command @free implementation
* @data: Trigger-specific data
*
* Common implementation of event trigger de-initialization.
@@ -516,8 +516,8 @@ clear_event_triggers(struct trace_array *tr)
list_for_each_entry_safe(data, n, &file->triggers, list) {
trace_event_trigger_enable_disable(file, 0);
list_del_rcu(&data->list);
- if (data->ops->free)
- data->ops->free(data);
+ if (data->cmd_ops->free)
+ data->cmd_ops->free(data);
}
}
}
@@ -582,8 +582,8 @@ static int register_trigger(char *glob,
}
}
- if (data->ops->init) {
- ret = data->ops->init(data);
+ if (data->cmd_ops->init) {
+ ret = data->cmd_ops->init(data);
if (ret < 0)
goto out;
}
@@ -629,8 +629,8 @@ static void unregister_trigger(char *glob,
}
}
- if (data && data->ops->free)
- data->ops->free(data);
+ if (data && data->cmd_ops->free)
+ data->cmd_ops->free(data);
}
/*
@@ -1378,29 +1378,21 @@ traceoff_trigger_print(struct seq_file *m, struct event_trigger_data *data)
static const struct event_trigger_ops traceon_trigger_ops = {
.trigger = traceon_trigger,
.print = traceon_trigger_print,
- .init = event_trigger_init,
- .free = event_trigger_free,
};
static const struct event_trigger_ops traceon_count_trigger_ops = {
.trigger = traceon_count_trigger,
.print = traceon_trigger_print,
- .init = event_trigger_init,
- .free = event_trigger_free,
};
static const struct event_trigger_ops traceoff_trigger_ops = {
.trigger = traceoff_trigger,
.print = traceoff_trigger_print,
- .init = event_trigger_init,
- .free = event_trigger_free,
};
static const struct event_trigger_ops traceoff_count_trigger_ops = {
.trigger = traceoff_count_trigger,
.print = traceoff_trigger_print,
- .init = event_trigger_init,
- .free = event_trigger_free,
};
static const struct event_trigger_ops *
@@ -1427,6 +1419,8 @@ static struct event_command trigger_traceon_cmd = {
.unreg = unregister_trigger,
.get_trigger_ops = onoff_get_trigger_ops,
.set_filter = set_trigger_filter,
+ .init = event_trigger_init,
+ .free = event_trigger_free,
};
static struct event_command trigger_traceoff_cmd = {
@@ -1438,6 +1432,8 @@ static struct event_command trigger_traceoff_cmd = {
.unreg = unregister_trigger,
.get_trigger_ops = onoff_get_trigger_ops,
.set_filter = set_trigger_filter,
+ .init = event_trigger_init,
+ .free = event_trigger_free,
};
#ifdef CONFIG_TRACER_SNAPSHOT
@@ -1491,15 +1487,11 @@ snapshot_trigger_print(struct seq_file *m, struct event_trigger_data *data)
static const struct event_trigger_ops snapshot_trigger_ops = {
.trigger = snapshot_trigger,
.print = snapshot_trigger_print,
- .init = event_trigger_init,
- .free = event_trigger_free,
};
static const struct event_trigger_ops snapshot_count_trigger_ops = {
.trigger = snapshot_count_trigger,
.print = snapshot_trigger_print,
- .init = event_trigger_init,
- .free = event_trigger_free,
};
static const struct event_trigger_ops *
@@ -1516,6 +1508,8 @@ static struct event_command trigger_snapshot_cmd = {
.unreg = unregister_trigger,
.get_trigger_ops = snapshot_get_trigger_ops,
.set_filter = set_trigger_filter,
+ .init = event_trigger_init,
+ .free = event_trigger_free,
};
static __init int register_trigger_snapshot_cmd(void)
@@ -1586,15 +1580,11 @@ stacktrace_trigger_print(struct seq_file *m, struct event_trigger_data *data)
static const struct event_trigger_ops stacktrace_trigger_ops = {
.trigger = stacktrace_trigger,
.print = stacktrace_trigger_print,
- .init = event_trigger_init,
- .free = event_trigger_free,
};
static const struct event_trigger_ops stacktrace_count_trigger_ops = {
.trigger = stacktrace_count_trigger,
.print = stacktrace_trigger_print,
- .init = event_trigger_init,
- .free = event_trigger_free,
};
static const struct event_trigger_ops *
@@ -1612,6 +1602,8 @@ static struct event_command trigger_stacktrace_cmd = {
.unreg = unregister_trigger,
.get_trigger_ops = stacktrace_get_trigger_ops,
.set_filter = set_trigger_filter,
+ .init = event_trigger_init,
+ .free = event_trigger_free,
};
static __init int register_trigger_stacktrace_cmd(void)
@@ -1711,29 +1703,21 @@ void event_enable_trigger_free(struct event_trigger_data *data)
static const struct event_trigger_ops event_enable_trigger_ops = {
.trigger = event_enable_trigger,
.print = event_enable_trigger_print,
- .init = event_trigger_init,
- .free = event_enable_trigger_free,
};
static const struct event_trigger_ops event_enable_count_trigger_ops = {
.trigger = event_enable_count_trigger,
.print = event_enable_trigger_print,
- .init = event_trigger_init,
- .free = event_enable_trigger_free,
};
static const struct event_trigger_ops event_disable_trigger_ops = {
.trigger = event_enable_trigger,
.print = event_enable_trigger_print,
- .init = event_trigger_init,
- .free = event_enable_trigger_free,
};
static const struct event_trigger_ops event_disable_count_trigger_ops = {
.trigger = event_enable_count_trigger,
.print = event_enable_trigger_print,
- .init = event_trigger_init,
- .free = event_enable_trigger_free,
};
int event_enable_trigger_parse(struct event_command *cmd_ops,
@@ -1867,8 +1851,8 @@ int event_enable_register_trigger(char *glob,
}
}
- if (data->ops->init) {
- ret = data->ops->init(data);
+ if (data->cmd_ops->init) {
+ ret = data->cmd_ops->init(data);
if (ret < 0)
goto out;
}
@@ -1909,8 +1893,8 @@ void event_enable_unregister_trigger(char *glob,
}
}
- if (data && data->ops->free)
- data->ops->free(data);
+ if (data && data->cmd_ops->free)
+ data->cmd_ops->free(data);
}
static const struct event_trigger_ops *
@@ -1943,6 +1927,8 @@ static struct event_command trigger_enable_cmd = {
.unreg = event_enable_unregister_trigger,
.get_trigger_ops = event_enable_get_trigger_ops,
.set_filter = set_trigger_filter,
+ .init = event_trigger_init,
+ .free = event_enable_trigger_free,
};
static struct event_command trigger_disable_cmd = {
@@ -1953,6 +1939,8 @@ static struct event_command trigger_disable_cmd = {
.unreg = event_enable_unregister_trigger,
.get_trigger_ops = event_enable_get_trigger_ops,
.set_filter = set_trigger_filter,
+ .init = event_trigger_init,
+ .free = event_enable_trigger_free,
};
static __init void unregister_trigger_enable_disable_cmds(void)
--
2.53.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 6.6.y 1/3] tracing: Constify struct event_trigger_ops
2026-09-16 14:19 FAILED: patch "[PATCH] tracing: Undo the registration when enabling the histogram" failed to apply to 6.6-stable tree gregkh
@ 2026-09-16 19:49 ` Sasha Levin
2026-09-16 19:49 ` [PATCH 6.6.y 2/3] tracing: Merge struct event_trigger_ops into struct event_command Sasha Levin
2026-09-16 19:49 ` [PATCH 6.6.y 3/3] tracing: Undo the registration when enabling the histogram trigger fails Sasha Levin
0 siblings, 2 replies; 6+ messages in thread
From: Sasha Levin @ 2026-09-16 19:49 UTC (permalink / raw)
To: stable
Cc: Christophe JAILLET, Masami Hiramatsu, Mathieu Desnoyers,
Steven Rostedt (Google), Sasha Levin
From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
[ Upstream commit 502d2e71a89fa706843fa9277f4d6de1947072c8 ]
'event_trigger_ops mwifiex_if_ops' are not modified in these drivers.
Constifying these structures moves some data to a read-only section, so
increase overall security, especially when the structure holds some
function pointers.
On a x86_64, with allmodconfig, as an example:
Before:
======
text data bss dec hex filename
31368 9024 6200 46592 b600 kernel/trace/trace_events_trigger.o
After:
=====
text data bss dec hex filename
31752 8608 6200 46560 b5e0 kernel/trace/trace_events_trigger.o
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/66e8f990e649678e4be37d4d1a19158ca0dea2f4.1741521295.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Stable-dep-of: 92383cef6679 ("tracing: Undo the registration when enabling the histogram trigger fails")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/trace/trace.h | 4 +--
kernel/trace/trace_eprobe.c | 6 ++---
kernel/trace/trace_events_hist.c | 20 +++++++--------
kernel/trace/trace_events_trigger.c | 38 ++++++++++++++---------------
4 files changed, 34 insertions(+), 34 deletions(-)
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 05ac2b5c8e208..cb3b9e3eabead 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1614,7 +1614,7 @@ struct event_trigger_data {
unsigned long count;
int ref;
int flags;
- struct event_trigger_ops *ops;
+ const struct event_trigger_ops *ops;
struct event_command *cmd_ops;
struct event_filter __rcu *filter;
char *filter_str;
@@ -1857,7 +1857,7 @@ struct event_command {
int (*set_filter)(char *filter_str,
struct event_trigger_data *data,
struct trace_event_file *file);
- struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
+ const struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
};
/**
diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index a9be1ed07ae38..c7763d67741cc 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -479,7 +479,7 @@ static void eprobe_trigger_func(struct event_trigger_data *data,
__eprobe_trace_func(edata, rec);
}
-static struct event_trigger_ops eprobe_trigger_ops = {
+static const struct event_trigger_ops eprobe_trigger_ops = {
.trigger = eprobe_trigger_func,
.print = eprobe_trigger_print,
.init = eprobe_trigger_init,
@@ -508,8 +508,8 @@ static void eprobe_trigger_unreg_func(char *glob,
}
-static struct event_trigger_ops *eprobe_trigger_get_ops(char *cmd,
- char *param)
+static const struct event_trigger_ops *eprobe_trigger_get_ops(char *cmd,
+ char *param)
{
return &eprobe_trigger_ops;
}
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index d7e8018559938..ae70e3007fe10 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -6334,7 +6334,7 @@ static void event_hist_trigger_free(struct event_trigger_data *data)
free_hist_pad();
}
-static struct event_trigger_ops event_hist_trigger_ops = {
+static const struct event_trigger_ops event_hist_trigger_ops = {
.trigger = event_hist_trigger,
.print = event_hist_trigger_print,
.init = event_hist_trigger_init,
@@ -6364,15 +6364,15 @@ static void event_hist_trigger_named_free(struct event_trigger_data *data)
}
}
-static struct event_trigger_ops event_hist_trigger_named_ops = {
+static const struct event_trigger_ops event_hist_trigger_named_ops = {
.trigger = event_hist_trigger,
.print = event_hist_trigger_print,
.init = event_hist_trigger_named_init,
.free = event_hist_trigger_named_free,
};
-static struct event_trigger_ops *event_hist_get_trigger_ops(char *cmd,
- char *param)
+static const struct event_trigger_ops *event_hist_get_trigger_ops(char *cmd,
+ char *param)
{
return &event_hist_trigger_ops;
}
@@ -6969,38 +6969,38 @@ hist_enable_count_trigger(struct event_trigger_data *data,
hist_enable_trigger(data, buffer, rec, event);
}
-static struct event_trigger_ops hist_enable_trigger_ops = {
+static const struct event_trigger_ops hist_enable_trigger_ops = {
.trigger = hist_enable_trigger,
.print = event_enable_trigger_print,
.init = event_trigger_init,
.free = event_enable_trigger_free,
};
-static struct event_trigger_ops hist_enable_count_trigger_ops = {
+static const struct event_trigger_ops hist_enable_count_trigger_ops = {
.trigger = hist_enable_count_trigger,
.print = event_enable_trigger_print,
.init = event_trigger_init,
.free = event_enable_trigger_free,
};
-static struct event_trigger_ops hist_disable_trigger_ops = {
+static const struct event_trigger_ops hist_disable_trigger_ops = {
.trigger = hist_enable_trigger,
.print = event_enable_trigger_print,
.init = event_trigger_init,
.free = event_enable_trigger_free,
};
-static struct event_trigger_ops hist_disable_count_trigger_ops = {
+static const struct event_trigger_ops hist_disable_count_trigger_ops = {
.trigger = hist_enable_count_trigger,
.print = event_enable_trigger_print,
.init = event_trigger_init,
.free = event_enable_trigger_free,
};
-static struct event_trigger_ops *
+static const struct event_trigger_ops *
hist_enable_get_trigger_ops(char *cmd, char *param)
{
- struct event_trigger_ops *ops;
+ const struct event_trigger_ops *ops;
bool enable;
enable = (strcmp(cmd, ENABLE_HIST_STR) == 0);
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 3ef1fe15493d3..48db99b7d61cb 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -833,7 +833,7 @@ struct event_trigger_data *trigger_data_alloc(struct event_command *cmd_ops,
void *private_data)
{
struct event_trigger_data *trigger_data;
- struct event_trigger_ops *trigger_ops;
+ const struct event_trigger_ops *trigger_ops;
trigger_ops = cmd_ops->get_trigger_ops(cmd, param);
@@ -1375,38 +1375,38 @@ traceoff_trigger_print(struct seq_file *m, struct event_trigger_data *data)
data->filter_str);
}
-static struct event_trigger_ops traceon_trigger_ops = {
+static const struct event_trigger_ops traceon_trigger_ops = {
.trigger = traceon_trigger,
.print = traceon_trigger_print,
.init = event_trigger_init,
.free = event_trigger_free,
};
-static struct event_trigger_ops traceon_count_trigger_ops = {
+static const struct event_trigger_ops traceon_count_trigger_ops = {
.trigger = traceon_count_trigger,
.print = traceon_trigger_print,
.init = event_trigger_init,
.free = event_trigger_free,
};
-static struct event_trigger_ops traceoff_trigger_ops = {
+static const struct event_trigger_ops traceoff_trigger_ops = {
.trigger = traceoff_trigger,
.print = traceoff_trigger_print,
.init = event_trigger_init,
.free = event_trigger_free,
};
-static struct event_trigger_ops traceoff_count_trigger_ops = {
+static const struct event_trigger_ops traceoff_count_trigger_ops = {
.trigger = traceoff_count_trigger,
.print = traceoff_trigger_print,
.init = event_trigger_init,
.free = event_trigger_free,
};
-static struct event_trigger_ops *
+static const struct event_trigger_ops *
onoff_get_trigger_ops(char *cmd, char *param)
{
- struct event_trigger_ops *ops;
+ const struct event_trigger_ops *ops;
/* we register both traceon and traceoff to this callback */
if (strcmp(cmd, "traceon") == 0)
@@ -1488,21 +1488,21 @@ snapshot_trigger_print(struct seq_file *m, struct event_trigger_data *data)
data->filter_str);
}
-static struct event_trigger_ops snapshot_trigger_ops = {
+static const struct event_trigger_ops snapshot_trigger_ops = {
.trigger = snapshot_trigger,
.print = snapshot_trigger_print,
.init = event_trigger_init,
.free = event_trigger_free,
};
-static struct event_trigger_ops snapshot_count_trigger_ops = {
+static const struct event_trigger_ops snapshot_count_trigger_ops = {
.trigger = snapshot_count_trigger,
.print = snapshot_trigger_print,
.init = event_trigger_init,
.free = event_trigger_free,
};
-static struct event_trigger_ops *
+static const struct event_trigger_ops *
snapshot_get_trigger_ops(char *cmd, char *param)
{
return param ? &snapshot_count_trigger_ops : &snapshot_trigger_ops;
@@ -1583,21 +1583,21 @@ stacktrace_trigger_print(struct seq_file *m, struct event_trigger_data *data)
data->filter_str);
}
-static struct event_trigger_ops stacktrace_trigger_ops = {
+static const struct event_trigger_ops stacktrace_trigger_ops = {
.trigger = stacktrace_trigger,
.print = stacktrace_trigger_print,
.init = event_trigger_init,
.free = event_trigger_free,
};
-static struct event_trigger_ops stacktrace_count_trigger_ops = {
+static const struct event_trigger_ops stacktrace_count_trigger_ops = {
.trigger = stacktrace_count_trigger,
.print = stacktrace_trigger_print,
.init = event_trigger_init,
.free = event_trigger_free,
};
-static struct event_trigger_ops *
+static const struct event_trigger_ops *
stacktrace_get_trigger_ops(char *cmd, char *param)
{
return param ? &stacktrace_count_trigger_ops : &stacktrace_trigger_ops;
@@ -1708,28 +1708,28 @@ void event_enable_trigger_free(struct event_trigger_data *data)
}
}
-static struct event_trigger_ops event_enable_trigger_ops = {
+static const struct event_trigger_ops event_enable_trigger_ops = {
.trigger = event_enable_trigger,
.print = event_enable_trigger_print,
.init = event_trigger_init,
.free = event_enable_trigger_free,
};
-static struct event_trigger_ops event_enable_count_trigger_ops = {
+static const struct event_trigger_ops event_enable_count_trigger_ops = {
.trigger = event_enable_count_trigger,
.print = event_enable_trigger_print,
.init = event_trigger_init,
.free = event_enable_trigger_free,
};
-static struct event_trigger_ops event_disable_trigger_ops = {
+static const struct event_trigger_ops event_disable_trigger_ops = {
.trigger = event_enable_trigger,
.print = event_enable_trigger_print,
.init = event_trigger_init,
.free = event_enable_trigger_free,
};
-static struct event_trigger_ops event_disable_count_trigger_ops = {
+static const struct event_trigger_ops event_disable_count_trigger_ops = {
.trigger = event_enable_count_trigger,
.print = event_enable_trigger_print,
.init = event_trigger_init,
@@ -1913,10 +1913,10 @@ void event_enable_unregister_trigger(char *glob,
data->ops->free(data);
}
-static struct event_trigger_ops *
+static const struct event_trigger_ops *
event_enable_get_trigger_ops(char *cmd, char *param)
{
- struct event_trigger_ops *ops;
+ const struct event_trigger_ops *ops;
bool enable;
#ifdef CONFIG_HIST_TRIGGERS
--
2.53.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 6.6.y 2/3] tracing: Merge struct event_trigger_ops into struct event_command
2026-09-16 19:49 ` [PATCH 6.6.y 1/3] tracing: Constify struct event_trigger_ops Sasha Levin
@ 2026-09-16 19:49 ` Sasha Levin
2026-09-16 19:49 ` [PATCH 6.6.y 3/3] tracing: Undo the registration when enabling the histogram trigger fails Sasha Levin
1 sibling, 0 replies; 6+ messages in thread
From: Sasha Levin @ 2026-09-16 19:49 UTC (permalink / raw)
To: stable
Cc: Steven Rostedt, Masami Hiramatsu, Mark Rutland, Mathieu Desnoyers,
Andrew Morton, Tom Zanussi, Sasha Levin
From: Steven Rostedt <rostedt@goodmis.org>
[ Upstream commit b052d70f7c9c156409a70e65c10d83b5650e7e78 ]
Now that there's pretty much a one to one mapping between the struct
event_trigger_ops and struct event_command, there's no reason to have two
different structures. Merge the function pointers of event_trigger_ops
into event_command.
There's one exception in trace_events_hist.c for the
event_hist_trigger_named_ops. This has special logic for the init and free
function pointers for "named histograms". In this case, allocate the
cmd_ops of the event_trigger_data and set it to the proper init and free
functions, which are used to initialize and free the event_trigger_data
respectively. Have the free function and the init function (on failure)
free the cmd_ops of the data element.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://patch.msgid.link/20251125200932.446322765@kernel.org
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Backport adaptation for 6.6:
The stable tree still selects separate counted-trigger callbacks through
get_trigger_ops(), and lacks the upstream count_func and trigger dispatch
refactors. Merge the operation tables into event_command while preserving
those existing counted callbacks as count_trigger. Select and cache the
appropriate callback in event_trigger_data at allocation time, including
the separately allocated eprobe triggers. No functions are added.
Keep the upstream named-histogram command copy and its init/free lifetime
handling. Do not import data_ops_trigger(), try_unregister_trigger(), or
other helpers absent from this stable tree.
Remove the redundant histogram out_free filter reset, since
trigger_data_free() already resets the filter. This also provides the
unchanged context needed by 92383cef6679. All three target hunks apply
without modification.
Stable-dep-of: 92383cef6679 ("tracing: Undo the registration when enabling the histogram trigger fails")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/trace/trace.h | 119 +++++++--------
kernel/trace/trace_eprobe.c | 20 +--
kernel/trace/trace_events_hist.c | 131 +++++++----------
kernel/trace/trace_events_trigger.c | 216 +++++++---------------------
4 files changed, 155 insertions(+), 331 deletions(-)
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index cb3b9e3eabead..2885a373dba4d 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1614,7 +1614,10 @@ struct event_trigger_data {
unsigned long count;
int ref;
int flags;
- const struct event_trigger_ops *ops;
+ void (*trigger)(struct event_trigger_data *data,
+ struct trace_buffer *buffer,
+ void *rec,
+ struct ring_buffer_event *rbe);
struct event_command *cmd_ops;
struct event_filter __rcu *filter;
char *filter_str;
@@ -1701,64 +1704,6 @@ extern void event_trigger_unregister(struct event_command *cmd_ops,
extern void event_file_get(struct trace_event_file *file);
extern void event_file_put(struct trace_event_file *file);
-/**
- * struct event_trigger_ops - callbacks for trace event triggers
- *
- * The methods in this structure provide per-event trigger hooks for
- * various trigger operations.
- *
- * The @init and @free methods are used during trigger setup and
- * teardown, typically called from an event_command's @parse()
- * function implementation.
- *
- * The @print method is used to print the trigger spec.
- *
- * The @trigger method is the function that actually implements the
- * trigger and is called in the context of the triggering event
- * whenever that event occurs.
- *
- * All the methods below, except for @init() and @free(), must be
- * implemented.
- *
- * @trigger: The trigger 'probe' function called when the triggering
- * event occurs. The data passed into this callback is the data
- * that was supplied to the event_command @reg() function that
- * registered the trigger (see struct event_command) along with
- * the trace record, rec.
- *
- * @init: An optional initialization function called for the trigger
- * when the trigger is registered (via the event_command reg()
- * function). This can be used to perform per-trigger
- * initialization such as incrementing a per-trigger reference
- * count, for instance. This is usually implemented by the
- * generic utility function @event_trigger_init() (see
- * trace_event_triggers.c).
- *
- * @free: An optional de-initialization function called for the
- * trigger when the trigger is unregistered (via the
- * event_command @reg() function). This can be used to perform
- * per-trigger de-initialization such as decrementing a
- * per-trigger reference count and freeing corresponding trigger
- * data, for instance. This is usually implemented by the
- * generic utility function @event_trigger_free() (see
- * trace_event_triggers.c).
- *
- * @print: The callback function invoked to have the trigger print
- * itself. This is usually implemented by a wrapper function
- * that calls the generic utility function @event_trigger_print()
- * (see trace_event_triggers.c).
- */
-struct event_trigger_ops {
- void (*trigger)(struct event_trigger_data *data,
- struct trace_buffer *buffer,
- void *rec,
- struct ring_buffer_event *rbe);
- int (*init)(struct event_trigger_data *data);
- void (*free)(struct event_trigger_data *data);
- int (*print)(struct seq_file *m,
- struct event_trigger_data *data);
-};
-
/**
* struct event_command - callbacks and data members for event commands
*
@@ -1808,7 +1753,7 @@ struct event_trigger_ops {
*
* @reg: Adds the trigger to the list of triggers associated with the
* event, and enables the event trigger itself, after
- * initializing it (via the event_trigger_ops @init() function).
+ * initializing it (via the event_command @init() function).
* This is also where commands can use the @trigger_type value to
* make the decision as to whether or not multiple instances of
* the trigger should be allowed. This is usually implemented by
@@ -1817,7 +1762,7 @@ struct event_trigger_ops {
*
* @unreg: Removes the trigger from the list of triggers associated
* with the event, and disables the event trigger itself, after
- * initializing it (via the event_trigger_ops @free() function).
+ * initializing it (via the event_command @free() function).
* This is usually implemented by the generic utility function
* @unregister_trigger() (see trace_event_triggers.c).
*
@@ -1831,12 +1776,37 @@ struct event_trigger_ops {
* ignored. This is usually implemented by the generic utility
* function @set_trigger_filter() (see trace_event_triggers.c).
*
- * @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.
+ * @trigger: The trigger 'probe' function called when the triggering
+ * event occurs. The data passed into this callback is the data
+ * that was supplied to the event_command @reg() function that
+ * registered the trigger (see struct event_command) along with
+ * the trace record, rec.
+ *
+ * @count_trigger: An optional trigger callback used instead of @trigger
+ * when a count parameter is supplied. This callback implements both
+ * the count handling and the trigger action.
+ *
+ * @init: An optional initialization function called for the trigger
+ * when the trigger is registered (via the event_command reg()
+ * function). This can be used to perform per-trigger
+ * initialization such as incrementing a per-trigger reference
+ * count, for instance. This is usually implemented by the
+ * generic utility function @event_trigger_init() (see
+ * trace_event_triggers.c).
+ *
+ * @free: An optional de-initialization function called for the
+ * trigger when the trigger is unregistered (via the
+ * event_command @reg() function). This can be used to perform
+ * per-trigger de-initialization such as decrementing a
+ * per-trigger reference count and freeing corresponding trigger
+ * data, for instance. This is usually implemented by the
+ * generic utility function @event_trigger_free() (see
+ * trace_event_triggers.c).
+ *
+ * @print: The callback function invoked to have the trigger print
+ * itself. This is usually implemented by a wrapper function
+ * that calls the generic utility function @event_trigger_print()
+ * (see trace_event_triggers.c).
*/
struct event_command {
struct list_head list;
@@ -1857,7 +1827,18 @@ struct event_command {
int (*set_filter)(char *filter_str,
struct event_trigger_data *data,
struct trace_event_file *file);
- const struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
+ void (*trigger)(struct event_trigger_data *data,
+ struct trace_buffer *buffer,
+ void *rec,
+ struct ring_buffer_event *rbe);
+ int (*init)(struct event_trigger_data *data);
+ void (*free)(struct event_trigger_data *data);
+ int (*print)(struct seq_file *m,
+ struct event_trigger_data *data);
+ void (*count_trigger)(struct event_trigger_data *data,
+ struct trace_buffer *buffer,
+ void *rec,
+ struct ring_buffer_event *rbe);
};
/**
@@ -1878,7 +1859,7 @@ struct event_command {
* either committed or discarded. At that point, if any commands
* have deferred their triggers, those commands are finally
* invoked following the close of the current event. In other
- * words, if the event_trigger_ops @func() probe implementation
+ * words, if the event_command @func() probe implementation
* itself logs to the trace buffer, this flag should be set,
* otherwise it can be left unspecified.
*
diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index c7763d67741cc..3189df23e8e9e 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -479,13 +479,6 @@ static void eprobe_trigger_func(struct event_trigger_data *data,
__eprobe_trace_func(edata, rec);
}
-static const struct event_trigger_ops eprobe_trigger_ops = {
- .trigger = eprobe_trigger_func,
- .print = eprobe_trigger_print,
- .init = eprobe_trigger_init,
- .free = eprobe_trigger_free,
-};
-
static int eprobe_trigger_cmd_parse(struct event_command *cmd_ops,
struct trace_event_file *file,
char *glob, char *cmd,
@@ -508,12 +501,6 @@ static void eprobe_trigger_unreg_func(char *glob,
}
-static const struct event_trigger_ops *eprobe_trigger_get_ops(char *cmd,
- char *param)
-{
- return &eprobe_trigger_ops;
-}
-
static struct event_command event_trigger_cmd = {
.name = "eprobe",
.trigger_type = ETT_EVENT_EPROBE,
@@ -522,8 +509,11 @@ static struct event_command event_trigger_cmd = {
.reg = eprobe_trigger_reg_func,
.unreg = eprobe_trigger_unreg_func,
.unreg_all = NULL,
- .get_trigger_ops = eprobe_trigger_get_ops,
.set_filter = NULL,
+ .trigger = eprobe_trigger_func,
+ .print = eprobe_trigger_print,
+ .init = eprobe_trigger_init,
+ .free = eprobe_trigger_free,
};
static struct event_trigger_data *
@@ -543,7 +533,7 @@ new_eprobe_trigger(struct trace_eprobe *ep, struct trace_event_file *file)
trigger->flags = EVENT_TRIGGER_FL_PROBE;
trigger->count = -1;
- trigger->ops = &eprobe_trigger_ops;
+ trigger->trigger = eprobe_trigger_func;
/*
* EVENT PROBE triggers are not registered as commands with
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index ae70e3007fe10..1ea2eff8a9f66 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -5704,7 +5704,7 @@ 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);
+ data->cmd_ops->print(m, data);
seq_puts(m, "#\n\n");
hist_data = data->private_data;
@@ -6026,7 +6026,7 @@ 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);
+ data->cmd_ops->print(m, data);
seq_puts(m, "#\n\n");
hist_data = data->private_data;
@@ -6334,20 +6334,21 @@ static void event_hist_trigger_free(struct event_trigger_data *data)
free_hist_pad();
}
-static const struct event_trigger_ops event_hist_trigger_ops = {
- .trigger = event_hist_trigger,
- .print = event_hist_trigger_print,
- .init = event_hist_trigger_init,
- .free = event_hist_trigger_free,
-};
-
static int event_hist_trigger_named_init(struct event_trigger_data *data)
{
+ int ret;
+
data->ref++;
save_named_trigger(data->named_data->name, data);
- return event_hist_trigger_init(data->named_data);
+ ret = event_hist_trigger_init(data->named_data);
+ if (ret < 0) {
+ kfree(data->cmd_ops);
+ data->cmd_ops = &trigger_hist_cmd;
+ }
+
+ return ret;
}
static void event_hist_trigger_named_free(struct event_trigger_data *data)
@@ -6359,24 +6360,14 @@ static void event_hist_trigger_named_free(struct event_trigger_data *data)
data->ref--;
if (!data->ref) {
+ struct event_command *cmd_ops = data->cmd_ops;
+
del_named_trigger(data);
trigger_data_free(data);
+ kfree(cmd_ops);
}
}
-static const struct event_trigger_ops event_hist_trigger_named_ops = {
- .trigger = event_hist_trigger,
- .print = event_hist_trigger_print,
- .init = event_hist_trigger_named_init,
- .free = event_hist_trigger_named_free,
-};
-
-static const struct event_trigger_ops *event_hist_get_trigger_ops(char *cmd,
- char *param)
-{
- return &event_hist_trigger_ops;
-}
-
static void hist_clear(struct event_trigger_data *data)
{
struct hist_trigger_data *hist_data = data->private_data;
@@ -6570,13 +6561,24 @@ static int hist_register_trigger(char *glob,
data->paused = true;
if (named_data) {
+ struct event_command *cmd_ops;
+
data->private_data = named_data->private_data;
set_named_trigger_data(data, named_data);
- data->ops = &event_hist_trigger_named_ops;
+ /* Copy the command ops and update some of the functions */
+ cmd_ops = kmalloc(sizeof(*cmd_ops), GFP_KERNEL);
+ if (!cmd_ops) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ *cmd_ops = *data->cmd_ops;
+ cmd_ops->init = event_hist_trigger_named_init;
+ cmd_ops->free = event_hist_trigger_named_free;
+ data->cmd_ops = cmd_ops;
}
- if (data->ops->init) {
- ret = data->ops->init(data);
+ if (data->cmd_ops->init) {
+ ret = data->cmd_ops->init(data);
if (ret < 0)
goto out;
}
@@ -6692,8 +6694,8 @@ static void hist_unregister_trigger(char *glob,
}
}
- if (test && test->ops->free)
- test->ops->free(test);
+ if (test && test->cmd_ops->free)
+ test->cmd_ops->free(test);
if (hist_data->enable_timestamps) {
if (!hist_data->remove || test)
@@ -6745,8 +6747,8 @@ static void hist_unreg_all(struct trace_event_file *file)
update_cond_flag(file);
if (hist_data->enable_timestamps)
tracing_set_filter_buffering(file->tr, false);
- if (test->ops->free)
- test->ops->free(test);
+ if (test->cmd_ops->free)
+ test->cmd_ops->free(test);
}
}
}
@@ -6904,8 +6906,6 @@ static int event_hist_trigger_parse(struct event_command *cmd_ops,
out_unreg:
event_trigger_unregister(cmd_ops, file, glob+1, trigger_data);
out_free:
- event_trigger_reset_filter(cmd_ops, trigger_data);
-
remove_hist_vars(hist_data);
trigger_data_free(trigger_data);
@@ -6922,8 +6922,11 @@ static struct event_command trigger_hist_cmd = {
.reg = hist_register_trigger,
.unreg = hist_unregister_trigger,
.unreg_all = hist_unreg_all,
- .get_trigger_ops = event_hist_get_trigger_ops,
.set_filter = set_trigger_filter,
+ .trigger = event_hist_trigger,
+ .print = event_hist_trigger_print,
+ .init = event_hist_trigger_init,
+ .free = event_hist_trigger_free,
};
__init int register_trigger_hist_cmd(void)
@@ -6969,52 +6972,6 @@ hist_enable_count_trigger(struct event_trigger_data *data,
hist_enable_trigger(data, buffer, rec, event);
}
-static const struct event_trigger_ops hist_enable_trigger_ops = {
- .trigger = hist_enable_trigger,
- .print = event_enable_trigger_print,
- .init = event_trigger_init,
- .free = event_enable_trigger_free,
-};
-
-static const struct event_trigger_ops hist_enable_count_trigger_ops = {
- .trigger = hist_enable_count_trigger,
- .print = event_enable_trigger_print,
- .init = event_trigger_init,
- .free = event_enable_trigger_free,
-};
-
-static const struct event_trigger_ops hist_disable_trigger_ops = {
- .trigger = hist_enable_trigger,
- .print = event_enable_trigger_print,
- .init = event_trigger_init,
- .free = event_enable_trigger_free,
-};
-
-static const struct event_trigger_ops hist_disable_count_trigger_ops = {
- .trigger = hist_enable_count_trigger,
- .print = event_enable_trigger_print,
- .init = event_trigger_init,
- .free = event_enable_trigger_free,
-};
-
-static const struct event_trigger_ops *
-hist_enable_get_trigger_ops(char *cmd, char *param)
-{
- const struct event_trigger_ops *ops;
- bool enable;
-
- enable = (strcmp(cmd, ENABLE_HIST_STR) == 0);
-
- if (enable)
- ops = param ? &hist_enable_count_trigger_ops :
- &hist_enable_trigger_ops;
- else
- ops = param ? &hist_disable_count_trigger_ops :
- &hist_disable_trigger_ops;
-
- return ops;
-}
-
static void hist_enable_unreg_all(struct trace_event_file *file)
{
struct event_trigger_data *test, *n;
@@ -7024,8 +6981,8 @@ static void hist_enable_unreg_all(struct trace_event_file *file)
list_del_rcu(&test->list);
update_cond_flag(file);
trace_event_trigger_enable_disable(file, 0);
- if (test->ops->free)
- test->ops->free(test);
+ if (test->cmd_ops->free)
+ test->cmd_ops->free(test);
}
}
}
@@ -7037,8 +6994,12 @@ static struct event_command trigger_hist_enable_cmd = {
.reg = event_enable_register_trigger,
.unreg = event_enable_unregister_trigger,
.unreg_all = hist_enable_unreg_all,
- .get_trigger_ops = hist_enable_get_trigger_ops,
.set_filter = set_trigger_filter,
+ .trigger = hist_enable_trigger,
+ .count_trigger = hist_enable_count_trigger,
+ .print = event_enable_trigger_print,
+ .init = event_trigger_init,
+ .free = event_enable_trigger_free,
};
static struct event_command trigger_hist_disable_cmd = {
@@ -7048,8 +7009,12 @@ static struct event_command trigger_hist_disable_cmd = {
.reg = event_enable_register_trigger,
.unreg = event_enable_unregister_trigger,
.unreg_all = hist_enable_unreg_all,
- .get_trigger_ops = hist_enable_get_trigger_ops,
.set_filter = set_trigger_filter,
+ .trigger = hist_enable_trigger,
+ .count_trigger = hist_enable_count_trigger,
+ .print = event_enable_trigger_print,
+ .init = event_trigger_init,
+ .free = event_enable_trigger_free,
};
static __init void unregister_trigger_hist_enable_disable_cmds(void)
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 48db99b7d61cb..1007e1041c004 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -73,7 +73,7 @@ event_triggers_call(struct trace_event_file *file,
if (data->paused)
continue;
if (!rec) {
- data->ops->trigger(data, buffer, rec, event);
+ data->trigger(data, buffer, rec, event);
continue;
}
filter = rcu_dereference_sched(data->filter);
@@ -83,7 +83,7 @@ event_triggers_call(struct trace_event_file *file,
tt |= data->cmd_ops->trigger_type;
continue;
}
- data->ops->trigger(data, buffer, rec, event);
+ data->trigger(data, buffer, rec, event);
}
return tt;
}
@@ -125,7 +125,7 @@ event_triggers_post_call(struct trace_event_file *file,
if (data->paused)
continue;
if (data->cmd_ops->trigger_type & tt)
- data->ops->trigger(data, NULL, NULL, NULL);
+ data->trigger(data, NULL, NULL, NULL);
}
}
EXPORT_SYMBOL_GPL(event_triggers_post_call);
@@ -194,7 +194,7 @@ static int trigger_show(struct seq_file *m, void *v)
}
data = list_entry(v, struct event_trigger_data, list);
- data->ops->print(m, data);
+ data->cmd_ops->print(m, data);
return 0;
}
@@ -402,7 +402,7 @@ __init int unregister_event_command(struct event_command *cmd)
}
/**
- * event_trigger_print - Generic event_trigger_ops @print implementation
+ * event_trigger_print - Generic event_command @print implementation
* @name: The name of the event trigger
* @m: The seq_file being printed to
* @data: Trigger-specific data
@@ -437,7 +437,7 @@ event_trigger_print(const char *name, struct seq_file *m,
}
/**
- * event_trigger_init - Generic event_trigger_ops @init implementation
+ * event_trigger_init - Generic event_command @init implementation
* @data: Trigger-specific data
*
* Common implementation of event trigger initialization.
@@ -454,7 +454,7 @@ int event_trigger_init(struct event_trigger_data *data)
}
/**
- * event_trigger_free - Generic event_trigger_ops @free implementation
+ * event_trigger_free - Generic event_command @free implementation
* @data: Trigger-specific data
*
* Common implementation of event trigger de-initialization.
@@ -516,8 +516,8 @@ clear_event_triggers(struct trace_array *tr)
list_for_each_entry_safe(data, n, &file->triggers, list) {
trace_event_trigger_enable_disable(file, 0);
list_del_rcu(&data->list);
- if (data->ops->free)
- data->ops->free(data);
+ if (data->cmd_ops->free)
+ data->cmd_ops->free(data);
}
}
}
@@ -582,8 +582,8 @@ static int register_trigger(char *glob,
}
}
- if (data->ops->init) {
- ret = data->ops->init(data);
+ if (data->cmd_ops->init) {
+ ret = data->cmd_ops->init(data);
if (ret < 0)
goto out;
}
@@ -629,8 +629,8 @@ static void unregister_trigger(char *glob,
}
}
- if (data && data->ops->free)
- data->ops->free(data);
+ if (data && data->cmd_ops->free)
+ data->cmd_ops->free(data);
}
/*
@@ -819,9 +819,9 @@ int event_trigger_separate_filter(char *param_and_filter, char **param,
* @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.
+ * @cmd_ops and @param select the trigger callback, using @count_trigger
+ * when a count parameter is supplied. @private_data can also be passed
+ * in and associated with the event_trigger_data.
*
* Use trigger_data_free() to free an event_trigger_data object.
*
@@ -833,16 +833,14 @@ struct event_trigger_data *trigger_data_alloc(struct event_command *cmd_ops,
void *private_data)
{
struct event_trigger_data *trigger_data;
- const 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->trigger = param && cmd_ops->count_trigger ?
+ cmd_ops->count_trigger : cmd_ops->trigger;
trigger_data->cmd_ops = cmd_ops;
trigger_data->private_data = private_data;
@@ -1375,58 +1373,18 @@ traceoff_trigger_print(struct seq_file *m, struct event_trigger_data *data)
data->filter_str);
}
-static const struct event_trigger_ops traceon_trigger_ops = {
- .trigger = traceon_trigger,
- .print = traceon_trigger_print,
- .init = event_trigger_init,
- .free = event_trigger_free,
-};
-
-static const struct event_trigger_ops traceon_count_trigger_ops = {
- .trigger = traceon_count_trigger,
- .print = traceon_trigger_print,
- .init = event_trigger_init,
- .free = event_trigger_free,
-};
-
-static const struct event_trigger_ops traceoff_trigger_ops = {
- .trigger = traceoff_trigger,
- .print = traceoff_trigger_print,
- .init = event_trigger_init,
- .free = event_trigger_free,
-};
-
-static const struct event_trigger_ops traceoff_count_trigger_ops = {
- .trigger = traceoff_count_trigger,
- .print = traceoff_trigger_print,
- .init = event_trigger_init,
- .free = event_trigger_free,
-};
-
-static const struct event_trigger_ops *
-onoff_get_trigger_ops(char *cmd, char *param)
-{
- const struct event_trigger_ops *ops;
-
- /* we register both traceon and traceoff to this callback */
- if (strcmp(cmd, "traceon") == 0)
- ops = param ? &traceon_count_trigger_ops :
- &traceon_trigger_ops;
- else
- ops = param ? &traceoff_count_trigger_ops :
- &traceoff_trigger_ops;
-
- return ops;
-}
-
static struct event_command trigger_traceon_cmd = {
.name = "traceon",
.trigger_type = ETT_TRACE_ONOFF,
.parse = event_trigger_parse,
.reg = register_trigger,
.unreg = unregister_trigger,
- .get_trigger_ops = onoff_get_trigger_ops,
.set_filter = set_trigger_filter,
+ .trigger = traceon_trigger,
+ .count_trigger = traceon_count_trigger,
+ .print = traceon_trigger_print,
+ .init = event_trigger_init,
+ .free = event_trigger_free,
};
static struct event_command trigger_traceoff_cmd = {
@@ -1436,8 +1394,12 @@ static struct event_command trigger_traceoff_cmd = {
.parse = event_trigger_parse,
.reg = register_trigger,
.unreg = unregister_trigger,
- .get_trigger_ops = onoff_get_trigger_ops,
.set_filter = set_trigger_filter,
+ .trigger = traceoff_trigger,
+ .count_trigger = traceoff_count_trigger,
+ .print = traceoff_trigger_print,
+ .init = event_trigger_init,
+ .free = event_trigger_free,
};
#ifdef CONFIG_TRACER_SNAPSHOT
@@ -1488,34 +1450,18 @@ snapshot_trigger_print(struct seq_file *m, struct event_trigger_data *data)
data->filter_str);
}
-static const struct event_trigger_ops snapshot_trigger_ops = {
- .trigger = snapshot_trigger,
- .print = snapshot_trigger_print,
- .init = event_trigger_init,
- .free = event_trigger_free,
-};
-
-static const struct event_trigger_ops snapshot_count_trigger_ops = {
- .trigger = snapshot_count_trigger,
- .print = snapshot_trigger_print,
- .init = event_trigger_init,
- .free = event_trigger_free,
-};
-
-static const struct event_trigger_ops *
-snapshot_get_trigger_ops(char *cmd, char *param)
-{
- return param ? &snapshot_count_trigger_ops : &snapshot_trigger_ops;
-}
-
static struct event_command trigger_snapshot_cmd = {
.name = "snapshot",
.trigger_type = ETT_SNAPSHOT,
.parse = event_trigger_parse,
.reg = register_snapshot_trigger,
.unreg = unregister_trigger,
- .get_trigger_ops = snapshot_get_trigger_ops,
.set_filter = set_trigger_filter,
+ .trigger = snapshot_trigger,
+ .count_trigger = snapshot_count_trigger,
+ .print = snapshot_trigger_print,
+ .init = event_trigger_init,
+ .free = event_trigger_free,
};
static __init int register_trigger_snapshot_cmd(void)
@@ -1583,26 +1529,6 @@ stacktrace_trigger_print(struct seq_file *m, struct event_trigger_data *data)
data->filter_str);
}
-static const struct event_trigger_ops stacktrace_trigger_ops = {
- .trigger = stacktrace_trigger,
- .print = stacktrace_trigger_print,
- .init = event_trigger_init,
- .free = event_trigger_free,
-};
-
-static const struct event_trigger_ops stacktrace_count_trigger_ops = {
- .trigger = stacktrace_count_trigger,
- .print = stacktrace_trigger_print,
- .init = event_trigger_init,
- .free = event_trigger_free,
-};
-
-static const struct event_trigger_ops *
-stacktrace_get_trigger_ops(char *cmd, char *param)
-{
- return param ? &stacktrace_count_trigger_ops : &stacktrace_trigger_ops;
-}
-
static struct event_command trigger_stacktrace_cmd = {
.name = "stacktrace",
.trigger_type = ETT_STACKTRACE,
@@ -1610,8 +1536,12 @@ static struct event_command trigger_stacktrace_cmd = {
.parse = event_trigger_parse,
.reg = register_trigger,
.unreg = unregister_trigger,
- .get_trigger_ops = stacktrace_get_trigger_ops,
.set_filter = set_trigger_filter,
+ .trigger = stacktrace_trigger,
+ .count_trigger = stacktrace_count_trigger,
+ .print = stacktrace_trigger_print,
+ .init = event_trigger_init,
+ .free = event_trigger_free,
};
static __init int register_trigger_stacktrace_cmd(void)
@@ -1708,34 +1638,6 @@ void event_enable_trigger_free(struct event_trigger_data *data)
}
}
-static const struct event_trigger_ops event_enable_trigger_ops = {
- .trigger = event_enable_trigger,
- .print = event_enable_trigger_print,
- .init = event_trigger_init,
- .free = event_enable_trigger_free,
-};
-
-static const struct event_trigger_ops event_enable_count_trigger_ops = {
- .trigger = event_enable_count_trigger,
- .print = event_enable_trigger_print,
- .init = event_trigger_init,
- .free = event_enable_trigger_free,
-};
-
-static const struct event_trigger_ops event_disable_trigger_ops = {
- .trigger = event_enable_trigger,
- .print = event_enable_trigger_print,
- .init = event_trigger_init,
- .free = event_enable_trigger_free,
-};
-
-static const struct event_trigger_ops event_disable_count_trigger_ops = {
- .trigger = event_enable_count_trigger,
- .print = event_enable_trigger_print,
- .init = event_trigger_init,
- .free = event_enable_trigger_free,
-};
-
int event_enable_trigger_parse(struct event_command *cmd_ops,
struct trace_event_file *file,
char *glob, char *cmd, char *param_and_filter)
@@ -1867,8 +1769,8 @@ int event_enable_register_trigger(char *glob,
}
}
- if (data->ops->init) {
- ret = data->ops->init(data);
+ if (data->cmd_ops->init) {
+ ret = data->cmd_ops->init(data);
if (ret < 0)
goto out;
}
@@ -1909,30 +1811,8 @@ void event_enable_unregister_trigger(char *glob,
}
}
- if (data && data->ops->free)
- data->ops->free(data);
-}
-
-static const struct event_trigger_ops *
-event_enable_get_trigger_ops(char *cmd, char *param)
-{
- const struct event_trigger_ops *ops;
- bool enable;
-
-#ifdef CONFIG_HIST_TRIGGERS
- enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) ||
- (strcmp(cmd, ENABLE_HIST_STR) == 0));
-#else
- enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
-#endif
- if (enable)
- ops = param ? &event_enable_count_trigger_ops :
- &event_enable_trigger_ops;
- else
- ops = param ? &event_disable_count_trigger_ops :
- &event_disable_trigger_ops;
-
- return ops;
+ if (data && data->cmd_ops->free)
+ data->cmd_ops->free(data);
}
static struct event_command trigger_enable_cmd = {
@@ -1941,8 +1821,12 @@ static struct event_command trigger_enable_cmd = {
.parse = event_enable_trigger_parse,
.reg = event_enable_register_trigger,
.unreg = event_enable_unregister_trigger,
- .get_trigger_ops = event_enable_get_trigger_ops,
.set_filter = set_trigger_filter,
+ .trigger = event_enable_trigger,
+ .count_trigger = event_enable_count_trigger,
+ .print = event_enable_trigger_print,
+ .init = event_trigger_init,
+ .free = event_enable_trigger_free,
};
static struct event_command trigger_disable_cmd = {
@@ -1951,8 +1835,12 @@ static struct event_command trigger_disable_cmd = {
.parse = event_enable_trigger_parse,
.reg = event_enable_register_trigger,
.unreg = event_enable_unregister_trigger,
- .get_trigger_ops = event_enable_get_trigger_ops,
.set_filter = set_trigger_filter,
+ .trigger = event_enable_trigger,
+ .count_trigger = event_enable_count_trigger,
+ .print = event_enable_trigger_print,
+ .init = event_trigger_init,
+ .free = event_enable_trigger_free,
};
static __init void unregister_trigger_enable_disable_cmds(void)
--
2.53.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 6.6.y 3/3] tracing: Undo the registration when enabling the histogram trigger fails
2026-09-16 19:49 ` [PATCH 6.6.y 1/3] tracing: Constify struct event_trigger_ops Sasha Levin
2026-09-16 19:49 ` [PATCH 6.6.y 2/3] tracing: Merge struct event_trigger_ops into struct event_command Sasha Levin
@ 2026-09-16 19:49 ` Sasha Levin
1 sibling, 0 replies; 6+ messages in thread
From: Sasha Levin @ 2026-09-16 19:49 UTC (permalink / raw)
To: stable; +Cc: Donggeun Yoo, Sashiko AI, Steven Rostedt, Sasha Levin
From: Donggeun Yoo <donggeunyoo.kernel@gmail.com>
[ Upstream commit 92383cef66791a0c63a2f27755cadbdb2fbf270b ]
Commit 6f86bdeab633 ("tracing: Fix bad hist from corrupting named_triggers
list") described how a trigger that is registered but not on file->triggers
ends up freed while still on the global named_triggers list, and moved the
registration down so that hist_trigger_enable() follows it immediately. One
path still gets there. hist_trigger_enable() adds the trigger and takes it
straight back out when the event cannot be enabled:
list_add_tail_rcu(&data->list, &file->triggers);
update_cond_flag(file);
if (trace_event_trigger_enable_disable(file, 1) < 0) {
list_del_rcu(&data->list);
update_cond_flag(file);
ret--;
}
so the list walk in hist_unregister_trigger() matches nothing, test stays
NULL, and the ->free() that would call del_named_trigger() is skipped.
out_unreg falls through to out_free, which frees the trigger anyway:
BUG: KASAN: slab-use-after-free in find_named_trigger+0xac/0xc0
Read of size 8 at addr ffff8880091d3160 by task init/1
find_named_trigger+0xac/0xc0
hist_register_trigger+0xc1/0xa00
event_hist_trigger_parse+0x3146/0x6af0
event_trigger_write+0xce/0x160
Freed by task 69:
kfree+0x154/0x420
trigger_kthread_fn+0xfd/0x160
Leave the trigger where hist_unregister_trigger() can find it and let that
undo the registration, which is the only code that knows all of what
cmd_ops->init() took: the named list entry, the hist_pad reference, the
reference on the trigger a named histogram is shared with, and the copied
cmd_ops. It also pairs the failed trace_event_trigger_enable_disable(),
whose sm_ref and buffered event reference are otherwise left behind.
Since ->free() releases trigger_data and, for a trigger that does not share
its histogram, hist_data with it, out_unreg can no longer fall through to
out_free. For a trigger that does share, hist_register_trigger() has
already destroyed the caller's hist_data, so the fall-through was reading
freed memory there as well.
Move the enable_timestamps check in hist_unregister_trigger() above the
->free() call for the same reason: hist_data does not outlive it once the
trigger being removed is the one that owns it.
Cc: stable@vger.kernel.org
Fixes: 067fe038e70f ("tracing: Add variable reference handling to hist triggers")
Reported-by: Sashiko AI <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/linux-trace-kernel/20260907092944.3950E1F00A3D@smtp.kernel.org/
Link: https://patch.msgid.link/20260907124420.607097-3-donggeunyoo.kernel@gmail.com
Signed-off-by: Donggeun Yoo <donggeunyoo.kernel@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/trace/trace_events_hist.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 1ea2eff8a9f66..ee3377ff4d588 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -6612,11 +6612,12 @@ static int hist_trigger_enable(struct event_trigger_data *data,
update_cond_flag(file);
- if (trace_event_trigger_enable_disable(file, 1) < 0) {
- list_del_rcu(&data->list);
- update_cond_flag(file);
+ /*
+ * On failure the caller undoes the registration, and
+ * hist_unregister_trigger() can only find the trigger here.
+ */
+ if (trace_event_trigger_enable_disable(file, 1) < 0)
ret--;
- }
return ret;
}
@@ -6694,13 +6695,13 @@ static void hist_unregister_trigger(char *glob,
}
}
- if (test && test->cmd_ops->free)
- test->cmd_ops->free(test);
-
if (hist_data->enable_timestamps) {
if (!hist_data->remove || test)
tracing_set_filter_buffering(file->tr, false);
}
+
+ if (test && test->cmd_ops->free)
+ test->cmd_ops->free(test);
}
static bool hist_file_check_refs(struct trace_event_file *file)
@@ -6905,6 +6906,8 @@ static int event_hist_trigger_parse(struct event_command *cmd_ops,
return ret;
out_unreg:
event_trigger_unregister(cmd_ops, file, glob+1, trigger_data);
+ /* The unregister frees trigger_data, skip out_free */
+ goto out;
out_free:
remove_hist_vars(hist_data);
--
2.53.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
end of thread, other threads:[~2026-09-16 19:49 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2026-09-16 14:19 FAILED: patch "[PATCH] tracing: Undo the registration when enabling the histogram" failed to apply to 6.6-stable tree gregkh
2026-09-16 19:49 ` [PATCH 6.6.y 1/3] tracing: Constify struct event_trigger_ops Sasha Levin
2026-09-16 19:49 ` [PATCH 6.6.y 2/3] tracing: Merge struct event_trigger_ops into struct event_command Sasha Levin
2026-09-16 19:49 ` [PATCH 6.6.y 3/3] tracing: Undo the registration when enabling the histogram trigger fails Sasha Levin
-- strict thread matches above, loose matches on Subject: below --
2026-09-16 14:18 FAILED: patch "[PATCH] tracing: Take the reference before publishing the named" failed to apply to 6.6-stable tree gregkh
2026-09-16 19:44 ` [PATCH 6.6.y 1/3] tracing: Constify struct event_trigger_ops Sasha Levin
2026-09-16 19:44 ` [PATCH 6.6.y 2/3] tracing: Merge struct event_trigger_ops into struct event_command Sasha Levin
2026-09-16 8:13 FAILED: patch "[PATCH] tracing: Set the trace clock before registering the histogram" failed to apply to 6.6-stable tree gregkh
2026-09-16 16:48 ` [PATCH 6.6.y 1/3] tracing: Constify struct event_trigger_ops Sasha Levin
2026-09-16 16:48 ` [PATCH 6.6.y 2/3] tracing: Merge struct event_trigger_ops into struct event_command Sasha Levin
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