Commit 0340a6b7 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

module: Fix up module_notifier return values 



While auditing all module notifiers I noticed a whole bunch of fail
wrt the return value. Notifiers have a 'special' return semantics.

As is; NOTIFY_DONE vs NOTIFY_OK is a bit vague; but
notifier_from_errno(0) results in NOTIFY_OK and NOTIFY_DONE has a
comment that says "Don't care".

From this I've used NOTIFY_DONE when the function completely ignores
the callback and notifier_to_error() isn't used.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Reviewed-by: default avatarMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: default avatarJoel Fernandes (Google) <joel@joelfernandes.org>
Reviewed-by: default avatarRobert Richter <rric@kernel.org>
Acked-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20200818135804.385360407@infradead.org
parent 70d93298

drivers/oprofile/buffer_sync.c

+2 −2
Original line number Diff line number Diff line
@@ -116,7 +116,7 @@ module_load_notify(struct notifier_block *self, unsigned long val, void *data) 
{

#ifdef CONFIG_MODULES

	if (val != MODULE_STATE_COMING)

		return 0;

		return NOTIFY_DONE;



	/* FIXME: should we process all CPU buffers ? */

	mutex_lock(&buffer_mutex);
@@ -124,7 +124,7 @@ module_load_notify(struct notifier_block *self, unsigned long val, void *data) 
	add_event_entry(MODULE_LOADED_CODE);

	mutex_unlock(&buffer_mutex);

#endif

	return 0;

	return NOTIFY_OK;

}

kernel/trace/bpf_trace.c

+6 −2
Original line number Diff line number Diff line
@@ -2027,10 +2027,11 @@ static int bpf_event_notify(struct notifier_block *nb, unsigned long op, 
{

	struct bpf_trace_module *btm, *tmp;

	struct module *mod = module;

	int ret = 0;



	if (mod->num_bpf_raw_events == 0 ||

	    (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING))

		return 0;

		goto out;



	mutex_lock(&bpf_module_mutex);
@@ -2040,6 +2041,8 @@ static int bpf_event_notify(struct notifier_block *nb, unsigned long op, 
		if (btm) {

			btm->module = module;

			list_add(&btm->list, &bpf_trace_modules);

		} else {

			ret = -ENOMEM;

		}

		break;

	case MODULE_STATE_GOING:
@@ -2055,7 +2058,8 @@ static int bpf_event_notify(struct notifier_block *nb, unsigned long op, 


	mutex_unlock(&bpf_module_mutex);



	return 0;

out:

	return notifier_from_errno(ret);

}



static struct notifier_block bpf_module_nb = {

kernel/trace/trace.c

+1 −1
Original line number Diff line number Diff line
@@ -9072,7 +9072,7 @@ static int trace_module_notify(struct notifier_block *self, 
		break;

	}



	return 0;

	return NOTIFY_OK;

}



static struct notifier_block trace_module_nb = {

kernel/trace/trace_events.c

+1 −1
Original line number Diff line number Diff line
@@ -2646,7 +2646,7 @@ static int trace_module_notify(struct notifier_block *self, 
	mutex_unlock(&trace_types_lock);

	mutex_unlock(&event_mutex);



	return 0;

	return NOTIFY_OK;

}



static struct notifier_block trace_module_nb = {

kernel/trace/trace_printk.c

+2 −2
Original line number Diff line number Diff line
@@ -96,7 +96,7 @@ static int module_trace_bprintk_format_notify(struct notifier_block *self, 
		if (val == MODULE_STATE_COMING)

			hold_module_trace_bprintk_format(start, end);

	}

	return 0;

	return NOTIFY_OK;

}



/*
@@ -174,7 +174,7 @@ __init static int 
module_trace_bprintk_format_notify(struct notifier_block *self,

		unsigned long val, void *data)

{

	return 0;

	return NOTIFY_OK;

}

static inline const char **

find_next_mod_format(int start_index, void *v, const char **fmt, loff_t *pos)

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