The following commit has been merged into the core/static_call branch of tip:
Commit-ID: 0340a6b7fb767f7f296b9bacc9a215920519a644 Gitweb: https://git.kernel.org/tip/0340a6b7fb767f7f296b9bacc9a215920519a644 Author: Peter Zijlstra <[email protected]> AuthorDate: Tue, 18 Aug 2020 15:57:37 +02:00 Committer: Ingo Molnar <[email protected]> CommitterDate: Tue, 01 Sep 2020 09:58:03 +02:00 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: Peter Zijlstra (Intel) <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Reviewed-by: Mathieu Desnoyers <[email protected]> Reviewed-by: Joel Fernandes (Google) <[email protected]> Reviewed-by: Robert Richter <[email protected]> Acked-by: Steven Rostedt (VMware) <[email protected]> Link: https://lore.kernel.org/r/[email protected] --- drivers/oprofile/buffer_sync.c | 4 ++-- kernel/trace/bpf_trace.c | 8 ++++++-- kernel/trace/trace.c | 2 +- kernel/trace/trace_events.c | 2 +- kernel/trace/trace_printk.c | 4 ++-- kernel/tracepoint.c | 2 +- 6 files changed, 13 insertions(+), 9 deletions(-) diff --git a/drivers/oprofile/buffer_sync.c b/drivers/oprofile/buffer_sync.c index 4d76952..cc91786 100644 --- a/drivers/oprofile/buffer_sync.c +++ b/drivers/oprofile/buffer_sync.c @@ -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; } diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index a8d4f25..2ecf789 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -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 = { diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index f40d850..df49992 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -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 = { diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index a85effb..beebf2c 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -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 = { diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c index d4e31e9..bb7783b 100644 --- a/kernel/trace/trace_printk.c +++ b/kernel/trace/trace_printk.c @@ -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) diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index 73956ea..8e05ed2 100644 --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -521,7 +521,7 @@ static int tracepoint_module_notify(struct notifier_block *self, case MODULE_STATE_UNFORMED: break; } - return ret; + return notifier_from_errno(ret); } static struct notifier_block tracepoint_module_nb = {
