[PATCH v4 03/18] module: Properly propagate MODULE_STATE_COMING failure

Peter Zijlstra
2020-05-01T20:31:45Z

Now that notifiers got unbroken; use the proper interface to handle
notifier errors and propagate them.

There were already MODULE_STATE_COMING notifiers that failed; notably:

- jump_label_module_notifier()
- tracepoint_module_notify()
- bpf_event_notify()

By propagating this error, we fix those users.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
kernel/module.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3751,9 +3751,13 @@ static int prepare_coming_module(struct
if (err)
return err;

- blocking_notifier_call_chain(&module_notify_list,
- MODULE_STATE_COMING, mod);
- return 0;
+ err = blocking_notifier_call_chain_robust(&module_notify_list,
+ MODULE_STATE_COMING, MODULE_STATE_GOING, mod);
+ err = notifier_to_errno(err);
+ if (err)
+ klp_module_going(mod);
+
+ return err;
}

static int unknown_module_param_cb(char *param, char *val, const char *modname,