On Mon, Nov 08, 2021 at 11:19:24AM +0100, Borislav Petkov wrote: > From: Borislav Petkov <bp@xxxxxxx> > > Hi all, > > this is a huge patchset for something which is really trivial - it > changes the notifier registration routines to return an error value > if a notifier callback is already present on the respective list of > callbacks. For more details scroll to the last patch. > > Everything before it is converting the callers to check the return value > of the registration routines and issue a warning, instead of the WARN() > notifier_chain_register() does now. What reason is there for moving the check into the callers? It seems like pointless churn. Why not add the error return code, change the WARN to pr_warn, and leave the callers as they are? Wouldn't that end up having exactly the same effect? For that matter, what sort of remedial action can a caller take if the return code is -EEXIST? Is there any point in forcing callers to check the return code if they can't do anything about it? > Before the last patch has been applied, though, that checking is a > NOP which would make the application of those patches trivial - every > maintainer can pick a patch at her/his discretion - only the last one > enables the build warnings and that one will be queued only after the > preceding patches have all been merged so that there are no build > warnings. Why should there be _any_ build warnings? The real problem occurs when a notifier callback is added twice, not when a caller fails to check the return code. Double-registration is not the sort of thing that can be detected at build time. Alan Stern > Due to the sheer volume of the patches, I have addressed the respective > patch and the last one, which enables the warning, with addressees for > each maintained area so as not to spam people unnecessarily. > > If people prefer I carry some through tip, instead, I'll gladly do so - > your call. > > And, if you think the warning messages need to be more precise, feel > free to adjust them before committing. > > Thanks!
