linux-kernel - Re: [PATCH 0/9 RFC] Make wake_up

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAHk-=wh4=w4pANpAPbx=Kw-jiExEabJ0pwYHFgAYXVaD0AJjrA@mail.gmail.com>
Date: Mon, 19 Aug 2024 14:12:45 -0700
From: Linus Torvalds <torvalds@...ux-foundation.org>
To: NeilBrown <neilb@...e.de>
Cc: Christian Brauner <brauner@...nel.org>, Peter Zijlstra <peterz@...radead.org>, 
	Ingo Molnar <mingo@...hat.com>, linux-kernel@...r.kernel.org, 
	linux-fsdevel@...r.kernel.org
Subject: Re: [PATCH 0/9 RFC] Make wake_up_{bit,var} less fragile

On Mon, 19 Aug 2024 at 13:52, NeilBrown <neilb@...e.de> wrote:
>
> You could fit those in a short and two bools which gives you three
> different addresses to pass to wake_up_var().

You don't actually have to even do that.

The address passed to 'wake_up_var()' doesn't actually have to *match*
anything. It's used purely as a cookie.

So you can literally do something like

   #define inode_state(X,inode) ((X)+(char *)&(inode)->i_state)

and then just use inode_state(0/1/2,inode) for waiting/waking the
different bits (and the numbers 0/1/2 do not have to bear any relation
to the bit numbers, although you may obviously do that).

              Linus