From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EE80B146D53; Wed, 20 Nov 2024 10:22:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732098144; cv=none; b=r9MIevaYhvbRcjSlfAOtm64MYA7IT19DEHCBoW+VSBzYOEBU7LQjwO8sXhhqJLCUAA4Lru/RCF9DY2kqE/gZE1Zawq7zhlrApIVSUBfbsTTbIW0egqC4vA5r58JDH0maIvge+J7WEwMa9q4wjY8ROJpGIZlkZxnk8fDRVW2VvtM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732098144; c=relaxed/simple; bh=kJQDEeMh5yQymd7/4zNyXAyvNMvAn8pbTvK9MW3F1j4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=M1ceEiXzERU9M72UwiT+gQJZQDpcD1vFAo2yEWOzV9bIFzwkcPB6qSUasV0hEUxEqxqh655Ly8zv0k7214q8WG6q6SvaW31gsjSlTrEAjQEVOQ+PMEuoW4u+HfEsI9mt3S0nQvsZ0w+IEFBRVEQwD7L9h40wXOTUnG+FnPKmaL0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=Ud7ivUQk; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Ud7ivUQk" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=6BHYRXy9lLaaBbd09VImTq6Rn50W4X4567EqZRkeTsQ=; b=Ud7ivUQkqoJelXj28zCQsU+gIU rPNqESkMj9Dvu0GcK3GwMBeifTq00wVepK50OM0ITEOdtka/jqFErp6Jd8j999ZICXAW3mvcrtkvK CusDuiYnEJ629rY55UUL/cBOjUKRFBuX/QQ0VICN6+DrH4L+Ho55jjI7IoNjs/cWvfyFbmptF1Klx vEhnAtqlle6ozdCc/aMWBNbBq7u2ct3VCOEy18Xvn1aIkiTLeG6uKCbmVgjwRnFMZT4eAurE+BZ5H x1Ct2ikx1ujlCMCd31kJ29lLgD5iVA3BgXaBQ3K/vEe5Jd7aBT4P21yj4cyyY2YhFQ7RnlBQHq7Pn jj1hI06g==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1tDhql-0000000582g-0cwS; Wed, 20 Nov 2024 10:22:20 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 04D013006AB; Wed, 20 Nov 2024 11:22:20 +0100 (CET) Date: Wed, 20 Nov 2024 11:22:19 +0100 From: Peter Zijlstra To: Josh Poimboeuf Cc: Valentin Schneider , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org, bpf@vger.kernel.org, x86@kernel.org, rcu@vger.kernel.org, linux-kselftest@vger.kernel.org, Steven Rostedt , Masami Hiramatsu , Jonathan Corbet , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Paolo Bonzini , Wanpeng Li , Vitaly Kuznetsov , Andy Lutomirski , Frederic Weisbecker , "Paul E. McKenney" , Neeraj Upadhyay , Joel Fernandes , Josh Triplett , Boqun Feng , Mathieu Desnoyers , Lai Jiangshan , Zqiang , Andrew Morton , Uladzislau Rezki , Christoph Hellwig , Lorenzo Stoakes , Jason Baron , Kees Cook , Sami Tolvanen , Ard Biesheuvel , Nicholas Piggin , Juerg Haefliger , Nicolas Saenz Julienne , "Kirill A. Shutemov" , Nadav Amit , Dan Carpenter , Chuang Wang , Yang Jihong , Petr Mladek , "Jason A. Donenfeld" , Song Liu , Julian Pidancet , Tom Lendacky , Dionna Glaze , Thomas =?iso-8859-1?Q?Wei=DFschuh?= , Juri Lelli , Marcelo Tosatti , Yair Podemsky , Daniel Wagner , Petr Tesarik Subject: Re: [RFC PATCH v3 06/15] jump_label: Add forceful jump label type Message-ID: <20241120102219.GF19989@noisy.programming.kicks-ass.net> References: <20241119153502.41361-1-vschneid@redhat.com> <20241119153502.41361-7-vschneid@redhat.com> <20241120000532.maqzgsn7m34lti6u@jpoimboe> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241120000532.maqzgsn7m34lti6u@jpoimboe> On Tue, Nov 19, 2024 at 04:05:32PM -0800, Josh Poimboeuf wrote: > On Tue, Nov 19, 2024 at 04:34:53PM +0100, Valentin Schneider wrote: > > +++ b/include/linux/jump_label.h > > @@ -200,7 +200,8 @@ struct module; > > #define JUMP_TYPE_FALSE 0UL > > #define JUMP_TYPE_TRUE 1UL > > #define JUMP_TYPE_LINKED 2UL > > -#define JUMP_TYPE_MASK 3UL > > +#define JUMP_TYPE_FORCEFUL 4UL > > +#define JUMP_TYPE_MASK 7UL > > Hm, I don't think we can (ab)use this pointer bit on 32-bit arches, as > the address could be 4 byte aligned? Right, you can force the alignment of the thing, workqueues do similar hacks to get more bits.