linux-kernel - Re: [PATCH v2] compiler: remove __ADDRESSABLE_ASM{

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] [day] [month] [year] [list]

Message-ID: <20250217202943.p57k76tpwpx7aw6q@jpoimboe>
Date: Mon, 17 Feb 2025 12:29:43 -0800
From: Josh Poimboeuf <jpoimboe@...hat.com>
To: Jan Beulich <jbeulich@...e.com>
Cc: lkml <linux-kernel@...r.kernel.org>, Juergen Gross <jgross@...e.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Luc Van Oostenryck <luc.vanoostenryck@...il.com>,
	Stefano Stabellini <sstabellini@...nel.org>
Subject: Re: [PATCH v2] compiler: remove __ADDRESSABLE_ASM{_STR,}() again

On Mon, Feb 17, 2025 at 05:40:09PM +0100, Jan Beulich wrote:
> __ADDRESSABLE_ASM_STR() is where the necessary stringification happens.
> As long as "sym" doesn't contain any odd characters, no quoting is
> required for its use with .quad / .long. In fact the quotation gets in
> the way with gas 2.25; it's only from 2.26 onwards that quoted symbols
> are half-way properly supported.
> 
> However, assembly being different from C anyway, drop
> __ADDRESSABLE_ASM_STR() and its helper macro altogether. A simple
> .global directive will suffice to get the symbol "declared", i.e. into
> the symbol table. While there also stop open-coding STATIC_CALL_TRAMP()
> and STATIC_CALL_KEY().
> 
> Fixes: 0ef8047b737d ("x86/static-call: provide a way to do very early static-call updates")
> Signed-off-by: Jan Beulich <jbeulich@...e.com>
> Cc: stable@...r.kernel.org
> ---
> v2: Drop constructs instead of fixing them. Use STATIC_CALL_KEY().
> ---
> Whether the "ADDRESSABLE" in __ADDRESSABLE_xen_hypercall is still
> meaningful to keep I'm uncertain about. The situation, as said, is quite
> different in assembly, compared to C's requirements.

The .global still makes it "addressable", so IMO it's named
appropriately.

Thanks!

Acked-by: Josh Poimboeuf <jpoimboe@...nel.org>

-- 
Josh