linux-kernel - Re: [PATCH 2/4] x86/vdso: Use 32-bit CHECKFLAGS for compat vDSO

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 for Android: free password hash cracker in your pocket

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

Message-Id: <edeb782d-f413-48e6-b6b5-36961aacfcdd@app.fastmail.com>
Date: Fri, 16 Jan 2026 08:49:12 +0100
From: "Arnd Bergmann" <arnd@...db.de>
To: Thomas Weißschuh <thomas.weissschuh@...utronix.de>,
 "David S . Miller" <davem@...emloft.net>,
 "Andreas Larsson" <andreas@...sler.com>, "Andy Lutomirski" <luto@...nel.org>,
 "Thomas Gleixner" <tglx@...nel.org>, "Ingo Molnar" <mingo@...hat.com>,
 "Borislav Petkov" <bp@...en8.de>,
 "Dave Hansen" <dave.hansen@...ux.intel.com>, x86@...nel.org,
 "H. Peter Anvin" <hpa@...or.com>, "Heiko Carstens" <hca@...ux.ibm.com>,
 "Vasily Gorbik" <gor@...ux.ibm.com>,
 "Alexander Gordeev" <agordeev@...ux.ibm.com>,
 "Christian Borntraeger" <borntraeger@...ux.ibm.com>,
 "Sven Schnelle" <svens@...ux.ibm.com>
Cc: sparclinux@...r.kernel.org, linux-kernel@...r.kernel.org,
 Linux-Arch <linux-arch@...r.kernel.org>, linux-s390@...r.kernel.org,
 "Sun Jian" <sun.jian.kdev@...il.com>
Subject: Re: [PATCH 2/4] x86/vdso: Use 32-bit CHECKFLAGS for compat vDSO

On Fri, Jan 16, 2026, at 08:40, Thomas Weißschuh wrote:
> When building the compat vDSO the CHECKFLAGS from the 64-bit kernel
> are used. These are combined with the 32-bit CFLAGS. This confuses
> sparse, producing false-positive warnings or potentially missing
> real issues.
>
> Manually override the CHECKFLAGS for the compat vDSO with the correct
> 32-bit configuration.
>
> Reported-by: Sun Jian <sun.jian.kdev@...il.com>
> Closes: 
> https://lore.kernel.org/lkml/20260114084529.1676356-1-sun.jian.kdev@gmail.com/
> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@...utronix.de>

Acked-by: Arnd Bergmann <arnd@...db.de>

> +CHECKFLAGS_32 := $(CHECKFLAGS) -U__x86_64__ -D__i386__ -m32
> +
>  $(obj)/vdso32.so.dbg: KBUILD_CFLAGS = $(KBUILD_CFLAGS_32)
> +$(obj)/vdso32.so.dbg: CHECKFLAGS = $(CHECKFLAGS_32)

Have you checked if something like this is needed for x32 as well?

     Arnd