netdev - Re: [PATCH v4 6/6] percpu/x86: Enable strict percpu checks via named AS qualifiers

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: <77B3F3ED-102D-4759-98F1-622629EBF9AF@zytor.com>
Date: Wed, 09 Apr 2025 08:09:26 -0700
From: "H. Peter Anvin" <hpa@...or.com>
To: Uros Bizjak <ubizjak@...il.com>, Jiri Slaby <jirislaby@...nel.org>
CC: x86@...nel.org, linux-mm@...ck.org, linux-kernel@...r.kernel.org,
        linux-bcachefs@...r.kernel.org, linux-arch@...r.kernel.org,
        netdev@...r.kernel.org, Nadav Amit <nadav.amit@...il.com>,
        Dennis Zhou <dennis@...nel.org>, Tejun Heo <tj@...nel.org>,
        Christoph Lameter <cl@...ux.com>, Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...nel.org>, Borislav Petkov <bp@...en8.de>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Andy Lutomirski <luto@...nel.org>, Brian Gerst <brgerst@...il.com>,
        Peter Zijlstra <peterz@...radead.org>
Subject: Re: [PATCH v4 6/6] percpu/x86: Enable strict percpu checks via named AS qualifiers

On April 9, 2025 4:43:27 AM PDT, Uros Bizjak <ubizjak@...il.com> wrote:
>On Wed, Apr 9, 2025 at 1:07 PM Jiri Slaby <jirislaby@...nel.org> wrote:
>>
>> On 27. 01. 25, 17:05, Uros Bizjak wrote:
>> > This patch declares percpu variables in __seg_gs/__seg_fs named AS
>> > and keeps them named AS qualified until they are dereferenced with
>> > percpu accessor. This approach enables various compiler check
>> > for cross-namespace variable assignments.
>>
>> So this causes modpost to fail to version some symbols:
>>
>> > WARNING: modpost: EXPORT symbol "xen_vcpu_id" [vmlinux] version generation failed, symbol will not be versioned.
>> > Is "xen_vcpu_id" prototyped in <asm/asm-prototypes.h>?
>> > WARNING: modpost: EXPORT symbol "irq_stat" [vmlinux] version generation failed, symbol will not be versioned.
>> > Is "irq_stat" prototyped in <asm/asm-prototypes.h>?
>> > WARNING: modpost: EXPORT symbol "fred_rsp0" [vmlinux] version generation failed, symbol will not be versioned.
>> > Is "fred_rsp0" prototyped in <asm/asm-prototypes.h>?
>> > WARNING: modpost: EXPORT symbol "cpu_dr7" [vmlinux] version generation failed, symbol will not be versioned.
>> > Is "cpu_dr7" prototyped in <asm/asm-prototypes.h>?
>> > WARNING: modpost: EXPORT symbol "cpu_tss_rw" [vmlinux] version generation failed, symbol will not be versioned.
>> > Is "cpu_tss_rw" prototyped in <asm/asm-prototypes.h>?
>> > WARNING: modpost: EXPORT symbol "__tss_limit_invalid" [vmlinux] version generation failed, symbol will not be versioned.
>> > Is "__tss_limit_invalid" prototyped in <asm/asm-prototypes.h>?
>> > WARNING: modpost: EXPORT symbol "irq_fpu_usable" [vmlinux] version generation failed, symbol will not be versioned.
>> > Is "irq_fpu_usable" prototyped in <asm/asm-prototypes.h>?
>> > WARNING: modpost: EXPORT symbol "cpu_info" [vmlinux] version generation failed, symbol will not be versioned.
>> > Is "cpu_info" prototyped in <asm/asm-prototypes.h>?
>> > WARNING: modpost: EXPORT symbol "gdt_page" [vmlinux] version generation failed, symbol will not be versioned.
>> > Is "gdt_page" prototyped in <asm/asm-prototypes.h>?
>>  > ...
>>
>> That happens both with 6.15-rc1 and today's -next. Ideas?
>
>https://lore.kernel.org/lkml/20250404102535.705090-1-ubizjak@gmail.com/
>
>Uros.
>

A lot of those seem to be things that definitely shouldn't be expected...