linux-kernel - Re: [PATCH v2] powerpc/kexec: Enable SMT before waking offline CPUs

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: <176680916364.22434.16517409166672279903.b4-ty@linux.ibm.com>
Date: Sat, 27 Dec 2025 09:54:06 +0530
From: Madhavan Srinivasan <maddy@...ux.ibm.com>
To: Sourabh Jain <sourabhjain@...ux.ibm.com>,
        Christophe Leroy <chleroy@...nel.org>,
        "Nysal Jan K.A." <nysal@...ux.ibm.com>
Cc: Srikar Dronamraju <srikar@...ux.ibm.com>,
        Sachin P Bappalige <sachinpb@...ux.ibm.com>, stable@...r.kernel.org,
        Michael Ellerman <mpe@...erman.id.au>,
        Nicholas Piggin <npiggin@...il.com>,
        Laurent Dufour <ldufour@...ux.ibm.com>,
        Thomas Gleixner <tglx@...utronix.de>, linuxppc-dev@...ts.ozlabs.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] powerpc/kexec: Enable SMT before waking offline CPUs

On Tue, 28 Oct 2025 16:25:12 +0530, Nysal Jan K.A. wrote:
> If SMT is disabled or a partial SMT state is enabled, when a new kernel
> image is loaded for kexec, on reboot the following warning is observed:
> 
> kexec: Waking offline cpu 228.
> WARNING: CPU: 0 PID: 9062 at arch/powerpc/kexec/core_64.c:223 kexec_prepare_cpus+0x1b0/0x1bc
> [snip]
>  NIP kexec_prepare_cpus+0x1b0/0x1bc
>  LR  kexec_prepare_cpus+0x1a0/0x1bc
>  Call Trace:
>   kexec_prepare_cpus+0x1a0/0x1bc (unreliable)
>   default_machine_kexec+0x160/0x19c
>   machine_kexec+0x80/0x88
>   kernel_kexec+0xd0/0x118
>   __do_sys_reboot+0x210/0x2c4
>   system_call_exception+0x124/0x320
>   system_call_vectored_common+0x15c/0x2ec
> 
> [...]

Applied to powerpc/fixes.

[1/1] powerpc/kexec: Enable SMT before waking offline CPUs
      https://git.kernel.org/powerpc/c/c2296a1e42418556efbeb5636c4fa6aa6106713a

cheers