From: Aboorva Devarajan <aboorvad@linux•ibm.com>
To: Shrikanth Hegde <sshegde@linux•ibm.com>,
Madhavan Srinivasan <maddy@linux•ibm.com>,
linuxppc-dev@lists•ozlabs.org
Cc: Athira Rajeev <atrajeev@linux•vnet.ibm.com>,
Christophe Leroy <chleroy@kernel•org>,
linux-kernel@vger•kernel.org,
Sourabh Jain <sourabhjain@linux•ibm.com>,
Ritesh Harjani <ritesh.list@gmail•com>
Subject: Re: [PATCH 0/3] powerpc: fix preempt_count imbalances in perf and kexec paths
Date: Wed, 03 Jun 2026 11:46:52 +0530 [thread overview]
Message-ID: <7d7c24d7900a30f53820feae952e2c2bd92d0a42.camel@linux.ibm.com> (raw)
In-Reply-To: <0c6d2855-61df-4fd2-bede-0c204f4fd2b1@linux.ibm.com>
On Mon, 2026-05-18 at 13:38 +0530, Shrikanth Hegde wrote:
> Hi Aboorva,
>
> On 5/18/26 10:38 AM, Aboorva Devarajan wrote:
> > Hi all,
> >
> > This patch series fixes some minor preempt_count bookkeeping issues in
> > arch/powerpc/ found during a preemption leak audit prompted by the
> > lazy/full preemption model changes. These are get_cpu/put_cpu and
> > get_cpu_var/put_cpu_var pairing errors that leave preempt_count
> > incorrectly elevated or underflowed.
> >
>
> Thanks for fixing some of these.
>
> while we do this, Can you fix these mismatch in preempt disable/enable in
> below files as well.
>
> 1. kernel/kprobes.c - kprobe_handler - Does disable, but doesn't enable in some return paths.
> A definite leak.
>
> 2. Maybe platforms/pseries/lpar.c and platforms/powernv/opal-tracepoints.c.
> In __trace_hcall_entry/exit. It maybe a very corner case,
> I don't see a big concern there. But it may be remotely possible.
> Need to evaluate whether it should be fixed or not.
Thanks for the pointers. I'll go through these and get back.
Regards,
Aboorva
prev parent reply other threads:[~2026-06-03 6:17 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-18 5:08 [PATCH 0/3] powerpc: fix preempt_count imbalances in perf and kexec paths Aboorva Devarajan
2026-05-18 5:08 ` [PATCH 1/3] powerpc/perf: fix preempt count underflow in fsl_emb_pmu_del Aboorva Devarajan
2026-05-18 6:13 ` Shrikanth Hegde
2026-06-03 5:59 ` Aboorva Devarajan
2026-05-18 5:08 ` [PATCH 2/3] powerpc/powernv: fix preempt count leak in pnv_kexec_wait_secondaries_down Aboorva Devarajan
2026-05-18 7:56 ` Shrikanth Hegde
2026-06-03 6:08 ` Aboorva Devarajan
2026-05-18 5:08 ` [PATCH 3/3] powerpc/kexec: fix double get_cpu() imbalance in kexec_prepare_cpus Aboorva Devarajan
2026-05-18 6:02 ` Shrikanth Hegde
2026-06-03 6:14 ` Aboorva Devarajan
2026-06-03 6:16 ` Shrikanth Hegde
2026-05-18 8:08 ` [PATCH 0/3] powerpc: fix preempt_count imbalances in perf and kexec paths Shrikanth Hegde
2026-06-03 6:16 ` Aboorva Devarajan [this message]
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