Re: [PATCH 0/3] powerpc: fix preempt_count imbalances in perf and kexec paths

[Shrikanth Hegde <sshegde@linux.ibm.com>]

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.