powerpc/perf: fix preempt count underflow in fsl_emb_pmu_del

fsl_emb_pmu_del() unconditionally calls put_cpu_var(cpu_hw_events) at
the 'out:' label, but only calls the matching get_cpu_var() after the
'i < 0' early-return check. When event->hw.idx is negative the
function jumps to 'out:' without having taken get_cpu_var(), and the
trailing put_cpu_var() then issues an unmatched preempt_enable(),
underflowing preempt_count.

On a CONFIG_PREEMPT=y kernel preempt_count would underflow and
eventually present as a 'scheduling while atomic' BUG.

Move put_cpu_var() to pair with get_cpu_var() so the percpu access is
correctly bracketed and the 'out:' label only handles perf_pmu_enable.

Fixes: a11106544f33 ("powerpc/perf: e500 support")
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Aboorva Devarajan <aboorvad@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260605082912.305100-2-aboorvad@linux.ibm.com

0 files changed, 0 insertions, 0 deletions