From: Aboorva Devarajan <aboorvad@linux.ibm.com> mainline inclusion from mainline-v7.2-rc1 commit 81e3a86030462824a67d697739cf3f387f4ba350 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/16381 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... ---------------------------------------------------------------------- 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 Signed-off-by: Luo Gengkun <luogengkun2@huawei.com> --- arch/powerpc/perf/core-fsl-emb.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/perf/core-fsl-emb.c b/arch/powerpc/perf/core-fsl-emb.c index 1a53ab08447c..31037df4178c 100644 --- a/arch/powerpc/perf/core-fsl-emb.c +++ b/arch/powerpc/perf/core-fsl-emb.c @@ -366,9 +366,10 @@ static void fsl_emb_pmu_del(struct perf_event *event, int flags) cpuhw->n_events--; + put_cpu_var(cpu_hw_events); + out: perf_pmu_enable(event->pmu); - put_cpu_var(cpu_hw_events); } static void fsl_emb_pmu_start(struct perf_event *event, int ef_flags) -- 2.34.1