From: Meng Li <meng...@windriver.com> When enable debug kernel configs,there will be calltrace as below:
BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1 caller is debug_smp_processor_id+0x20/0x30 CPU: 6 PID: 1 Comm: swapper/0 Not tainted 5.10.63-yocto-standard #1 Hardware name: NXP Layerscape LX2160ARDB (DT) Call trace: dump_backtrace+0x0/0x1a0 show_stack+0x24/0x30 dump_stack+0xf0/0x13c check_preemption_disabled+0x100/0x110 debug_smp_processor_id+0x20/0x30 dpaa2_io_query_fq_count+0xdc/0x154 dpaa2_eth_stop+0x144/0x314 __dev_close_many+0xdc/0x160 __dev_change_flags+0xe8/0x220 dev_change_flags+0x30/0x70 ic_close_devs+0x50/0x78 ip_auto_config+0xed0/0xf10 do_one_initcall+0xac/0x460 kernel_init_freeable+0x30c/0x378 kernel_init+0x20/0x128 ret_from_fork+0x10/0x38 Because smp_processor_id() should be invoked in preempt disable status. So, add preempt_disable/enable() to protect smp_processor_id(). Fixes: c89105c9b390 ("staging: fsl-mc: Move DPIO from staging to drivers/soc/fsl") Cc: sta...@vger.kernel.org Signed-off-by: Meng Li <meng...@windriver.com> --- drivers/soc/fsl/dpio/dpio-service.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/soc/fsl/dpio/dpio-service.c b/drivers/soc/fsl/dpio/dpio-service.c index 19f47ea9dab0..afc3b89b0fc5 100644 --- a/drivers/soc/fsl/dpio/dpio-service.c +++ b/drivers/soc/fsl/dpio/dpio-service.c @@ -58,8 +58,11 @@ static inline struct dpaa2_io *service_select_by_cpu(struct dpaa2_io *d, * If cpu == -1, choose the current cpu, with no guarantees about * potentially being migrated away. */ - if (cpu < 0) - cpu = smp_processor_id(); + if (cpu < 0) { + preempt_disable(); + cpu = smp_processor_id(); + preempt_enable(); + } /* If a specific cpu was requested, pick it up immediately */ return dpio_by_cpu[cpu]; -- 2.17.1