On 2021-10-15 07:36, meng...@windriver.com wrote:
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().
If preemption doesn't matter anyway, as the comment in the context
implies, then it probably makes more sense just to use
raw_smp_processor_id() instead.
Robin.
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];
