Skip to content
Commit 76871206 authored by HariBabu Gattem's avatar HariBabu Gattem Committed by Quanyang Wang
Browse files

soc: xilinx: Fix for call trace due to the usage of smp_processor_id()

commit fbb9d2073fcff5fbf12dc273385c292d14996532 from
https://github.com/Xilinx/linux-xlnx.git

 xlnx_rebase_v5.15

When preemption is enabled in kernel and if any task which can be
preempted should not use smp_processor_id() directly, since CPU
switch can happen at any time, the previous value of cpu_id
differs with current cpu_id. As a result we see the below call trace
during xlnx_event_manager_probe.

[ 6.140197] dump_backtrace+0x0/0x190
[ 6.143884] show_stack+0x18/0x40
[ 6.147220] dump_stack_lvl+0x7c/0xa0
[ 6.150907] dump_stack+0x18/0x34
[ 6.154241] check_preemption_disabled+0x124/0x134
[ 6.159068] debug_smp_processor_id+0x20/0x2c
[ 6.163453] xlnx_event_manager_probe+0x48/0x250

To protect cpu_id, It is recommended to use get_cpu()/put_cpu()
to disable preemption, get the cpu_id and enable preemption respectively.
(For Reference, Documentation/locking/preempt-locking.rst and
Documentation/kernel-hacking/hacking.rst)

Use preempt_disable()/smp_processor_id()/preempt_enable()
API's to achieve the same.

Signed-off-by: default avatarHariBabu Gattem <haribabu.gattem@xilinx.com>
Signed-off-by: default avatarYoung Kwan <young.kwa.nam@xilinx.com>

State: pending
Signed-off-by: default avatarQuanyang Wang <quanyang.wang@windriver.com>
parent 1ff88409
Loading
Loading
Loading
Loading
0% Loading or .
You are about to add 0 people to the discussion. Proceed with caution.
Please register or to comment