Commit 987db5d1 authored by Srinivas Pandruvada's avatar Srinivas Pandruvada Committed by Jialin Zhang
Browse files

thermal: intel_powerclamp: Use get_cpu() instead of smp_processor_id() to avoid crash

stable inclusion
from stable-v5.10.150
commit 513943bf879d45005213e6f5cfb7d9e9943f589f
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6D0XA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=513943bf879d45005213e6f5cfb7d9e9943f589f



--------------------------------

[ Upstream commit 68b99e94 ]

When CPU 0 is offline and intel_powerclamp is used to inject
idle, it generates kernel BUG:

BUG: using smp_processor_id() in preemptible [00000000] code: bash/15687
caller is debug_smp_processor_id+0x17/0x20
CPU: 4 PID: 15687 Comm: bash Not tainted 5.19.0-rc7+ #57
Call Trace:
<TASK>
dump_stack_lvl+0x49/0x63
dump_stack+0x10/0x16
check_preemption_disabled+0xdd/0xe0
debug_smp_processor_id+0x17/0x20
powerclamp_set_cur_state+0x7f/0xf9 [intel_powerclamp]
...
...

Here CPU 0 is the control CPU by default and changed to the current CPU,
if CPU 0 offlined. This check has to be performed under cpus_read_lock(),
hence the above warning.

Use get_cpu() instead of smp_processor_id() to avoid this BUG.

Suggested-by: default avatarChen Yu <yu.c.chen@intel.com>
Signed-off-by: default avatarSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
[ rjw: Subject edits ]
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
Signed-off-by: default avatarJialin Zhang <zhangjialin11@huawei.com>
parent 70398e31
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