WSL2-Linux-Kernel/drivers/cpuidle
Russell Currey 2935443dc9 powerpc/pseries: Rework lppaca_shared_proc() to avoid DEBUG_PREEMPT
[ Upstream commit eac030b22e ]

lppaca_shared_proc() takes a pointer to the lppaca which is typically
accessed through get_lppaca().  With DEBUG_PREEMPT enabled, this leads
to checking if preemption is enabled, for example:

  BUG: using smp_processor_id() in preemptible [00000000] code: grep/10693
  caller is lparcfg_data+0x408/0x19a0
  CPU: 4 PID: 10693 Comm: grep Not tainted 6.5.0-rc3 #2
  Call Trace:
    dump_stack_lvl+0x154/0x200 (unreliable)
    check_preemption_disabled+0x214/0x220
    lparcfg_data+0x408/0x19a0
    ...

This isn't actually a problem however, as it does not matter which
lppaca is accessed, the shared proc state will be the same.
vcpudispatch_stats_procfs_init() already works around this by disabling
preemption, but the lparcfg code does not, erroring any time
/proc/powerpc/lparcfg is accessed with DEBUG_PREEMPT enabled.

Instead of disabling preemption on the caller side, rework
lppaca_shared_proc() to not take a pointer and instead directly access
the lppaca, bypassing any potential preemption checks.

Fixes: f13c13a005 ("powerpc: Stop using non-architected shared_proc field in lppaca")
Signed-off-by: Russell Currey <ruscur@russell.cc>
[mpe: Rework to avoid needing a definition in paca.h and lppaca.h]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230823055317.751786-4-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-19 12:22:42 +02:00
..
governors cpuidle: teo: Rename two local variables in teo_select() 2021-08-03 15:18:57 +02:00
Kconfig
Kconfig.arm cpuidle: Fix ARM_QCOM_SPM_CPUIDLE configuration 2021-04-08 19:54:14 +02:00
Kconfig.mips
Kconfig.powerpc
Makefile cpuidle: psci: Split into two separate build objects 2020-07-29 18:38:30 +02:00
coupled.c smp: Cleanup smp_call_function*() 2020-11-24 16:47:49 +01:00
cpuidle-arm.c
cpuidle-at91.c
cpuidle-big_little.c cpuidle: big.LITTLE: enable driver only on Peach-Pit/Pi Chromebooks 2020-10-26 10:15:24 +01:00
cpuidle-calxeda.c
cpuidle-clps711x.c
cpuidle-cps.c
cpuidle-exynos.c
cpuidle-haltpoll.c
cpuidle-kirkwood.c
cpuidle-mvebu-v7.c
cpuidle-powernv.c powerpc/powernv/idle: add a basic stop 0-3 driver for POWER10 2020-09-15 22:13:38 +10:00
cpuidle-psci-domain.c cpuidle: psci: Iterate backwards over list in psci_pd_remove() 2023-03-22 13:31:36 +01:00
cpuidle-psci.c cpuidle: PSCI: Improve support for suspend-to-RAM for PSCI OSI mode 2022-06-09 10:22:33 +02:00
cpuidle-psci.h cpuidle: psci: Fix error path via converting to a platform driver 2020-07-29 18:38:30 +02:00
cpuidle-pseries.c powerpc/pseries: Rework lppaca_shared_proc() to avoid DEBUG_PREEMPT 2023-09-19 12:22:42 +02:00
cpuidle-qcom-spm.c cpuidle: qcom: Add SPM register data for MSM8226 2021-06-16 20:03:26 +02:00
cpuidle-tegra.c cpuidle: tegra: Remove do_idle firmware call 2021-04-08 19:54:14 +02:00
cpuidle-ux500.c mfd/cpuidle: ux500: Rename driver symbol 2021-08-16 13:42:34 +01:00
cpuidle-zynq.c
cpuidle.c cpuidle: Select polling interval based on a c-state with a longer target residency 2020-12-01 17:59:18 +01:00
cpuidle.h
driver.c cpuidle: Use s64 as exit_latency_ns and target_residency_ns data type 2021-04-07 19:26:44 +02:00
dt_idle_states.c cpuidle: dt: Return the correct numbers of parsed idle states 2022-12-31 13:14:01 +01:00
dt_idle_states.h
governor.c
poll_state.c
sysfs.c cpuidle: Fix kobject memory leaks in error paths 2021-11-18 19:16:29 +01:00