mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2026-08-09 06:14:34 +02:00
Reinette ChatreandThomas Gleixner
9c91efd1d6
lockdep_is_cpus_held() and lockdep_is_cpus_write_held() are undefined when !CONFIG_HOTPLUG_CPU. This is ok because their few callers protect the calls with a "if (IS_ENABLED(CONFIG_HOTPLUG_CPU) ..." check. It is error prone to require callers to protect lockdep_is_cpus_held() and lockdep_is_cpus_write_held() with an IS_ENABLED(CONFIG_HOTPLUG_CPU) check while the custom for equivalent functions, for example the more prevalent lockdep_is_held(), is to not require similar protection. It is also inconsistent with CPU hotplug lockdep code self since related call lockdep_assert_cpus_held() does not require protection. Create stubs for lockdep_is_cpus_held() and lockdep_is_cpus_write_held() that returns 1 (LOCK_STATE_UNKNOWN/LOCK_STATE_HELD) when !CONFIG_HOTPLUG_CPU. This makes the CPU hotplug lockdep checks consistent while following existing lockdep custom. Drop the "extern" from the function declaration as part of the move to match kernel coding style. Keep the IS_ENABLED(CONFIG_HOTPLUG_CPU) checks in existing users since removing them would change the logic of these expressions. Reported-by: Sashiko <sashiko-bot@kernel.org> Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Link: https://patch.msgid.link/7484f0b58fd86153d445819cc4e172adba16cff9.1780543665.git.reinette.chatre@intel.com Closes: https://sashiko.dev/#/patchset/cover.1780456704.git.reinette.chatre%40intel.com?part=1
52 lines
1.7 KiB
C
52 lines
1.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* include/linux/cpuhplock.h - CPU hotplug locking
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*
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* Locking functions for CPU hotplug.
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*/
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#ifndef _LINUX_CPUHPLOCK_H_
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#define _LINUX_CPUHPLOCK_H_
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#include <linux/cleanup.h>
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#include <linux/errno.h>
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struct device;
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#ifdef CONFIG_HOTPLUG_CPU
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void cpus_write_lock(void);
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void cpus_write_unlock(void);
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void cpus_read_lock(void);
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void cpus_read_unlock(void);
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int cpus_read_trylock(void);
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void lockdep_assert_cpus_held(void);
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int lockdep_is_cpus_held(void);
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int lockdep_is_cpus_write_held(void);
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void cpu_hotplug_disable_offlining(void);
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void cpu_hotplug_disable(void);
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void cpu_hotplug_enable(void);
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void clear_tasks_mm_cpumask(int cpu);
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int remove_cpu(unsigned int cpu);
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int cpu_device_down(struct device *dev);
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void smp_shutdown_nonboot_cpus(unsigned int primary_cpu);
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#else /* CONFIG_HOTPLUG_CPU */
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static inline void cpus_write_lock(void) { }
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static inline void cpus_write_unlock(void) { }
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static inline void cpus_read_lock(void) { }
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static inline void cpus_read_unlock(void) { }
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static inline int cpus_read_trylock(void) { return true; }
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static inline void lockdep_assert_cpus_held(void) { }
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static inline int lockdep_is_cpus_held(void) { return 1; }
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static inline int lockdep_is_cpus_write_held(void) { return 1; }
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static inline void cpu_hotplug_disable_offlining(void) { }
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static inline void cpu_hotplug_disable(void) { }
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static inline void cpu_hotplug_enable(void) { }
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static inline int remove_cpu(unsigned int cpu) { return -EPERM; }
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static inline void smp_shutdown_nonboot_cpus(unsigned int primary_cpu) { }
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#endif /* !CONFIG_HOTPLUG_CPU */
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DEFINE_LOCK_GUARD_0(cpus_read_lock, cpus_read_lock(), cpus_read_unlock())
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#endif /* _LINUX_CPUHPLOCK_H_ */
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