Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge branch 'rework/threaded-printk' into for-linus
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kernel/printk/printk.c
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kernel/printk/printk.c
···
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}
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/*
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* Legacy console printing from printk() caller context does not respect
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* raw_spinlock/spinlock nesting. For !PREEMPT_RT the lockdep warning is a
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* false positive. For PREEMPT_RT the false positive condition does not
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* occur.
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*
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* This map is used to temporarily establish LD_WAIT_SLEEP context for the
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* console write() callback when legacy printing to avoid false positive
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* lockdep complaints, thus allowing lockdep to continue to function for
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* real issues.
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* The legacy console always acquires a spinlock_t from its printing
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* callback. This violates lock nesting if the caller acquired an always
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* spinning lock (raw_spinlock_t) while invoking printk(). This is not a
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* problem on PREEMPT_RT because legacy consoles print always from a
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* dedicated thread and never from within printk(). Therefore we tell
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* lockdep that a sleeping spin lock (spinlock_t) is valid here.
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*/
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#ifdef CONFIG_PREEMPT_RT
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static inline void printk_legacy_allow_spinlock_enter(void) { }
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static inline void printk_legacy_allow_spinlock_exit(void) { }
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#else
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static DEFINE_WAIT_OVERRIDE_MAP(printk_legacy_map, LD_WAIT_SLEEP);
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static DEFINE_WAIT_OVERRIDE_MAP(printk_legacy_map, LD_WAIT_CONFIG);
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static inline void printk_legacy_allow_spinlock_enter(void)
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{