Merge branch 'for-4.19-nmi' into for-linus (9f68cb57) · Commits · e / devices / android_kernel_xiaomi_nabu

include/linux/printk.h

+4 −0

Original line number	Original line	Diff line number	Diff line
	@@ -148,9 +148,13 @@ void early_printk(const char *s, ...) { }
	#ifdef CONFIG_PRINTK_NMI		#ifdef CONFIG_PRINTK_NMI
	extern void printk_nmi_enter(void);		extern void printk_nmi_enter(void);
	extern void printk_nmi_exit(void);		extern void printk_nmi_exit(void);
			extern void printk_nmi_direct_enter(void);
			extern void printk_nmi_direct_exit(void);
	#else		#else
	static inline void printk_nmi_enter(void) { }		static inline void printk_nmi_enter(void) { }
	static inline void printk_nmi_exit(void) { }		static inline void printk_nmi_exit(void) { }
			static inline void printk_nmi_direct_enter(void) { }
			static inline void printk_nmi_direct_exit(void) { }
	#endif /* PRINTK_NMI */		#endif /* PRINTK_NMI */

	#ifdef CONFIG_PRINTK		#ifdef CONFIG_PRINTK

kernel/printk/internal.h

+8 −1

Original line number	Original line	Diff line number	Diff line
	@@ -19,11 +19,16 @@
	#ifdef CONFIG_PRINTK		#ifdef CONFIG_PRINTK

	#define PRINTK_SAFE_CONTEXT_MASK 0x3fffffff		#define PRINTK_SAFE_CONTEXT_MASK 0x3fffffff
	#define PRINTK_NMI_DEFERRED_CONTEXT_MASK 0x40000000		#define PRINTK_NMI_DIRECT_CONTEXT_MASK 0x40000000
	#define PRINTK_NMI_CONTEXT_MASK 0x80000000		#define PRINTK_NMI_CONTEXT_MASK 0x80000000

	extern raw_spinlock_t logbuf_lock;		extern raw_spinlock_t logbuf_lock;

			__printf(5, 0)
			int vprintk_store(int facility, int level,
			const char *dict, size_t dictlen,
			const char *fmt, va_list args);

	__printf(1, 0) int vprintk_default(const char *fmt, va_list args);		__printf(1, 0) int vprintk_default(const char *fmt, va_list args);
	__printf(1, 0) int vprintk_deferred(const char *fmt, va_list args);		__printf(1, 0) int vprintk_deferred(const char *fmt, va_list args);
	__printf(1, 0) int vprintk_func(const char *fmt, va_list args);		__printf(1, 0) int vprintk_func(const char *fmt, va_list args);
	@@ -54,6 +59,8 @@ void __printk_safe_exit(void);
	local_irq_enable(); \		local_irq_enable(); \
	} while (0)		} while (0)

			void defer_console_output(void);

	#else		#else

	__printf(1, 0) int vprintk_func(const char *fmt, va_list args) { return 0; }		__printf(1, 0) int vprintk_func(const char *fmt, va_list args) { return 0; }

kernel/printk/printk.c

+35 −22

Original line number	Original line	Diff line number	Diff line
	@@ -1829,7 +1829,8 @@ static size_t log_output(int facility, int level, enum log_flags lflags, const c
	return log_store(facility, level, lflags, 0, dict, dictlen, text, text_len);		return log_store(facility, level, lflags, 0, dict, dictlen, text, text_len);
	}		}

	asmlinkage int vprintk_emit(int facility, int level,		/* Must be called under logbuf_lock. */
			int vprintk_store(int facility, int level,
	const char *dict, size_t dictlen,		const char *dict, size_t dictlen,
	const char *fmt, va_list args)		const char *fmt, va_list args)
	{		{
	@@ -1837,20 +1838,7 @@ asmlinkage int vprintk_emit(int facility, int level,
	char *text = textbuf;		char *text = textbuf;
	size_t text_len;		size_t text_len;
	enum log_flags lflags = 0;		enum log_flags lflags = 0;
	unsigned long flags;
	int printed_len;
	bool in_sched = false;

	if (level == LOGLEVEL_SCHED) {
	level = LOGLEVEL_DEFAULT;
	in_sched = true;
	}

	boot_delay_msec(level);
	printk_delay();

	/* This stops the holder of console_sem just where we want him */
	logbuf_lock_irqsave(flags);
	/*		/*
	* The printf needs to come first; we need the syslog		* The printf needs to come first; we need the syslog
	* prefix which might be passed-in as a parameter.		* prefix which might be passed-in as a parameter.
	@@ -1894,8 +1882,29 @@ asmlinkage int vprintk_emit(int facility, int level,
	if (suppress_message_printing(level))		if (suppress_message_printing(level))
	lflags \|= LOG_NOCONS;		lflags \|= LOG_NOCONS;

	printed_len = log_output(facility, level, lflags, dict, dictlen, text, text_len);		return log_output(facility, level, lflags,
			dict, dictlen, text, text_len);
			}

			asmlinkage int vprintk_emit(int facility, int level,
			const char *dict, size_t dictlen,
			const char *fmt, va_list args)
			{
			int printed_len;
			bool in_sched = false;
			unsigned long flags;

			if (level == LOGLEVEL_SCHED) {
			level = LOGLEVEL_DEFAULT;
			in_sched = true;
			}

			boot_delay_msec(level);
			printk_delay();

			/* This stops the holder of console_sem just where we want him */
			logbuf_lock_irqsave(flags);
			printed_len = vprintk_store(facility, level, dict, dictlen, fmt, args);
	logbuf_unlock_irqrestore(flags);		logbuf_unlock_irqrestore(flags);

	/* If called from the scheduler, we can not call up(). */		/* If called from the scheduler, we can not call up(). */
	@@ -2884,16 +2893,20 @@ void wake_up_klogd(void)
	preempt_enable();		preempt_enable();
	}		}

	int vprintk_deferred(const char *fmt, va_list args)		void defer_console_output(void)
	{		{
	int r;

	r = vprintk_emit(0, LOGLEVEL_SCHED, NULL, 0, fmt, args);

	preempt_disable();		preempt_disable();
	__this_cpu_or(printk_pending, PRINTK_PENDING_OUTPUT);		__this_cpu_or(printk_pending, PRINTK_PENDING_OUTPUT);
	irq_work_queue(this_cpu_ptr(&wake_up_klogd_work));		irq_work_queue(this_cpu_ptr(&wake_up_klogd_work));
	preempt_enable();		preempt_enable();
			}

			int vprintk_deferred(const char *fmt, va_list args)
			{
			int r;

			r = vprintk_emit(0, LOGLEVEL_SCHED, NULL, 0, fmt, args);
			defer_console_output();

	return r;		return r;
	}		}

kernel/printk/printk_safe.c

+37 −21

Original line number	Original line	Diff line number	Diff line
	@@ -308,24 +308,33 @@ static __printf(1, 0) int vprintk_nmi(const char *fmt, va_list args)

	void printk_nmi_enter(void)		void printk_nmi_enter(void)
	{		{
	/*
	* The size of the extra per-CPU buffer is limited. Use it only when
	* the main one is locked. If this CPU is not in the safe context,
	* the lock must be taken on another CPU and we could wait for it.
	*/
	if ((this_cpu_read(printk_context) & PRINTK_SAFE_CONTEXT_MASK) &&
	raw_spin_is_locked(&logbuf_lock)) {
	this_cpu_or(printk_context, PRINTK_NMI_CONTEXT_MASK);		this_cpu_or(printk_context, PRINTK_NMI_CONTEXT_MASK);
	} else {
	this_cpu_or(printk_context, PRINTK_NMI_DEFERRED_CONTEXT_MASK);
	}
	}		}

	void printk_nmi_exit(void)		void printk_nmi_exit(void)
	{		{
	this_cpu_and(printk_context,		this_cpu_and(printk_context, ~PRINTK_NMI_CONTEXT_MASK);
	~(PRINTK_NMI_CONTEXT_MASK \|		}
	PRINTK_NMI_DEFERRED_CONTEXT_MASK));
			/*
			* Marks a code that might produce many messages in NMI context
			* and the risk of losing them is more critical than eventual
			* reordering.
			*
			* It has effect only when called in NMI context. Then printk()
			* will try to store the messages into the main logbuf directly
			* and use the per-CPU buffers only as a fallback when the lock
			* is not available.
			*/
			void printk_nmi_direct_enter(void)
			{
			if (this_cpu_read(printk_context) & PRINTK_NMI_CONTEXT_MASK)
			this_cpu_or(printk_context, PRINTK_NMI_DIRECT_CONTEXT_MASK);
			}

			void printk_nmi_direct_exit(void)
			{
			this_cpu_and(printk_context, ~PRINTK_NMI_DIRECT_CONTEXT_MASK);
	}		}

	#else		#else
	@@ -363,6 +372,20 @@ void __printk_safe_exit(void)

	__printf(1, 0) int vprintk_func(const char *fmt, va_list args)		__printf(1, 0) int vprintk_func(const char *fmt, va_list args)
	{		{
			/*
			* Try to use the main logbuf even in NMI. But avoid calling console
			* drivers that might have their own locks.
			*/
			if ((this_cpu_read(printk_context) & PRINTK_NMI_DIRECT_CONTEXT_MASK) &&
			raw_spin_trylock(&logbuf_lock)) {
			int len;

			len = vprintk_store(0, LOGLEVEL_DEFAULT, NULL, 0, fmt, args);
			raw_spin_unlock(&logbuf_lock);
			defer_console_output();
			return len;
			}

	/* Use extra buffer in NMI when logbuf_lock is taken or in safe mode. */		/* Use extra buffer in NMI when logbuf_lock is taken or in safe mode. */
	if (this_cpu_read(printk_context) & PRINTK_NMI_CONTEXT_MASK)		if (this_cpu_read(printk_context) & PRINTK_NMI_CONTEXT_MASK)
	return vprintk_nmi(fmt, args);		return vprintk_nmi(fmt, args);
	@@ -371,13 +394,6 @@ __printf(1, 0) int vprintk_func(const char *fmt, va_list args)
	if (this_cpu_read(printk_context) & PRINTK_SAFE_CONTEXT_MASK)		if (this_cpu_read(printk_context) & PRINTK_SAFE_CONTEXT_MASK)
	return vprintk_safe(fmt, args);		return vprintk_safe(fmt, args);

	/*
	* Use the main logbuf when logbuf_lock is available in NMI.
	* But avoid calling console drivers that might have their own locks.
	*/
	if (this_cpu_read(printk_context) & PRINTK_NMI_DEFERRED_CONTEXT_MASK)
	return vprintk_deferred(fmt, args);

	/* No obstacles. */		/* No obstacles. */
	return vprintk_default(fmt, args);		return vprintk_default(fmt, args);
	}		}

kernel/trace/trace.c

+3 −1

Original line number	Original line	Diff line number	Diff line
	@@ -8265,6 +8265,7 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
	tracing_off();		tracing_off();

	local_irq_save(flags);		local_irq_save(flags);
			printk_nmi_direct_enter();

	/* Simulate the iterator */		/* Simulate the iterator */
	trace_init_global_iter(&iter);		trace_init_global_iter(&iter);
	@@ -8345,6 +8346,7 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
	atomic_dec(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled);		atomic_dec(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled);
	}		}
	atomic_dec(&dump_running);		atomic_dec(&dump_running);
			printk_nmi_direct_exit();
	local_irq_restore(flags);		local_irq_restore(flags);
	}		}
	EXPORT_SYMBOL_GPL(ftrace_dump);		EXPORT_SYMBOL_GPL(ftrace_dump);