Merge branch 'for-4.13' into for-linus (a5707eef) · Commits · e / devices / android_kernel_oneplus_sm7250

kernel/printk/internal.h

+4 −2

Original line number	Diff line number	Diff line
		@@ -18,12 +18,14 @@

		#ifdef CONFIG_PRINTK

		#define PRINTK_SAFE_CONTEXT_MASK 0x7fffffff
		#define PRINTK_SAFE_CONTEXT_MASK 0x3fffffff
		#define PRINTK_NMI_DEFERRED_CONTEXT_MASK 0x40000000
		#define PRINTK_NMI_CONTEXT_MASK 0x80000000

		extern raw_spinlock_t logbuf_lock;

		__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_func(const char *fmt, va_list args);
		void __printk_safe_enter(void);
		void __printk_safe_exit(void);

kernel/printk/printk.c

+14 −5

Original line number	Diff line number	Diff line
		@@ -2720,16 +2720,13 @@ void wake_up_klogd(void)
		preempt_enable();
		}

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

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

		preempt_disable();
		__this_cpu_or(printk_pending, PRINTK_PENDING_OUTPUT);
		irq_work_queue(this_cpu_ptr(&wake_up_klogd_work));
		preempt_enable();
		@@ -2737,6 +2734,18 @@ int printk_deferred(const char *fmt, ...)
		return r;
		}

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

		va_start(args, fmt);
		r = vprintk_deferred(fmt, args);
		va_end(args);

		return r;
		}

		/*
		* printk rate limiting, lifted from the networking subsystem.
		*

kernel/printk/printk_safe.c

+29 −7

Original line number	Diff line number	Diff line
		@@ -80,7 +80,7 @@ static void queue_flush_work(struct printk_safe_seq_buf *s)
		* happen, printk_safe_log_store() will notice the buffer->len mismatch
		* and repeat the write.
		*/
		static int printk_safe_log_store(struct printk_safe_seq_buf *s,
		static __printf(2, 0) int printk_safe_log_store(struct printk_safe_seq_buf *s,
		const char *fmt, va_list args)
		{
		int add;
		@@ -299,7 +299,7 @@ void printk_safe_flush_on_panic(void)
		* one writer running. But the buffer might get flushed from another
		* CPU, so we need to be careful.
		*/
		static int vprintk_nmi(const char *fmt, va_list args)
		static __printf(1, 0) int vprintk_nmi(const char *fmt, va_list args)
		{
		struct printk_safe_seq_buf *s = this_cpu_ptr(&nmi_print_seq);

		@@ -308,17 +308,29 @@ static int vprintk_nmi(const char *fmt, va_list args)

		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);
		} else {
		this_cpu_or(printk_context, PRINTK_NMI_DEFERRED_CONTEXT_MASK);
		}
		}

		void printk_nmi_exit(void)
		{
		this_cpu_and(printk_context, ~PRINTK_NMI_CONTEXT_MASK);
		this_cpu_and(printk_context,
		~(PRINTK_NMI_CONTEXT_MASK \|
		PRINTK_NMI_DEFERRED_CONTEXT_MASK));
		}

		#else

		static int vprintk_nmi(const char *fmt, va_list args)
		static __printf(1, 0) int vprintk_nmi(const char *fmt, va_list args)
		{
		return 0;
		}
		@@ -330,7 +342,7 @@ static int vprintk_nmi(const char *fmt, va_list args)
		* into itself. It uses a per-CPU buffer to store the message, just like
		* NMI.
		*/
		static int vprintk_safe(const char *fmt, va_list args)
		static __printf(1, 0) int vprintk_safe(const char *fmt, va_list args)
		{
		struct printk_safe_seq_buf *s = this_cpu_ptr(&safe_print_seq);

		@@ -351,12 +363,22 @@ void __printk_safe_exit(void)

		__printf(1, 0) int vprintk_func(const char *fmt, va_list args)
		{
		/* Use extra buffer in NMI when logbuf_lock is taken or in safe mode. */
		if (this_cpu_read(printk_context) & PRINTK_NMI_CONTEXT_MASK)
		return vprintk_nmi(fmt, args);

		/* Use extra buffer to prevent a recursion deadlock in safe mode. */
		if (this_cpu_read(printk_context) & PRINTK_SAFE_CONTEXT_MASK)
		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. */
		return vprintk_default(fmt, args);
		}

lib/nmi_backtrace.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -86,9 +86,11 @@ void nmi_trigger_cpumask_backtrace(const cpumask_t *mask,

		bool nmi_cpu_backtrace(struct pt_regs *regs)
		{
		static arch_spinlock_t lock = __ARCH_SPIN_LOCK_UNLOCKED;
		int cpu = smp_processor_id();

		if (cpumask_test_cpu(cpu, to_cpumask(backtrace_mask))) {
		arch_spin_lock(&lock);
		if (regs && cpu_in_idle(instruction_pointer(regs))) {
		pr_warn("NMI backtrace for cpu %d skipped: idling at pc %#lx\n",
		cpu, instruction_pointer(regs));
		@@ -99,6 +101,7 @@ bool nmi_cpu_backtrace(struct pt_regs *regs)
		else
		dump_stack();
		}
		arch_spin_unlock(&lock);
		cpumask_clear_cpu(cpu, to_cpumask(backtrace_mask));
		return true;
		}