x86/mce: Handle "action required" errors (a8c321fb) · Commits · e / devices / android_kernel_oneplus_sm8150

arch/x86/kernel/cpu/mcheck/mce.c

+53 −42

Original line number	Original line	Diff line number	Diff line
	@@ -982,7 +982,9 @@ void do_machine_check(struct pt_regs *regs, long error_code)
	barrier();		barrier();

	/*		/*
	* When no restart IP must always kill or panic.		* When no restart IP might need to kill or panic.
			* Assume the worst for now, but if we find the
			* severity is MCE_AR_SEVERITY we have other options.
	*/		*/
	if (!(m.mcgstatus & MCG_STATUS_RIPV))		if (!(m.mcgstatus & MCG_STATUS_RIPV))
	kill_it = 1;		kill_it = 1;
	@@ -1036,12 +1038,6 @@ void do_machine_check(struct pt_regs *regs, long error_code)
	continue;		continue;
	}		}

	/*
	* Kill on action required.
	*/
	if (severity == MCE_AR_SEVERITY)
	kill_it = 1;

	mce_read_aux(&m, i);		mce_read_aux(&m, i);

	/*		/*
	@@ -1062,6 +1058,9 @@ void do_machine_check(struct pt_regs *regs, long error_code)
	}		}
	}		}

			/* mce_clear_state will clear final, save locally for use later /
			m = *final;

	if (!no_way_out)		if (!no_way_out)
	mce_clear_state(toclear);		mce_clear_state(toclear);

	@@ -1073,27 +1072,22 @@ void do_machine_check(struct pt_regs *regs, long error_code)
	no_way_out = worst >= MCE_PANIC_SEVERITY;		no_way_out = worst >= MCE_PANIC_SEVERITY;

	/*		/*
	* If we have decided that we just CAN'T continue, and the user		* At insane "tolerant" levels we take no action. Otherwise
	* has not set tolerant to an insane level, give up and die.		* we only die if we have no other choice. For less serious
	*		* issues we try to recover, or limit damage to the current
	* This is mainly used in the case when the system doesn't		* process.
	* support MCE broadcasting or it has been disabled.
	*/
	if (no_way_out && tolerant < 3)
	mce_panic("Fatal machine check on current CPU", final, msg);

	/*
	* If the error seems to be unrecoverable, something should be
	* done. Try to kill as little as possible. If we can kill just
	* one task, do that. If the user has set the tolerance very
	* high, don't try to do anything at all.
	*/		*/
			if (tolerant < 3) {
	if (kill_it && tolerant < 3)		if (no_way_out)
	force_sig(SIGBUS, current);		mce_panic("Fatal machine check on current CPU", &m, msg);
			if (worst == MCE_AR_SEVERITY) {
	/* notify userspace ASAP */		/* schedule action before return to userland */
			mce_save_info(m.addr);
	set_thread_flag(TIF_MCE_NOTIFY);		set_thread_flag(TIF_MCE_NOTIFY);
			} else if (kill_it) {
			force_sig(SIGBUS, current);
			}
			}

	if (worst > 0)		if (worst > 0)
	mce_report_event(regs);		mce_report_event(regs);
	@@ -1107,6 +1101,8 @@ EXPORT_SYMBOL_GPL(do_machine_check);
	#ifndef CONFIG_MEMORY_FAILURE		#ifndef CONFIG_MEMORY_FAILURE
	int memory_failure(unsigned long pfn, int vector, int flags)		int memory_failure(unsigned long pfn, int vector, int flags)
	{		{
			/* mce_severity() should not hand us an ACTION_REQUIRED error */
			BUG_ON(flags & MF_ACTION_REQUIRED);
	printk(KERN_ERR "Uncorrected memory error in page 0x%lx ignored\n"		printk(KERN_ERR "Uncorrected memory error in page 0x%lx ignored\n"
	"Rebuild kernel with CONFIG_MEMORY_FAILURE=y for smarter handling\n", pfn);		"Rebuild kernel with CONFIG_MEMORY_FAILURE=y for smarter handling\n", pfn);

	@@ -1115,27 +1111,44 @@ int memory_failure(unsigned long pfn, int vector, int flags)
	#endif		#endif

	/*		/*
	* Called after mce notification in process context. This code		* Called in process context that interrupted by MCE and marked with
	* is allowed to sleep. Call the high level VM handler to process		* TIF_MCE_NOTIFY, just before returning to erroneous userland.
	* any corrupted pages.		* This code is allowed to sleep.
	* Assume that the work queue code only calls this one at a time		* Attempt possible recovery such as calling the high level VM handler to
	* per CPU.		* process any corrupted pages, and kill/signal current process if required.
	* Note we don't disable preemption, so this code might run on the wrong		* Action required errors are handled here.
	* CPU. In this case the event is picked up by the scheduled work queue.
	* This is merely a fast path to expedite processing in some common
	* cases.
	*/		*/
	void mce_notify_process(void)		void mce_notify_process(void)
	{		{
	unsigned long pfn;		unsigned long pfn;
	mce_notify_irq();		struct mce_info *mi = mce_find_info();
	while (mce_ring_get(&pfn))
	memory_failure(pfn, MCE_VECTOR, 0);		if (!mi)
			mce_panic("Lost physical address for unconsumed uncorrectable error", NULL, NULL);
			pfn = mi->paddr >> PAGE_SHIFT;

			clear_thread_flag(TIF_MCE_NOTIFY);

			pr_err("Uncorrected hardware memory error in user-access at %llx",
			mi->paddr);
			if (memory_failure(pfn, MCE_VECTOR, MF_ACTION_REQUIRED) < 0) {
			pr_err("Memory error not recovered");
			force_sig(SIGBUS, current);
			}
			mce_clear_info(mi);
	}		}

			/*
			* Action optional processing happens here (picking up
			* from the list of faulting pages that do_machine_check()
			* placed into the "ring").
			*/
	static void mce_process_work(struct work_struct *dummy)		static void mce_process_work(struct work_struct *dummy)
	{		{
	mce_notify_process();		unsigned long pfn;

			while (mce_ring_get(&pfn))
			memory_failure(pfn, MCE_VECTOR, 0);
	}		}

	#ifdef CONFIG_X86_MCE_INTEL		#ifdef CONFIG_X86_MCE_INTEL
	@@ -1225,8 +1238,6 @@ int mce_notify_irq(void)
	/* Not more than two messages every minute */		/* Not more than two messages every minute */
	static DEFINE_RATELIMIT_STATE(ratelimit, 60*HZ, 2);		static DEFINE_RATELIMIT_STATE(ratelimit, 60*HZ, 2);

	clear_thread_flag(TIF_MCE_NOTIFY);

	if (test_and_clear_bit(0, &mce_need_notify)) {		if (test_and_clear_bit(0, &mce_need_notify)) {
	/* wake processes polling /dev/mcelog */		/* wake processes polling /dev/mcelog */
	wake_up_interruptible(&mce_chrdev_wait);		wake_up_interruptible(&mce_chrdev_wait);