x86/mce: Send #MC singal from task work (5567d11c) · Commits · 戴 / test

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

+31 −25

Original line number	Diff line number	Diff line
		@@ -42,6 +42,7 @@
		#include <linux/export.h>
		#include <linux/jump_label.h>
		#include <linux/set_memory.h>
		#include <linux/task_work.h>

		#include <asm/intel-family.h>
		#include <asm/processor.h>
		@@ -1086,23 +1087,6 @@ static void mce_clear_state(unsigned long *toclear)
		}
		}

		static int do_memory_failure(struct mce *m)
		{
		int flags = MF_ACTION_REQUIRED;
		int ret;

		pr_err("Uncorrected hardware memory error in user-access at %llx", m->addr);
		if (!(m->mcgstatus & MCG_STATUS_RIPV))
		flags \|= MF_MUST_KILL;
		ret = memory_failure(m->addr >> PAGE_SHIFT, flags);
		if (ret)
		pr_err("Memory error not recovered");
		else
		set_mce_nospec(m->addr >> PAGE_SHIFT);
		return ret;
		}


		/*
		* Cases where we avoid rendezvous handler timeout:
		* 1) If this CPU is offline.
		@@ -1204,6 +1188,29 @@ static void __mc_scan_banks(struct mce m, struct mce final,
		m = final;
		}

		static void kill_me_now(struct callback_head *ch)
		{
		force_sig(SIGBUS);
		}

		static void kill_me_maybe(struct callback_head *cb)
		{
		struct task_struct *p = container_of(cb, struct task_struct, mce_kill_me);
		int flags = MF_ACTION_REQUIRED;

		pr_err("Uncorrected hardware memory error in user-access at %llx", p->mce_addr);
		if (!(p->mce_status & MCG_STATUS_RIPV))
		flags \|= MF_MUST_KILL;

		if (!memory_failure(p->mce_addr >> PAGE_SHIFT, flags)) {
		set_mce_nospec(p->mce_addr >> PAGE_SHIFT);
		return;
		}

		pr_err("Memory error not recovered");
		kill_me_now(cb);
		}

		/*
		* The actual machine check handler. This only handles real
		* exceptions when something got corrupted coming in through int 18.
		@@ -1222,7 +1229,7 @@ static void __mc_scan_banks(struct mce m, struct mce final,
		* backing the user stack, tracing that reads the user stack will cause
		* potentially infinite recursion.
		*/
		void notrace do_machine_check(struct pt_regs *regs, long error_code)
		void noinstr do_machine_check(struct pt_regs *regs, long error_code)
		{
		DECLARE_BITMAP(valid_banks, MAX_NR_BANKS);
		DECLARE_BITMAP(toclear, MAX_NR_BANKS);
		@@ -1354,13 +1361,13 @@ void notrace do_machine_check(struct pt_regs *regs, long error_code)
		if ((m.cs & 3) == 3) {
		/* If this triggers there is no way to recover. Die hard. */
		BUG_ON(!on_thread_stack() \|\| !user_mode(regs));
		local_irq_enable();
		preempt_enable();

		if (kill_it \|\| do_memory_failure(&m))
		force_sig(SIGBUS);
		preempt_disable();
		local_irq_disable();
		current->mce_addr = m.addr;
		current->mce_status = m.mcgstatus;
		current->mce_kill_me.func = kill_me_maybe;
		if (kill_it)
		current->mce_kill_me.func = kill_me_now;
		task_work_add(current, &current->mce_kill_me, true);
		} else {
		if (!fixup_exception(regs, X86_TRAP_MC, error_code, 0))
		mce_panic("Failed kernel mode recovery", &m, msg);
		@@ -1370,7 +1377,6 @@ out_ist:
		ist_exit(regs);
		}
		EXPORT_SYMBOL_GPL(do_machine_check);
		NOKPROBE_SYMBOL(do_machine_check);

		#ifndef CONFIG_MEMORY_FAILURE
		int memory_failure(unsigned long pfn, int flags)

include/linux/sched.h

+6 −0

Original line number	Diff line number	Diff line
		@@ -1297,6 +1297,12 @@ struct task_struct {
		unsigned long prev_lowest_stack;
		#endif

		#ifdef CONFIG_X86_MCE
		u64 mce_addr;
		u64 mce_status;
		struct callback_head mce_kill_me;
		#endif

		/*
		* New fields for task_struct should be added above here, so that
		* they are included in the randomized portion of task_struct.

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