x86/mce: Check for faults tagged in EXTABLE_CLASS_FAULT exception table entries (b2f9d678) · Commits · 戴 / test

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

+20 −2

Original line number	Diff line number	Diff line
		@@ -14,6 +14,7 @@
		#include <linux/init.h>
		#include <linux/debugfs.h>
		#include <asm/mce.h>
		#include <asm/uaccess.h>

		#include "mce-internal.h"

		@@ -29,7 +30,7 @@
		* panic situations)
		*/

		enum context { IN_KERNEL = 1, IN_USER = 2 };
		enum context { IN_KERNEL = 1, IN_USER = 2, IN_KERNEL_RECOV = 3 };
		enum ser { SER_REQUIRED = 1, NO_SER = 2 };
		enum exception { EXCP_CONTEXT = 1, NO_EXCP = 2 };

		@@ -48,6 +49,7 @@ static struct severity {
		#define MCESEV(s, m, c...) { .sev = MCE_ ## s ## _SEVERITY, .msg = m, ## c }
		#define KERNEL .context = IN_KERNEL
		#define USER .context = IN_USER
		#define KERNEL_RECOV .context = IN_KERNEL_RECOV
		#define SER .ser = SER_REQUIRED
		#define NOSER .ser = NO_SER
		#define EXCP .excp = EXCP_CONTEXT
		@@ -86,6 +88,10 @@ static struct severity {
		PANIC, "In kernel and no restart IP",
		EXCP, KERNEL, MCGMASK(MCG_STATUS_RIPV, 0)
		),
		MCESEV(
		PANIC, "In kernel and no restart IP",
		EXCP, KERNEL_RECOV, MCGMASK(MCG_STATUS_RIPV, 0)
		),
		MCESEV(
		DEFERRED, "Deferred error",
		NOSER, MASK(MCI_STATUS_UC\|MCI_STATUS_DEFERRED\|MCI_STATUS_POISON, MCI_STATUS_DEFERRED)
		@@ -122,6 +128,11 @@ static struct severity {
		SER, MASK(MCI_STATUS_OVER\|MCI_UC_SAR\|MCI_ADDR, MCI_UC_SAR\|MCI_ADDR),
		MCGMASK(MCG_STATUS_RIPV\|MCG_STATUS_EIPV, MCG_STATUS_RIPV)
		),
		MCESEV(
		AR, "Action required: data load in error recoverable area of kernel",
		SER, MASK(MCI_STATUS_OVER\|MCI_UC_SAR\|MCI_ADDR\|MCACOD, MCI_UC_SAR\|MCI_ADDR\|MCACOD_DATA),
		KERNEL_RECOV
		),
		MCESEV(
		AR, "Action required: data load error in a user process",
		SER, MASK(MCI_STATUS_OVER\|MCI_UC_SAR\|MCI_ADDR\|MCACOD, MCI_UC_SAR\|MCI_ADDR\|MCACOD_DATA),
		@@ -170,6 +181,9 @@ static struct severity {
		) /* always matches. keep at end */
		};

		#define mc_recoverable(mcg) (((mcg) & (MCG_STATUS_RIPV\|MCG_STATUS_EIPV)) == \
		(MCG_STATUS_RIPV\|MCG_STATUS_EIPV))

		/*
		* If mcgstatus indicated that ip/cs on the stack were
		* no good, then "m->cs" will be zero and we will have
		@@ -183,7 +197,11 @@ static struct severity {
		*/
		static int error_context(struct mce *m)
		{
		return ((m->cs & 3) == 3) ? IN_USER : IN_KERNEL;
		if ((m->cs & 3) == 3)
		return IN_USER;
		if (mc_recoverable(m->mcgstatus) && ex_has_fault_handler(m->ip))
		return IN_KERNEL_RECOV;
		return IN_KERNEL;
		}

		/*

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

+36 −34

Original line number	Diff line number	Diff line
		@@ -961,6 +961,20 @@ 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, MCE_VECTOR, flags);
		if (ret)
		pr_err("Memory error not recovered");
		return ret;
		}

		/*
		* The actual machine check handler. This only handles real
		* exceptions when something got corrupted coming in through int 18.
		@@ -998,8 +1012,6 @@ void do_machine_check(struct pt_regs *regs, long error_code)
		DECLARE_BITMAP(toclear, MAX_NR_BANKS);
		DECLARE_BITMAP(valid_banks, MAX_NR_BANKS);
		char *msg = "Unknown";
		u64 recover_paddr = ~0ull;
		int flags = MF_ACTION_REQUIRED;
		int lmce = 0;

		/* If this CPU is offline, just bail out. */
		@@ -1136,22 +1148,13 @@ void do_machine_check(struct pt_regs *regs, long error_code)
		}

		/*
		* At insane "tolerant" levels we take no action. Otherwise
		* we only die if we have no other choice. For less serious
		* issues we try to recover, or limit damage to the current
		* process.
		* If tolerant is at an insane level we drop requests to kill
		* processes and continue even when there is no way out.
		*/
		if (cfg->tolerant < 3) {
		if (no_way_out)
		if (cfg->tolerant == 3)
		kill_it = 0;
		else if (no_way_out)
		mce_panic("Fatal machine check on current CPU", &m, msg);
		if (worst == MCE_AR_SEVERITY) {
		recover_paddr = m.addr;
		if (!(m.mcgstatus & MCG_STATUS_RIPV))
		flags \|= MF_MUST_KILL;
		} else if (kill_it) {
		force_sig(SIGBUS, current);
		}
		}

		if (worst > 0)
		mce_report_event(regs);
		@@ -1159,25 +1162,24 @@ void do_machine_check(struct pt_regs *regs, long error_code)
		out:
		sync_core();

		if (recover_paddr == ~0ull)
		goto done;
		if (worst != MCE_AR_SEVERITY && !kill_it)
		goto out_ist;

		pr_err("Uncorrected hardware memory error in user-access at %llx",
		recover_paddr);
		/*
		* We must call memory_failure() here even if the current process is
		* doomed. We still need to mark the page as poisoned and alert any
		* other users of the page.
		*/
		/* Fault was in user mode and we need to take some action */
		if ((m.cs & 3) == 3) {
		ist_begin_non_atomic(regs);
		local_irq_enable();
		if (memory_failure(recover_paddr >> PAGE_SHIFT, MCE_VECTOR, flags) < 0) {
		pr_err("Memory error not recovered");

		if (kill_it \|\| do_memory_failure(&m))
		force_sig(SIGBUS, current);
		}
		local_irq_disable();
		ist_end_non_atomic();
		done:
		} else {
		if (!fixup_exception(regs, X86_TRAP_MC))
		mce_panic("Failed kernel mode recovery", &m, NULL);
		}

		out_ist:
		ist_exit(regs);
		}
		EXPORT_SYMBOL_GPL(do_machine_check);

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