Merge commit 'fixes.2015.02.23a' into core/rcu

[cascardo/linux.git] / arch / x86 / kernel / cpu / mcheck / mce.c

diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index a006f4c..524f2a8 100644 (file)
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -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)
-                       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 (cfg->tolerant == 3)
+               kill_it = 0;
+       else if (no_way_out)
+               mce_panic("Fatal machine check on current CPU", &m, msg);
 
        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.
-        */
-       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");
-               force_sig(SIGBUS, current);
+       /* 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 (kill_it || do_memory_failure(&m))
+                       force_sig(SIGBUS, current);
+               local_irq_disable();
+               ist_end_non_atomic();
+       } else {
+               if (!fixup_exception(regs, X86_TRAP_MC))
+                       mce_panic("Failed kernel mode recovery", &m, NULL);
        }
-       local_irq_disable();
-       ist_end_non_atomic();
-done:
+
+out_ist:
        ist_exit(regs);
 }
 EXPORT_SYMBOL_GPL(do_machine_check);
@@ -1617,10 +1619,10 @@ static void __mcheck_cpu_init_vendor(struct cpuinfo_x86 *c)
        case X86_VENDOR_AMD: {
                u32 ebx = cpuid_ebx(0x80000007);
 
-               mce_amd_feature_init(c);
                mce_flags.overflow_recov = !!(ebx & BIT(0));
                mce_flags.succor         = !!(ebx & BIT(1));
                mce_flags.smca           = !!(ebx & BIT(3));
+               mce_amd_feature_init(c);
 
                break;
                }