return ret;
}
- #ifndef mce_unmap_kpfn
- static void mce_unmap_kpfn(unsigned long pfn)
- {
- unsigned long decoy_addr;
-
- /*
- * Unmap this page from the kernel 1:1 mappings to make sure
- * we don't log more errors because of speculative access to
- * the page.
- * We would like to just call:
- * set_memory_np((unsigned long)pfn_to_kaddr(pfn), 1);
- * but doing that would radically increase the odds of a
- * speculative access to the poison page because we'd have
- * the virtual address of the kernel 1:1 mapping sitting
- * around in registers.
- * Instead we get tricky. We create a non-canonical address
- * that looks just like the one we want, but has bit 63 flipped.
- * This relies on set_memory_np() not checking whether we passed
- * a legal address.
- */
-
- decoy_addr = (pfn << PAGE_SHIFT) + (PAGE_OFFSET ^ BIT(63));
-
- if (set_memory_np(decoy_addr, 1))
- pr_warn("Could not invalidate pfn=0x%lx from 1:1 map\n", pfn);
- }
- #endif
-
+
+/*
+ * Cases where we avoid rendezvous handler timeout:
+ * 1) If this CPU is offline.
+ *
+ * 2) If crashing_cpu was set, e.g. we're entering kdump and we need to
+ * skip those CPUs which remain looping in the 1st kernel - see
+ * crash_nmi_callback().
+ *
+ * Note: there still is a small window between kexec-ing and the new,
+ * kdump kernel establishing a new #MC handler where a broadcasted MCE
+ * might not get handled properly.
+ */
+static bool __mc_check_crashing_cpu(int cpu)
+{
+ if (cpu_is_offline(cpu) ||
+ (crashing_cpu != -1 && crashing_cpu != cpu)) {
+ u64 mcgstatus;
+
+ mcgstatus = mce_rdmsrl(MSR_IA32_MCG_STATUS);
+ if (mcgstatus & MCG_STATUS_RIPV) {
+ mce_wrmsrl(MSR_IA32_MCG_STATUS, 0);
+ return true;
+ }
+ }
+ return false;
+}
+
+static void __mc_scan_banks(struct mce *m, struct mce *final,
+ unsigned long *toclear, unsigned long *valid_banks,
+ int no_way_out, int *worst)
+{
+ struct mca_config *cfg = &mca_cfg;
+ int severity, i;
+
+ for (i = 0; i < cfg->banks; i++) {
+ __clear_bit(i, toclear);
+ if (!test_bit(i, valid_banks))
+ continue;
+
+ if (!mce_banks[i].ctl)
+ continue;
+
+ m->misc = 0;
+ m->addr = 0;
+ m->bank = i;
+
+ m->status = mce_rdmsrl(msr_ops.status(i));
+ if (!(m->status & MCI_STATUS_VAL))
+ continue;
+
+ /*
+ * Corrected or non-signaled errors are handled by
+ * machine_check_poll(). Leave them alone, unless this panics.
+ */
+ if (!(m->status & (cfg->ser ? MCI_STATUS_S : MCI_STATUS_UC)) &&
+ !no_way_out)
+ continue;
+
+ /* Set taint even when machine check was not enabled. */
+ add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
+
+ severity = mce_severity(m, cfg->tolerant, NULL, true);
+
+ /*
+ * When machine check was for corrected/deferred handler don't
+ * touch, unless we're panicking.
+ */
+ if ((severity == MCE_KEEP_SEVERITY ||
+ severity == MCE_UCNA_SEVERITY) && !no_way_out)
+ continue;
+
+ __set_bit(i, toclear);
+
+ /* Machine check event was not enabled. Clear, but ignore. */
+ if (severity == MCE_NO_SEVERITY)
+ continue;
+
+ mce_read_aux(m, i);
+
+ /* assuming valid severity level != 0 */
+ m->severity = severity;
+
+ mce_log(m);
+
+ if (severity > *worst) {
+ *final = *m;
+ *worst = severity;
+ }
+ }
+
+ /* mce_clear_state will clear *final, save locally for use later */
+ *m = *final;
+}
+
/*
* The actual machine check handler. This only handles real
* exceptions when something got corrupted coming in through int 18.
projects / mirror_ubuntu-kernels.git / commitdiff