3 files changed, 29 insertions, 9 deletions

diff --git a/arch/x86/kernel/cpu/mcheck/dev-mcelog.c b/arch/x86/kernel/cpu/mcheck/dev-mcelog.c
index 213e8c2ca702..97685a0c3175 100644
--- a/arch/x86/kernel/cpu/mcheck/dev-mcelog.c
+++ b/arch/x86/kernel/cpu/mcheck/dev-mcelog.c
@@ -247,9 +247,9 @@ static __poll_t mce_chrdev_poll(struct file *file, poll_table *wait)
 {
 	poll_wait(file, &mce_chrdev_wait, wait);
 	if (READ_ONCE(mcelog.next))
-		return POLLIN | POLLRDNORM;
+		return EPOLLIN | EPOLLRDNORM;
 	if (!mce_apei_read_done && apei_check_mce())
-		return POLLIN | POLLRDNORM;
+		return EPOLLIN | EPOLLRDNORM;
 	return 0;
 }
 
diff --git a/arch/x86/kernel/cpu/mcheck/mce-internal.h b/arch/x86/kernel/cpu/mcheck/mce-internal.h
index aa0d5df9dc60..e956eb267061 100644
--- a/arch/x86/kernel/cpu/mcheck/mce-internal.h
+++ b/arch/x86/kernel/cpu/mcheck/mce-internal.h
@@ -115,4 +115,19 @@ static inline void mce_unregister_injector_chain(struct notifier_block *nb)	{ }
 
 extern struct mca_config mca_cfg;
 
+#ifndef CONFIG_X86_64
+/*
+ * On 32-bit systems it would be difficult to safely unmap a poison page
+ * from the kernel 1:1 map because there are no non-canonical addresses that
+ * we can use to refer to the address without risking a speculative access.
+ * However, this isn't much of an issue because:
+ * 1) Few unmappable pages are in the 1:1 map. Most are in HIGHMEM which
+ *    are only mapped into the kernel as needed
+ * 2) Few people would run a 32-bit kernel on a machine that supports
+ *    recoverable errors because they have too much memory to boot 32-bit.
+ */
+static inline void mce_unmap_kpfn(unsigned long pfn) {}
+#define mce_unmap_kpfn mce_unmap_kpfn
+#endif
+
 #endif /* __X86_MCE_INTERNAL_H__ */
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 3a8e88a611eb..8ff94d1e2dce 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -105,6 +105,10 @@ static struct irq_work mce_irq_work;
 
 static void (*quirk_no_way_out)(int bank, struct mce *m, struct pt_regs *regs);
 
+#ifndef mce_unmap_kpfn
+static void mce_unmap_kpfn(unsigned long pfn);
+#endif
+
 /*
  * CPU/chipset specific EDAC code can register a notifier call here to print
  * MCE errors in a human-readable form.
@@ -234,7 +238,7 @@ static void __print_mce(struct mce *m)
 			m->cs, m->ip);
 
 		if (m->cs == __KERNEL_CS)
-			pr_cont("{%pS}", (void *)m->ip);
+			pr_cont("{%pS}", (void *)(unsigned long)m->ip);
 		pr_cont("\n");
 	}
 
@@ -590,7 +594,8 @@ static int srao_decode_notifier(struct notifier_block *nb, unsigned long val,
 
 	if (mce_usable_address(mce) && (mce->severity == MCE_AO_SEVERITY)) {
 		pfn = mce->addr >> PAGE_SHIFT;
-		memory_failure(pfn, 0);
+		if (!memory_failure(pfn, 0))
+			mce_unmap_kpfn(pfn);
 	}
 
 	return NOTIFY_OK;
@@ -1057,12 +1062,13 @@ static int do_memory_failure(struct mce *m)
 	ret = memory_failure(m->addr >> PAGE_SHIFT, flags);
 	if (ret)
 		pr_err("Memory error not recovered");
+	else
+		mce_unmap_kpfn(m->addr >> PAGE_SHIFT);
 	return ret;
 }
 
-#if defined(arch_unmap_kpfn) && defined(CONFIG_MEMORY_FAILURE)
-
-void arch_unmap_kpfn(unsigned long pfn)
+#ifndef mce_unmap_kpfn
+static void mce_unmap_kpfn(unsigned long pfn)
 {
 	unsigned long decoy_addr;
 
@@ -1073,7 +1079,7 @@ void arch_unmap_kpfn(unsigned long pfn)
 	 * 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 posion page because we'd have
+	 * 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
@@ -1098,7 +1104,6 @@ void arch_unmap_kpfn(unsigned long pfn)
 
 	if (set_memory_np(decoy_addr, 1))
 		pr_warn("Could not invalidate pfn=0x%lx from 1:1 map\n", pfn);
-
 }
 #endif