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-rw-r--r--arch/x86/include/asm/page_64.h4
-rw-r--r--arch/x86/kernel/cpu/mcheck/mce-internal.h15
-rw-r--r--arch/x86/kernel/cpu/mcheck/mce.c17
3 files changed, 26 insertions, 10 deletions
diff --git a/arch/x86/include/asm/page_64.h b/arch/x86/include/asm/page_64.h
index 4baa6bceb232..d652a3808065 100644
--- a/arch/x86/include/asm/page_64.h
+++ b/arch/x86/include/asm/page_64.h
@@ -52,10 +52,6 @@ static inline void clear_page(void *page)
void copy_page(void *to, void *from);
-#ifdef CONFIG_X86_MCE
-#define arch_unmap_kpfn arch_unmap_kpfn
-#endif
-
#endif /* !__ASSEMBLY__ */
#ifdef CONFIG_X86_VSYSCALL_EMULATION
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 75f405ac085c..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.
@@ -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