1 files changed, 22 insertions, 18 deletions

diff --git a/arch/x86/mm/kmmio.c b/arch/x86/mm/kmmio.c
index d29777520af3..4c66bd3a240d 100644
--- a/arch/x86/mm/kmmio.c
+++ b/arch/x86/mm/kmmio.c
@@ -232,28 +232,32 @@ int kmmio_handler(struct pt_regs *regs, unsigned long addr)
 
         ctx = &get_cpu_var(kmmio_ctx);
         if (ctx->active) {
-                disarm_kmmio_fault_page(faultpage);
                 if (addr == ctx->addr) {
                         /*
-                         * On SMP we sometimes get recursive probe hits on the
-                         * same address. Context is already saved, fall out.
+                         * A second fault on the same page means some other
+                         * condition needs handling by do_page_fault(), the
+                         * page really not being present is the most common.
                          */
-                        pr_debug("kmmio: duplicate probe hit on CPU %d, for "
-                                                "address 0x%08lx.\n",
-                                                smp_processor_id(), addr);
-                        ret = 1;
-                        goto no_kmmio_ctx;
-                }
-                /*
-                 * Prevent overwriting already in-flight context.
-                 * This should not happen, let's hope disarming at least
-                 * prevents a panic.
-                 */
-                pr_emerg("kmmio: recursive probe hit on CPU %d, "
+                        pr_debug("kmmio: secondary hit for 0x%08lx CPU %d.\n",
+                                        addr, smp_processor_id());
+
+                        if (!faultpage->old_presence)
+                                pr_info("kmmio: unexpected secondary hit for "
+                                        "address 0x%08lx on CPU %d.\n", addr,
+                                        smp_processor_id());
+                } else {
+                        /*
+                         * Prevent overwriting already in-flight context.
+                         * This should not happen, let's hope disarming at
+                         * least prevents a panic.
+                         */
+                        pr_emerg("kmmio: recursive probe hit on CPU %d, "
                                         "for address 0x%08lx. Ignoring.\n",
                                         smp_processor_id(), addr);
-                pr_emerg("kmmio: previous hit was at 0x%08lx.\n",
-                                        ctx->addr);
+                        pr_emerg("kmmio: previous hit was at 0x%08lx.\n",
+                                                ctx->addr);
+                        disarm_kmmio_fault_page(faultpage);
+                }
                 goto no_kmmio_ctx;
         }
         ctx->active++;
@@ -305,7 +309,7 @@ static int post_kmmio_handler(unsigned long condition, struct pt_regs *regs)
         struct kmmio_context *ctx = &get_cpu_var(kmmio_ctx);
 
         if (!ctx->active) {
-                pr_debug("kmmio: spurious debug trap on CPU %d.\n",
+                pr_warning("kmmio: spurious debug trap on CPU %d.\n",
                                                         smp_processor_id());
                 goto out;
         }