3 files changed, 48 insertions, 36 deletions

diff --git a/mm/memory.c b/mm/memory.c
index 89339c61f8e5..cda04b19f733 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -52,6 +52,9 @@
 #include <linux/writeback.h>
 #include <linux/memcontrol.h>
 #include <linux/mmu_notifier.h>
+#include <linux/kallsyms.h>
+#include <linux/swapops.h>
+#include <linux/elf.h>
 
 #include <asm/pgalloc.h>
 #include <asm/uaccess.h>
@@ -59,9 +62,6 @@
 #include <asm/tlbflush.h>
 #include <asm/pgtable.h>
 
-#include <linux/swapops.h>
-#include <linux/elf.h>
-
 #include "internal.h"
 
 #ifndef CONFIG_NEED_MULTIPLE_NODES
@@ -375,15 +375,41 @@ static inline void add_mm_rss(struct mm_struct *mm, int file_rss, int anon_rss)
  *
  * The calling function must still handle the error.
  */
-static void print_bad_pte(struct vm_area_struct *vma, pte_t pte,
-                          unsigned long vaddr)
-{
-        printk(KERN_ERR "Bad pte = %08llx, process = %s, "
-                        "vm_flags = %lx, vaddr = %lx\n",
-                (long long)pte_val(pte),
-                (vma->vm_mm == current->mm ? current->comm : "???"),
-                vma->vm_flags, vaddr);
+static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr,
+                          pte_t pte, struct page *page)
+{
+        pgd_t *pgd = pgd_offset(vma->vm_mm, addr);
+        pud_t *pud = pud_offset(pgd, addr);
+        pmd_t *pmd = pmd_offset(pud, addr);
+        struct address_space *mapping;
+        pgoff_t index;
+
+        mapping = vma->vm_file ? vma->vm_file->f_mapping : NULL;
+        index = linear_page_index(vma, addr);
+
+        printk(KERN_EMERG "Bad page map in process %s  pte:%08llx pmd:%08llx\n",
+                current->comm,
+                (long long)pte_val(pte), (long long)pmd_val(*pmd));
+        if (page) {
+                printk(KERN_EMERG
+                "page:%p flags:%p count:%d mapcount:%d mapping:%p index:%lx\n",
+                page, (void *)page->flags, page_count(page),
+                page_mapcount(page), page->mapping, page->index);
+        }
+        printk(KERN_EMERG
+                "addr:%p vm_flags:%08lx anon_vma:%p mapping:%p index:%lx\n",
+                (void *)addr, vma->vm_flags, vma->anon_vma, mapping, index);
+        /*
+         * Choose text because data symbols depend on CONFIG_KALLSYMS_ALL=y
+         */
+        if (vma->vm_ops)
+                print_symbol(KERN_EMERG "vma->vm_ops->fault: %s\n",
+                                (unsigned long)vma->vm_ops->fault);
+        if (vma->vm_file && vma->vm_file->f_op)
+                print_symbol(KERN_EMERG "vma->vm_file->f_op->mmap: %s\n",
+                                (unsigned long)vma->vm_file->f_op->mmap);
         dump_stack();
+        add_taint(TAINT_BAD_PAGE);
 }
 
 static inline int is_cow_mapping(unsigned int flags)
@@ -773,6 +799,8 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,
                                 file_rss--;
                         }
                         page_remove_rmap(page, vma);
+                        if (unlikely(page_mapcount(page) < 0))
+                                print_bad_pte(vma, addr, ptent, page);
                         tlb_remove_page(tlb, page);
                         continue;
                 }
@@ -2684,7 +2712,7 @@ static int do_nonlinear_fault(struct mm_struct *mm, struct vm_area_struct *vma,
                 /*
                  * Page table corrupted: show pte and kill process.
                  */
-                print_bad_pte(vma, orig_pte, address);
+                print_bad_pte(vma, address, orig_pte, NULL);
                 return VM_FAULT_OOM;
         }
 
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index bd330252fc77..3acb216e9a78 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -222,14 +222,14 @@ static inline int bad_range(struct zone *zone, struct page *page)
 
 static void bad_page(struct page *page)
 {
-        printk(KERN_EMERG "Bad page state in process '%s'\n" KERN_EMERG
-                "page:%p flags:0x%0*lx mapping:%p mapcount:%d count:%d\n",
-                current->comm, page, (int)(2*sizeof(unsigned long)),
-                (unsigned long)page->flags, page->mapping,
-                page_mapcount(page), page_count(page));
-
-        printk(KERN_EMERG "Trying to fix it up, but a reboot is needed\n"
-                KERN_EMERG "Backtrace:\n");
+        printk(KERN_EMERG "Bad page state in process %s  pfn:%05lx\n",
+                current->comm, page_to_pfn(page));
+        printk(KERN_EMERG
+                "page:%p flags:%p count:%d mapcount:%d mapping:%p index:%lx\n",
+                page, (void *)page->flags, page_count(page),
+                page_mapcount(page), page->mapping, page->index);
+        printk(KERN_EMERG "Trying to fix it up, but a reboot is needed\n");
+
         dump_stack();
 
         /* Leave bad fields for debug, except PageBuddy could make trouble */
diff --git a/mm/rmap.c b/mm/rmap.c
index b1770b11a571..32098255082e 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -47,7 +47,6 @@
 #include <linux/rmap.h>
 #include <linux/rcupdate.h>
 #include <linux/module.h>
-#include <linux/kallsyms.h>
 #include <linux/memcontrol.h>
 #include <linux/mmu_notifier.h>
 #include <linux/migrate.h>
@@ -725,21 +724,6 @@ void page_dup_rmap(struct page *page, struct vm_area_struct *vma, unsigned long
 void page_remove_rmap(struct page *page, struct vm_area_struct *vma)
 {
         if (atomic_add_negative(-1, &page->_mapcount)) {
-                if (unlikely(page_mapcount(page) < 0)) {
-                        printk (KERN_EMERG "Eeek! page_mapcount(page) went negative! (%d)\n", page_mapcount(page));
-                        printk (KERN_EMERG "  page pfn = %lx\n", page_to_pfn(page));
-                        printk (KERN_EMERG "  page->flags = %lx\n", page->flags);
-                        printk (KERN_EMERG "  page->count = %x\n", page_count(page));
-                        printk (KERN_EMERG "  page->mapping = %p\n", page->mapping);
-                        print_symbol (KERN_EMERG "  vma->vm_ops = %s\n", (unsigned long)vma->vm_ops);
-                        if (vma->vm_ops) {
-                                print_symbol (KERN_EMERG "  vma->vm_ops->fault = %s\n", (unsigned long)vma->vm_ops->fault);
-                        }
-                        if (vma->vm_file && vma->vm_file->f_op)
-                                print_symbol (KERN_EMERG "  vma->vm_file->f_op->mmap = %s\n", (unsigned long)vma->vm_file->f_op->mmap);
-                        BUG();
-                }
-
                 /*
                  * Now that the last pte has gone, s390 must transfer dirty
                  * flag from storage key to struct page.  We can usually skip