8 files changed, 94 insertions, 51 deletions

diff --git a/arch/x86/include/asm/vdso.h b/arch/x86/include/asm/vdso.h
index d0a2c909c72d..30be253dd283 100644
--- a/arch/x86/include/asm/vdso.h
+++ b/arch/x86/include/asm/vdso.h
@@ -7,10 +7,14 @@
 
 #ifndef __ASSEMBLER__
 
+#include <linux/mm_types.h>
+
 struct vdso_image {
         void *data;
         unsigned long size;   /* Always a multiple of PAGE_SIZE */
-        struct page **pages;  /* Big enough for data/size page pointers */
+
+        /* text_mapping.pages is big enough for data/size page pointers */
+        struct vm_special_mapping text_mapping;
 
         unsigned long alt, alt_len;
 
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 6f881842116c..9deb59b0baea 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1223,9 +1223,6 @@ int in_gate_area_no_mm(unsigned long addr)
 
 const char *arch_vma_name(struct vm_area_struct *vma)
 {
-        if (vma->vm_mm && vma->vm_start ==
-            (long __force)vma->vm_mm->context.vdso)
-                return "[vdso]";
         if (vma == &gate_vma)
                 return "[vsyscall]";
         return NULL;
diff --git a/arch/x86/vdso/vdso2c.h b/arch/x86/vdso/vdso2c.h
index ed2e894e89ab..3dcc61e796e9 100644
--- a/arch/x86/vdso/vdso2c.h
+++ b/arch/x86/vdso/vdso2c.h
@@ -136,7 +136,10 @@ static int GOFUNC(void *addr, size_t len, FILE *outfile, const char *name)
         fprintf(outfile, "const struct vdso_image %s = {\n", name);
         fprintf(outfile, "\t.data = raw_data,\n");
         fprintf(outfile, "\t.size = %lu,\n", data_size);
-        fprintf(outfile, "\t.pages = pages,\n");
+        fprintf(outfile, "\t.text_mapping = {\n");
+        fprintf(outfile, "\t\t.name = \"[vdso]\",\n");
+        fprintf(outfile, "\t\t.pages = pages,\n");
+        fprintf(outfile, "\t},\n");
         if (alt_sec) {
                 fprintf(outfile, "\t.alt = %lu,\n",
                         (unsigned long)alt_sec->sh_offset);
diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c
index c3ed708e50f4..e4f7781ee162 100644
--- a/arch/x86/vdso/vdso32-setup.c
+++ b/arch/x86/vdso/vdso32-setup.c
@@ -119,13 +119,6 @@ __initcall(ia32_binfmt_init);
 
 #else  /* CONFIG_X86_32 */
 
-const char *arch_vma_name(struct vm_area_struct *vma)
-{
-        if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
-                return "[vdso]";
-        return NULL;
-}
-
 struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
 {
         return NULL;
diff --git a/arch/x86/vdso/vma.c b/arch/x86/vdso/vma.c
index 8ad0081df7a8..e1513c47872a 100644
--- a/arch/x86/vdso/vma.c
+++ b/arch/x86/vdso/vma.c
@@ -30,7 +30,8 @@ void __init init_vdso_image(const struct vdso_image *image)
 
         BUG_ON(image->size % PAGE_SIZE != 0);
         for (i = 0; i < npages; i++)
-                image->pages[i] = virt_to_page(image->data + i*PAGE_SIZE);
+                image->text_mapping.pages[i] =
+                        virt_to_page(image->data + i*PAGE_SIZE);
 
         apply_alternatives((struct alt_instr *)(image->data + image->alt),
                            (struct alt_instr *)(image->data + image->alt +
@@ -91,6 +92,10 @@ static int map_vdso(const struct vdso_image *image, bool calculate_addr)
         unsigned long addr;
         int ret = 0;
         static struct page *no_pages[] = {NULL};
+        static struct vm_special_mapping vvar_mapping = {
+                .name = "[vvar]",
+                .pages = no_pages,
+        };
 
         if (calculate_addr) {
                 addr = vdso_addr(current->mm->start_stack,
@@ -112,21 +117,23 @@ static int map_vdso(const struct vdso_image *image, bool calculate_addr)
         /*
          * MAYWRITE to allow gdb to COW and set breakpoints
          */
-        ret = install_special_mapping(mm,
-                                      addr,
-                                      image->size,
-                                      VM_READ|VM_EXEC|
-                                      VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
-                                      image->pages);
+        vma = _install_special_mapping(mm,
+                                       addr,
+                                       image->size,
+                                       VM_READ|VM_EXEC|
+                                       VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
+                                       &image->text_mapping);
 
-        if (ret)
+        if (IS_ERR(vma)) {
+                ret = PTR_ERR(vma);
                 goto up_fail;
+        }
 
         vma = _install_special_mapping(mm,
                                        addr + image->size,
                                        image->sym_end_mapping - image->size,
                                        VM_READ,
-                                       no_pages);
+                                       &vvar_mapping);
 
         if (IS_ERR(vma)) {
                 ret = PTR_ERR(vma);
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 63f8d4efe303..05aab09803e6 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1782,7 +1782,9 @@ extern struct file *get_mm_exe_file(struct mm_struct *mm);
 extern int may_expand_vm(struct mm_struct *mm, unsigned long npages);
 extern struct vm_area_struct *_install_special_mapping(struct mm_struct *mm,
                                    unsigned long addr, unsigned long len,
-                                   unsigned long flags, struct page **pages);
+                                   unsigned long flags,
+                                   const struct vm_special_mapping *spec);
+/* This is an obsolete alternative to _install_special_mapping. */
 extern int install_special_mapping(struct mm_struct *mm,
                                    unsigned long addr, unsigned long len,
                                    unsigned long flags, struct page **pages);
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 8967e20cbe57..22c6f4e16d10 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -510,4 +510,10 @@ static inline void clear_tlb_flush_pending(struct mm_struct *mm)
 }
 #endif
 
+struct vm_special_mapping
+{
+        const char *name;
+        struct page **pages;
+};
+
 #endif /* _LINUX_MM_TYPES_H */
diff --git a/mm/mmap.c b/mm/mmap.c
index b1202cf81f4b..52bbc9514d9d 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2872,6 +2872,31 @@ int may_expand_vm(struct mm_struct *mm, unsigned long npages)
         return 1;
 }
 
+static int special_mapping_fault(struct vm_area_struct *vma,
+                                 struct vm_fault *vmf);
+
+/*
+ * Having a close hook prevents vma merging regardless of flags.
+ */
+static void special_mapping_close(struct vm_area_struct *vma)
+{
+}
+
+static const char *special_mapping_name(struct vm_area_struct *vma)
+{
+        return ((struct vm_special_mapping *)vma->vm_private_data)->name;
+}
+
+static const struct vm_operations_struct special_mapping_vmops = {
+        .close = special_mapping_close,
+        .fault = special_mapping_fault,
+        .name = special_mapping_name,
+};
+
+static const struct vm_operations_struct legacy_special_mapping_vmops = {
+        .close = special_mapping_close,
+        .fault = special_mapping_fault,
+};
 
 static int special_mapping_fault(struct vm_area_struct *vma,
                                 struct vm_fault *vmf)
@@ -2887,7 +2912,13 @@ static int special_mapping_fault(struct vm_area_struct *vma,
          */
         pgoff = vmf->pgoff - vma->vm_pgoff;
 
-        for (pages = vma->vm_private_data; pgoff && *pages; ++pages)
+        if (vma->vm_ops == &legacy_special_mapping_vmops)
+                pages = vma->vm_private_data;
+        else
+                pages = ((struct vm_special_mapping *)vma->vm_private_data)->
+                        pages;
+
+        for (; pgoff && *pages; ++pages)
                 pgoff--;
 
         if (*pages) {
@@ -2900,30 +2931,11 @@ static int special_mapping_fault(struct vm_area_struct *vma,
         return VM_FAULT_SIGBUS;
 }
 
-/*
- * Having a close hook prevents vma merging regardless of flags.
- */
-static void special_mapping_close(struct vm_area_struct *vma)
-{
-}
-
-static const struct vm_operations_struct special_mapping_vmops = {
-        .close = special_mapping_close,
-        .fault = special_mapping_fault,
-};
-
-/*
- * Called with mm->mmap_sem held for writing.
- * Insert a new vma covering the given region, with the given flags.
- * Its pages are supplied by the given array of struct page *.
- * The array can be shorter than len >> PAGE_SHIFT if it's null-terminated.
- * The region past the last page supplied will always produce SIGBUS.
- * The array pointer and the pages it points to are assumed to stay alive
- * for as long as this mapping might exist.
- */
-struct vm_area_struct *_install_special_mapping(struct mm_struct *mm,
-                            unsigned long addr, unsigned long len,
-                            unsigned long vm_flags, struct page **pages)
+static struct vm_area_struct *__install_special_mapping(
+        struct mm_struct *mm,
+        unsigned long addr, unsigned long len,
+        unsigned long vm_flags, const struct vm_operations_struct *ops,
+        void *priv)
 {
         int ret;
         struct vm_area_struct *vma;
@@ -2940,8 +2952,8 @@ struct vm_area_struct *_install_special_mapping(struct mm_struct *mm,
         vma->vm_flags = vm_flags | mm->def_flags | VM_DONTEXPAND | VM_SOFTDIRTY;
         vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
 
-        vma->vm_ops = &special_mapping_vmops;
-        vma->vm_private_data = pages;
+        vma->vm_ops = ops;
+        vma->vm_private_data = priv;
 
         ret = insert_vm_struct(mm, vma);
         if (ret)
@@ -2958,12 +2970,31 @@ out:
         return ERR_PTR(ret);
 }
 
+/*
+ * Called with mm->mmap_sem held for writing.
+ * Insert a new vma covering the given region, with the given flags.
+ * Its pages are supplied by the given array of struct page *.
+ * The array can be shorter than len >> PAGE_SHIFT if it's null-terminated.
+ * The region past the last page supplied will always produce SIGBUS.
+ * The array pointer and the pages it points to are assumed to stay alive
+ * for as long as this mapping might exist.
+ */
+struct vm_area_struct *_install_special_mapping(
+        struct mm_struct *mm,
+        unsigned long addr, unsigned long len,
+        unsigned long vm_flags, const struct vm_special_mapping *spec)
+{
+        return __install_special_mapping(mm, addr, len, vm_flags,
+                                         &special_mapping_vmops, (void *)spec);
+}
+
 int install_special_mapping(struct mm_struct *mm,
                             unsigned long addr, unsigned long len,
                             unsigned long vm_flags, struct page **pages)
 {
-        struct vm_area_struct *vma = _install_special_mapping(mm,
-                            addr, len, vm_flags, pages);
+        struct vm_area_struct *vma = __install_special_mapping(
+                mm, addr, len, vm_flags, &legacy_special_mapping_vmops,
+                (void *)pages);
 
         if (IS_ERR(vma))
                 return PTR_ERR(vma);