sh: Try again at getting the initial return address for an unwind

[safe/jmp/linux-2.6] / mm / nommu.c

diff --git a/mm/nommu.c b/mm/nommu.c
index 809998a..53cab10 100644 (file)
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -66,9 +66,12 @@ struct percpu_counter vm_committed_as;
 int sysctl_overcommit_memory = OVERCOMMIT_GUESS; /* heuristic overcommit */
 int sysctl_overcommit_ratio = 50; /* default is 50% */
 int sysctl_max_map_count = DEFAULT_MAX_MAP_COUNT;
-int sysctl_nr_trim_pages = 1; /* page trimming behaviour */
+int sysctl_nr_trim_pages = CONFIG_NOMMU_INITIAL_TRIM_EXCESS;
 int heap_stack_gap = 0;
 
+/* amount of vm to protect from userspace access */
+unsigned long mmap_min_addr = CONFIG_DEFAULT_MMAP_MIN_ADDR;
+
 atomic_long_t mmap_pages_allocated;
 
 EXPORT_SYMBOL(mem_map);
@@ -170,8 +173,8 @@ unsigned int kobjsize(const void *objp)
 }
 
 int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
-                    unsigned long start, int len, int flags,
-               struct page **pages, struct vm_area_struct **vmas)
+                    unsigned long start, int nr_pages, int flags,
+                    struct page **pages, struct vm_area_struct **vmas)
 {
        struct vm_area_struct *vma;
        unsigned long vm_flags;
@@ -186,7 +189,7 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
        vm_flags  = write ? (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD);
        vm_flags &= force ? (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE);
 
-       for (i = 0; i < len; i++) {
+       for (i = 0; i < nr_pages; i++) {
                vma = find_vma(mm, start);
                if (!vma)
                        goto finish_or_fault;
@@ -221,7 +224,7 @@ finish_or_fault:
  * - don't permit access to VMAs that don't support it, such as I/O mappings
  */
 int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
-       unsigned long start, int len, int write, int force,
+       unsigned long start, int nr_pages, int write, int force,
        struct page **pages, struct vm_area_struct **vmas)
 {
        int flags = 0;
@@ -231,12 +234,31 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
        if (force)
                flags |= GUP_FLAGS_FORCE;
 
-       return __get_user_pages(tsk, mm,
-                               start, len, flags,
-                               pages, vmas);
+       return __get_user_pages(tsk, mm, start, nr_pages, flags, pages, vmas);
 }
 EXPORT_SYMBOL(get_user_pages);
 
+/**
+ * follow_pfn - look up PFN at a user virtual address
+ * @vma: memory mapping
+ * @address: user virtual address
+ * @pfn: location to store found PFN
+ *
+ * Only IO mappings and raw PFN mappings are allowed.
+ *
+ * Returns zero and the pfn at @pfn on success, -ve otherwise.
+ */
+int follow_pfn(struct vm_area_struct *vma, unsigned long address,
+       unsigned long *pfn)
+{
+       if (!(vma->vm_flags & (VM_IO | VM_PFNMAP)))
+               return -EINVAL;
+
+       *pfn = address >> PAGE_SHIFT;
+       return 0;
+}
+EXPORT_SYMBOL(follow_pfn);
+
 DEFINE_RWLOCK(vmlist_lock);
 struct vm_struct *vmlist;
 
@@ -515,8 +537,6 @@ static void add_nommu_region(struct vm_region *region)
 
        validate_nommu_regions();
 
-       BUG_ON(region->vm_start & ~PAGE_MASK);
-
        parent = NULL;
        p = &nommu_region_tree.rb_node;
        while (*p) {