Merge branch 'upstream-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/linvil...

[linux.git] / mm / mmap.c

diff --git a/mm/mmap.c b/mm/mmap.c
index 4f5b5709136abbe6c08b306ac35ac92740cb04d8..c1868ecdbc5facfd8ba25835e71e05cfee9d9680 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -96,7 +96,7 @@ int __vm_enough_memory(long pages, int cap_sys_admin)
        if (sysctl_overcommit_memory == OVERCOMMIT_GUESS) {
                unsigned long n;
 
-               free = get_page_cache_size();
+               free = global_page_state(NR_FILE_PAGES);
                free += nr_swap_pages;
 
                /*
@@ -121,14 +121,26 @@ int __vm_enough_memory(long pages, int cap_sys_admin)
                 * only call if we're about to fail.
                 */
                n = nr_free_pages();
+
+               /*
+                * Leave reserved pages. The pages are not for anonymous pages.
+                */
+               if (n <= totalreserve_pages)
+                       goto error;
+               else
+                       n -= totalreserve_pages;
+
+               /*
+                * Leave the last 3% for root
+                */
                if (!cap_sys_admin)
                        n -= n / 32;
                free += n;
 
                if (free > pages)
                        return 0;
-               vm_unacct_memory(pages);
-               return -ENOMEM;
+
+               goto error;
        }
 
        allowed = (totalram_pages - hugetlb_total_pages())
@@ -150,7 +162,7 @@ int __vm_enough_memory(long pages, int cap_sys_admin)
         */
        if (atomic_read(&vm_committed_space) < (long)allowed)
                return 0;
-
+error:
        vm_unacct_memory(pages);
 
        return -ENOMEM;
@@ -220,6 +232,17 @@ asmlinkage unsigned long sys_brk(unsigned long brk)
 
        if (brk < mm->end_code)
                goto out;
+
+       /*
+        * Check against rlimit here. If this check is done later after the test
+        * of oldbrk with newbrk then it can escape the test and let the data
+        * segment grow beyond its set limit the in case where the limit is
+        * not page aligned -Ram Gupta
+        */
+       rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
+       if (rlim < RLIM_INFINITY && brk - mm->start_data > rlim)
+               goto out;
+
        newbrk = PAGE_ALIGN(brk);
        oldbrk = PAGE_ALIGN(mm->brk);
        if (oldbrk == newbrk)
@@ -232,11 +255,6 @@ asmlinkage unsigned long sys_brk(unsigned long brk)
                goto out;
        }
 
-       /* Check against rlimit.. */
-       rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
-       if (rlim < RLIM_INFINITY && brk - mm->start_data > rlim)
-               goto out;
-
        /* Check against existing mmap mappings. */
        if (find_vma_intersection(mm, oldbrk, newbrk+PAGE_SIZE))
                goto out;
@@ -294,8 +312,7 @@ void validate_mm(struct mm_struct *mm)
        i = browse_rb(&mm->mm_rb);
        if (i != mm->map_count)
                printk("map_count %d rb %d\n", mm->map_count, i), bug = 1;
-       if (bug)
-               BUG();
+       BUG_ON(bug);
 }
 #else
 #define validate_mm(mm) do { } while (0)
@@ -432,8 +449,7 @@ __insert_vm_struct(struct mm_struct * mm, struct vm_area_struct * vma)
        struct rb_node ** rb_link, * rb_parent;
 
        __vma = find_vma_prepare(mm, vma->vm_start,&prev, &rb_link, &rb_parent);
-       if (__vma && __vma->vm_start < vma->vm_end)
-               BUG();
+       BUG_ON(__vma && __vma->vm_start < vma->vm_end);
        __vma_link(mm, vma, prev, rb_link, rb_parent);
        mm->map_count++;
 }
@@ -813,8 +829,7 @@ try_prev:
         * (e.g. stash info in next's anon_vma_node when assigning
         * an anon_vma, or when trying vma_merge).  Another time.
         */
-       if (find_vma_prev(vma->vm_mm, vma->vm_start, &near) != vma)
-               BUG();
+       BUG_ON(find_vma_prev(vma->vm_mm, vma->vm_start, &near) != vma);
        if (!near)
                goto none;
 
@@ -1050,7 +1065,8 @@ munmap_back:
        vma->vm_start = addr;
        vma->vm_end = addr + len;
        vma->vm_flags = vm_flags;
-       vma->vm_page_prot = protection_map[vm_flags & 0x0f];
+       vma->vm_page_prot = protection_map[vm_flags &
+                               (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)];
        vma->vm_pgoff = pgoff;
 
        if (file) {
@@ -1074,6 +1090,12 @@ munmap_back:
                        goto free_vma;
        }
 
+       /* Don't make the VMA automatically writable if it's shared, but the
+        * backer wishes to know when pages are first written to */
+       if (vma->vm_ops && vma->vm_ops->page_mkwrite)
+               vma->vm_page_prot =
+                       protection_map[vm_flags & (VM_READ|VM_WRITE|VM_EXEC)];
+
        /* We set VM_ACCOUNT in a shared mapping's vm_flags, to inform
         * shmem_zero_setup (perhaps called through /dev/zero's ->mmap)
         * that memory reservation must be checked; but that reservation
@@ -1906,7 +1928,8 @@ unsigned long do_brk(unsigned long addr, unsigned long len)
        vma->vm_end = addr + len;
        vma->vm_pgoff = pgoff;
        vma->vm_flags = flags;
-       vma->vm_page_prot = protection_map[flags & 0x0f];
+       vma->vm_page_prot = protection_map[flags &
+                               (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)];
        vma_link(mm, vma, prev, rb_link, rb_parent);
 out:
        mm->total_vm += len >> PAGE_SHIFT;