intelfb: add preliminary i2c support
[safe/jmp/linux-2.6] / mm / mmap.c
index d931d7e..6446c61 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -13,6 +13,7 @@
 #include <linux/pagemap.h>
 #include <linux/swap.h>
 #include <linux/syscalls.h>
+#include <linux/capability.h>
 #include <linux/init.h>
 #include <linux/file.h>
 #include <linux/fs.h>
@@ -120,14 +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())
@@ -149,16 +162,12 @@ 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;
 }
 
-EXPORT_SYMBOL(sysctl_overcommit_memory);
-EXPORT_SYMBOL(sysctl_overcommit_ratio);
-EXPORT_SYMBOL(sysctl_max_map_count);
-EXPORT_SYMBOL(vm_committed_space);
 EXPORT_SYMBOL(__vm_enough_memory);
 
 /*
@@ -203,14 +212,6 @@ static struct vm_area_struct *remove_vma(struct vm_area_struct *vma)
 {
        struct vm_area_struct *next = vma->vm_next;
 
-       /*
-        * Hide vma from rmap and vmtruncate before freeing page tables:
-        * to be moved into free_pgtables once page_table_lock is lifted
-        * from it, but until then lock ordering forbids that move.
-        */
-       anon_vma_unlink(vma);
-       unlink_file_vma(vma);
-
        might_sleep();
        if (vma->vm_ops && vma->vm_ops->close)
                vma->vm_ops->close(vma);
@@ -231,6 +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)
@@ -243,11 +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;
@@ -305,8 +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)
@@ -443,8 +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++;
 }
@@ -623,7 +628,7 @@ again:                      remove_next = 1 + (end > next->vm_end);
  * If the vma has a ->close operation then the driver probably needs to release
  * per-vma resources, so we don't attempt to merge those.
  */
-#define VM_SPECIAL (VM_IO | VM_DONTCOPY | VM_DONTEXPAND | VM_RESERVED)
+#define VM_SPECIAL (VM_IO | VM_DONTEXPAND | VM_RESERVED | VM_PFNMAP)
 
 static inline int is_mergeable_vma(struct vm_area_struct *vma,
                        struct file *file, unsigned long vm_flags)
@@ -824,8 +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;
 
@@ -856,14 +860,6 @@ void vm_stat_account(struct mm_struct *mm, unsigned long flags,
        const unsigned long stack_flags
                = VM_STACK_FLAGS & (VM_GROWSUP|VM_GROWSDOWN);
 
-#ifdef CONFIG_HUGETLB
-       if (flags & VM_HUGETLB) {
-               if (!(flags & VM_DONTCOPY))
-                       mm->shared_vm += pages;
-               return;
-       }
-#endif /* CONFIG_HUGETLB */
-
        if (file) {
                mm->shared_vm += pages;
                if ((flags & (VM_EXEC|VM_WRITE)) == VM_EXEC)
@@ -1059,18 +1055,18 @@ munmap_back:
         * specific mapper. the address has already been validated, but
         * not unmapped, but the maps are removed from the list.
         */
-       vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
+       vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
        if (!vma) {
                error = -ENOMEM;
                goto unacct_error;
        }
-       memset(vma, 0, sizeof(*vma));
 
        vma->vm_mm = mm;
        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) {
@@ -1088,23 +1084,18 @@ munmap_back:
                error = file->f_op->mmap(file, vma);
                if (error)
                        goto unmap_and_free_vma;
-               if ((vma->vm_flags & (VM_SHARED | VM_WRITE | VM_RESERVED))
-                                               == (VM_WRITE | VM_RESERVED)) {
-                       printk(KERN_WARNING "program %s is using MAP_PRIVATE, "
-                               "PROT_WRITE mmap of VM_RESERVED memory, which "
-                               "is deprecated. Please report this to "
-                               "linux-kernel@vger.kernel.org\n",current->comm);
-                       if (vma->vm_ops && vma->vm_ops->close)
-                               vma->vm_ops->close(vma);
-                       error = -EACCES;
-                       goto unmap_and_free_vma;
-               }
        } else if (vm_flags & VM_SHARED) {
                error = shmem_zero_setup(vma);
                if (error)
                        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
@@ -1513,7 +1504,7 @@ static int acct_stack_growth(struct vm_area_struct * vma, unsigned long size, un
  * PA-RISC uses this for its stack; IA64 for its Register Backing Store.
  * vma is the last one with address > vma->vm_end.  Have to extend vma.
  */
-#ifdef CONFIG_STACK_GROWSUP
+#ifndef CONFIG_IA64
 static inline
 #endif
 int expand_upwards(struct vm_area_struct *vma, unsigned long address)
@@ -1679,15 +1670,13 @@ static void unmap_region(struct mm_struct *mm,
        unsigned long nr_accounted = 0;
 
        lru_add_drain();
-       spin_lock(&mm->page_table_lock);
        tlb = tlb_gather_mmu(mm, 0);
        update_hiwater_rss(mm);
-       unmap_vmas(&tlb, mm, vma, start, end, &nr_accounted, NULL);
+       unmap_vmas(&tlb, vma, start, end, &nr_accounted, NULL);
        vm_unacct_memory(nr_accounted);
        free_pgtables(&tlb, vma, prev? prev->vm_end: FIRST_USER_ADDRESS,
                                 next? next->vm_start: 0);
        tlb_finish_mmu(tlb, start, end);
-       spin_unlock(&mm->page_table_lock);
 }
 
 /*
@@ -1850,7 +1839,7 @@ asmlinkage long sys_munmap(unsigned long addr, size_t len)
 
 static inline void verify_mm_writelocked(struct mm_struct *mm)
 {
-#ifdef CONFIG_DEBUG_KERNEL
+#ifdef CONFIG_DEBUG_VM
        if (unlikely(down_read_trylock(&mm->mmap_sem))) {
                WARN_ON(1);
                up_read(&mm->mmap_sem);
@@ -1928,19 +1917,19 @@ unsigned long do_brk(unsigned long addr, unsigned long len)
        /*
         * create a vma struct for an anonymous mapping
         */
-       vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
+       vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
        if (!vma) {
                vm_unacct_memory(len >> PAGE_SHIFT);
                return -ENOMEM;
        }
-       memset(vma, 0, sizeof(*vma));
 
        vma->vm_mm = mm;
        vma->vm_start = addr;
        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;
@@ -1962,23 +1951,18 @@ void exit_mmap(struct mm_struct *mm)
        unsigned long end;
 
        lru_add_drain();
-
-       spin_lock(&mm->page_table_lock);
-
        flush_cache_mm(mm);
        tlb = tlb_gather_mmu(mm, 1);
        /* Don't update_hiwater_rss(mm) here, do_exit already did */
        /* Use -1 here to ensure all VMAs in the mm are unmapped */
-       end = unmap_vmas(&tlb, mm, vma, 0, -1, &nr_accounted, NULL);
+       end = unmap_vmas(&tlb, vma, 0, -1, &nr_accounted, NULL);
        vm_unacct_memory(nr_accounted);
        free_pgtables(&tlb, vma, FIRST_USER_ADDRESS, 0);
        tlb_finish_mmu(tlb, 0, end);
 
-       spin_unlock(&mm->page_table_lock);
-
        /*
-        * Walk the list again, actually closing and freeing it
-        * without holding any MM locks.
+        * Walk the list again, actually closing and freeing it,
+        * with preemption enabled, without holding any MM locks.
         */
        while (vma)
                vma = remove_vma(vma);