X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=mm%2Fmmap.c;h=a32d28ce31cda697aff68fdc6c939560096e3a50;hb=932e2d23c8529c39fe74549dcbe4b2c8b2d66ba4;hp=facc1a75bd4fdbc9f274dbc26a7e536f0eb8f561;hpb=4c5cdb1e1f2a502069f57a60b5c6b97b8106c73c;p=linux-2.6

diff --git a/mm/mmap.c b/mm/mmap.c
index facc1a75bd..a32d28ce31 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -36,6 +36,10 @@
 #define arch_mmap_check(addr, len, flags)	(0)
 #endif
 
+#ifndef arch_rebalance_pgtables
+#define arch_rebalance_pgtables(addr, len)		(addr)
+#endif
+
 static void unmap_region(struct mm_struct *mm,
 		struct vm_area_struct *vma, struct vm_area_struct *prev,
 		unsigned long start, unsigned long end);
@@ -241,7 +245,7 @@ asmlinkage unsigned long sys_brk(unsigned long brk)
 
 	down_write(&mm->mmap_sem);
 
-	if (brk < mm->end_code)
+	if (brk < mm->start_brk)
 		goto out;
 
 	/*
@@ -251,7 +255,8 @@ asmlinkage unsigned long sys_brk(unsigned long brk)
 	 * not page aligned -Ram Gupta
 	 */
 	rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
-	if (rlim < RLIM_INFINITY && brk - mm->start_data > rlim)
+	if (rlim < RLIM_INFINITY && (brk - mm->start_brk) +
+			(mm->end_data - mm->start_data) > rlim)
 		goto out;
 
 	newbrk = PAGE_ALIGN(brk);
@@ -912,6 +917,9 @@ unsigned long do_mmap_pgoff(struct file * file, unsigned long addr,
 	if (!len)
 		return -EINVAL;
 
+	if (!(flags & MAP_FIXED))
+		addr = round_hint_to_min(addr);
+
 	error = arch_mmap_check(addr, len, flags);
 	if (error)
 		return error;
@@ -1420,7 +1428,7 @@ get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
 	if (addr & ~PAGE_MASK)
 		return -EINVAL;
 
-	return addr;
+	return arch_rebalance_pgtables(addr, len);
 }
 
 EXPORT_SYMBOL(get_unmapped_area);
@@ -1615,6 +1623,12 @@ static inline int expand_downwards(struct vm_area_struct *vma,
 	 */
 	if (unlikely(anon_vma_prepare(vma)))
 		return -ENOMEM;
+
+	address &= PAGE_MASK;
+	error = security_file_mmap(NULL, 0, 0, 0, address, 1);
+	if (error)
+		return error;
+
 	anon_vma_lock(vma);
 
 	/*
@@ -1622,8 +1636,6 @@ static inline int expand_downwards(struct vm_area_struct *vma,
 	 * is required to hold the mmap_sem in read mode.  We need the
 	 * anon_vma lock to serialize against concurrent expand_stacks.
 	 */
-	address &= PAGE_MASK;
-	error = 0;
 
 	/* Somebody else might have raced and expanded it already */
 	if (address < vma->vm_start) {
@@ -1934,6 +1946,10 @@ unsigned long do_brk(unsigned long addr, unsigned long len)
 	if (is_hugepage_only_range(mm, addr, len))
 		return -EINVAL;
 
+	error = security_file_mmap(NULL, 0, 0, 0, addr, 1);
+	if (error)
+		return error;
+
 	flags = VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags;
 
 	error = arch_mmap_check(addr, len, flags);
@@ -2149,24 +2165,31 @@ int may_expand_vm(struct mm_struct *mm, unsigned long npages)
 }
 
 
-static struct page *special_mapping_nopage(struct vm_area_struct *vma,
-					   unsigned long address, int *type)
+static int special_mapping_fault(struct vm_area_struct *vma,
+				struct vm_fault *vmf)
 {
+	pgoff_t pgoff;
 	struct page **pages;
 
-	BUG_ON(address < vma->vm_start || address >= vma->vm_end);
+	/*
+	 * special mappings have no vm_file, and in that case, the mm
+	 * uses vm_pgoff internally. So we have to subtract it from here.
+	 * We are allowed to do this because we are the mm; do not copy
+	 * this code into drivers!
+	 */
+	pgoff = vmf->pgoff - vma->vm_pgoff;
 
-	address -= vma->vm_start;
-	for (pages = vma->vm_private_data; address > 0 && *pages; ++pages)
-		address -= PAGE_SIZE;
+	for (pages = vma->vm_private_data; pgoff && *pages; ++pages)
+		pgoff--;
 
 	if (*pages) {
 		struct page *page = *pages;
 		get_page(page);
-		return page;
+		vmf->page = page;
+		return 0;
 	}
 
-	return NOPAGE_SIGBUS;
+	return VM_FAULT_SIGBUS;
 }
 
 /*
@@ -2178,7 +2201,7 @@ static void special_mapping_close(struct vm_area_struct *vma)
 
 static struct vm_operations_struct special_mapping_vmops = {
 	.close = special_mapping_close,
-	.nopage	= special_mapping_nopage,
+	.fault = special_mapping_fault,
 };
 
 /*
@@ -2204,7 +2227,7 @@ int install_special_mapping(struct mm_struct *mm,
 	vma->vm_start = addr;
 	vma->vm_end = addr + len;
 
-	vma->vm_flags = vm_flags | mm->def_flags;
+	vma->vm_flags = vm_flags | mm->def_flags | VM_DONTEXPAND;
 	vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
 
 	vma->vm_ops = &special_mapping_vmops;