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Diffstat (limited to 'mm/nommu.c')
-rw-r--r--mm/nommu.c37
1 files changed, 37 insertions, 0 deletions
diff --git a/mm/nommu.c b/mm/nommu.c
index 23fb033e596..2b16b00a5b1 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -45,6 +45,7 @@ int heap_stack_gap = 0;
EXPORT_SYMBOL(mem_map);
EXPORT_SYMBOL(__vm_enough_memory);
+EXPORT_SYMBOL(num_physpages);
/* list of shareable VMAs */
struct rb_root nommu_vma_tree = RB_ROOT;
@@ -261,6 +262,14 @@ void vunmap(void *addr)
}
/*
+ * Implement a stub for vmalloc_sync_all() if the architecture chose not to
+ * have one.
+ */
+void __attribute__((weak)) vmalloc_sync_all(void)
+{
+}
+
+/*
* sys_brk() for the most part doesn't need the global kernel
* lock, except when an application is doing something nasty
* like trying to un-brk an area that has already been mapped
@@ -826,6 +835,11 @@ unsigned long do_mmap_pgoff(struct file *file,
unsigned long pglen = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
unsigned long vmpglen;
+ /* suppress VMA sharing for shared regions */
+ if (vm_flags & VM_SHARED &&
+ capabilities & BDI_CAP_MAP_DIRECT)
+ goto dont_share_VMAs;
+
for (rb = rb_first(&nommu_vma_tree); rb; rb = rb_next(rb)) {
vma = rb_entry(rb, struct vm_area_struct, vm_rb);
@@ -859,6 +873,7 @@ unsigned long do_mmap_pgoff(struct file *file,
goto shared;
}
+ dont_share_VMAs:
vma = NULL;
/* obtain the address at which to make a shared mapping
@@ -1193,6 +1208,28 @@ void unmap_mapping_range(struct address_space *mapping,
EXPORT_SYMBOL(unmap_mapping_range);
/*
+ * ask for an unmapped area at which to create a mapping on a file
+ */
+unsigned long get_unmapped_area(struct file *file, unsigned long addr,
+ unsigned long len, unsigned long pgoff,
+ unsigned long flags)
+{
+ unsigned long (*get_area)(struct file *, unsigned long, unsigned long,
+ unsigned long, unsigned long);
+
+ get_area = current->mm->get_unmapped_area;
+ if (file && file->f_op && file->f_op->get_unmapped_area)
+ get_area = file->f_op->get_unmapped_area;
+
+ if (!get_area)
+ return -ENOSYS;
+
+ return get_area(file, addr, len, pgoff, flags);
+}
+
+EXPORT_SYMBOL(get_unmapped_area);
+
+/*
* Check that a process has enough memory to allocate a new virtual
* mapping. 0 means there is enough memory for the allocation to
* succeed and -ENOMEM implies there is not.