mm: Make generic weak get_user_pages_fast and EXPORT_GPL it
Out of line get_user_pages_fast fallback implementation, make it a weak
symbol, get rid of CONFIG_HAVE_GET_USER_PAGES_FAST.
Export the symbol to modules so lguest can use it.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/mm/Kconfig b/mm/Kconfig
index 446c658..0bd9c2d 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -77,9 +77,6 @@
def_bool y
depends on !SPARSEMEM
-config HAVE_GET_USER_PAGES_FAST
- bool
-
#
# Both the NUMA code and DISCONTIGMEM use arrays of pg_data_t's
# to represent different areas of memory. This variable allows
diff --git a/mm/util.c b/mm/util.c
index 9341ca7..cb00b74 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -171,3 +171,18 @@
mm->unmap_area = arch_unmap_area;
}
#endif
+
+int __attribute__((weak)) get_user_pages_fast(unsigned long start,
+ int nr_pages, int write, struct page **pages)
+{
+ struct mm_struct *mm = current->mm;
+ int ret;
+
+ down_read(&mm->mmap_sem);
+ ret = get_user_pages(current, mm, start, nr_pages,
+ write, 0, pages, NULL);
+ up_read(&mm->mmap_sem);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(get_user_pages_fast);