Commit db08ca25 authored Dec 25, 2019 by Jens Axboe

mm: make do_madvise() available internally



This is in preparation for enabling this functionality through io_uring.
Add a helper that is just exporting what sys_madvise() does, and have the
system call use it.

No functional changes in this patch.

Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent 4840e418

include/linux/mm.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -2328,6 +2328,7 @@ extern int __do_munmap(struct mm_struct *, unsigned long, size_t,
		struct list_head *uf, bool downgrade);
		extern int do_munmap(struct mm_struct *, unsigned long, size_t,
		struct list_head *uf);
		extern int do_madvise(unsigned long start, size_t len_in, int behavior);

		static inline unsigned long
		do_mmap_pgoff(struct file *file, unsigned long addr,

mm/madvise.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -1044,7 +1044,7 @@ madvise_behavior_valid(int behavior)
		* -EBADF - map exists, but area maps something that isn't a file.
		* -EAGAIN - a kernel resource was temporarily unavailable.
		*/
		SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior)
		int do_madvise(unsigned long start, size_t len_in, int behavior)
		{
		unsigned long end, tmp;
		struct vm_area_struct vma, prev;
		@@ -1141,3 +1141,8 @@ SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior)

		return error;
		}

		SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior)
		{
		return do_madvise(start, len_in, behavior);
		}