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Commit 493af578 authored by Jörn Engel's avatar Jörn Engel Committed by Linus Torvalds
Browse files

mmap: allow MAP_HUGETLB for hugetlbfs files v2 



It is counterintuitive at best that mmap'ing a hugetlbfs file with
MAP_HUGETLB fails, while mmap'ing it without will a) succeed and b)
return huge pages.

v2: use is_file_hugepages(), as suggested by Jianguo

Signed-off-by: default avatarJoern Engel <joern@logfs.org>
Cc: Jianguo Wu <wujianguo@huawei.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 918fc718

mm/mmap.c

+4 −2
Original line number Diff line number Diff line
@@ -1358,13 +1358,14 @@ SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len, 


	if (!(flags & MAP_ANONYMOUS)) {

		audit_mmap_fd(fd, flags);

		if (unlikely(flags & MAP_HUGETLB))

			return -EINVAL;

		file = fget(fd);

		if (!file)

			goto out;

		if (is_file_hugepages(file))

			len = ALIGN(len, huge_page_size(hstate_file(file)));

		retval = -EINVAL;

		if (unlikely(flags & MAP_HUGETLB && !is_file_hugepages(file)))

			goto out_fput;

	} else if (flags & MAP_HUGETLB) {

		struct user_struct *user = NULL;

		struct hstate *hs = hstate_sizelog((flags >> MAP_HUGE_SHIFT) &
@@ -1391,6 +1392,7 @@ SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len, 
	flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);



	retval = vm_mmap_pgoff(file, addr, len, prot, flags, pgoff);

out_fput:

	if (file)

		fput(file);

out: