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: Joern Engel <joern@logfs.org>
Cc: Jianguo Wu <wujianguo@huawei.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jörn Engel 2013-07-08 16:00:26 -07:00 committed by Linus Torvalds
parent 918fc718c5
commit 493af57804
1 changed files with 4 additions and 2 deletions

View File

@ -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: