[PATCH 1/3] mm: move argument checkers of mmap_pgoff() to separated routine
From: Yury Norov <hidden>
Date: 2016-12-11 12:57:56
Also in:
linux-arch, lkml
Subsystem:
memory management, memory mapping, the rest · Maintainers:
Andrew Morton, Liam R. Howlett, Lorenzo Stoakes, Linus Torvalds
Signed-off-by: Yury Norov <redacted> --- mm/mmap.c | 34 +++++++++++++++++++++++++--------- 1 file changed, 25 insertions(+), 9 deletions(-)
diff --git a/mm/mmap.c b/mm/mmap.c
index 1af87c1..fc1c943 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c@@ -1455,12 +1455,12 @@ unsigned long do_mmap(struct file *file, unsigned long addr, return addr; } -SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len, - unsigned long, prot, unsigned long, flags, - unsigned long, fd, unsigned long, pgoff) +static int mmap_pgoff_prepare(struct file **f, unsigned long *l, + unsigned long *fl, unsigned long fd) { - struct file *file = NULL; - unsigned long retval; + struct file *file = *f; + unsigned long flags = *fl; + unsigned long len = *l; if (!(flags & MAP_ANONYMOUS)) { audit_mmap_fd(fd, flags);
@@ -1469,9 +1469,10 @@ SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len, return -EBADF; 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; + if (unlikely(flags & MAP_HUGETLB && !is_file_hugepages(file))) { + fput(file); + return -EINVAL; + } } else if (flags & MAP_HUGETLB) { struct user_struct *user = NULL; struct hstate *hs;
@@ -1497,8 +1498,23 @@ SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len, flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE); + *f = file; + *l = len; + *fl = flags; + return 0; +} + +SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len, + unsigned long, prot, unsigned long, flags, + unsigned long, fd, unsigned long, pgoff) +{ + struct file *file = NULL; + unsigned long retval; + int err = mmap_pgoff_prepare(&file, &len, &flags, fd); + if (err) + return err; + retval = vm_mmap_pgoff(file, addr, len, prot, flags, pgoff); -out_fput: if (file) fput(file); return retval;
--
2.7.4