* [PATCH] mm: remap_file_pages: grab file ref to prevent race while mmaping
@ 2014-05-14 3:35 Sasha Levin
2014-05-14 9:15 ` Kirill A. Shutemov
0 siblings, 1 reply; 2+ messages in thread
From: Sasha Levin @ 2014-05-14 3:35 UTC (permalink / raw)
To: linux-mm
Cc: kirill.shutemov, davej, linux-kernel, viro, peterz, mingo, Sasha Levin
A file reference should be held while a file is mmaped, otherwise it might
be freed while being used.
Suggested-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
---
mm/mmap.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/mm/mmap.c b/mm/mmap.c
index 2a0e0a8..da3c212 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2593,6 +2593,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
struct vm_area_struct *vma;
unsigned long populate = 0;
unsigned long ret = -EINVAL;
+ struct file *file;
pr_warn_once("%s (%d) uses deprecated remap_file_pages() syscall. "
"See Documentation/vm/remap_file_pages.txt.\n",
@@ -2636,8 +2637,10 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
munlock_vma_pages_range(vma, start, start + size);
}
+ file = get_file(vma->vm_file);
ret = do_mmap_pgoff(vma->vm_file, start, size,
prot, flags, pgoff, &populate);
+ fput(file);
out:
up_write(&mm->mmap_sem);
if (populate)
--
1.7.10.4
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] mm: remap_file_pages: grab file ref to prevent race while mmaping
2014-05-14 3:35 [PATCH] mm: remap_file_pages: grab file ref to prevent race while mmaping Sasha Levin
@ 2014-05-14 9:15 ` Kirill A. Shutemov
0 siblings, 0 replies; 2+ messages in thread
From: Kirill A. Shutemov @ 2014-05-14 9:15 UTC (permalink / raw)
To: Sasha Levin
Cc: linux-mm, kirill.shutemov, davej, linux-kernel, viro, peterz, mingo
On Tue, May 13, 2014 at 11:35:42PM -0400, Sasha Levin wrote:
> A file reference should be held while a file is mmaped, otherwise it might
> be freed while being used.
>
> Suggested-by: Hugh Dickins <hughd@google.com>
> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Sorry, again. :-/
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> ---
> mm/mmap.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/mm/mmap.c b/mm/mmap.c
> index 2a0e0a8..da3c212 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -2593,6 +2593,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
> struct vm_area_struct *vma;
> unsigned long populate = 0;
> unsigned long ret = -EINVAL;
> + struct file *file;
>
> pr_warn_once("%s (%d) uses deprecated remap_file_pages() syscall. "
> "See Documentation/vm/remap_file_pages.txt.\n",
> @@ -2636,8 +2637,10 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
> munlock_vma_pages_range(vma, start, start + size);
> }
>
> + file = get_file(vma->vm_file);
> ret = do_mmap_pgoff(vma->vm_file, start, size,
> prot, flags, pgoff, &populate);
> + fput(file);
> out:
> up_write(&mm->mmap_sem);
> if (populate)
> --
> 1.7.10.4
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
--
Kirill A. Shutemov
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2014-05-14 9:18 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-05-14 3:35 [PATCH] mm: remap_file_pages: grab file ref to prevent race while mmaping Sasha Levin
2014-05-14 9:15 ` Kirill A. Shutemov
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).