Commit 6128b3af authored by David Hildenbrand's avatar David Hildenbrand
Browse files

mm: ignore MAP_DENYWRITE in ksys_mmap_pgoff() 



Let's also remove masking off MAP_DENYWRITE from ksys_mmap_pgoff():
the last in-tree occurrence of MAP_DENYWRITE is now in LEGACY_MAP_MASK,
which accepts the flag e.g., for MAP_SHARED_VALIDATE; however, the flag
is ignored throughout the kernel now.

Add a comment to LEGACY_MAP_MASK stating that MAP_DENYWRITE is ignored.

Acked-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: default avatarChristian König <christian.koenig@amd.com>
Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
parent 8d0920bd

include/linux/mman.h

+2 −1
Original line number Diff line number Diff line
@@ -32,7 +32,8 @@ 
 * The historical set of flags that all mmap implementations implicitly

 * support when a ->mmap_validate() op is not provided in file_operations.

 *

 * MAP_EXECUTABLE is completely ignored throughout the kernel.

 * MAP_EXECUTABLE and MAP_DENYWRITE are completely ignored throughout the

 * kernel.

 */

#define LEGACY_MAP_MASK (MAP_SHARED \

		| MAP_PRIVATE \

mm/mmap.c

+0 −2
Original line number Diff line number Diff line
@@ -1626,8 +1626,6 @@ unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len, 
			return PTR_ERR(file);

	}



	flags &= ~MAP_DENYWRITE;



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

out_fput:

	if (file)

mm/nommu.c

+0 −2
Original line number Diff line number Diff line
@@ -1296,8 +1296,6 @@ unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len, 
			goto out;

	}



	flags &= ~MAP_DENYWRITE;



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



	if (file)