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shmem: unexport shmem_add_seals()/shmem_get_seals() 

Patch series "memfd: add sealing to hugetlb-backed memory", v3.

Recently, Mike Kravetz added hugetlbfs support to memfd.  However, he
didn't add sealing support.  One of the reasons to use memfd is to have
shared memory sealing when doing IPC or sharing memory with another
process with some extra safety.  qemu uses shared memory & hugetables
with vhost-user (used by dpdk), so it is reasonable to use memfd now
instead for convenience and security reasons.

This patch (of 9):

The functions are called through shmem_fcntl() only.  And no danger in
removing the EXPORTs as the routines only work with shmem file structs.

Link: http://lkml.kernel.org/r/20171107122800.25517-2-marcandre.lureau@redhat.com
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Marc-André Lureau 2018-01-31 16:19:14 -08:00 committed by Linus Torvalds
parent ab8928b72f
commit e9d586a821
2 changed files with 2 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
include/linux/shmem_fs.h
View File

@ -112,8 +112,6 @@ extern void shmem_uncharge(struct inode *inode, long pages);
#ifdef CONFIG_TMPFS
extern int shmem_add_seals(struct file *file, unsigned int seals);
extern int shmem_get_seals(struct file *file);
extern long shmem_fcntl(struct file *file, unsigned int cmd, unsigned long arg);
#else

6
mm/shmem.c
View File

@ -2722,7 +2722,7 @@ static int shmem_wait_for_pins(struct address_space *mapping)
F_SEAL_GROW | \
F_SEAL_WRITE)
int shmem_add_seals(struct file *file, unsigned int seals)
static int shmem_add_seals(struct file *file, unsigned int seals)
{
struct inode *inode = file_inode(file);
struct shmem_inode_info *info = SHMEM_I(inode);
@ -2791,16 +2791,14 @@ int shmem_add_seals(struct file *file, unsigned int seals)
inode_unlock(inode);
return error;
}
EXPORT_SYMBOL_GPL(shmem_add_seals);
int shmem_get_seals(struct file *file)
static int shmem_get_seals(struct file *file)
{
if (file->f_op != &shmem_file_operations)
return -EINVAL;
return SHMEM_I(file_inode(file))->seals;
}
EXPORT_SYMBOL_GPL(shmem_get_seals);
long shmem_fcntl(struct file *file, unsigned int cmd, unsigned long arg)
{