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authorLinus Torvalds <torvalds@linux-foundation.org>2018-08-13 19:58:36 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-08-13 19:58:36 -0700
commita66b4cd1e7163adb327838a3c81faaf6a9330d5a (patch)
tree2b123a010bb0f1566ff6f34e529f01ddf10ee308 /ipc
parentb16528466786a540cb00148acb124e0149d62710 (diff)
parent5f336e722cc961be94d264d96b90c92888fffae1 (diff)
downloadlinux-stericsson-a66b4cd1e7163adb327838a3c81faaf6a9330d5a.tar.gz
Merge branch 'work.open3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs open-related updates from Al Viro: - "do we need fput() or put_filp()" rules are gone - it's always fput() now. We keep track of that state where it belongs - in ->f_mode. - int *opened mess killed - in finish_open(), in ->atomic_open() instances and in fs/namei.c code around do_last()/lookup_open()/atomic_open(). - alloc_file() wrappers with saner calling conventions are introduced (alloc_file_clone() and alloc_file_pseudo()); callers converted, with much simplification. - while we are at it, saner calling conventions for path_init() and link_path_walk(), simplifying things inside fs/namei.c (both on open-related paths and elsewhere). * 'work.open3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (40 commits) few more cleanups of link_path_walk() callers allow link_path_walk() to take ERR_PTR() make path_init() unconditionally paired with terminate_walk() document alloc_file() changes make alloc_file() static do_shmat(): grab shp->shm_file earlier, switch to alloc_file_clone() new helper: alloc_file_clone() create_pipe_files(): switch the first allocation to alloc_file_pseudo() anon_inode_getfile(): switch to alloc_file_pseudo() hugetlb_file_setup(): switch to alloc_file_pseudo() ocxlflash_getfile(): switch to alloc_file_pseudo() cxl_getfile(): switch to alloc_file_pseudo() ... and switch shmem_file_setup() to alloc_file_pseudo() __shmem_file_setup(): reorder allocations new wrapper: alloc_file_pseudo() kill FILE_{CREATED,OPENED} switch atomic_open() and lookup_open() to returning 0 in all success cases document ->atomic_open() changes ->atomic_open(): return 0 in all success cases get rid of 'opened' in path_openat() and the helpers downstream ...
Diffstat (limited to 'ipc')
-rw-r--r--ipc/shm.c45
1 files changed, 21 insertions, 24 deletions
diff --git a/ipc/shm.c b/ipc/shm.c
index fefa00d310fb..d8a38b3be5dd 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -1366,15 +1366,14 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg,
struct shmid_kernel *shp;
unsigned long addr = (unsigned long)shmaddr;
unsigned long size;
- struct file *file;
+ struct file *file, *base;
int err;
unsigned long flags = MAP_SHARED;
unsigned long prot;
int acc_mode;
struct ipc_namespace *ns;
struct shm_file_data *sfd;
- struct path path;
- fmode_t f_mode;
+ int f_flags;
unsigned long populate = 0;
err = -EINVAL;
@@ -1407,11 +1406,11 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg,
if (shmflg & SHM_RDONLY) {
prot = PROT_READ;
acc_mode = S_IRUGO;
- f_mode = FMODE_READ;
+ f_flags = O_RDONLY;
} else {
prot = PROT_READ | PROT_WRITE;
acc_mode = S_IRUGO | S_IWUGO;
- f_mode = FMODE_READ | FMODE_WRITE;
+ f_flags = O_RDWR;
}
if (shmflg & SHM_EXEC) {
prot |= PROT_EXEC;
@@ -1447,46 +1446,44 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg,
goto out_unlock;
}
- path = shp->shm_file->f_path;
- path_get(&path);
+ /*
+ * We need to take a reference to the real shm file to prevent the
+ * pointer from becoming stale in cases where the lifetime of the outer
+ * file extends beyond that of the shm segment. It's not usually
+ * possible, but it can happen during remap_file_pages() emulation as
+ * that unmaps the memory, then does ->mmap() via file reference only.
+ * We'll deny the ->mmap() if the shm segment was since removed, but to
+ * detect shm ID reuse we need to compare the file pointers.
+ */
+ base = get_file(shp->shm_file);
shp->shm_nattch++;
- size = i_size_read(d_inode(path.dentry));
+ size = i_size_read(file_inode(base));
ipc_unlock_object(&shp->shm_perm);
rcu_read_unlock();
err = -ENOMEM;
sfd = kzalloc(sizeof(*sfd), GFP_KERNEL);
if (!sfd) {
- path_put(&path);
+ fput(base);
goto out_nattch;
}
- file = alloc_file(&path, f_mode,
- is_file_hugepages(shp->shm_file) ?
+ file = alloc_file_clone(base, f_flags,
+ is_file_hugepages(base) ?
&shm_file_operations_huge :
&shm_file_operations);
err = PTR_ERR(file);
if (IS_ERR(file)) {
kfree(sfd);
- path_put(&path);
+ fput(base);
goto out_nattch;
}
- file->private_data = sfd;
- file->f_mapping = shp->shm_file->f_mapping;
sfd->id = shp->shm_perm.id;
sfd->ns = get_ipc_ns(ns);
- /*
- * We need to take a reference to the real shm file to prevent the
- * pointer from becoming stale in cases where the lifetime of the outer
- * file extends beyond that of the shm segment. It's not usually
- * possible, but it can happen during remap_file_pages() emulation as
- * that unmaps the memory, then does ->mmap() via file reference only.
- * We'll deny the ->mmap() if the shm segment was since removed, but to
- * detect shm ID reuse we need to compare the file pointers.
- */
- sfd->file = get_file(shp->shm_file);
+ sfd->file = base;
sfd->vm_ops = NULL;
+ file->private_data = sfd;
err = security_mmap_file(file, prot, flags);
if (err)