nsfs: clean-up ns_get_path() signature to return int

ns_get_path() and ns_get_path_cb() only ever return either NULL or an
ERR_PTR. It is far more idiomatic to simply return an integer, and it
makes all of the callers of ns_get_path() more straightforward to read.

Fixes: e149ed2b805f ("take the targets of /proc/*/ns/* symlinks to separate fs")
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/nsfs.c b/fs/nsfs.c
index a0431642c6b55f4d80f66ddb29d7f0f8f5314bf8..f3d2833c57811afe47588ac51edbfc1043b2228d 100644 (file)
--- a/fs/nsfs.c
+++ b/fs/nsfs.c
@@ -52,7 +52,7 @@ static void nsfs_evict(struct inode *inode)
        ns->ops->put(ns);
 }
 
-static void *__ns_get_path(struct path *path, struct ns_common *ns)
+static int __ns_get_path(struct path *path, struct ns_common *ns)
 {
        struct vfsmount *mnt = nsfs_mnt;
        struct dentry *dentry;
@@ -71,13 +71,13 @@ static void *__ns_get_path(struct path *path, struct ns_common *ns)
 got_it:
        path->mnt = mntget(mnt);
        path->dentry = dentry;
-       return NULL;
+       return 0;
 slow:
        rcu_read_unlock();
        inode = new_inode_pseudo(mnt->mnt_sb);
        if (!inode) {
                ns->ops->put(ns);
-               return ERR_PTR(-ENOMEM);
+               return -ENOMEM;
        }
        inode->i_ino = ns->inum;
        inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
@@ -89,7 +89,7 @@ slow:
        dentry = d_alloc_anon(mnt->mnt_sb);
        if (!dentry) {
                iput(inode);
-               return ERR_PTR(-ENOMEM);
+               return -ENOMEM;
        }
        d_instantiate(dentry, inode);
        dentry->d_fsdata = (void *)ns->ops;
@@ -98,23 +98,22 @@ slow:
                d_delete(dentry);       /* make sure ->d_prune() does nothing */
                dput(dentry);
                cpu_relax();
-               return ERR_PTR(-EAGAIN);
+               return -EAGAIN;
        }
        goto got_it;
 }
 
-void *ns_get_path_cb(struct path *path, ns_get_path_helper_t *ns_get_cb,
+int ns_get_path_cb(struct path *path, ns_get_path_helper_t *ns_get_cb,
                     void *private_data)
 {
-       void *ret;
+       int ret;
 
        do {
                struct ns_common *ns = ns_get_cb(private_data);
                if (!ns)
-                       return ERR_PTR(-ENOENT);
-
+                       return -ENOENT;
                ret = __ns_get_path(path, ns);
-       } while (ret == ERR_PTR(-EAGAIN));
+       } while (ret == -EAGAIN);
 
        return ret;
 }
@@ -131,7 +130,7 @@ static struct ns_common *ns_get_path_task(void *private_data)
        return args->ns_ops->get(args->task);
 }
 
-void *ns_get_path(struct path *path, struct task_struct *task,
+int ns_get_path(struct path *path, struct task_struct *task,
                  const struct proc_ns_operations *ns_ops)
 {
        struct ns_get_path_task_args args = {
@@ -147,7 +146,7 @@ int open_related_ns(struct ns_common *ns,
 {
        struct path path = {};
        struct file *f;
-       void *err;
+       int err;
        int fd;
 
        fd = get_unused_fd_flags(O_CLOEXEC);
@@ -164,11 +163,11 @@ int open_related_ns(struct ns_common *ns,
                }
 
                err = __ns_get_path(&path, relative);
-       } while (err == ERR_PTR(-EAGAIN));
+       } while (err == -EAGAIN);
 
-       if (IS_ERR(err)) {
+       if (err) {
                put_unused_fd(fd);
-               return PTR_ERR(err);
+               return err;
        }
 
        f = dentry_open(&path, O_RDONLY, current_cred());

diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
index dd2b35f78b09c1fd7d341224773ace3e61650474..08dd94df1a669a834a7331249aea8f2535f60b1c 100644 (file)
--- a/fs/proc/namespaces.c
+++ b/fs/proc/namespaces.c
@@ -42,14 +42,14 @@ static const char *proc_ns_get_link(struct dentry *dentry,
        const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns_ops;
        struct task_struct *task;
        struct path ns_path;
-       void *error = ERR_PTR(-EACCES);
+       int error = -EACCES;
 
        if (!dentry)
                return ERR_PTR(-ECHILD);
 
        task = get_proc_task(inode);
        if (!task)
-               return error;
+               return ERR_PTR(-EACCES);
 
        if (ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
                error = ns_get_path(&ns_path, task, ns_ops);
@@ -57,7 +57,7 @@ static const char *proc_ns_get_link(struct dentry *dentry,
                        nd_jump_link(&ns_path);
        }
        put_task_struct(task);
-       return error;
+       return ERR_PTR(error);
 }
 
 static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int buflen)

diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h
index d31cb6215905c2f719f2393185b2e3ea3d05d493..aed366b4795c067005e45106ec7d1e14cdbb9c3e 100644 (file)
--- a/include/linux/proc_ns.h
+++ b/include/linux/proc_ns.h
@@ -76,10 +76,10 @@ static inline int ns_alloc_inum(struct ns_common *ns)
 
 extern struct file *proc_ns_fget(int fd);
 #define get_proc_ns(inode) ((struct ns_common *)(inode)->i_private)
-extern void *ns_get_path(struct path *path, struct task_struct *task,
+extern int ns_get_path(struct path *path, struct task_struct *task,
                        const struct proc_ns_operations *ns_ops);
 typedef struct ns_common *ns_get_path_helper_t(void *);
-extern void *ns_get_path_cb(struct path *path, ns_get_path_helper_t ns_get_cb,
+extern int ns_get_path_cb(struct path *path, ns_get_path_helper_t ns_get_cb,
                            void *private_data);
 
 extern int ns_get_name(char *buf, size_t size, struct task_struct *task,

diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c
index 5b9da0954a27f4266eaf9a1e14ea1eeb85b270ca..2c5dc6541eceed031acd4b0953d29b8f2a48870a 100644 (file)
--- a/kernel/bpf/offload.c
+++ b/kernel/bpf/offload.c
@@ -302,14 +302,14 @@ int bpf_prog_offload_info_fill(struct bpf_prog_info *info,
        struct inode *ns_inode;
        struct path ns_path;
        char __user *uinsns;
-       void *res;
+       int res;
        u32 ulen;
 
        res = ns_get_path_cb(&ns_path, bpf_prog_offload_info_fill_ns, &args);
-       if (IS_ERR(res)) {
+       if (res) {
                if (!info->ifindex)
                        return -ENODEV;
-               return PTR_ERR(res);
+               return res;
        }
 
        down_read(&bpf_devs_lock);
@@ -526,13 +526,13 @@ int bpf_map_offload_info_fill(struct bpf_map_info *info, struct bpf_map *map)
        };
        struct inode *ns_inode;
        struct path ns_path;
-       void *res;
+       int res;
 
        res = ns_get_path_cb(&ns_path, bpf_map_offload_info_fill_ns, &args);
-       if (IS_ERR(res)) {
+       if (res) {
                if (!info->ifindex)
                        return -ENODEV;
-               return PTR_ERR(res);
+               return res;
        }
 
        ns_inode = ns_path.dentry->d_inode;

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 4ff86d57f9e5309905e7e5cffe5a1eb875b45e30..c0b11b2342905a0c021ba9e0e13561fca711dde5 100644 (file)
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -7495,7 +7495,7 @@ static void perf_fill_ns_link_info(struct perf_ns_link_info *ns_link_info,
 {
        struct path ns_path;
        struct inode *ns_inode;
-       void *error;
+       int error;
 
        error = ns_get_path(&ns_path, task, ns_ops);
        if (!error) {