diff options
Diffstat (limited to 'fs/pidfs.c')
| -rw-r--r-- | fs/pidfs.c | 54 |
1 files changed, 37 insertions, 17 deletions
diff --git a/fs/pidfs.c b/fs/pidfs.c index aaa609ddab04..b57ecc96e967 100644 --- a/fs/pidfs.c +++ b/fs/pidfs.c @@ -1,5 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 #include <linux/anon_inodes.h> +#include <linux/compat.h> #include <linux/exportfs.h> #include <linux/file.h> #include <linux/fs.h> @@ -107,7 +108,7 @@ struct pidfs_attr { #if BITS_PER_LONG == 32 -DEFINE_SPINLOCK(pidfs_ino_lock); +static DEFINE_SPINLOCK(pidfs_ino_lock); static u64 pidfs_ino_nr = 1; static inline unsigned long pidfs_ino(u64 ino) @@ -659,6 +660,17 @@ static long pidfd_ioctl(struct file *file, unsigned int cmd, unsigned long arg) return open_namespace(ns_common); } +#ifdef CONFIG_COMPAT +static long pidfd_compat_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + if (cmd == FS_IOC32_GETVERSION) + cmd = FS_IOC_GETVERSION; + + return pidfd_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); +} +#endif + static int pidfs_file_release(struct inode *inode, struct file *file) { struct pid *pid = inode->i_private; @@ -686,7 +698,9 @@ static const struct file_operations pidfs_file_operations = { .show_fdinfo = pidfd_show_fdinfo, #endif .unlocked_ioctl = pidfd_ioctl, - .compat_ioctl = compat_ptr_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = pidfd_compat_ioctl, +#endif }; struct pid *pidfd_pid(const struct file *file) @@ -915,6 +929,20 @@ static struct dentry *pidfs_fh_to_dentry(struct super_block *sb, return path.dentry; } +static struct file *pidfs_dentry_open(const struct path *path, + unsigned int flags, + const struct cred *cred) +{ + struct file *file; + + /* pidfds are always O_RDWR. */ + file = dentry_open(path, flags | O_RDWR, cred); + /* do_dentry_open() strips O_EXCL and O_TRUNC. */ + if (!IS_ERR(file)) + file->f_flags |= flags & (PIDFD_THREAD | PIDFD_AUTOKILL); + return file; +} + /* * Make sure that we reject any nonsensical flags that users pass via * open_by_handle_at(). Note that PIDFD_THREAD is defined as O_EXCL, and @@ -940,11 +968,13 @@ static int pidfs_export_permission(struct handle_to_path_ctx *ctx, static struct file *pidfs_export_open(const struct path *path, unsigned int oflags) { /* - * Clear O_LARGEFILE as open_by_handle_at() forces it and raise - * O_RDWR as pidfds always are. + * Opening via file handle may never raise PIDFD_AUTOKILL. That can + * only be done at task creation! */ - oflags &= ~O_LARGEFILE; - return dentry_open(path, oflags | O_RDWR, current_cred()); + if (WARN_ON_ONCE(oflags & PIDFD_AUTOKILL)) + return ERR_PTR(-EINVAL); + /* Clear O_LARGEFILE as open_by_handle_at() forces it. */ + return pidfs_dentry_open(path, oflags & ~O_LARGEFILE, current_cred()); } static const struct export_operations pidfs_export_operations = { @@ -1108,7 +1138,6 @@ static struct file_system_type pidfs_type = { struct file *pidfs_alloc_file(struct pid *pid, unsigned int flags) { - struct file *pidfd_file; struct path path __free(path_put) = {}; int ret; @@ -1126,16 +1155,7 @@ struct file *pidfs_alloc_file(struct pid *pid, unsigned int flags) VFS_WARN_ON_ONCE(!pid->attr); flags &= ~PIDFD_STALE; - flags |= O_RDWR; - pidfd_file = dentry_open(&path, flags, current_cred()); - /* - * Raise PIDFD_THREAD and PIDFD_AUTOKILL explicitly as - * do_dentry_open() strips O_EXCL and O_TRUNC. - */ - if (!IS_ERR(pidfd_file)) - pidfd_file->f_flags |= (flags & (PIDFD_THREAD | PIDFD_AUTOKILL)); - - return pidfd_file; + return pidfs_dentry_open(&path, flags, current_cred()); } void __init pidfs_init(void) |