diff options
| -rw-r--r-- | arch/x86/entry/syscalls/syscall_32.tbl | 2 | ||||
| -rw-r--r-- | arch/x86/entry/syscalls/syscall_64.tbl | 1 | ||||
| -rw-r--r-- | fs/fsopen.c | 57 | ||||
| -rw-r--r-- | include/linux/syscalls.h | 1 | ||||
| -rw-r--r-- | include/uapi/linux/mount.h | 8 |
5 files changed, 68 insertions, 1 deletions
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl index 5b5c9189c507..4cd5f982b1e5 100644 --- a/arch/x86/entry/syscalls/syscall_32.tbl +++ b/arch/x86/entry/syscalls/syscall_32.tbl @@ -403,7 +403,7 @@ 389 i386 fsopen sys_fsopen __ia32_sys_fsopen 390 i386 fsconfig sys_fsconfig __ia32_sys_fsconfig 391 i386 fsmount sys_fsmount __ia32_sys_fsmount -# don't use number 392, add new calls at the end +392 i386 fspick sys_fspick __ia32_sys_fspick 393 i386 semget sys_semget __ia32_sys_semget 394 i386 semctl sys_semctl __ia32_compat_sys_semctl 395 i386 shmget sys_shmget __ia32_sys_shmget diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl index 984ad594bb2b..64ca0d06259a 100644 --- a/arch/x86/entry/syscalls/syscall_64.tbl +++ b/arch/x86/entry/syscalls/syscall_64.tbl @@ -348,6 +348,7 @@ 337 common fsopen __x64_sys_fsopen 338 common fsconfig __x64_sys_fsconfig 339 common fsmount __x64_sys_fsmount +340 common fspick __x64_sys_fspick # don't use numbers 387 through 423, add new calls after the last # 'common' entry 424 common pidfd_send_signal __x64_sys_pidfd_send_signal diff --git a/fs/fsopen.c b/fs/fsopen.c index 65cc2f68f994..3bb9c0c8cbcc 100644 --- a/fs/fsopen.c +++ b/fs/fsopen.c @@ -157,6 +157,63 @@ err_fc: } /* + * Pick a superblock into a context for reconfiguration. + */ +SYSCALL_DEFINE3(fspick, int, dfd, const char __user *, path, unsigned int, flags) +{ + struct fs_context *fc; + struct path target; + unsigned int lookup_flags; + int ret; + + if (!ns_capable(current->nsproxy->mnt_ns->user_ns, CAP_SYS_ADMIN)) + return -EPERM; + + if ((flags & ~(FSPICK_CLOEXEC | + FSPICK_SYMLINK_NOFOLLOW | + FSPICK_NO_AUTOMOUNT | + FSPICK_EMPTY_PATH)) != 0) + return -EINVAL; + + lookup_flags = LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT; + if (flags & FSPICK_SYMLINK_NOFOLLOW) + lookup_flags &= ~LOOKUP_FOLLOW; + if (flags & FSPICK_NO_AUTOMOUNT) + lookup_flags &= ~LOOKUP_AUTOMOUNT; + if (flags & FSPICK_EMPTY_PATH) + lookup_flags |= LOOKUP_EMPTY; + ret = user_path_at(dfd, path, lookup_flags, &target); + if (ret < 0) + goto err; + + ret = -EINVAL; + if (target.mnt->mnt_root != target.dentry) + goto err_path; + + fc = fs_context_for_reconfigure(target.dentry, 0, 0); + if (IS_ERR(fc)) { + ret = PTR_ERR(fc); + goto err_path; + } + + fc->phase = FS_CONTEXT_RECONF_PARAMS; + + ret = fscontext_alloc_log(fc); + if (ret < 0) + goto err_fc; + + path_put(&target); + return fscontext_create_fd(fc, flags & FSPICK_CLOEXEC ? O_CLOEXEC : 0); + +err_fc: + put_fs_context(fc); +err_path: + path_put(&target); +err: + return ret; +} + +/* * Check the state and apply the configuration. Note that this function is * allowed to 'steal' the value by setting param->xxx to NULL before returning. */ diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 0e697f595278..e2870fe1be5b 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -993,6 +993,7 @@ asmlinkage long sys_fsopen(const char __user *fs_name, unsigned int flags); asmlinkage long sys_fsconfig(int fs_fd, unsigned int cmd, const char __user *key, const void __user *value, int aux); asmlinkage long sys_fsmount(int fs_fd, unsigned int flags, unsigned int ms_flags); +asmlinkage long sys_fspick(int dfd, const char __user *path, unsigned int flags); asmlinkage long sys_pidfd_send_signal(int pidfd, int sig, siginfo_t __user *info, unsigned int flags); diff --git a/include/uapi/linux/mount.h b/include/uapi/linux/mount.h index 3888d3b91dc5..96a0240f23fe 100644 --- a/include/uapi/linux/mount.h +++ b/include/uapi/linux/mount.h @@ -78,6 +78,14 @@ #define FSOPEN_CLOEXEC 0x00000001 /* + * fspick() flags. + */ +#define FSPICK_CLOEXEC 0x00000001 +#define FSPICK_SYMLINK_NOFOLLOW 0x00000002 +#define FSPICK_NO_AUTOMOUNT 0x00000004 +#define FSPICK_EMPTY_PATH 0x00000008 + +/* * The type of fsconfig() call made. */ enum fsconfig_command { |