| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * arch/arm/kernel/sys_oabi-compat.c |
| * |
| * Compatibility wrappers for syscalls that are used from |
| * old ABI user space binaries with an EABI kernel. |
| * |
| * Author: Nicolas Pitre |
| * Created: Oct 7, 2005 |
| * Copyright: MontaVista Software, Inc. |
| */ |
| |
| /* |
| * The legacy ABI and the new ARM EABI have different rules making some |
| * syscalls incompatible especially with structure arguments. |
| * Most notably, Eabi says 64-bit members should be 64-bit aligned instead of |
| * simply word aligned. EABI also pads structures to the size of the largest |
| * member it contains instead of the invariant 32-bit. |
| * |
| * The following syscalls are affected: |
| * |
| * sys_stat64: |
| * sys_lstat64: |
| * sys_fstat64: |
| * sys_fstatat64: |
| * |
| * struct stat64 has different sizes and some members are shifted |
| * Compatibility wrappers are needed for them and provided below. |
| * |
| * sys_fcntl64: |
| * |
| * struct flock64 has different sizes and some members are shifted |
| * A compatibility wrapper is needed and provided below. |
| * |
| * sys_statfs64: |
| * sys_fstatfs64: |
| * |
| * struct statfs64 has extra padding with EABI growing its size from |
| * 84 to 88. This struct is now __attribute__((packed,aligned(4))) |
| * with a small assembly wrapper to force the sz argument to 84 if it is 88 |
| * to avoid copying the extra padding over user space unexpecting it. |
| * |
| * sys_newuname: |
| * |
| * struct new_utsname has no padding with EABI. No problem there. |
| * |
| * sys_epoll_ctl: |
| * sys_epoll_wait: |
| * |
| * struct epoll_event has its second member shifted also affecting the |
| * structure size. Compatibility wrappers are needed and provided below. |
| * |
| * sys_ipc: |
| * sys_semop: |
| * sys_semtimedop: |
| * |
| * struct sembuf loses its padding with EABI. Since arrays of them are |
| * used they have to be copyed to remove the padding. Compatibility wrappers |
| * provided below. |
| * |
| * sys_bind: |
| * sys_connect: |
| * sys_sendmsg: |
| * sys_sendto: |
| * sys_socketcall: |
| * |
| * struct sockaddr_un loses its padding with EABI. Since the size of the |
| * structure is used as a validation test in unix_mkname(), we need to |
| * change the length argument to 110 whenever it is 112. Compatibility |
| * wrappers provided below. |
| */ |
| |
| #include <linux/syscalls.h> |
| #include <linux/errno.h> |
| #include <linux/fs.h> |
| #include <linux/filelock.h> |
| #include <linux/cred.h> |
| #include <linux/fcntl.h> |
| #include <linux/eventpoll.h> |
| #include <linux/sem.h> |
| #include <linux/socket.h> |
| #include <linux/net.h> |
| #include <linux/ipc.h> |
| #include <linux/ipc_namespace.h> |
| #include <linux/uaccess.h> |
| #include <linux/slab.h> |
| |
| #include <asm/syscall.h> |
| |
| struct oldabi_stat64 { |
| unsigned long long st_dev; |
| unsigned int __pad1; |
| unsigned long __st_ino; |
| unsigned int st_mode; |
| unsigned int st_nlink; |
| |
| unsigned long st_uid; |
| unsigned long st_gid; |
| |
| unsigned long long st_rdev; |
| unsigned int __pad2; |
| |
| long long st_size; |
| unsigned long st_blksize; |
| unsigned long long st_blocks; |
| |
| unsigned long st_atime; |
| unsigned long st_atime_nsec; |
| |
| unsigned long st_mtime; |
| unsigned long st_mtime_nsec; |
| |
| unsigned long st_ctime; |
| unsigned long st_ctime_nsec; |
| |
| unsigned long long st_ino; |
| } __attribute__ ((packed,aligned(4))); |
| |
| static long cp_oldabi_stat64(struct kstat *stat, |
| struct oldabi_stat64 __user *statbuf) |
| { |
| struct oldabi_stat64 tmp; |
| |
| tmp.st_dev = huge_encode_dev(stat->dev); |
| tmp.__pad1 = 0; |
| tmp.__st_ino = stat->ino; |
| tmp.st_mode = stat->mode; |
| tmp.st_nlink = stat->nlink; |
| tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid); |
| tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid); |
| tmp.st_rdev = huge_encode_dev(stat->rdev); |
| tmp.st_size = stat->size; |
| tmp.st_blocks = stat->blocks; |
| tmp.__pad2 = 0; |
| tmp.st_blksize = stat->blksize; |
| tmp.st_atime = stat->atime.tv_sec; |
| tmp.st_atime_nsec = stat->atime.tv_nsec; |
| tmp.st_mtime = stat->mtime.tv_sec; |
| tmp.st_mtime_nsec = stat->mtime.tv_nsec; |
| tmp.st_ctime = stat->ctime.tv_sec; |
| tmp.st_ctime_nsec = stat->ctime.tv_nsec; |
| tmp.st_ino = stat->ino; |
| return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0; |
| } |
| |
| asmlinkage long sys_oabi_stat64(const char __user * filename, |
| struct oldabi_stat64 __user * statbuf) |
| { |
| struct kstat stat; |
| int error = vfs_stat(filename, &stat); |
| if (!error) |
| error = cp_oldabi_stat64(&stat, statbuf); |
| return error; |
| } |
| |
| asmlinkage long sys_oabi_lstat64(const char __user * filename, |
| struct oldabi_stat64 __user * statbuf) |
| { |
| struct kstat stat; |
| int error = vfs_lstat(filename, &stat); |
| if (!error) |
| error = cp_oldabi_stat64(&stat, statbuf); |
| return error; |
| } |
| |
| asmlinkage long sys_oabi_fstat64(unsigned long fd, |
| struct oldabi_stat64 __user * statbuf) |
| { |
| struct kstat stat; |
| int error = vfs_fstat(fd, &stat); |
| if (!error) |
| error = cp_oldabi_stat64(&stat, statbuf); |
| return error; |
| } |
| |
| asmlinkage long sys_oabi_fstatat64(int dfd, |
| const char __user *filename, |
| struct oldabi_stat64 __user *statbuf, |
| int flag) |
| { |
| struct kstat stat; |
| int error; |
| |
| error = vfs_fstatat(dfd, filename, &stat, flag); |
| if (error) |
| return error; |
| return cp_oldabi_stat64(&stat, statbuf); |
| } |
| |
| struct oabi_flock64 { |
| short l_type; |
| short l_whence; |
| loff_t l_start; |
| loff_t l_len; |
| pid_t l_pid; |
| } __attribute__ ((packed,aligned(4))); |
| |
| static int get_oabi_flock(struct flock64 *kernel, struct oabi_flock64 __user *arg) |
| { |
| struct oabi_flock64 user; |
| |
| if (copy_from_user(&user, (struct oabi_flock64 __user *)arg, |
| sizeof(user))) |
| return -EFAULT; |
| |
| kernel->l_type = user.l_type; |
| kernel->l_whence = user.l_whence; |
| kernel->l_start = user.l_start; |
| kernel->l_len = user.l_len; |
| kernel->l_pid = user.l_pid; |
| |
| return 0; |
| } |
| |
| static int put_oabi_flock(struct flock64 *kernel, struct oabi_flock64 __user *arg) |
| { |
| struct oabi_flock64 user; |
| |
| user.l_type = kernel->l_type; |
| user.l_whence = kernel->l_whence; |
| user.l_start = kernel->l_start; |
| user.l_len = kernel->l_len; |
| user.l_pid = kernel->l_pid; |
| |
| if (copy_to_user((struct oabi_flock64 __user *)arg, |
| &user, sizeof(user))) |
| return -EFAULT; |
| |
| return 0; |
| } |
| |
| asmlinkage long sys_oabi_fcntl64(unsigned int fd, unsigned int cmd, |
| unsigned long arg) |
| { |
| void __user *argp = (void __user *)arg; |
| struct fd f = fdget_raw(fd); |
| struct flock64 flock; |
| long err = -EBADF; |
| |
| if (!f.file) |
| goto out; |
| |
| switch (cmd) { |
| case F_GETLK64: |
| case F_OFD_GETLK: |
| err = security_file_fcntl(f.file, cmd, arg); |
| if (err) |
| break; |
| err = get_oabi_flock(&flock, argp); |
| if (err) |
| break; |
| err = fcntl_getlk64(f.file, cmd, &flock); |
| if (!err) |
| err = put_oabi_flock(&flock, argp); |
| break; |
| case F_SETLK64: |
| case F_SETLKW64: |
| case F_OFD_SETLK: |
| case F_OFD_SETLKW: |
| err = security_file_fcntl(f.file, cmd, arg); |
| if (err) |
| break; |
| err = get_oabi_flock(&flock, argp); |
| if (err) |
| break; |
| err = fcntl_setlk64(fd, f.file, cmd, &flock); |
| break; |
| default: |
| err = sys_fcntl64(fd, cmd, arg); |
| break; |
| } |
| fdput(f); |
| out: |
| return err; |
| } |
| |
| struct oabi_epoll_event { |
| __poll_t events; |
| __u64 data; |
| } __attribute__ ((packed,aligned(4))); |
| |
| #ifdef CONFIG_EPOLL |
| asmlinkage long sys_oabi_epoll_ctl(int epfd, int op, int fd, |
| struct oabi_epoll_event __user *event) |
| { |
| struct oabi_epoll_event user; |
| struct epoll_event kernel; |
| |
| if (ep_op_has_event(op) && |
| copy_from_user(&user, event, sizeof(user))) |
| return -EFAULT; |
| |
| kernel.events = user.events; |
| kernel.data = user.data; |
| |
| return do_epoll_ctl(epfd, op, fd, &kernel, false); |
| } |
| #else |
| asmlinkage long sys_oabi_epoll_ctl(int epfd, int op, int fd, |
| struct oabi_epoll_event __user *event) |
| { |
| return -EINVAL; |
| } |
| #endif |
| |
| struct epoll_event __user * |
| epoll_put_uevent(__poll_t revents, __u64 data, |
| struct epoll_event __user *uevent) |
| { |
| if (in_oabi_syscall()) { |
| struct oabi_epoll_event __user *oevent = (void __user *)uevent; |
| |
| if (__put_user(revents, &oevent->events) || |
| __put_user(data, &oevent->data)) |
| return NULL; |
| |
| return (void __user *)(oevent+1); |
| } |
| |
| if (__put_user(revents, &uevent->events) || |
| __put_user(data, &uevent->data)) |
| return NULL; |
| |
| return uevent+1; |
| } |
| |
| struct oabi_sembuf { |
| unsigned short sem_num; |
| short sem_op; |
| short sem_flg; |
| unsigned short __pad; |
| }; |
| |
| #define sc_semopm sem_ctls[2] |
| |
| #ifdef CONFIG_SYSVIPC |
| asmlinkage long sys_oabi_semtimedop(int semid, |
| struct oabi_sembuf __user *tsops, |
| unsigned nsops, |
| const struct old_timespec32 __user *timeout) |
| { |
| struct ipc_namespace *ns; |
| struct sembuf *sops; |
| long err; |
| int i; |
| |
| ns = current->nsproxy->ipc_ns; |
| if (nsops > ns->sc_semopm) |
| return -E2BIG; |
| if (nsops < 1 || nsops > SEMOPM) |
| return -EINVAL; |
| sops = kvmalloc_array(nsops, sizeof(*sops), GFP_KERNEL); |
| if (!sops) |
| return -ENOMEM; |
| err = 0; |
| for (i = 0; i < nsops; i++) { |
| struct oabi_sembuf osb; |
| err |= copy_from_user(&osb, tsops, sizeof(osb)); |
| sops[i].sem_num = osb.sem_num; |
| sops[i].sem_op = osb.sem_op; |
| sops[i].sem_flg = osb.sem_flg; |
| tsops++; |
| } |
| if (err) { |
| err = -EFAULT; |
| goto out; |
| } |
| |
| if (timeout) { |
| struct timespec64 ts; |
| err = get_old_timespec32(&ts, timeout); |
| if (err) |
| goto out; |
| err = __do_semtimedop(semid, sops, nsops, &ts, ns); |
| goto out; |
| } |
| err = __do_semtimedop(semid, sops, nsops, NULL, ns); |
| out: |
| kvfree(sops); |
| return err; |
| } |
| |
| asmlinkage long sys_oabi_semop(int semid, struct oabi_sembuf __user *tsops, |
| unsigned nsops) |
| { |
| return sys_oabi_semtimedop(semid, tsops, nsops, NULL); |
| } |
| |
| asmlinkage int sys_oabi_ipc(uint call, int first, int second, int third, |
| void __user *ptr, long fifth) |
| { |
| switch (call & 0xffff) { |
| case SEMOP: |
| return sys_oabi_semtimedop(first, |
| (struct oabi_sembuf __user *)ptr, |
| second, NULL); |
| case SEMTIMEDOP: |
| return sys_oabi_semtimedop(first, |
| (struct oabi_sembuf __user *)ptr, |
| second, |
| (const struct old_timespec32 __user *)fifth); |
| default: |
| return sys_ipc(call, first, second, third, ptr, fifth); |
| } |
| } |
| #else |
| asmlinkage long sys_oabi_semtimedop(int semid, |
| struct oabi_sembuf __user *tsops, |
| unsigned nsops, |
| const struct old_timespec32 __user *timeout) |
| { |
| return -ENOSYS; |
| } |
| |
| asmlinkage long sys_oabi_semop(int semid, struct oabi_sembuf __user *tsops, |
| unsigned nsops) |
| { |
| return -ENOSYS; |
| } |
| |
| asmlinkage int sys_oabi_ipc(uint call, int first, int second, int third, |
| void __user *ptr, long fifth) |
| { |
| return -ENOSYS; |
| } |
| #endif |
| |
| asmlinkage long sys_oabi_bind(int fd, struct sockaddr __user *addr, int addrlen) |
| { |
| sa_family_t sa_family; |
| if (addrlen == 112 && |
| get_user(sa_family, &addr->sa_family) == 0 && |
| sa_family == AF_UNIX) |
| addrlen = 110; |
| return sys_bind(fd, addr, addrlen); |
| } |
| |
| asmlinkage long sys_oabi_connect(int fd, struct sockaddr __user *addr, int addrlen) |
| { |
| sa_family_t sa_family; |
| if (addrlen == 112 && |
| get_user(sa_family, &addr->sa_family) == 0 && |
| sa_family == AF_UNIX) |
| addrlen = 110; |
| return sys_connect(fd, addr, addrlen); |
| } |
| |
| asmlinkage long sys_oabi_sendto(int fd, void __user *buff, |
| size_t len, unsigned flags, |
| struct sockaddr __user *addr, |
| int addrlen) |
| { |
| sa_family_t sa_family; |
| if (addrlen == 112 && |
| get_user(sa_family, &addr->sa_family) == 0 && |
| sa_family == AF_UNIX) |
| addrlen = 110; |
| return sys_sendto(fd, buff, len, flags, addr, addrlen); |
| } |
| |
| asmlinkage long sys_oabi_sendmsg(int fd, struct user_msghdr __user *msg, unsigned flags) |
| { |
| struct sockaddr __user *addr; |
| int msg_namelen; |
| sa_family_t sa_family; |
| if (msg && |
| get_user(msg_namelen, &msg->msg_namelen) == 0 && |
| msg_namelen == 112 && |
| get_user(addr, &msg->msg_name) == 0 && |
| get_user(sa_family, &addr->sa_family) == 0 && |
| sa_family == AF_UNIX) |
| { |
| /* |
| * HACK ALERT: there is a limit to how much backward bending |
| * we should do for what is actually a transitional |
| * compatibility layer. This already has known flaws with |
| * a few ioctls that we don't intend to fix. Therefore |
| * consider this blatent hack as another one... and take care |
| * to run for cover. In most cases it will "just work fine". |
| * If it doesn't, well, tough. |
| */ |
| put_user(110, &msg->msg_namelen); |
| } |
| return sys_sendmsg(fd, msg, flags); |
| } |
| |
| asmlinkage long sys_oabi_socketcall(int call, unsigned long __user *args) |
| { |
| unsigned long r = -EFAULT, a[6]; |
| |
| switch (call) { |
| case SYS_BIND: |
| if (copy_from_user(a, args, 3 * sizeof(long)) == 0) |
| r = sys_oabi_bind(a[0], (struct sockaddr __user *)a[1], a[2]); |
| break; |
| case SYS_CONNECT: |
| if (copy_from_user(a, args, 3 * sizeof(long)) == 0) |
| r = sys_oabi_connect(a[0], (struct sockaddr __user *)a[1], a[2]); |
| break; |
| case SYS_SENDTO: |
| if (copy_from_user(a, args, 6 * sizeof(long)) == 0) |
| r = sys_oabi_sendto(a[0], (void __user *)a[1], a[2], a[3], |
| (struct sockaddr __user *)a[4], a[5]); |
| break; |
| case SYS_SENDMSG: |
| if (copy_from_user(a, args, 3 * sizeof(long)) == 0) |
| r = sys_oabi_sendmsg(a[0], (struct user_msghdr __user *)a[1], a[2]); |
| break; |
| default: |
| r = sys_socketcall(call, args); |
| } |
| |
| return r; |
| } |