/* * 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. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ /* * 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/fcntl.h> #include <linux/eventpoll.h> #include <linux/sem.h> #include <linux/socket.h> #include <linux/net.h> #include <linux/ipc.h> #include <asm/uaccess.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 = stat->uid; tmp.st_gid = 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(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(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, char __user *filename, struct oldabi_stat64 __user *statbuf, int flag) { struct kstat stat; int error = -EINVAL; if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) goto out; if (flag & AT_SYMLINK_NOFOLLOW) error = vfs_lstat_fd(dfd, filename, &stat); else error = vfs_stat_fd(dfd, filename, &stat); if (!error) error = cp_oldabi_stat64(&stat, statbuf); out: return error; } 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))); asmlinkage long sys_oabi_fcntl64(unsigned int fd, unsigned int cmd, unsigned long arg) { struct oabi_flock64 user; struct flock64 kernel; mm_segment_t fs = USER_DS; /* initialized to kill a warning */ unsigned long local_arg = arg; int ret; switch (cmd) { case F_GETLK64: case F_SETLK64: case F_SETLKW64: 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; local_arg = (unsigned long)&kernel; fs = get_fs(); set_fs(KERNEL_DS); } ret = sys_fcntl64(fd, cmd, local_arg); switch (cmd) { case F_GETLK64: if (!ret) { 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))) ret = -EFAULT; } case F_SETLK64: case F_SETLKW64: set_fs(fs); } return ret; } struct oabi_epoll_event { __u32 events; __u64 data; } __attribute__ ((packed,aligned(4))); 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; mm_segment_t fs; long ret; if (op == EPOLL_CTL_DEL) return sys_epoll_ctl(epfd, op, fd, NULL); if (copy_from_user(&user, event, sizeof(user))) return -EFAULT; kernel.events = user.events; kernel.data = user.data; fs = get_fs(); set_fs(KERNEL_DS); ret = sys_epoll_ctl(epfd, op, fd, &kernel); set_fs(fs); return ret; } asmlinkage long sys_oabi_epoll_wait(int epfd, struct oabi_epoll_event __user *events, int maxevents, int timeout) { struct epoll_event *kbuf; mm_segment_t fs; long ret, err, i; if (maxevents <= 0 || maxevents > (INT_MAX/sizeof(struct epoll_event))) return -EINVAL; kbuf = kmalloc(sizeof(*kbuf) * maxevents, GFP_KERNEL); if (!kbuf) return -ENOMEM; fs = get_fs(); set_fs(KERNEL_DS); ret = sys_epoll_wait(epfd, kbuf, maxevents, timeout); set_fs(fs); err = 0; for (i = 0; i < ret; i++) { __put_user_error(kbuf[i].events, &events->events, err); __put_user_error(kbuf[i].data, &events->data, err); events++; } kfree(kbuf); return err ? -EFAULT : ret; } struct oabi_sembuf { unsigned short sem_num; short sem_op; short sem_flg; unsigned short __pad; }; asmlinkage long sys_oabi_semtimedop(int semid, struct oabi_sembuf __user *tsops, unsigned nsops, const struct timespec __user *timeout) { struct sembuf *sops; struct timespec local_timeout; long err; int i; if (nsops < 1) return -EINVAL; sops = kmalloc(sizeof(*sops) * nsops, GFP_KERNEL); if (!sops) return -ENOMEM; err = 0; for (i = 0; i < nsops; i++) { __get_user_error(sops[i].sem_num, &tsops->sem_num, err); __get_user_error(sops[i].sem_op, &tsops->sem_op, err); __get_user_error(sops[i].sem_flg, &tsops->sem_flg, err); tsops++; } if (timeout) { /* copy this as well before changing domain protection */ err |= copy_from_user(&local_timeout, timeout, sizeof(*timeout)); timeout = &local_timeout; } if (err) { err = -EFAULT; } else { mm_segment_t fs = get_fs(); set_fs(KERNEL_DS); err = sys_semtimedop(semid, sops, nsops, timeout); set_fs(fs); } kfree(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); } extern asmlinkage int sys_ipc(uint call, int first, int second, int third, void __user *ptr, long fifth); 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 timespec __user *)fifth); default: return sys_ipc(call, first, second, third, ptr, fifth); } } 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 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 msghdr __user *)a[1], a[2]); break; default: r = sys_socketcall(call, args); } return r; }