/arch/arm/kernel/sys_oabi-compat.c
C | 467 lines | 346 code | 41 blank | 80 comment | 56 complexity | d83542f4c95422872fd3befae9c740f2 MD5 | raw file
Possible License(s): LGPL-2.0, AGPL-1.0, GPL-2.0
- // 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/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/uaccess.h>
- #include <linux/slab.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 long do_locks(unsigned int fd, unsigned int cmd,
- unsigned long arg)
- {
- struct flock64 kernel;
- struct oabi_flock64 user;
- mm_segment_t fs;
- long ret;
- 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;
- fs = get_fs();
- set_fs(KERNEL_DS);
- ret = sys_fcntl64(fd, cmd, (unsigned long)&kernel);
- set_fs(fs);
- if (!ret && (cmd == F_GETLK64 || cmd == F_OFD_GETLK)) {
- 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;
- }
- return ret;
- }
- asmlinkage long sys_oabi_fcntl64(unsigned int fd, unsigned int cmd,
- unsigned long arg)
- {
- switch (cmd) {
- case F_OFD_GETLK:
- case F_OFD_SETLK:
- case F_OFD_SETLKW:
- case F_GETLK64:
- case F_SETLK64:
- case F_SETLKW64:
- return do_locks(fd, cmd, arg);
- default:
- return sys_fcntl64(fd, cmd, arg);
- }
- }
- 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;
- struct oabi_epoll_event e;
- mm_segment_t fs;
- long ret, err, i;
- if (maxevents <= 0 ||
- maxevents > (INT_MAX/sizeof(*kbuf)) ||
- maxevents > (INT_MAX/sizeof(*events)))
- return -EINVAL;
- if (!access_ok(events, sizeof(*events) * maxevents))
- return -EFAULT;
- kbuf = kmalloc_array(maxevents, sizeof(*kbuf), 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++) {
- e.events = kbuf[i].events;
- e.data = kbuf[i].data;
- err = __copy_to_user(events, &e, sizeof(e));
- if (err)
- break;
- 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 old_timespec32 __user *timeout)
- {
- struct sembuf *sops;
- struct old_timespec32 local_timeout;
- long err;
- int i;
- if (nsops < 1 || nsops > SEMOPM)
- return -EINVAL;
- if (!access_ok(tsops, sizeof(*tsops) * nsops))
- return -EFAULT;
- sops = kmalloc_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 (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_time32(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);
- }
- 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);
- }
- }
- 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;
- }