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-rw-r--r--arch/arm/kernel/sys_oabi-compat.c477
1 files changed, 477 insertions, 0 deletions
diff --git a/arch/arm/kernel/sys_oabi-compat.c b/arch/arm/kernel/sys_oabi-compat.c
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+++ b/arch/arm/kernel/sys_oabi-compat.c
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+// 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)));
+
+#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);
+}
+
+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;
+}
+#else
+asmlinkage long sys_oabi_epoll_ctl(int epfd, int op, int fd,
+ struct oabi_epoll_event __user *event)
+{
+ return -EINVAL;
+}
+
+asmlinkage long sys_oabi_epoll_wait(int epfd,
+ struct oabi_epoll_event __user *events,
+ int maxevents, int timeout)
+{
+ return -EINVAL;
+}
+#endif
+
+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;
+}
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