arch/x86/kernel/sys_ia32.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * sys_ia32.c: Conversion between 32bit and 64bit native syscalls. Based on
   4  *             sys_sparc32
   5  *
   6  * Copyright (C) 2000           VA Linux Co
   7  * Copyright (C) 2000           Don Dugger <n0ano@valinux.com>
   8  * Copyright (C) 1999           Arun Sharma <arun.sharma@intel.com>
   9  * Copyright (C) 1997,1998      Jakub Jelinek (jj@sunsite.mff.cuni.cz)
  10  * Copyright (C) 1997           David S. Miller (davem@caip.rutgers.edu)
  11  * Copyright (C) 2000           Hewlett-Packard Co.
  12  * Copyright (C) 2000           David Mosberger-Tang <davidm@hpl.hp.com>
  13  * Copyright (C) 2000,2001,2002 Andi Kleen, SuSE Labs (x86-64 port)
  14  *
  15  * These routines maintain argument size conversion between 32bit and 64bit
  16  * environment. In 2.5 most of this should be moved to a generic directory.
  17  *
  18  * This file assumes that there is a hole at the end of user address space.
  19  *
  20  * Some of the functions are LE specific currently. These are
  21  * hopefully all marked.  This should be fixed.
  22  */
  23
  24 #include <linux/kernel.h>
  25 #include <linux/sched.h>
  26 #include <linux/fs.h>
  27 #include <linux/file.h>
  28 #include <linux/signal.h>
  29 #include <linux/syscalls.h>
  30 #include <linux/times.h>
  31 #include <linux/utsname.h>
  32 #include <linux/mm.h>
  33 #include <linux/uio.h>
  34 #include <linux/poll.h>
  35 #include <linux/personality.h>
  36 #include <linux/stat.h>
  37 #include <linux/rwsem.h>
  38 #include <linux/compat.h>
  39 #include <linux/vfs.h>
  40 #include <linux/ptrace.h>
  41 #include <linux/highuid.h>
  42 #include <linux/sysctl.h>
  43 #include <linux/slab.h>
  44 #include <linux/sched/task.h>
  45 #include <asm/mman.h>
  46 #include <asm/types.h>
  47 #include <linux/uaccess.h>
  48 #include <linux/atomic.h>
  49 #include <asm/vgtod.h>
  50 #include <asm/ia32.h>
  51
  52 #define AA(__x)         ((unsigned long)(__x))
  53
  54 SYSCALL_DEFINE3(ia32_truncate64, const char __user *, filename,
  55                 unsigned long, offset_low, unsigned long, offset_high)
  56 {
  57         return ksys_truncate(filename,
  58                             ((loff_t) offset_high << 32) | offset_low);
  59 }
  60
  61 SYSCALL_DEFINE3(ia32_ftruncate64, unsigned int, fd,
  62                 unsigned long, offset_low, unsigned long, offset_high)
  63 {
  64         return ksys_ftruncate(fd, ((loff_t) offset_high << 32) | offset_low);
  65 }
  66
  67 /* warning: next two assume little endian */
  68 SYSCALL_DEFINE5(ia32_pread64, unsigned int, fd, char __user *, ubuf,
  69                 u32, count, u32, poslo, u32, poshi)
  70 {
  71         return ksys_pread64(fd, ubuf, count,
  72                             ((loff_t)AA(poshi) << 32) | AA(poslo));
  73 }
  74
  75 SYSCALL_DEFINE5(ia32_pwrite64, unsigned int, fd, const char __user *, ubuf,
  76                 u32, count, u32, poslo, u32, poshi)
  77 {
  78         return ksys_pwrite64(fd, ubuf, count,
  79                              ((loff_t)AA(poshi) << 32) | AA(poslo));
  80 }
  81
  82
  83 /*
  84  * Some system calls that need sign extended arguments. This could be
  85  * done by a generic wrapper.
  86  */
  87 SYSCALL_DEFINE6(ia32_fadvise64_64, int, fd, __u32, offset_low,
  88                 __u32, offset_high, __u32, len_low, __u32, len_high,
  89                 int, advice)
  90 {
  91         return ksys_fadvise64_64(fd,
  92                                  (((u64)offset_high)<<32) | offset_low,
  93                                  (((u64)len_high)<<32) | len_low,
  94                                  advice);
  95 }
  96
  97 SYSCALL_DEFINE4(ia32_readahead, int, fd, unsigned int, off_lo,
  98                 unsigned int, off_hi, size_t, count)
  99 {
 100         return ksys_readahead(fd, ((u64)off_hi << 32) | off_lo, count);
 101 }
 102
 103 SYSCALL_DEFINE6(ia32_sync_file_range, int, fd, unsigned int, off_low,
 104                 unsigned int, off_hi, unsigned int, n_low,
 105                 unsigned int, n_hi, int, flags)
 106 {
 107         return ksys_sync_file_range(fd,
 108                                     ((u64)off_hi << 32) | off_low,
 109                                     ((u64)n_hi << 32) | n_low, flags);
 110 }
 111
 112 SYSCALL_DEFINE5(ia32_fadvise64, int, fd, unsigned int, offset_lo,
 113                 unsigned int, offset_hi, size_t, len, int, advice)
 114 {
 115         return ksys_fadvise64_64(fd, ((u64)offset_hi << 32) | offset_lo,
 116                                  len, advice);
 117 }
 118
 119 SYSCALL_DEFINE6(ia32_fallocate, int, fd, int, mode,
 120                 unsigned int, offset_lo, unsigned int, offset_hi,
 121                 unsigned int, len_lo, unsigned int, len_hi)
 122 {
 123         return ksys_fallocate(fd, mode, ((u64)offset_hi << 32) | offset_lo,
 124                               ((u64)len_hi << 32) | len_lo);
 125 }
 126
 127 #ifdef CONFIG_IA32_EMULATION
 128 /*
 129  * Another set for IA32/LFS -- x86_64 struct stat is different due to
 130  * support for 64bit inode numbers.
 131  */
 132 static int cp_stat64(struct stat64 __user *ubuf, struct kstat *stat)
 133 {
 134         typeof(ubuf->st_uid) uid = 0;
 135         typeof(ubuf->st_gid) gid = 0;
 136         SET_UID(uid, from_kuid_munged(current_user_ns(), stat->uid));
 137         SET_GID(gid, from_kgid_munged(current_user_ns(), stat->gid));
 138         if (!access_ok(ubuf, sizeof(struct stat64)) ||
 139             __put_user(huge_encode_dev(stat->dev), &ubuf->st_dev) ||
 140             __put_user(stat->ino, &ubuf->__st_ino) ||
 141             __put_user(stat->ino, &ubuf->st_ino) ||
 142             __put_user(stat->mode, &ubuf->st_mode) ||
 143             __put_user(stat->nlink, &ubuf->st_nlink) ||
 144             __put_user(uid, &ubuf->st_uid) ||
 145             __put_user(gid, &ubuf->st_gid) ||
 146             __put_user(huge_encode_dev(stat->rdev), &ubuf->st_rdev) ||
 147             __put_user(stat->size, &ubuf->st_size) ||
 148             __put_user(stat->atime.tv_sec, &ubuf->st_atime) ||
 149             __put_user(stat->atime.tv_nsec, &ubuf->st_atime_nsec) ||
 150             __put_user(stat->mtime.tv_sec, &ubuf->st_mtime) ||
 151             __put_user(stat->mtime.tv_nsec, &ubuf->st_mtime_nsec) ||
 152             __put_user(stat->ctime.tv_sec, &ubuf->st_ctime) ||
 153             __put_user(stat->ctime.tv_nsec, &ubuf->st_ctime_nsec) ||
 154             __put_user(stat->blksize, &ubuf->st_blksize) ||
 155             __put_user(stat->blocks, &ubuf->st_blocks))
 156                 return -EFAULT;
 157         return 0;
 158 }
 159
 160 COMPAT_SYSCALL_DEFINE2(ia32_stat64, const char __user *, filename,
 161                        struct stat64 __user *, statbuf)
 162 {
 163         struct kstat stat;
 164         int ret = vfs_stat(filename, &stat);
 165
 166         if (!ret)
 167                 ret = cp_stat64(statbuf, &stat);
 168         return ret;
 169 }
 170
 171 COMPAT_SYSCALL_DEFINE2(ia32_lstat64, const char __user *, filename,
 172                        struct stat64 __user *, statbuf)
 173 {
 174         struct kstat stat;
 175         int ret = vfs_lstat(filename, &stat);
 176         if (!ret)
 177                 ret = cp_stat64(statbuf, &stat);
 178         return ret;
 179 }
 180
 181 COMPAT_SYSCALL_DEFINE2(ia32_fstat64, unsigned int, fd,
 182                        struct stat64 __user *, statbuf)
 183 {
 184         struct kstat stat;
 185         int ret = vfs_fstat(fd, &stat);
 186         if (!ret)
 187                 ret = cp_stat64(statbuf, &stat);
 188         return ret;
 189 }
 190
 191 COMPAT_SYSCALL_DEFINE4(ia32_fstatat64, unsigned int, dfd,
 192                        const char __user *, filename,
 193                        struct stat64 __user *, statbuf, int, flag)
 194 {
 195         struct kstat stat;
 196         int error;
 197
 198         error = vfs_fstatat(dfd, filename, &stat, flag);
 199         if (error)
 200                 return error;
 201         return cp_stat64(statbuf, &stat);
 202 }
 203
 204 /*
 205  * Linux/i386 didn't use to be able to handle more than
 206  * 4 system call parameters, so these system calls used a memory
 207  * block for parameter passing..
 208  */
 209
 210 struct mmap_arg_struct32 {
 211         unsigned int addr;
 212         unsigned int len;
 213         unsigned int prot;
 214         unsigned int flags;
 215         unsigned int fd;
 216         unsigned int offset;
 217 };
 218
 219 COMPAT_SYSCALL_DEFINE1(ia32_mmap, struct mmap_arg_struct32 __user *, arg)
 220 {
 221         struct mmap_arg_struct32 a;
 222
 223         if (copy_from_user(&a, arg, sizeof(a)))
 224                 return -EFAULT;
 225
 226         if (a.offset & ~PAGE_MASK)
 227                 return -EINVAL;
 228
 229         return ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd,
 230                                a.offset>>PAGE_SHIFT);
 231 }
 232
 233 /*
 234  * The 32-bit clone ABI is CONFIG_CLONE_BACKWARDS
 235  */
 236 COMPAT_SYSCALL_DEFINE5(ia32_clone, unsigned long, clone_flags,
 237                        unsigned long, newsp, int __user *, parent_tidptr,
 238                        unsigned long, tls_val, int __user *, child_tidptr)
 239 {
 240         struct kernel_clone_args args = {
 241                 .flags          = (clone_flags & ~CSIGNAL),
 242                 .pidfd          = parent_tidptr,
 243                 .child_tid      = child_tidptr,
 244                 .parent_tid     = parent_tidptr,
 245                 .exit_signal    = (clone_flags & CSIGNAL),
 246                 .stack          = newsp,
 247                 .tls            = tls_val,
 248         };
 249
 250         if (!legacy_clone_args_valid(&args))
 251                 return -EINVAL;
 252
 253         return _do_fork(&args);
 254 }
 255 #endif /* CONFIG_IA32_EMULATION */