x86/kernel/sys_ia32.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * sys_ia32.c: Conversion between 32bit and 64bit native syscalls. Based on
0004  *             sys_sparc32
0005  *
0006  * Copyright (C) 2000       VA Linux Co
0007  * Copyright (C) 2000       Don Dugger <n0ano@valinux.com>
0008  * Copyright (C) 1999       Arun Sharma <arun.sharma@intel.com>
0009  * Copyright (C) 1997,1998  Jakub Jelinek (jj@sunsite.mff.cuni.cz)
0010  * Copyright (C) 1997       David S. Miller (davem@caip.rutgers.edu)
0011  * Copyright (C) 2000       Hewlett-Packard Co.
0012  * Copyright (C) 2000       David Mosberger-Tang <davidm@hpl.hp.com>
0013  * Copyright (C) 2000,2001,2002 Andi Kleen, SuSE Labs (x86-64 port)
0014  *
0015  * These routines maintain argument size conversion between 32bit and 64bit
0016  * environment. In 2.5 most of this should be moved to a generic directory.
0017  *
0018  * This file assumes that there is a hole at the end of user address space.
0019  *
0020  * Some of the functions are LE specific currently. These are
0021  * hopefully all marked.  This should be fixed.
0022  */
0023
0024 #include <linux/kernel.h>
0025 #include <linux/sched.h>
0026 #include <linux/fs.h>
0027 #include <linux/file.h>
0028 #include <linux/signal.h>
0029 #include <linux/syscalls.h>
0030 #include <linux/times.h>
0031 #include <linux/utsname.h>
0032 #include <linux/mm.h>
0033 #include <linux/uio.h>
0034 #include <linux/poll.h>
0035 #include <linux/personality.h>
0036 #include <linux/stat.h>
0037 #include <linux/rwsem.h>
0038 #include <linux/compat.h>
0039 #include <linux/vfs.h>
0040 #include <linux/ptrace.h>
0041 #include <linux/highuid.h>
0042 #include <linux/sysctl.h>
0043 #include <linux/slab.h>
0044 #include <linux/sched/task.h>
0045 #include <asm/mman.h>
0046 #include <asm/types.h>
0047 #include <linux/uaccess.h>
0048 #include <linux/atomic.h>
0049 #include <asm/vgtod.h>
0050 #include <asm/ia32.h>
0051
0052 #define AA(__x)     ((unsigned long)(__x))
0053
0054 SYSCALL_DEFINE3(ia32_truncate64, const char __user *, filename,
0055         unsigned long, offset_low, unsigned long, offset_high)
0056 {
0057     return ksys_truncate(filename,
0058                 ((loff_t) offset_high << 32) | offset_low);
0059 }
0060
0061 SYSCALL_DEFINE3(ia32_ftruncate64, unsigned int, fd,
0062         unsigned long, offset_low, unsigned long, offset_high)
0063 {
0064     return ksys_ftruncate(fd, ((loff_t) offset_high << 32) | offset_low);
0065 }
0066
0067 /* warning: next two assume little endian */
0068 SYSCALL_DEFINE5(ia32_pread64, unsigned int, fd, char __user *, ubuf,
0069         u32, count, u32, poslo, u32, poshi)
0070 {
0071     return ksys_pread64(fd, ubuf, count,
0072                 ((loff_t)AA(poshi) << 32) | AA(poslo));
0073 }
0074
0075 SYSCALL_DEFINE5(ia32_pwrite64, unsigned int, fd, const char __user *, ubuf,
0076         u32, count, u32, poslo, u32, poshi)
0077 {
0078     return ksys_pwrite64(fd, ubuf, count,
0079                  ((loff_t)AA(poshi) << 32) | AA(poslo));
0080 }
0081
0082
0083 /*
0084  * Some system calls that need sign extended arguments. This could be
0085  * done by a generic wrapper.
0086  */
0087 SYSCALL_DEFINE6(ia32_fadvise64_64, int, fd, __u32, offset_low,
0088         __u32, offset_high, __u32, len_low, __u32, len_high,
0089         int, advice)
0090 {
0091     return ksys_fadvise64_64(fd,
0092                  (((u64)offset_high)<<32) | offset_low,
0093                  (((u64)len_high)<<32) | len_low,
0094                  advice);
0095 }
0096
0097 SYSCALL_DEFINE4(ia32_readahead, int, fd, unsigned int, off_lo,
0098         unsigned int, off_hi, size_t, count)
0099 {
0100     return ksys_readahead(fd, ((u64)off_hi << 32) | off_lo, count);
0101 }
0102
0103 SYSCALL_DEFINE6(ia32_sync_file_range, int, fd, unsigned int, off_low,
0104         unsigned int, off_hi, unsigned int, n_low,
0105         unsigned int, n_hi, int, flags)
0106 {
0107     return ksys_sync_file_range(fd,
0108                     ((u64)off_hi << 32) | off_low,
0109                     ((u64)n_hi << 32) | n_low, flags);
0110 }
0111
0112 SYSCALL_DEFINE5(ia32_fadvise64, int, fd, unsigned int, offset_lo,
0113         unsigned int, offset_hi, size_t, len, int, advice)
0114 {
0115     return ksys_fadvise64_64(fd, ((u64)offset_hi << 32) | offset_lo,
0116                  len, advice);
0117 }
0118
0119 SYSCALL_DEFINE6(ia32_fallocate, int, fd, int, mode,
0120         unsigned int, offset_lo, unsigned int, offset_hi,
0121         unsigned int, len_lo, unsigned int, len_hi)
0122 {
0123     return ksys_fallocate(fd, mode, ((u64)offset_hi << 32) | offset_lo,
0124                   ((u64)len_hi << 32) | len_lo);
0125 }
0126
0127 #ifdef CONFIG_IA32_EMULATION
0128 /*
0129  * Another set for IA32/LFS -- x86_64 struct stat is different due to
0130  * support for 64bit inode numbers.
0131  */
0132 static int cp_stat64(struct stat64 __user *ubuf, struct kstat *stat)
0133 {
0134     typeof(ubuf->st_uid) uid = 0;
0135     typeof(ubuf->st_gid) gid = 0;
0136     SET_UID(uid, from_kuid_munged(current_user_ns(), stat->uid));
0137     SET_GID(gid, from_kgid_munged(current_user_ns(), stat->gid));
0138     if (!user_write_access_begin(ubuf, sizeof(struct stat64)))
0139         return -EFAULT;
0140     unsafe_put_user(huge_encode_dev(stat->dev), &ubuf->st_dev, Efault);
0141     unsafe_put_user(stat->ino, &ubuf->__st_ino, Efault);
0142     unsafe_put_user(stat->ino, &ubuf->st_ino, Efault);
0143     unsafe_put_user(stat->mode, &ubuf->st_mode, Efault);
0144     unsafe_put_user(stat->nlink, &ubuf->st_nlink, Efault);
0145     unsafe_put_user(uid, &ubuf->st_uid, Efault);
0146     unsafe_put_user(gid, &ubuf->st_gid, Efault);
0147     unsafe_put_user(huge_encode_dev(stat->rdev), &ubuf->st_rdev, Efault);
0148     unsafe_put_user(stat->size, &ubuf->st_size, Efault);
0149     unsafe_put_user(stat->atime.tv_sec, &ubuf->st_atime, Efault);
0150     unsafe_put_user(stat->atime.tv_nsec, &ubuf->st_atime_nsec, Efault);
0151     unsafe_put_user(stat->mtime.tv_sec, &ubuf->st_mtime, Efault);
0152     unsafe_put_user(stat->mtime.tv_nsec, &ubuf->st_mtime_nsec, Efault);
0153     unsafe_put_user(stat->ctime.tv_sec, &ubuf->st_ctime, Efault);
0154     unsafe_put_user(stat->ctime.tv_nsec, &ubuf->st_ctime_nsec, Efault);
0155     unsafe_put_user(stat->blksize, &ubuf->st_blksize, Efault);
0156     unsafe_put_user(stat->blocks, &ubuf->st_blocks, Efault);
0157     user_access_end();
0158     return 0;
0159 Efault:
0160     user_write_access_end();
0161     return -EFAULT;
0162 }
0163
0164 COMPAT_SYSCALL_DEFINE2(ia32_stat64, const char __user *, filename,
0165                struct stat64 __user *, statbuf)
0166 {
0167     struct kstat stat;
0168     int ret = vfs_stat(filename, &stat);
0169
0170     if (!ret)
0171         ret = cp_stat64(statbuf, &stat);
0172     return ret;
0173 }
0174
0175 COMPAT_SYSCALL_DEFINE2(ia32_lstat64, const char __user *, filename,
0176                struct stat64 __user *, statbuf)
0177 {
0178     struct kstat stat;
0179     int ret = vfs_lstat(filename, &stat);
0180     if (!ret)
0181         ret = cp_stat64(statbuf, &stat);
0182     return ret;
0183 }
0184
0185 COMPAT_SYSCALL_DEFINE2(ia32_fstat64, unsigned int, fd,
0186                struct stat64 __user *, statbuf)
0187 {
0188     struct kstat stat;
0189     int ret = vfs_fstat(fd, &stat);
0190     if (!ret)
0191         ret = cp_stat64(statbuf, &stat);
0192     return ret;
0193 }
0194
0195 COMPAT_SYSCALL_DEFINE4(ia32_fstatat64, unsigned int, dfd,
0196                const char __user *, filename,
0197                struct stat64 __user *, statbuf, int, flag)
0198 {
0199     struct kstat stat;
0200     int error;
0201
0202     error = vfs_fstatat(dfd, filename, &stat, flag);
0203     if (error)
0204         return error;
0205     return cp_stat64(statbuf, &stat);
0206 }
0207
0208 /*
0209  * Linux/i386 didn't use to be able to handle more than
0210  * 4 system call parameters, so these system calls used a memory
0211  * block for parameter passing..
0212  */
0213
0214 struct mmap_arg_struct32 {
0215     unsigned int addr;
0216     unsigned int len;
0217     unsigned int prot;
0218     unsigned int flags;
0219     unsigned int fd;
0220     unsigned int offset;
0221 };
0222
0223 COMPAT_SYSCALL_DEFINE1(ia32_mmap, struct mmap_arg_struct32 __user *, arg)
0224 {
0225     struct mmap_arg_struct32 a;
0226
0227     if (copy_from_user(&a, arg, sizeof(a)))
0228         return -EFAULT;
0229
0230     if (a.offset & ~PAGE_MASK)
0231         return -EINVAL;
0232
0233     return ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd,
0234                    a.offset>>PAGE_SHIFT);
0235 }
0236
0237 /*
0238  * The 32-bit clone ABI is CONFIG_CLONE_BACKWARDS
0239  */
0240 COMPAT_SYSCALL_DEFINE5(ia32_clone, unsigned long, clone_flags,
0241                unsigned long, newsp, int __user *, parent_tidptr,
0242                unsigned long, tls_val, int __user *, child_tidptr)
0243 {
0244     struct kernel_clone_args args = {
0245         .flags      = (clone_flags & ~CSIGNAL),
0246         .pidfd      = parent_tidptr,
0247         .child_tid  = child_tidptr,
0248         .parent_tid = parent_tidptr,
0249         .exit_signal    = (clone_flags & CSIGNAL),
0250         .stack      = newsp,
0251         .tls        = tls_val,
0252     };
0253
0254     return kernel_clone(&args);
0255 }
0256 #endif /* CONFIG_IA32_EMULATION */