arch/powerpc/kernel/syscalls.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Implementation of various system calls for Linux/PowerPC
   4  *
   5  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   6  *
   7  * Derived from "arch/i386/kernel/sys_i386.c"
   8  * Adapted from the i386 version by Gary Thomas
   9  * Modified by Cort Dougan (cort@cs.nmt.edu)
  10  * and Paul Mackerras (paulus@cs.anu.edu.au).
  11  *
  12  * This file contains various random system calls that
  13  * have a non-standard calling sequence on the Linux/PPC
  14  * platform.
  15  */
  16
  17 #include <linux/errno.h>
  18 #include <linux/sched.h>
  19 #include <linux/syscalls.h>
  20 #include <linux/mm.h>
  21 #include <linux/fs.h>
  22 #include <linux/smp.h>
  23 #include <linux/sem.h>
  24 #include <linux/msg.h>
  25 #include <linux/shm.h>
  26 #include <linux/stat.h>
  27 #include <linux/mman.h>
  28 #include <linux/sys.h>
  29 #include <linux/ipc.h>
  30 #include <linux/utsname.h>
  31 #include <linux/file.h>
  32 #include <linux/personality.h>
  33
  34 #include <linux/uaccess.h>
  35 #include <asm/syscalls.h>
  36 #include <asm/time.h>
  37 #include <asm/unistd.h>
  38 #include <asm/asm-prototypes.h>
  39
  40 static inline long do_mmap2(unsigned long addr, size_t len,
  41                         unsigned long prot, unsigned long flags,
  42                         unsigned long fd, unsigned long off, int shift)
  43 {
  44         long ret = -EINVAL;
  45
  46         if (!arch_validate_prot(prot, addr))
  47                 goto out;
  48
  49         if (shift) {
  50                 if (off & ((1 << shift) - 1))
  51                         goto out;
  52                 off >>= shift;
  53         }
  54
  55         ret = ksys_mmap_pgoff(addr, len, prot, flags, fd, off);
  56 out:
  57         return ret;
  58 }
  59
  60 SYSCALL_DEFINE6(mmap2, unsigned long, addr, size_t, len,
  61                 unsigned long, prot, unsigned long, flags,
  62                 unsigned long, fd, unsigned long, pgoff)
  63 {
  64         return do_mmap2(addr, len, prot, flags, fd, pgoff, PAGE_SHIFT-12);
  65 }
  66
  67 SYSCALL_DEFINE6(mmap, unsigned long, addr, size_t, len,
  68                 unsigned long, prot, unsigned long, flags,
  69                 unsigned long, fd, off_t, offset)
  70 {
  71         return do_mmap2(addr, len, prot, flags, fd, offset, PAGE_SHIFT);
  72 }
  73
  74 #ifdef CONFIG_PPC32
  75 /*
  76  * Due to some executables calling the wrong select we sometimes
  77  * get wrong args.  This determines how the args are being passed
  78  * (a single ptr to them all args passed) then calls
  79  * sys_select() with the appropriate args. -- Cort
  80  */
  81 int
  82 ppc_select(int n, fd_set __user *inp, fd_set __user *outp, fd_set __user *exp, struct __kernel_old_timeval __user *tvp)
  83 {
  84         if ( (unsigned long)n >= 4096 )
  85         {
  86                 unsigned long __user *buffer = (unsigned long __user *)n;
  87                 if (!access_ok(buffer, 5*sizeof(unsigned long))
  88                     || __get_user(n, buffer)
  89                     || __get_user(inp, ((fd_set __user * __user *)(buffer+1)))
  90                     || __get_user(outp, ((fd_set  __user * __user *)(buffer+2)))
  91                     || __get_user(exp, ((fd_set  __user * __user *)(buffer+3)))
  92                     || __get_user(tvp, ((struct __kernel_old_timeval  __user * __user *)(buffer+4))))
  93                         return -EFAULT;
  94         }
  95         return sys_select(n, inp, outp, exp, tvp);
  96 }
  97 #endif
  98
  99 #ifdef CONFIG_PPC64
 100 long ppc64_personality(unsigned long personality)
 101 {
 102         long ret;
 103
 104         if (personality(current->personality) == PER_LINUX32
 105             && personality(personality) == PER_LINUX)
 106                 personality = (personality & ~PER_MASK) | PER_LINUX32;
 107         ret = sys_personality(personality);
 108         if (personality(ret) == PER_LINUX32)
 109                 ret = (ret & ~PER_MASK) | PER_LINUX;
 110         return ret;
 111 }
 112 #endif
 113
 114 long ppc_fadvise64_64(int fd, int advice, u32 offset_high, u32 offset_low,
 115                       u32 len_high, u32 len_low)
 116 {
 117         return ksys_fadvise64_64(fd, (u64)offset_high << 32 | offset_low,
 118                                  (u64)len_high << 32 | len_low, advice);
 119 }
 120
 121 SYSCALL_DEFINE0(switch_endian)
 122 {
 123         struct thread_info *ti;
 124
 125         current->thread.regs->msr ^= MSR_LE;
 126
 127         /*
 128          * Set TIF_RESTOREALL so that r3 isn't clobbered on return to
 129          * userspace. That also has the effect of restoring the non-volatile
 130          * GPRs, so we saved them on the way in here.
 131          */
 132         ti = current_thread_info();
 133         ti->flags |= _TIF_RESTOREALL;
 134
 135         return 0;
 136 }