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
  39 static long do_mmap2(unsigned long addr, size_t len,
  40                      unsigned long prot, unsigned long flags,
  41                      unsigned long fd, unsigned long off, int shift)
  42 {
  43         if (!arch_validate_prot(prot, addr))
  44                 return -EINVAL;
  45
  46         if (!IS_ALIGNED(off, 1 << shift))
  47                 return -EINVAL;
  48
  49         return ksys_mmap_pgoff(addr, len, prot, flags, fd, off >> shift);
  50 }
  51
  52 SYSCALL_DEFINE6(mmap2, unsigned long, addr, size_t, len,
  53                 unsigned long, prot, unsigned long, flags,
  54                 unsigned long, fd, unsigned long, pgoff)
  55 {
  56         return do_mmap2(addr, len, prot, flags, fd, pgoff, PAGE_SHIFT-12);
  57 }
  58
  59 #ifdef CONFIG_COMPAT
  60 COMPAT_SYSCALL_DEFINE6(mmap2,
  61                        unsigned long, addr, size_t, len,
  62                        unsigned long, prot, unsigned long, flags,
  63                        unsigned long, fd, unsigned long, off_4k)
  64 {
  65         return do_mmap2(addr, len, prot, flags, fd, off_4k, PAGE_SHIFT-12);
  66 }
  67 #endif
  68
  69 SYSCALL_DEFINE6(mmap, unsigned long, addr, size_t, len,
  70                 unsigned long, prot, unsigned long, flags,
  71                 unsigned long, fd, off_t, offset)
  72 {
  73         return do_mmap2(addr, len, prot, flags, fd, offset, PAGE_SHIFT);
  74 }
  75
  76 #ifdef CONFIG_PPC64
  77 static long do_ppc64_personality(unsigned long personality)
  78 {
  79         long ret;
  80
  81         if (personality(current->personality) == PER_LINUX32
  82             && personality(personality) == PER_LINUX)
  83                 personality = (personality & ~PER_MASK) | PER_LINUX32;
  84         ret = ksys_personality(personality);
  85         if (personality(ret) == PER_LINUX32)
  86                 ret = (ret & ~PER_MASK) | PER_LINUX;
  87         return ret;
  88 }
  89
  90 SYSCALL_DEFINE1(ppc64_personality, unsigned long, personality)
  91 {
  92         return do_ppc64_personality(personality);
  93 }
  94
  95 #ifdef CONFIG_COMPAT
  96 COMPAT_SYSCALL_DEFINE1(ppc64_personality, unsigned long, personality)
  97 {
  98         return do_ppc64_personality(personality);
  99 }
 100 #endif /* CONFIG_COMPAT */
 101 #endif /* CONFIG_PPC64 */
 102
 103 SYSCALL_DEFINE6(ppc_fadvise64_64,
 104                 int, fd, int, advice, u32, offset_high, u32, offset_low,
 105                 u32, len_high, u32, len_low)
 106 {
 107         return ksys_fadvise64_64(fd, merge_64(offset_high, offset_low),
 108                                  merge_64(len_high, len_low), advice);
 109 }
 110
 111 SYSCALL_DEFINE0(switch_endian)
 112 {
 113         struct thread_info *ti;
 114
 115         regs_set_return_msr(current->thread.regs,
 116                                 current->thread.regs->msr ^ MSR_LE);
 117
 118         /*
 119          * Set TIF_RESTOREALL so that r3 isn't clobbered on return to
 120          * userspace. That also has the effect of restoring the non-volatile
 121          * GPRs, so we saved them on the way in here.
 122          */
 123         ti = current_thread_info();
 124         ti->flags |= _TIF_RESTOREALL;
 125
 126         return 0;
 127 }