arch/score/kernel/sys_score.c

   1 /*
   2  * arch/score/kernel/syscall.c
   3  *
   4  * Score Processor version.
   5  *
   6  * Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
   7  *  Chen Liqin <liqin.chen@sunplusct.com>
   8  *  Lennox Wu <lennox.wu@sunplusct.com>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, see the file COPYING, or write
  22  * to the Free Software Foundation, Inc.,
  23  * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  24  */
  25
  26 #include <linux/file.h>
  27 #include <linux/fs.h>
  28 #include <linux/mman.h>
  29 #include <linux/module.h>
  30 #include <linux/unistd.h>
  31
  32 unsigned long shm_align_mask = PAGE_SIZE - 1;
  33 EXPORT_SYMBOL(shm_align_mask);
  34
  35 asmlinkage unsigned long
  36 sys_mmap2(unsigned long addr, unsigned long len, unsigned long prot,
  37           unsigned long flags, unsigned long fd, unsigned long pgoff)
  38 {
  39         int error = -EBADF;
  40         struct file *file = NULL;
  41
  42         if (pgoff & (~PAGE_MASK >> 12))
  43                 return -EINVAL;
  44
  45         flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
  46         if (!(flags & MAP_ANONYMOUS)) {
  47                 file = fget(fd);
  48                 if (!file)
  49                         return error;
  50         }
  51
  52         down_write(&current->mm->mmap_sem);
  53         error = do_mmap_pgoff(file, addr, len, prot, flags,
  54                         pgoff >> (PAGE_SHIFT - 12));
  55         up_write(&current->mm->mmap_sem);
  56
  57         if (file)
  58                 fput(file);
  59
  60         return error;
  61 }
  62
  63 /*
  64  * Clone a task - this clones the calling program thread.
  65  * This is called indirectly via a small wrapper
  66  */
  67 asmlinkage int
  68 score_clone(struct pt_regs *regs)
  69 {
  70         unsigned long clone_flags;
  71         unsigned long newsp;
  72         int __user *parent_tidptr, *child_tidptr;
  73
  74         clone_flags = regs->regs[4];
  75         newsp = regs->regs[5];
  76         if (!newsp)
  77                 newsp = regs->regs[0];
  78         parent_tidptr = (int __user *)regs->regs[6];
  79
  80         child_tidptr = NULL;
  81         if (clone_flags & (CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID)) {
  82                 int __user *__user *usp = (int __user *__user *)regs->regs[0];
  83
  84                 if (get_user(child_tidptr, &usp[4]))
  85                         return -EFAULT;
  86         }
  87
  88         return do_fork(clone_flags, newsp, regs, 0,
  89                         parent_tidptr, child_tidptr);
  90 }
  91
  92 /*
  93  * sys_execve() executes a new program.
  94  * This is called indirectly via a small wrapper
  95  */
  96 asmlinkage int score_execve(struct pt_regs *regs)
  97 {
  98         int error;
  99         char *filename;
 100
 101         filename = getname((char *) (long) regs->regs[4]);
 102         error = PTR_ERR(filename);
 103         if (IS_ERR(filename))
 104                 return error;
 105
 106         error = do_execve(filename, (char **) (long) regs->regs[5],
 107                           (char **) (long) regs->regs[6], regs);
 108
 109         putname(filename);
 110         return error;
 111 }
 112
 113 /*
 114  * If we ever come here the user sp is bad.  Zap the process right away.
 115  * Due to the bad stack signaling wouldn't work.
 116  */
 117 asmlinkage void bad_stack(void)
 118 {
 119         do_exit(SIGSEGV);
 120 }
 121
 122 /*
 123  * Do a system call from kernel instead of calling sys_execve so we
 124  * end up with proper pt_regs.
 125  */
 126 int kernel_execve(const char *filename, char *const argv[], char *const envp[])
 127 {
 128         register unsigned long __r4 asm("r4") = (unsigned long) filename;
 129         register unsigned long __r5 asm("r5") = (unsigned long) argv;
 130         register unsigned long __r6 asm("r6") = (unsigned long) envp;
 131         register unsigned long __r7 asm("r7");
 132
 133         __asm__ __volatile__ (" \n"
 134                 "ldi    r27, %5         \n"
 135                 "syscall                \n"
 136                 "mv     %0, r4          \n"
 137                 "mv     %1, r7          \n"
 138                 : "=&r" (__r4), "=r" (__r7)
 139                 : "r" (__r4), "r" (__r5), "r" (__r6), "i" (__NR_execve)
 140                 : "r8", "r9", "r10", "r11", "r22", "r23", "r24", "r25",
 141                   "r26", "r27", "memory");
 142
 143         if (__r7 == 0)
 144                 return __r4;
 145
 146         return -__r4;
 147 }