arch/hexagon/kernel/syscall.c

   1 /*
   2  * Hexagon system calls
   3  *
   4  * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 and
   8  * only version 2 as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  18  * 02110-1301, USA.
  19  */
  20
  21 #include <linux/file.h>
  22 #include <linux/fs.h>
  23 #include <linux/linkage.h>
  24 #include <linux/mm.h>
  25 #include <linux/module.h>
  26 #include <linux/sched.h>
  27 #include <linux/slab.h>
  28 #include <linux/syscalls.h>
  29 #include <linux/unistd.h>
  30 #include <asm/mman.h>
  31 #include <asm/registers.h>
  32
  33 /*
  34  * System calls with architecture-specific wrappers.
  35  * See signal.c for signal-related system call wrappers.
  36  */
  37
  38 asmlinkage int sys_execve(char __user *ufilename,
  39                           const char __user *const __user *argv,
  40                           const char __user *const __user *envp)
  41 {
  42         struct pt_regs *pregs = current_thread_info()->regs;
  43         struct filename *filename;
  44         int retval;
  45
  46         filename = getname(ufilename);
  47         retval = PTR_ERR(filename);
  48         if (IS_ERR(filename))
  49                 return retval;
  50
  51         retval = do_execve(filename->name, argv, envp, pregs);
  52         putname(filename);
  53
  54         return retval;
  55 }
  56
  57 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
  58                          unsigned long parent_tidp, unsigned long child_tidp)
  59 {
  60         struct pt_regs *pregs = current_thread_info()->regs;
  61
  62         if (!newsp)
  63                 newsp = pregs->SP;
  64         return do_fork(clone_flags, newsp, pregs, 0, (int __user *)parent_tidp,
  65                        (int __user *)child_tidp);
  66 }
  67
  68 /*
  69  * Do a system call from the kernel, so as to have a proper pt_regs
  70  * and recycle the sys_execvpe infrustructure.
  71  */
  72 int kernel_execve(const char *filename,
  73                   const char *const argv[], const char *const envp[])
  74 {
  75         register unsigned long __a0 asm("r0") = (unsigned long) filename;
  76         register unsigned long __a1 asm("r1") = (unsigned long) argv;
  77         register unsigned long __a2 asm("r2") = (unsigned long) envp;
  78         int retval;
  79
  80         __asm__ volatile(
  81                 "       R6 = #%4;\n"
  82                 "       trap0(#1);\n"
  83                 "       %0 = R0;\n"
  84                 : "=r" (retval)
  85                 : "r" (__a0), "r" (__a1), "r" (__a2), "i" (__NR_execve)
  86         );
  87
  88         return retval;
  89 }