Linux Kernel  3.7.1
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syscall.c
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1 /*
2  * Hexagon system calls
3  *
4  * Copyright (c) 2010-2011, The Linux Foundation. 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 }