arch/unicore32/kernel/sys.c

   1 /*
   2  * linux/arch/unicore32/kernel/sys.c
   3  *
   4  * Code specific to PKUnity SoC and UniCore ISA
   5  *
   6  * Copyright (C) 2001-2010 GUAN Xue-tao
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12 #include <linux/module.h>
  13 #include <linux/errno.h>
  14 #include <linux/sched.h>
  15 #include <linux/slab.h>
  16 #include <linux/mm.h>
  17 #include <linux/sem.h>
  18 #include <linux/msg.h>
  19 #include <linux/shm.h>
  20 #include <linux/stat.h>
  21 #include <linux/syscalls.h>
  22 #include <linux/mman.h>
  23 #include <linux/fs.h>
  24 #include <linux/file.h>
  25 #include <linux/ipc.h>
  26 #include <linux/uaccess.h>
  27
  28 #include <asm/syscalls.h>
  29 #include <asm/cacheflush.h>
  30
  31 /* Clone a task - this clones the calling program thread.
  32  * This is called indirectly via a small wrapper
  33  */
  34 asmlinkage long __sys_clone(unsigned long clone_flags, unsigned long newsp,
  35                          void __user *parent_tid, void __user *child_tid,
  36                          struct pt_regs *regs)
  37 {
  38         if (!newsp)
  39                 newsp = regs->UCreg_sp;
  40
  41         return do_fork(clone_flags, newsp, regs, 0,
  42                         parent_tid, child_tid);
  43 }
  44
  45 /* sys_execve() executes a new program.
  46  * This is called indirectly via a small wrapper
  47  */
  48 asmlinkage long __sys_execve(const char __user *filename,
  49                           const char __user *const __user *argv,
  50                           const char __user *const __user *envp,
  51                           struct pt_regs *regs)
  52 {
  53         int error;
  54         char *fn;
  55
  56         fn = getname(filename);
  57         error = PTR_ERR(fn);
  58         if (IS_ERR(fn))
  59                 goto out;
  60         error = do_execve(fn, argv, envp, regs);
  61         putname(fn);
  62 out:
  63         return error;
  64 }
  65
  66 int kernel_execve(const char *filename,
  67                   const char *const argv[],
  68                   const char *const envp[])
  69 {
  70         struct pt_regs regs;
  71         int ret;
  72
  73         memset(&regs, 0, sizeof(struct pt_regs));
  74         ret = do_execve(filename,
  75                         (const char __user *const __user *)argv,
  76                         (const char __user *const __user *)envp, &regs);
  77         if (ret < 0)
  78                 goto out;
  79
  80         /*
  81          * Save argc to the register structure for userspace.
  82          */
  83         regs.UCreg_00 = ret;
  84
  85         /*
  86          * We were successful.  We won't be returning to our caller, but
  87          * instead to user space by manipulating the kernel stack.
  88          */
  89         asm("add        r0, %0, %1\n\t"
  90                 "mov    r1, %2\n\t"
  91                 "mov    r2, %3\n\t"
  92                 "mov    r22, #0\n\t"    /* not a syscall */
  93                 "mov    r23, %0\n\t"    /* thread structure */
  94                 "b.l    memmove\n\t"    /* copy regs to top of stack */
  95                 "mov    sp, r0\n\t"     /* reposition stack pointer */
  96                 "b      ret_to_user"
  97                 :
  98                 : "r" (current_thread_info()),
  99                   "Ir" (THREAD_START_SP - sizeof(regs)),
 100                   "r" (&regs),
 101                   "Ir" (sizeof(regs))
 102                 : "r0", "r1", "r2", "r3", "ip", "lr", "memory");
 103
 104  out:
 105         return ret;
 106 }
 107 EXPORT_SYMBOL(kernel_execve);
 108
 109 /* Note: used by the compat code even in 64-bit Linux. */
 110 SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
 111                 unsigned long, prot, unsigned long, flags,
 112                 unsigned long, fd, unsigned long, off_4k)
 113 {
 114         return sys_mmap_pgoff(addr, len, prot, flags, fd,
 115                               off_4k);
 116 }
 117
 118 /* Provide the actual syscall number to call mapping. */
 119 #undef __SYSCALL
 120 #define __SYSCALL(nr, call)     [nr] = (call),
 121
 122 /* Note that we don't include <linux/unistd.h> but <asm/unistd.h> */
 123 void *sys_call_table[__NR_syscalls] = {
 124         [0 ... __NR_syscalls-1] = sys_ni_syscall,
 125 #include <asm/unistd.h>
 126 };