/*
* arch/xtensa/kernel/syscalls.c
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2001 - 2005 Tensilica Inc.
* Copyright (C) 2000 Silicon Graphics, Inc.
* Copyright (C) 1995 - 2000 by Ralf Baechle
*
* Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
* Marc Gauthier <marc@tensilica.com, marc@alumni.uwaterloo.ca>
* Chris Zankel <chris@zankel.net>
* Kevin Chea
*
*/
#define DEBUG 0
#include <linux/linkage.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/mman.h>
#include <linux/sched.h>
#include <linux/file.h>
#include <linux/slab.h>
#include <linux/utsname.h>
#include <linux/unistd.h>
#include <linux/stringify.h>
#include <linux/syscalls.h>
#include <linux/sem.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/errno.h>
#include <asm/ptrace.h>
#include <asm/signal.h>
#include <asm/uaccess.h>
#include <asm/hardirq.h>
#include <asm/mman.h>
#include <asm/shmparam.h>
#include <asm/page.h>
extern void do_syscall_trace(void);
typedef int (*syscall_t)(void *a0,...);
extern syscall_t sys_call_table[];
extern unsigned char sys_narg_table[];
/*
* sys_pipe() is the normal C calling standard for creating a pipe. It's not
* the way unix traditional does this, though.
*/
int sys_pipe(int __user *userfds)
{
int fd[2];
int error;
error = do_pipe(fd);
if (!error) {
if (copy_to_user(userfds, fd, 2 * sizeof(int)))
error = -EFAULT;
}
return error;
}
/*
* Common code for old and new mmaps.
*/
long sys_mmap(unsigned long addr, unsigned long len, unsigned long prot,
unsigned long flags, unsigned long fd, unsigned long pgoff)
{
int error = -EBADF;
struct file * file = NULL;
flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
if (!(flags & MAP_ANONYMOUS)) {
file = fget(fd);
if (!file)
goto out;
}
down_write(¤t->mm->mmap_sem);
error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
up_write(¤t->mm->mmap_sem);
if (file)
fput(file);
out:
return error;
}
int sys_clone(struct pt_regs *regs)
{
unsigned long clone_flags;
unsigned long newsp;
int __user *parent_tidptr, *child_tidptr;
clone_flags = regs->areg[4];
newsp = regs->areg[3];
parent_tidptr = (int __user *)regs->areg[5];
child_tidptr = (int __user *)regs->areg[6];
if (!newsp)
newsp = regs->areg[1];
return do_fork(clone_flags,newsp,regs,0,parent_tidptr,child_tidptr);
}
/*
* sys_execve() executes a new program.
*/
int sys_execve(struct pt_regs *regs)
{
int error;
char * filename;
filename = getname((char *) (long)regs->areg[5]);
error = PTR_ERR(filename);
if (IS_ERR(filename))
goto out;
error = do_execve(filename, (char **) (long)regs->areg[3],
(char **) (long)regs->areg[4], regs);
putname(filename);
out:
return error;
}
int sys_uname(struct old_utsname * name)
{
if (name && !copy_to_user(name, utsname(), sizeof (*name)))
return 0;
return -EFAULT;
}
/*
* Build the string table for the builtin "poor man's strace".
*/
#if DEBUG
#define SYSCALL(fun, narg) #fun,
static char *sfnames[] = {
#include "syscalls.h"
};
#undef SYS
#endif
void system_call (struct pt_regs *regs)
{
syscall_t syscall;
unsigned long parm0, parm1, parm2, parm3, parm4, parm5;
int nargs, res;
unsigned int syscallnr;
int ps;
#if DEBUG
int i;
unsigned long parms[6];
char *sysname;
#endif
regs->syscall = regs->areg[2];
do_syscall_trace();
/* Have to load after syscall_trace because strace
* sometimes changes regs->syscall.
*/
syscallnr = regs->syscall;
parm0 = parm1 = parm2 = parm3 = parm4 = parm5 = 0;
/* Restore interrupt level to syscall invoker's.
* If this were in assembly, we wouldn't disable
* interrupts in the first place:
*/
local_save_flags (ps);
local_irq_restore((ps & ~XCHAL_PS_INTLEVEL_MASK) |
(regs->ps & XCHAL_PS_INTLEVEL_MASK) );
if (syscallnr > __NR_Linux_syscalls) {
regs->areg[2] = -ENOSYS;
return;
}
syscall = sys_call_table[syscallnr];
nargs = sys_narg_table[syscallnr];
if (syscall == NULL) {
regs->areg[2] = -ENOSYS;
return;
}
/* There shouldn't be more than six arguments in the table! */
if (nargs > 6)
panic("Internal error - too many syscall arguments (%d)!\n",
nargs);
/* Linux takes system-call arguments in registers. The ABI
* and Xtensa software conventions require the system-call
* number in a2. If an argument exists in a2, we move it to
* the next available register. Note that for improved
* efficiency, we do NOT shift all parameters down one
* register to maintain the original order.
*
* At best case (zero arguments), we just write the syscall
* number to a2. At worst case (1 to 6 arguments), we move
* the argument in a2 to the next available register, then
* write the syscall number to a2.
*
* For clarity, the following truth table enumerates all
* possibilities.
*
* arguments syscall number arg0, arg1, arg2, arg3, arg4, arg5
* --------- -------------- ----------------------------------
* 0 a2
* 1 a2 a3
* 2 a2 a4, a3
* 3 a2 a5, a3, a4
* 4 a2 a6, a3, a4, a5
* 5 a2 a7, a3, a4, a5, a6
* 6 a2 a8, a3, a4, a5, a6, a7
*/
if (nargs) {
parm0 = regs->areg[nargs+2];
parm1 = regs->areg[3];
parm2 = regs->areg[4];
parm3 = regs->areg[5];
parm4 = regs->areg[6];
parm5 = regs->areg[7];
} else /* nargs == 0 */
parm0 = (unsigned long) regs;
#if DEBUG
parms[0] = parm0;
parms[1] = parm1;
parms[2] = parm2;
parms[3] = parm3;
parms[4] = parm4;
parms[5] = parm5;
sysname = sfnames[syscallnr];
if (strncmp(sysname, "sys_", 4) == 0)
sysname = sysname + 4;
printk("\017SYSCALL:I:%x:%d:%s %s(", regs->pc, current->pid,
current->comm, sysname);
for (i = 0; i < nargs; i++)
printk((i>0) ? ", %#lx" : "%#lx", parms[i]);
printk(")\n");
#endif
res = syscall((void *)parm0, parm1, parm2, parm3, parm4, parm5);
#if DEBUG
printk("\017SYSCALL:O:%d:%s %s(",current->pid, current->comm, sysname);
for (i = 0; i < nargs; i++)
printk((i>0) ? ", %#lx" : "%#lx", parms[i]);
if (res < 4096)
printk(") = %d\n", res);
else
printk(") = %#x\n", res);
#endif /* DEBUG */
regs->areg[2] = res;
do_syscall_trace();
}
/*
* Do a system call from kernel instead of calling sys_execve so we
* end up with proper pt_regs.
*/
int kernel_execve(const char *filename, char *const argv[], char *const envp[])
{
long __res;
asm volatile (
" mov a5, %2 \n"
" mov a4, %4 \n"
" mov a3, %3 \n"
" movi a2, %1 \n"
" syscall \n"
" mov %0, a2 \n"
: "=a" (__res)
: "i" (__NR_execve), "a" (filename), "a" (argv), "a" (envp)
: "a2", "a3", "a4", "a5");
return __res;
}
