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