source: trunk/kernel/syscalls/sys_getcwd.c @ 39

Last change on this file since 39 was 23, checked in by alain, 8 years ago

Introduce syscalls.

File size: 2.5 KB
RevLine 
[1]1/*
[23]2 * sys_getcwd.c - get process current work directory
[1]3 *
[23]4 * Author    Alain Greiner (2016,2017)
[1]5 *
[23]6 * Copyright (c)  UPMC Sorbonne Universites
[1]7 *
[23]8 * This file is part of ALMOS-MKH.
9 *
10 * ALMOS-MKH is free software; you can redistribute it and/or modify it
[1]11 * under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; version 2.0 of the License.
13 *
[23]14 * ALMOS-MKH is distributed in the hope that it will be useful, but
[1]15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17 * General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
[23]20 * along with ALMOS-MKH; if not, write to the Free Software Foundation,
[1]21 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
[23]24#include <kernel_config.h>
25#include <hal_types.h>
26#include <hal_uspace.h>
27#include <hal_special.h>
28#include <errno.h>
[1]29#include <vfs.h>
[23]30#include <vmm.h>
31#include <process.h>
[1]32#include <thread.h>
[23]33#include <printk.h>
[1]34
[23]35/* TODO: user page(s) need to be locked  [AG] */
[1]36
[23]37////////////////////////////////
38int sys_getcwd ( char     * buf, 
39                 uint32_t   nbytes )
[1]40{
[23]41        error_t    error;
42    paddr_t    paddr;
43    char       kbuf[CONFIG_VFS_MAX_PATH_LENGTH];
[1]44 
[23]45        thread_t  * this    = CURRENT_THREAD;
46    process_t * process = this->process;
[1]47
[23]48    // check buffer size
49        if( nbytes < CONFIG_VFS_MAX_PATH_LENGTH )
[1]50        {
[23]51        printk("\n[ERROR] in %s : buffer too small\n", __FUNCTION__ );
52                this->errno = ERANGE;
53        return -1;
[1]54        }
55
[23]56    // check buffer in user space
57    error = vmm_v2p_translate( false , buf , &paddr );
58
59        if( error )
[1]60        {
[23]61        printk("\n[ERROR] in %s : user buffer unmapped\n", __FUNCTION__ );
62                this->errno = EFAULT;
63        return -1;
[1]64        }
65
[23]66    // get reference process cluster and local pointer
67    xptr_t      ref_xp  = process->ref_xp;
68    cxy_t       ref_cxy = GET_CXY( ref_xp );
69    process_t * ref_ptr = (process_t *)GET_PTR( ref_xp );
[1]70
[23]71    // get CWD lock in read mode
72        remote_rwlock_rd_lock( XPTR( ref_cxy , &ref_ptr->cwd_lock ) );
[1]73
[23]74    // call relevant VFS function
75        error = vfs_get_path( XPTR( ref_cxy , &ref_ptr->vfs_cwd_xp ) ,
76                          kbuf , CONFIG_VFS_MAX_PATH_LENGTH );
[1]77
[23]78    // release CWD lock
79        remote_rwlock_rd_unlock( XPTR( ref_cxy , &ref_ptr->cwd_lock ) );
[1]80
[23]81    // copy kernel buffer to user space
82    hal_copy_to_uspace( buf , kbuf , CONFIG_VFS_MAX_PATH_LENGTH );
[1]83
[23]84    hal_wbflush();
85
86        return 0;
87
88}  // end sys_getcwd()
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