source: trunk/kernel/syscalls/sys_getcwd.c @ 124

Last change on this file since 124 was 124, checked in by max@…, 5 years ago

rename hal_wbflush->hal_fence

File size: 2.5 KB
Line 
1/*
2 * sys_getcwd.c - get process current work directory
3 *
4 * Author    Alain Greiner (2016,2017)
5 *
6 * Copyright (c)  UPMC Sorbonne Universites
7 *
8 * This file is part of ALMOS-MKH.
9 *
10 * ALMOS-MKH is free software; you can redistribute it and/or modify it
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 *
14 * ALMOS-MKH is distributed in the hope that it will be useful, but
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
20 * along with ALMOS-MKH; if not, write to the Free Software Foundation,
21 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 */
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>
29#include <vfs.h>
30#include <vmm.h>
31#include <process.h>
32#include <thread.h>
33#include <printk.h>
34
35/* TODO: user page(s) need to be locked  [AG] */
36
37////////////////////////////////
38int sys_getcwd ( char     * buf, 
39                 uint32_t   nbytes )
40{
41        error_t    error;
42    paddr_t    paddr;
43    char       kbuf[CONFIG_VFS_MAX_PATH_LENGTH];
44 
45        thread_t  * this    = CURRENT_THREAD;
46    process_t * process = this->process;
47
48    // check buffer size
49        if( nbytes < CONFIG_VFS_MAX_PATH_LENGTH )
50        {
51        printk("\n[ERROR] in %s : buffer too small\n", __FUNCTION__ );
52                this->errno = ERANGE;
53        return -1;
54        }
55
56    // check buffer in user space
57    error = vmm_v2p_translate( false , buf , &paddr );
58
59        if( error )
60        {
61        printk("\n[ERROR] in %s : user buffer unmapped\n", __FUNCTION__ );
62                this->errno = EFAULT;
63        return -1;
64        }
65
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 );
70
71    // get CWD lock in read mode
72        remote_rwlock_rd_lock( XPTR( ref_cxy , &ref_ptr->cwd_lock ) );
73
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 );
77
78    // release CWD lock
79        remote_rwlock_rd_unlock( XPTR( ref_cxy , &ref_ptr->cwd_lock ) );
80
81    // copy kernel buffer to user space
82    hal_copy_to_uspace( buf , kbuf , CONFIG_VFS_MAX_PATH_LENGTH );
83
84    hal_fence();
85
86        return 0;
87
88}  // end sys_getcwd()
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