source: trunk/kernel/syscalls/sys_stat.c @ 459

Last change on this file since 459 was 457, checked in by alain, 3 years ago

This version modifies the exec syscall and fixes a large number of small bugs.
The version number has been updated (0.1)

File size: 3.5 KB
Line 
1/*
2 * sys_stat.c - Return statistics on a file or directory.
3 *
4 * Author    Alain Greiner  (2016,2017,2018)
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 <hal_kernel_types.h>
25#include <hal_uspace.h>
26#include <hal_special.h>
27#include <errno.h>
28#include <thread.h>
29#include <printk.h>
30#include <vfs.h>
31#include <vmm.h>
32#include <process.h>
33
34/////////////////////////////////////
35int sys_stat( char        * pathname,
36              struct stat * u_stat )
37{
38    error_t       error;
39    vseg_t      * vseg;         // for user space checking
40    struct stat   k_stat;       // kernel space
41    xptr_t        file_xp;
42    char          kbuf[CONFIG_VFS_MAX_PATH_LENGTH];
43       
44        thread_t  * this    = CURRENT_THREAD;
45        process_t * process = this->process;
46
47    // check stat structure in user space
48    error = vmm_get_vseg( process , (intptr_t)u_stat , &vseg );
49
50        if( error )
51        {
52
53#if DEBUG_SYCALL_ERROR
54printk("\n[ERROR] in %s : stat structure unmapped %x / thread %x / process %x\n",
55__FUNCTION__ , (intptr_t)u_stat , this->trdid , process->pid );
56vmm_display( process , false );
57#endif
58                this->errno = EINVAL;
59                return -1;
60        }       
61
62    // check pathname length
63    if( hal_strlen_from_uspace( pathname ) >= CONFIG_VFS_MAX_PATH_LENGTH )
64    {
65        printk("\n[ERROR] in %s : pathname too long\n", __FUNCTION__ );
66        this->errno = ENFILE;
67        return -1;
68    }
69
70    // copy pathname in kernel space
71    hal_strcpy_from_uspace( kbuf , pathname , CONFIG_VFS_MAX_PATH_LENGTH );
72
73    // get cluster and local pointer on reference process
74    xptr_t      ref_xp  = process->ref_xp;
75    process_t * ref_ptr = (process_t *)GET_PTR( ref_xp );
76    cxy_t       ref_cxy = GET_CXY( ref_xp );
77
78    // get extended pointer on cwd inode
79    xptr_t cwd_xp = hal_remote_lwd( XPTR( ref_cxy , &ref_ptr->vfs_cwd_xp ) );
80
81    // get the cwd lock in read mode from reference process
82    remote_rwlock_rd_lock( XPTR( ref_cxy , &ref_ptr->cwd_lock ) );
83
84    // get extended pointer on remote file descriptor
85    error = vfs_lookup( cwd_xp,
86                        pathname,
87                        0,
88                        &file_xp );
89
90    // release the cwd lock
91    remote_rwlock_rd_unlock( XPTR( ref_cxy , &ref_ptr->cwd_lock ) );
92
93    if( error )
94    {
95        printk("\n[ERROR] in %s : cannot found file <%s> for thread %x in process %x\n",
96               __FUNCTION__ , pathname , this->trdid , process->pid );
97        this->errno = error;
98        return -1;
99    }
100
101    // call VFS function to get stat info
102    error = vfs_stat( file_xp,
103                      &k_stat );
104    if( error )
105        {
106        printk("\n[ERROR] in %s : cannot get stats for file %s\n",
107               __FUNCTION__ , pathname );
108                this->errno = error;
109                return -1;
110        }
111   
112    // copy k_stat to u_stat
113    hal_copy_to_uspace( u_stat , &k_stat , sizeof(struct stat) );
114
115    hal_fence();
116
117        return 0;
118
119}  // end sys_stat()
120
Note: See TracBrowser for help on using the repository browser.