source: trunk/kernel/syscalls/sys_stat.c @ 483

Last change on this file since 483 was 457, checked in by alain, 6 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
RevLine 
[1]1/*
[23]2 * sys_stat.c - Return statistics on a file or directory.
[1]3 *
[440]4 * Author    Alain Greiner  (2016,2017,2018)
[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
[457]24#include <hal_kernel_types.h>
[23]25#include <hal_uspace.h>
26#include <hal_special.h>
[1]27#include <errno.h>
28#include <thread.h>
[23]29#include <printk.h>
[1]30#include <vfs.h>
[23]31#include <vmm.h>
32#include <process.h>
[1]33
[407]34/////////////////////////////////////
35int sys_stat( char        * pathname,
36              struct stat * u_stat )
[1]37{
[407]38    error_t       error;
[440]39    vseg_t      * vseg;         // for user space checking
[407]40    struct stat   k_stat;       // kernel space
41    xptr_t        file_xp;
42    char          kbuf[CONFIG_VFS_MAX_PATH_LENGTH];
[23]43       
44        thread_t  * this    = CURRENT_THREAD;
45        process_t * process = this->process;
[1]46
[23]47    // check stat structure in user space
[440]48    error = vmm_get_vseg( process , (intptr_t)u_stat , &vseg );
[1]49
[23]50        if( error )
[1]51        {
[440]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
[23]58                this->errno = EINVAL;
[1]59                return -1;
[23]60        }       
[1]61
[407]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
[23]84    // get extended pointer on remote file descriptor
[407]85    error = vfs_lookup( cwd_xp,
86                        pathname,
87                        0,
88                        &file_xp );
[23]89
[407]90    // release the cwd lock
91    remote_rwlock_rd_unlock( XPTR( ref_cxy , &ref_ptr->cwd_lock ) );
92
93    if( error )
[23]94    {
[407]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;
[23]98        return -1;
99    }
100
[407]101    // call VFS function to get stat info
[23]102    error = vfs_stat( file_xp,
103                      &k_stat );
104    if( error )
[1]105        {
[407]106        printk("\n[ERROR] in %s : cannot get stats for file %s\n",
107               __FUNCTION__ , pathname );
[23]108                this->errno = error;
[1]109                return -1;
110        }
[23]111   
[407]112    // copy k_stat to u_stat
113    hal_copy_to_uspace( u_stat , &k_stat , sizeof(struct stat) );
[1]114
[124]115    hal_fence();
[23]116
[1]117        return 0;
[23]118
119}  // end sys_stat()
120
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