source: trunk/kernel/syscalls/sys_write.c @ 318

Last change on this file since 318 was 315, checked in by alain, 7 years ago

Redefine the fuctions ppm_base2page() / ppm_page2base() / ppm_page2ppn() / ppm_ppn2page() / ppm_base2ppn() / ppm_ppn2base(),
to use explicitely extended pointers.

File size: 3.1 KB
Line 
1/*
2 * sys_write.c - write bytes to a file
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 <thread.h>
31#include <printk.h>
32#include <process.h>
33
34/* TODO: user page(s) need to be locked  [AG] */
35
36//////////////////////////////////
37int sys_write( uint32_t   file_id,
38               void     * buf,
39               uint32_t   count )
40{
41    error_t      error;
42    paddr_t      paddr;                // required for user space checking
43        xptr_t       file_xp;              // remote file extended pointer
44
45        thread_t   * this = CURRENT_THREAD;
46        process_t  * process = this->process;
47 
48    // check file_id argument
49        if( file_id >= CONFIG_PROCESS_FILE_MAX_NR )
50        {
51        printk("\n[ERROR] in %s : illegal file descriptor index\n", __FUNCTION__ );
52        this->errno = EBADFD;
53                return -1;
54        }
55
56    // check user 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 = %x\n",
62               __FUNCTION__ , (intptr_t)buf );
63                this->errno = EINVAL;
64                return -1;
65    }
66
67    // get extended pointer on remote file descriptor
68    file_xp = process_fd_get_xptr( process , file_id );
69
70    if( file_xp == XPTR_NULL )
71    {
72        printk("\n[ERROR] in %s : undefined file descriptor index = %d\n",
73               __FUNCTION__ , file_id );
74                this->errno = EBADFD;
75                return -1;
76    }
77
78    // get file descriptor cluster and local pointer
79    vfs_file_t * file_ptr = (vfs_file_t *)GET_PTR( file_xp );
80    cxy_t        file_cxy = GET_CXY( file_xp );
81
82    // check file writable
83    uint32_t attr = hal_remote_lw( XPTR( file_cxy , &file_ptr->attr ) );
84    if( (attr & FD_ATTR_WRITE_ENABLE) == 0 )
85        {
86        printk("\n[ERROR] in %s : file %d not writable\n",
87               __FUNCTION__ , file_id );
88                this->errno = EBADFD;
89                return -1;
90        }
91   
92    // transfer count bytes directly from user buffer to mapper
93    error = vfs_user_move( false,               // from buffer
94                           file_xp,
95                           buf , 
96                           count );
97
98    if( error )
99    {
100        printk("\n[ERROR] in %s cannot read data from file %d\n",
101               __FUNCTION__ , file_id );
102        this->errno = error;
103        return -1;
104    }
105
106    hal_fence();
107
108        return 0;
109
110}  // end sys_write()
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