source: trunk/kernel/syscalls/sys_write.c @ 407

Last change on this file since 407 was 407, checked in by alain, 6 years ago

First implementation of fork/exec.

File size: 4.2 KB
RevLine 
[1]1/*
[23]2 * sys_write.c - write bytes to a file
[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>
[1]28#include <errno.h>
29#include <vfs.h>
30#include <thread.h>
[23]31#include <printk.h>
32#include <process.h>
[1]33
[407]34/* TODO: concurrent user page(s) unmap need to be handled [AG] */
[23]35
36//////////////////////////////////
37int sys_write( uint32_t   file_id,
[407]38               void     * vaddr,
[23]39               uint32_t   count )
[1]40{
[23]41    error_t      error;
[407]42    paddr_t      paddr;                // unused, but required for user space checking
[313]43        xptr_t       file_xp;              // remote file extended pointer
[407]44    uint32_t     nbytes;               // number of bytes actually written
[1]45
[407]46        uint32_t     tm_start;
47        uint32_t     tm_end;
48
49        tm_start = hal_get_cycles();
50
[23]51        thread_t   * this = CURRENT_THREAD;
52        process_t  * process = this->process;
[1]53 
[23]54    // check file_id argument
55        if( file_id >= CONFIG_PROCESS_FILE_MAX_NR )
[1]56        {
[23]57        printk("\n[ERROR] in %s : illegal file descriptor index\n", __FUNCTION__ );
58        this->errno = EBADFD;
[1]59                return -1;
60        }
61
[23]62    // check user buffer in user space
[407]63    error = vmm_v2p_translate( false , vaddr , &paddr );
[23]64
65    if ( error )
66    {
67        printk("\n[ERROR] in %s : user buffer unmapped = %x\n",
[407]68        __FUNCTION__ , (intptr_t)vaddr );
[23]69                this->errno = EINVAL;
70                return -1;
71    }
72
73    // get extended pointer on remote file descriptor
74    file_xp = process_fd_get_xptr( process , file_id );
75
76    if( file_xp == XPTR_NULL )
77    {
[407]78        printk("\n[ERROR] in %s : undefined file descriptor index = %d in process %x\n",
79        __FUNCTION__ , file_id , process->pid );
[23]80                this->errno = EBADFD;
81                return -1;
82    }
83
84    // get file descriptor cluster and local pointer
85    vfs_file_t * file_ptr = (vfs_file_t *)GET_PTR( file_xp );
86    cxy_t        file_cxy = GET_CXY( file_xp );
87
88    // check file writable
89    uint32_t attr = hal_remote_lw( XPTR( file_cxy , &file_ptr->attr ) );
90    if( (attr & FD_ATTR_WRITE_ENABLE) == 0 )
[1]91        {
[407]92        printk("\n[ERROR] in %s : file %d not writable in process %x\n",
93        __FUNCTION__ , file_id , process->pid );
[23]94                this->errno = EBADFD;
[1]95                return -1;
96        }
97   
[407]98    // get file type
99    vfs_inode_type_t type = hal_remote_lw( XPTR( file_cxy , &file_ptr->type ) );
[313]100
[407]101    // action depend on file type
102    if( type == INODE_TYPE_FILE )      // transfer count bytes to file mapper
[23]103    {
[407]104        nbytes = vfs_user_move( false,               // from buffer to mapper
105                                file_xp,
106                                vaddr, 
107                                count );
108    }
109    else if( type == INODE_TYPE_DEV )  // transfer count bytes to device
110    {
111        nbytes = devfs_user_move( false,             // from buffer to device
112                                 file_xp,
113                                 vaddr,
114                                 count );
115    }
116    else
117    {
118        nbytes = 0;
119        panic("file type %d non supported", type );
120    }
121
122    if( nbytes != count )
123    {
124        printk("\n[ERROR] in %s cannot write data to file %d in process %x\n",
125        __FUNCTION__ , file_id , process->pid );
[313]126        this->errno = error;
127        return -1;
[23]128    }
129
[124]130    hal_fence();
[23]131
[407]132    tm_end = hal_get_cycles();
[23]133
[407]134syscall_dmsg("\n[DBG] %s : core[%x,%d] / thread %x / nbytes = %d / cycle %d\n"
135" first byte = %c / file_id = %d / cost = %d\n",
136__FUNCTION__ , local_cxy , this->core->lid , this->trdid , nbytes , tm_start ,
137*((char *)(intptr_t)paddr) , file_id , tm_end - tm_start );
138 
139        return nbytes;
140
[23]141}  // end sys_write()
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