source: trunk/kernel/syscalls/sys_write.c @ 438

Last change on this file since 438 was 438, checked in by alain, 4 years ago

Fix a bug in scheduler related to RPC blocking.

File size: 6.8 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_irqmask.h>
28#include <hal_special.h>
29#include <errno.h>
30#include <vfs.h>
31#include <thread.h>
32#include <printk.h>
33#include <process.h>
34
35/* TODO: concurrent user page(s) unmap need to be handled [AG] */
36
37//////////////////////////////////
38int sys_write( uint32_t   file_id,
39               void     * vaddr,
40               uint32_t   count )
41{
42    error_t      error;
43    paddr_t      paddr;           // required for user space checking
44        xptr_t       file_xp;         // remote file extended pointer
45    uint32_t     nbytes;          // number of bytes actually written
46    reg_t        save_sr;         // required to enable IRQs during syscall
47
48#if (DEBUG_SYS_WRITE_DEBUG & 1)
49enter_sys_read = (uint32_t)tm_start;
50#endif
51
52        thread_t   * this = CURRENT_THREAD;
53        process_t  * process = this->process;
54
55#if DEBUG_SYS_WRITE
56uint32_t     tm_start;
57uint32_t     tm_end;
58tm_start = hal_get_cycles();
59if( DEBUG_SYS_WRITE < tm_start )
60printk("\n[DBG] %s : thread %x enter / process %x / vaddr %x / count %d / cycle %d\n",
61__FUNCTION__, this, process->pid, vaddr, count, (uint32_t)tm_start );
62#endif
63 
64    // check file_id argument
65        if( file_id >= CONFIG_PROCESS_FILE_MAX_NR )
66        {
67
68#if DEBUG_SYSCALLS_ERROR
69printk("\n[ERROR] in %s : illegal file descriptor index\n", __FUNCTION__ );
70#endif
71        this->errno = EBADFD;
72                return -1;
73        }
74
75    // check user buffer in user space
76    error = vmm_v2p_translate( false , vaddr , &paddr );
77
78    if ( error )
79    {
80
81#if DEBUG_SYSCALLS_ERROR
82printk("\n[ERROR] in %s : user buffer unmapped = %x\n", __FUNCTION__ , (intptr_t)vaddr );
83#endif
84                this->errno = EINVAL;
85                return -1;
86    }
87
88    // enable IRQs
89    hal_enable_irq( &save_sr );
90
91    // get extended pointer on remote file descriptor
92    file_xp = process_fd_get_xptr( process , file_id );
93
94    if( file_xp == XPTR_NULL )
95    {
96
97#if DEBUG_SYSCALLS_ERROR
98printk("\n[ERROR] in %s : undefined file descriptor index = %d in process %x\n",
99__FUNCTION__ , file_id , process->pid );
100#endif
101                this->errno = EBADFD;
102                return -1;
103    }
104
105    // get file descriptor cluster and local pointer
106    vfs_file_t * file_ptr = (vfs_file_t *)GET_PTR( file_xp );
107    cxy_t        file_cxy = GET_CXY( file_xp );
108
109 
110    // get file type
111    vfs_inode_type_t type = hal_remote_lw( XPTR( file_cxy , &file_ptr->type ) );
112
113    // action depend on file type
114    if( type == INODE_TYPE_FILE )  // check file writable & write to mapper
115    {
116        // check file writable
117        uint32_t attr = hal_remote_lw( XPTR( file_cxy , &file_ptr->attr ) );
118        if( (attr & FD_ATTR_WRITE_ENABLE) == 0 )
119            {
120
121#if DEBUG_SYSCALLS_ERROR
122printk("\n[ERROR] in %s : file %d not writable in process %x\n",
123__FUNCTION__ , file_id , process->pid );
124#endif
125                    this->errno = EBADFD;
126                    return -1;
127            }
128
129        // move count bytes to mapper
130        nbytes = vfs_user_move( false,               // from buffer to mapper
131                                file_xp,
132                                vaddr, 
133                                count );
134    }
135    else if( type == INODE_TYPE_DEV )  // check ownership & write to device
136    {
137        // move count bytes to device
138        nbytes = devfs_user_move( false,             // from buffer to device
139                                 file_xp,
140                                 vaddr,
141                                 count );
142    }
143    else
144    {
145        nbytes = 0;
146        assert( false , __FUNCTION__ , "file type %d non supported\n", type );
147    }
148
149    if( nbytes != count )
150    {
151
152#if DEBUG_SYSCALLS_ERROR
153printk("\n[ERROR] in %s cannot write data to file %d in process %x\n",
154__FUNCTION__ , file_id , process->pid );
155#endif
156        this->errno = error;
157        return -1;
158    }
159
160    // restore IRQs
161    hal_restore_irq( save_sr );
162
163    hal_fence();
164
165#if DEBUG_SYS_WRITE
166tm_end = hal_get_cycles();
167if( DEBUG_SYS_WRITE < tm_end )
168printk("\n[DBG] %s : thread %x exit / process %x / cycle %d\n"
169"nbytes = %d / first byte = %c / file_id = %d / cost = %d\n",
170__FUNCTION__, this, process->pid, (uint32_t)tm_start,
171nbytes, *((char *)(intptr_t)paddr) , file_id , (uint32_t)(tm_end - tm_start) );
172#endif
173 
174#if (DEBUG_SYS_WRITE & 1)
175exit_sys_write = (uint32_t)tm_end;
176
177printk("\n@@@@@@@@@@@@ timing to write string %c\n"
178" - enter_sys_write          = %d / delta %d\n"
179" - enter_devfs_write        = %d / delta %d\n"
180" - enter_txt_write          = %d / delta %d\n"
181" - enter_chdev_cmd_write    = %d / delta %d\n"
182" - enter_chdev_server_write = %d / delta %d\n"
183" - enter_tty_cmd_write      = %d / delta %d\n"
184" - enter_tty_isr_write      = %d / delta %d\n"
185" - exit_tty_isr_write       = %d / delta %d\n"
186" - exit_tty_cmd_write       = %d / delta %d\n"
187" - exit_chdev_server_write  = %d / delta %d\n"
188" - exit_chdev_cmd_write     = %d / delta %d\n"
189" - exit_txt_write           = %d / delta %d\n"
190" - exit_devfs_write         = %d / delta %d\n"
191" - exit_sys_write           = %d / delta %d\n",
192*((char *)(intptr_t)paddr) ,
193enter_sys_write          , 0 ,
194enter_devfs_write        , enter_devfs_write        - enter_sys_write          ,
195enter_txt_write          , enter_txt_write          - enter_devfs_write        ,
196enter_chdev_cmd_write    , enter_chdev_cmd_write    - enter_txt_write          ,
197enter_chdev_server_write , enter_chdev_server_write - enter_chdev_cmd_write    ,
198enter_tty_cmd_write      , enter_tty_cmd_write      - enter_chdev_server_write ,
199enter_tty_isr_write      , enter_tty_isr_write      - enter_tty_cmd_write      ,
200exit_tty_isr_write       , exit_tty_isr_write       - enter_tty_isr_write      ,
201exit_tty_cmd_write       , exit_tty_cmd_write       - exit_tty_isr_write       ,
202exit_chdev_server_write  , exit_chdev_server_write  - exit_tty_cmd_write       ,
203exit_chdev_cmd_write     , exit_chdev_cmd_write     - exit_chdev_server_write  ,
204exit_txt_write           , exit_txt_write           - exit_chdev_cmd_write     ,
205exit_devfs_write         , exit_devfs_write         - exit_txt_write           ,
206exit_sys_write           , exit_sys_write           - exit_devfs_write         );
207#endif
208 
209        return nbytes;
210
211}  // end sys_write()
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