source: trunk/kernel/syscalls/sys_write.c @ 610

Last change on this file since 610 was 610, checked in by alain, 3 years ago

Fix several bugs in VFS to support the following
ksh commandis : cp, mv, rm, mkdir, cd, pwd

File size: 8.9 KB
Line 
1/*
2 * sys_write.c - Kernel function implementing the "write" system call.
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 <kernel_config.h>
25#include <hal_kernel_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 <vmm.h>
32#include <thread.h>
33#include <printk.h>
34#include <process.h>
35
36
37extern uint32_t enter_sys_write;
38extern uint32_t enter_devfs_write;
39extern uint32_t enter_txt_write;
40extern uint32_t enter_chdev_cmd_write;
41extern uint32_t enter_chdev_server_write;
42extern uint32_t enter_tty_cmd_write;
43extern uint32_t enter_tty_isr_write;
44extern uint32_t exit_tty_isr_write;
45extern uint32_t exit_tty_cmd_write;
46extern uint32_t exit_chdev_server_write;
47extern uint32_t exit_chdev_cmd_write;
48extern uint32_t exit_txt_write;
49extern uint32_t exit_devfs_write;
50extern uint32_t exit_sys_write;
51
52//////////////////////////////////
53int sys_write( uint32_t   file_id,
54               void     * vaddr,
55               uint32_t   count )
56{
57    error_t       error;
58    vseg_t      * vseg;            // required for user space checking
59        xptr_t        file_xp;         // remote file extended pointer
60    vfs_file_t  * file_ptr;        // remote file local pointer
61    cxy_t         file_cxy;        // remote file cluster identifier
62    uint32_t      file_type;       // file type
63    uint32_t      file_offset;     // current file offset
64    uint32_t      file_attr;       // file_attribute
65    vfs_inode_t * inode_ptr;       // local pointer on associated inode
66    uint32_t      nbytes;          // number of bytes actually written
67    reg_t         save_sr;         // required to enable IRQs during syscall
68
69        thread_t    * this = CURRENT_THREAD;
70        process_t   * process = this->process;
71
72#if (DEBUG_SYS_WRITE || CONFIG_INSTRUMENTATION_SYSCALLS)
73uint64_t     tm_start = hal_get_cycles();
74#endif
75
76#if DEBUG_SYS_WRITE
77tm_start = hal_get_cycles();
78if( DEBUG_SYS_WRITE < tm_start )
79printk("\n[%s] thread[%x,%x] enter / vaddr %x / count %d / cycle %d\n",
80__FUNCTION__, process->pid, this->trdid, vaddr, count, (uint32_t)tm_start );
81#endif
82 
83#if (DEBUG_SYS_WRITE & 1)
84enter_sys_write = (uint32_t)tm_start;
85#endif
86
87    // check file_id argument
88        if( file_id >= CONFIG_PROCESS_FILE_MAX_NR )
89        {
90
91#if DEBUG_SYSCALLS_ERROR
92printk("\n[ERROR] in %s : thread[%x,%x] illegal file descriptor index %d\n",
93__FUNCTION__, process->pid, this->trdid, file_id );
94#endif
95        this->errno = EBADFD;
96                return -1;
97        }
98
99    // check user buffer in user space
100    error = vmm_get_vseg( process , (intptr_t)vaddr , &vseg );
101
102    if ( error )
103    {
104
105#if DEBUG_SYSCALLS_ERROR
106printk("\n[ERROR] in %s : thread[%x,%x] user buffer unmapped %x\n",
107__FUNCTION__ , process->pid, this->trdid, (intptr_t)vaddr );
108vmm_display( process , false );
109#endif
110                this->errno = EINVAL;
111                return -1;
112    }
113
114    // get extended pointer on remote file descriptor
115    file_xp = process_fd_get_xptr( process , file_id );
116
117    if( file_xp == XPTR_NULL )
118    {
119
120#if DEBUG_SYSCALLS_ERROR
121printk("\n[ERROR] in %s : thread[%x,%x] undefined file descriptor = %d\n",
122__FUNCTION__, process->pid, this->trdid, file_id );
123#endif
124                this->errno = EBADFD;
125                return -1;
126    }
127
128    // get file descriptor cluster and local pointer
129    file_ptr = GET_PTR( file_xp );
130    file_cxy = GET_CXY( file_xp );
131
132    // get file type, offset, aatributes, and associated inode
133    file_type   = hal_remote_l32( XPTR( file_cxy , &file_ptr->type ) );
134    file_offset = hal_remote_l32( XPTR( file_cxy , &file_ptr->offset ) );
135    inode_ptr   = hal_remote_lpt( XPTR( file_cxy , &file_ptr->inode ) );
136    file_attr   = hal_remote_l32( XPTR( file_cxy , &file_ptr->attr ) );
137
138    // enable IRQs
139    hal_enable_irq( &save_sr );
140
141   // action depend on file type
142    if( file_type == INODE_TYPE_FILE )  // write to file mapper
143    {
144        // check file writable
145        if( (file_attr & FD_ATTR_WRITE_ENABLE) == 0 )
146            {
147
148#if DEBUG_SYSCALLS_ERROR
149printk("\n[ERROR] in %s : thread[%x,%x] file %d not writable\n",
150__FUNCTION__ , process->pid, this->trdid, file_id );
151#endif
152            hal_restore_irq( save_sr );
153                    this->errno = EBADFD;
154                    return -1;
155            }
156
157        // move count bytes to mapper
158        nbytes = vfs_user_move( false,               // from buffer to mapper
159                                file_xp,
160                                vaddr, 
161                                count );
162        if ( nbytes != count )
163        {
164
165#if DEBUG_SYSCALLS_ERROR
166printk("\n[ERROR] in %s : thread[%x,%x] cannot write %d bytes into file %d\n",
167__FUNCTION__ , process->pid, this->trdid, count, file_id );
168#endif
169            hal_restore_irq( save_sr );
170            this->errno = EIO;
171            return -1;
172
173        }
174
175        // update size field in inode if required
176        xptr_t   size_xp    = XPTR( file_cxy , &inode_ptr->size );
177        uint32_t inode_size = hal_remote_l32( size_xp );
178        if ( (file_offset + count) > inode_size )
179        {
180            hal_remote_s32( size_xp , file_offset + count );
181        }
182    }
183    else if( file_type == INODE_TYPE_DEV )  // write to TXT device
184    {
185        // move count bytes to device
186        nbytes = devfs_user_move( false,             // from buffer to device
187                                  file_xp,
188                                  vaddr,
189                                  count );
190        if( nbytes != count )
191        {
192
193#if DEBUG_SYSCALLS_ERROR
194printk("\n[ERROR] in %s : thread[%x,‰x] cannot write data to file %d\n",
195__FUNCTION__ , process->pid, this->trdid, file_id );
196#endif
197            hal_restore_irq( save_sr );
198            this->errno = EIO;
199            return -1;
200        }
201    }
202    else  // not FILE and not DEV
203    {
204
205#if DEBUG_SYSCALLS_ERROR
206printk("\n[ERROR] in %s : thread[%x,%x] / illegal inode type %\n",
207__FUNCTION__, vfs_inode_type_str( file_type ) );
208#endif
209        hal_restore_irq( save_sr );
210                this->errno = EBADFD;
211                return -1;
212    }
213
214    // restore IRQs
215    hal_restore_irq( save_sr );
216
217    hal_fence();
218
219#if (DEBUG_SYS_WRITE || CONFIG_INSTRUMENTATION_SYSCALLS)
220uint64_t     tm_end = hal_get_cycles();
221#endif
222
223#if DEBUG_SYS_WRITE
224if( DEBUG_SYS_WRITE < tm_end )
225printk("\n[%s] thread[%x,%x] exit / cycle %d\n",
226__FUNCTION__, process->pid, this->trdid, (uint32_t)tm_end );
227#endif
228 
229#if CONFIG_INSTRUMENTATION_SYSCALLS
230hal_atomic_add( &syscalls_cumul_cost[SYS_WRITE] , tm_end - tm_start );
231hal_atomic_add( &syscalls_occurences[SYS_WRITE] , 1 );
232#endif
233
234#if (DEBUG_SYS_WRITE & 1)
235exit_sys_write = (uint32_t)tm_end;
236
237printk("\n***** timing to write a string *****\n"
238" - enter_sys_write          = %d / delta %d\n"
239" - enter_devfs_write        = %d / delta %d\n"
240" - enter_txt_write          = %d / delta %d\n"
241" - enter_chdev_cmd_write    = %d / delta %d\n"
242" - enter_chdev_server_write = %d / delta %d\n"
243" - enter_tty_cmd_write      = %d / delta %d\n"
244" - enter_tty_isr_write      = %d / delta %d\n"
245" - exit_tty_isr_write       = %d / delta %d\n"
246" - exit_tty_cmd_write       = %d / delta %d\n"
247" - exit_chdev_server_write  = %d / delta %d\n"
248" - exit_chdev_cmd_write     = %d / delta %d\n"
249" - exit_txt_write           = %d / delta %d\n"
250" - exit_devfs_write         = %d / delta %d\n"
251" - exit_sys_write           = %d / delta %d\n",
252enter_sys_write          , 0 ,
253enter_devfs_write        , enter_devfs_write        - enter_sys_write          ,
254enter_txt_write          , enter_txt_write          - enter_devfs_write        ,
255enter_chdev_cmd_write    , enter_chdev_cmd_write    - enter_txt_write          ,
256enter_chdev_server_write , enter_chdev_server_write - enter_chdev_cmd_write    ,
257enter_tty_cmd_write      , enter_tty_cmd_write      - enter_chdev_server_write ,
258enter_tty_isr_write      , enter_tty_isr_write      - enter_tty_cmd_write      ,
259exit_tty_isr_write       , exit_tty_isr_write       - enter_tty_isr_write      ,
260exit_tty_cmd_write       , exit_tty_cmd_write       - exit_tty_isr_write       ,
261exit_chdev_server_write  , exit_chdev_server_write  - exit_tty_cmd_write       ,
262exit_chdev_cmd_write     , exit_chdev_cmd_write     - exit_chdev_server_write  ,
263exit_txt_write           , exit_txt_write           - exit_chdev_cmd_write     ,
264exit_devfs_write         , exit_devfs_write         - exit_txt_write           ,
265exit_sys_write           , exit_sys_write           - exit_devfs_write         );
266#endif
267 
268        return nbytes;
269
270}  // end sys_write()
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