source: trunk/kernel/syscalls/sys_read.c @ 594

Last change on this file since 594 was 594, checked in by alain, 3 years ago

Fix various bugs in sys_stat() and sys_mmap() functions.
Improve debug in other functions.

File size: 8.6 KB
Line 
1/*
2 * sys_read.c - read bytes from a file
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_read;
38extern uint32_t enter_devfs_read;
39extern uint32_t enter_txt_read;
40extern uint32_t enter_chdev_cmd_read;
41extern uint32_t enter_chdev_server_read;
42extern uint32_t enter_tty_cmd_read;
43extern uint32_t enter_tty_isr_read;
44extern uint32_t exit_tty_isr_read;
45extern uint32_t exit_tty_cmd_read;
46extern uint32_t exit_chdev_server_read;
47extern uint32_t exit_chdev_cmd_read;
48extern uint32_t exit_txt_read;
49extern uint32_t exit_devfs_read;
50extern uint32_t exit_sys_read;
51
52
53/////////////////////////////////
54int sys_read( uint32_t   file_id,
55              void     * vaddr,
56              uint32_t   count )
57{
58    error_t      error;
59    vseg_t     * vseg;        // required for user space checking
60        xptr_t       file_xp;     // remote file extended pointer
61    uint32_t     nbytes;      // number of bytes actually read
62    reg_t        save_sr;     // required to enable IRQs during syscall
63
64        thread_t  *  this             = CURRENT_THREAD;
65        process_t *  process          = this->process;
66    xptr_t       process_owner_xp = process->owner_xp;
67 
68#if (DEBUG_SYS_READ || CONFIG_INSTRUMENTATION_SYSCALLS)
69uint64_t     tm_start = hal_get_cycles();
70#endif
71
72#if DEBUG_SYS_READ
73if( DEBUG_SYS_READ < tm_start )
74printk("\n[DBG] %s : thread[%x,%x] enter / vaddr %x / count %d / cycle %d\n",
75__FUNCTION__, process->pid, this->trdid, vaddr, count, (uint32_t)tm_start );
76#endif
77
78#if (DEBUG_SYS_READ & 1)
79enter_sys_read = (uint32_t)tm_start;
80#endif
81
82    // check file_id argument
83        if( file_id >= CONFIG_PROCESS_FILE_MAX_NR )
84        {
85
86#if DEBUG_SYSCALLS_ERROR
87printk("\n[ERROR] in %s : thread[%x,%x] illegal file descriptor index = %d\n",
88__FUNCTION__ , process->pid, this->trdid, file_id );
89#endif
90                this->errno = EBADFD;
91                return -1;
92        }
93
94    // check user buffer in user space
95    error = vmm_get_vseg( process , (intptr_t)vaddr , &vseg );
96
97    if ( error )
98    {
99
100#if DEBUG_SYSCALLS_ERROR
101printk("\n[ERROR] in %s : thread[%x,%x] user buffer unmapped %x\n",
102__FUNCTION__ , process->pid, this->trdid, (intptr_t)vaddr );
103vmm_display( process , false );
104#endif
105                this->errno = EINVAL;
106                return -1;
107    }
108
109    // enable IRQs
110    hal_enable_irq( &save_sr );
111
112    // get extended pointer on remote file descriptor
113    file_xp = process_fd_get_xptr( process , file_id );
114
115    if( file_xp == XPTR_NULL )
116    {
117
118#if DEBUG_SYSCALLS_ERROR
119printk("\n[ERROR] in %s : thread[%x,%x] undefined fd_id %d\n",
120__FUNCTION__, process->pid, this->trdid, file_id );
121#endif
122        this->errno = EBADFD;
123        return -1;
124    }
125
126    // get file descriptor cluster and local pointer
127    vfs_file_t * file_ptr = GET_PTR( file_xp );
128    cxy_t        file_cxy = GET_CXY( file_xp );
129
130    // get file type
131    vfs_inode_type_t type = hal_remote_l32( XPTR( file_cxy , &file_ptr->type ) );
132
133    // action depend on file type
134    if( type == INODE_TYPE_FILE )      // check file readable & read from mapper
135    {
136        // check file readable
137        uint32_t attr = hal_remote_l32( XPTR( file_cxy , &file_ptr->attr ) );
138
139        if( (attr & FD_ATTR_READ_ENABLE) == 0 )
140            {
141
142#if DEBUG_SYSCALLS_ERROR
143printk("\n[ERROR] in %s : thread[%x,%x] file %d not readable\n",
144__FUNCTION__, process->pid, this->trdid, file_id );
145#endif
146                    this->errno = EBADFD;
147                    return -1;
148            }
149
150        // move count bytes from mapper
151        nbytes = vfs_user_move( true,               // from mapper to buffer
152                                file_xp,
153                                vaddr, 
154                                count );
155    }
156    else if( type == INODE_TYPE_DEV )  // check ownership & read from device
157    {
158        // get cluster and pointers on TXT_RX chdev
159        xptr_t    chdev_xp  = chdev_from_file( file_xp );
160        cxy_t     chdev_cxy = GET_CXY( chdev_xp );
161        chdev_t * chdev_ptr = GET_PTR( chdev_xp );
162
163        volatile xptr_t    txt_owner_xp;   
164        uint32_t           iter = 0;
165
166        while( 1 )
167        {
168            // extended pointer on TXT owner process
169            txt_owner_xp  = hal_remote_l64( XPTR( chdev_cxy , &chdev_ptr->ext.txt.owner_xp ) );
170
171            // check TXT_RX ownership
172            if ( process_owner_xp != txt_owner_xp )
173            {
174                if( (iter & 0xFFF) == 0 )
175                printk("\n[WARNING] in %s : thread[%x,%x] wait TXT_RX / cycle %d\n",
176                __FUNCTION__, process->pid, this->trdid, (uint32_t)hal_get_cycles() );
177
178                // deschedule without blocking
179                sched_yield( "wait TXT_RX ownership" );
180
181                iter++;
182            }
183            else
184            {
185                break;
186            }
187        }
188
189        // move count bytes from device
190        nbytes = devfs_user_move( true,             // from device to buffer
191                                  file_xp,
192                                  vaddr,
193                                  count );
194
195    }
196    else    // not FILE and not DEV
197    {
198
199#if DEBUG_SYSCALLS_ERROR
200printk("\n[ERROR] in %s : thread[%x,%x] / illegal inode type %\n",
201__FUNCTION__, vfs_inode_type_str( type ) );
202#endif
203                this->errno = EBADFD;
204                return -1;
205    }
206
207    if( nbytes != count )
208    {
209
210#if DEBUG_SYSCALLS_ERROR
211printk("\n[ERROR] in %s : thread[%x,‰x] cannot read data from file %d\n",
212__FUNCTION__, process->pid, this->trdid, file_id );
213#endif
214        this->errno = EIO;
215        return -1;
216    }
217
218    // restore IRQs
219    hal_restore_irq( save_sr );
220
221    hal_fence();
222
223#if (DEBUG_SYS_READ || CONFIG_INSTRUMENTATION_SYSCALLS)
224uint64_t     tm_end = hal_get_cycles();
225#endif
226
227#if DEBUG_SYS_READ
228if( DEBUG_SYS_READ < tm_end )
229printk("\n[DBG] %s : thread[%x,%x] exit / cycle %d\n",
230__FUNCTION__ , process->pid, this->trdid, (uint32_t)tm_end );
231#endif
232
233#if CONFIG_INSTRUMENTATION_SYSCALLS
234hal_atomic_add( &syscalls_cumul_cost[SYS_READ] , tm_end - tm_start );
235hal_atomic_add( &syscalls_occurences[SYS_READ] , 1 );
236#endif
237
238#if (DEBUG_SYS_READ & 1)
239exit_sys_read = (uint32_t)tm_end;
240
241printk("\n***** timing to read one character *****\n"
242" - enter_sys_read          = %d / delta %d\n"
243" - enter_devfs_read        = %d / delta %d\n"
244" - enter_txt_read          = %d / delta %d\n"
245" - enter_chdev_cmd_read    = %d / delta %d\n"
246" - enter_chdev_server_read = %d / delta %d\n"
247" - enter_tty_cmd_read      = %d / delta %d\n"
248" - enter_tty_isr_read      = %d / delta %d\n"
249" - exit_tty_isr_read       = %d / delta %d\n"
250" - exit_tty_cmd_read       = %d / delta %d\n"
251" - exit_chdev_server_read  = %d / delta %d\n"
252" - exit_chdev_cmd_read     = %d / delta %d\n"
253" - exit_txt_read           = %d / delta %d\n"
254" - exit_devfs_read         = %d / delta %d\n"
255" - exit_sys_read           = %d / delta %d\n",
256enter_sys_read          , 0 ,
257enter_devfs_read        , enter_devfs_read        - enter_sys_read          ,
258enter_txt_read          , enter_txt_read          - enter_devfs_read        ,
259enter_chdev_cmd_read    , enter_chdev_cmd_read    - enter_txt_read          ,
260enter_chdev_server_read , enter_chdev_server_read - enter_chdev_cmd_read    ,
261enter_tty_cmd_read      , enter_tty_cmd_read      - enter_chdev_server_read ,
262enter_tty_isr_read      , enter_tty_isr_read      - enter_tty_cmd_read      ,
263exit_tty_isr_read       , exit_tty_isr_read       - enter_tty_isr_read      ,
264exit_tty_cmd_read       , exit_tty_cmd_read       - exit_tty_isr_read       ,
265exit_chdev_server_read  , exit_chdev_server_read  - exit_tty_cmd_read       ,
266exit_chdev_cmd_read     , exit_chdev_cmd_read     - exit_chdev_server_read  ,
267exit_txt_read           , exit_txt_read           - exit_chdev_cmd_read     ,
268exit_devfs_read         , exit_devfs_read         - exit_txt_read           ,
269exit_sys_read           , exit_sys_read           - exit_devfs_read         );
270#endif
271 
272        return nbytes;
273
274}  // end sys_read()
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