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
RevLine 
[1]1/*
[23]2 * sys_read.c - read bytes from a file
[1]3 *
[440]4 * Author     Alain Greiner (2016,2017,2018)
[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>
[457]25#include <hal_kernel_types.h>
[23]26#include <hal_uspace.h>
[409]27#include <hal_irqmask.h>
[23]28#include <hal_special.h>
[1]29#include <errno.h>
[23]30#include <vfs.h>
31#include <vmm.h>
[1]32#include <thread.h>
[23]33#include <printk.h>
34#include <process.h>
[1]35
[506]36
[407]37extern uint32_t enter_sys_read;
[436]38extern uint32_t enter_devfs_read;
[407]39extern uint32_t enter_txt_read;
[436]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;
[407]48extern uint32_t exit_txt_read;
[436]49extern uint32_t exit_devfs_read;
[407]50extern uint32_t exit_sys_read;
51
52
[23]53/////////////////////////////////
54int sys_read( uint32_t   file_id,
[407]55              void     * vaddr,
[23]56              uint32_t   count )
[1]57{
[23]58    error_t      error;
[440]59    vseg_t     * vseg;        // required for user space checking
[23]60        xptr_t       file_xp;     // remote file extended pointer
[407]61    uint32_t     nbytes;      // number of bytes actually read
[408]62    reg_t        save_sr;     // required to enable IRQs during syscall
[407]63
[446]64        thread_t  *  this             = CURRENT_THREAD;
65        process_t *  process          = this->process;
66    xptr_t       process_owner_xp = process->owner_xp;
[23]67 
[566]68#if (DEBUG_SYS_READ || CONFIG_INSTRUMENTATION_SYSCALLS)
69uint64_t     tm_start = hal_get_cycles();
70#endif
71
[438]72#if DEBUG_SYS_READ
73if( DEBUG_SYS_READ < tm_start )
[584]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 );
[433]76#endif
77
[438]78#if (DEBUG_SYS_READ & 1)
[436]79enter_sys_read = (uint32_t)tm_start;
80#endif
81
[23]82    // check file_id argument
83        if( file_id >= CONFIG_PROCESS_FILE_MAX_NR )
[1]84        {
[435]85
[438]86#if DEBUG_SYSCALLS_ERROR
[584]87printk("\n[ERROR] in %s : thread[%x,%x] illegal file descriptor index = %d\n",
88__FUNCTION__ , process->pid, this->trdid, file_id );
[435]89#endif
[23]90                this->errno = EBADFD;
[1]91                return -1;
92        }
93
[23]94    // check user buffer in user space
[440]95    error = vmm_get_vseg( process , (intptr_t)vaddr , &vseg );
[23]96
97    if ( error )
98    {
[435]99
[438]100#if DEBUG_SYSCALLS_ERROR
[584]101printk("\n[ERROR] in %s : thread[%x,%x] user buffer unmapped %x\n",
102__FUNCTION__ , process->pid, this->trdid, (intptr_t)vaddr );
[440]103vmm_display( process , false );
[435]104#endif
[23]105                this->errno = EINVAL;
106                return -1;
107    }
108
[408]109    // enable IRQs
[421]110    hal_enable_irq( &save_sr );
[408]111
[23]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    {
[435]117
[438]118#if DEBUG_SYSCALLS_ERROR
[584]119printk("\n[ERROR] in %s : thread[%x,%x] undefined fd_id %d\n",
120__FUNCTION__, process->pid, this->trdid, file_id );
[435]121#endif
[23]122        this->errno = EBADFD;
123        return -1;
124    }
125
126    // get file descriptor cluster and local pointer
[436]127    vfs_file_t * file_ptr = GET_PTR( file_xp );
[23]128    cxy_t        file_cxy = GET_CXY( file_xp );
129
[407]130    // get file type
[566]131    vfs_inode_type_t type = hal_remote_l32( XPTR( file_cxy , &file_ptr->type ) );
[313]132
[407]133    // action depend on file type
[421]134    if( type == INODE_TYPE_FILE )      // check file readable & read from mapper
[23]135    {
[421]136        // check file readable
[566]137        uint32_t attr = hal_remote_l32( XPTR( file_cxy , &file_ptr->attr ) );
[443]138
[421]139        if( (attr & FD_ATTR_READ_ENABLE) == 0 )
140            {
[435]141
[438]142#if DEBUG_SYSCALLS_ERROR
[584]143printk("\n[ERROR] in %s : thread[%x,%x] file %d not readable\n",
144__FUNCTION__, process->pid, this->trdid, file_id );
[435]145#endif
[421]146                    this->errno = EBADFD;
147                    return -1;
148            }
149
150        // move count bytes from mapper
[407]151        nbytes = vfs_user_move( true,               // from mapper to buffer
152                                file_xp,
153                                vaddr, 
154                                count );
155    }
[446]156    else if( type == INODE_TYPE_DEV )  // check ownership & read from device
[407]157    {
[436]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
[446]163        volatile xptr_t    txt_owner_xp;   
164        uint32_t           iter = 0;
[436]165
166        while( 1 )
167        {
[446]168            // extended pointer on TXT owner process
[566]169            txt_owner_xp  = hal_remote_l64( XPTR( chdev_cxy , &chdev_ptr->ext.txt.owner_xp ) );
[436]170
171            // check TXT_RX ownership
[446]172            if ( process_owner_xp != txt_owner_xp )
[436]173            {
[446]174                if( (iter & 0xFFF) == 0 )
[584]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() );
[446]177
[436]178                // deschedule without blocking
[446]179                sched_yield( "wait TXT_RX ownership" );
180
181                iter++;
[436]182            }
183            else
184            {
185                break;
186            }
187        }
188
[421]189        // move count bytes from device
[407]190        nbytes = devfs_user_move( true,             // from device to buffer
191                                  file_xp,
192                                  vaddr,
193                                  count );
[421]194
[407]195    }
[594]196    else    // not FILE and not DEV
[407]197    {
[594]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;
[407]205    }
206
207    if( nbytes != count )
208    {
[435]209
[438]210#if DEBUG_SYSCALLS_ERROR
[584]211printk("\n[ERROR] in %s : thread[%x,‰x] cannot read data from file %d\n",
212__FUNCTION__, process->pid, this->trdid, file_id );
[435]213#endif
[594]214        this->errno = EIO;
[313]215        return -1;
[23]216    }
217
[408]218    // restore IRQs
[421]219    hal_restore_irq( save_sr );
[408]220
[124]221    hal_fence();
[23]222
[566]223#if (DEBUG_SYS_READ || CONFIG_INSTRUMENTATION_SYSCALLS)
224uint64_t     tm_end = hal_get_cycles();
225#endif
226
[438]227#if DEBUG_SYS_READ
228if( DEBUG_SYS_READ < tm_end )
[584]229printk("\n[DBG] %s : thread[%x,%x] exit / cycle %d\n",
230__FUNCTION__ , process->pid, this->trdid, (uint32_t)tm_end );
[409]231#endif
[23]232
[566]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
[438]238#if (DEBUG_SYS_READ & 1)
[418]239exit_sys_read = (uint32_t)tm_end;
[407]240
[443]241printk("\n***** timing to read one character *****\n"
[435]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         );
[407]270#endif
271 
272        return nbytes;
273
[23]274}  // end sys_read()
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