source: trunk/kernel/syscalls/sys_read.c@ 440

Last change on this file since 440 was 440, checked in by alain, 8 years ago

1/ Fix a bug in the Multithreaded "sort" applicationr:
The pthread_create() arguments must be declared as global variables.
2/ The exit syscall can be called by any thread of a process..

File size: 8.4 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_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// TODO: concurrent user page(s) munmap need to be handled [AG]
37
38extern uint32_t enter_sys_read;
39extern uint32_t enter_devfs_read;
40extern uint32_t enter_txt_read;
41extern uint32_t enter_chdev_cmd_read;
42extern uint32_t enter_chdev_server_read;
43extern uint32_t enter_tty_cmd_read;
44extern uint32_t enter_tty_isr_read;
45extern uint32_t exit_tty_isr_read;
46extern uint32_t exit_tty_cmd_read;
47extern uint32_t exit_chdev_server_read;
48extern uint32_t exit_chdev_cmd_read;
49extern uint32_t exit_txt_read;
50extern uint32_t exit_devfs_read;
51extern uint32_t exit_sys_read;
52
53
54/////////////////////////////////
55int sys_read( uint32_t file_id,
56 void * vaddr,
57 uint32_t count )
58{
59 error_t error;
60 vseg_t * vseg; // required for user space checking
61 xptr_t file_xp; // remote file extended pointer
62 uint32_t nbytes; // number of bytes actually read
63 reg_t save_sr; // required to enable IRQs during syscall
64
65 thread_t * this = CURRENT_THREAD;
66 process_t * process = this->process;
67
68#if DEBUG_SYS_READ
69uint64_t tm_start;
70uint64_t tm_end;
71tm_start = hal_get_cycles();
72if( DEBUG_SYS_READ < tm_start )
73printk("\n[DBG] %s : thread %x enter / process %x / vaddr = %x / count %d / cycle %d\n",
74__FUNCTION__, this, process->pid, vaddr, count, (uint32_t)tm_start );
75#endif
76
77#if (DEBUG_SYS_READ & 1)
78enter_sys_read = (uint32_t)tm_start;
79#endif
80
81 // check file_id argument
82 if( file_id >= CONFIG_PROCESS_FILE_MAX_NR )
83 {
84
85#if DEBUG_SYSCALLS_ERROR
86printk("\n[ERROR] in %s : illegal file descriptor index = %d\n", __FUNCTION__ , file_id );
87#endif
88 this->errno = EBADFD;
89 return -1;
90 }
91
92 // check user buffer in user space
93 error = vmm_get_vseg( process , (intptr_t)vaddr , &vseg );
94
95 if ( error )
96 {
97
98#if DEBUG_SYSCALLS_ERROR
99printk("\n[ERROR] in %s : user buffer unmapped %x / thread %x / process %x\n",
100__FUNCTION__ , (intptr_t)vaddr, this->trdid, process->pid );
101vmm_display( process , false );
102#endif
103 this->errno = EINVAL;
104 return -1;
105 }
106
107 // enable IRQs
108 hal_enable_irq( &save_sr );
109
110 // get extended pointer on remote file descriptor
111 file_xp = process_fd_get_xptr( process , file_id );
112
113 if( file_xp == XPTR_NULL )
114 {
115
116#if DEBUG_SYSCALLS_ERROR
117printk("\n[ERROR] in %s : undefined fd_id %d in process %x\n",
118__FUNCTION__ , file_id , process->pid );
119#endif
120 this->errno = EBADFD;
121 return -1;
122 }
123
124 // get file descriptor cluster and local pointer
125 vfs_file_t * file_ptr = GET_PTR( file_xp );
126 cxy_t file_cxy = GET_CXY( file_xp );
127
128 // check file readable
129 uint32_t attr = hal_remote_lw( XPTR( file_cxy , &file_ptr->attr ) );
130 if( (attr & FD_ATTR_READ_ENABLE) == 0 )
131 {
132
133#if DEBUG_SYSCALLS_ERROR
134printk("\n[ERROR] in %s : file %d not readable in process %x\n",
135__FUNCTION__ , file_id , process->pid );
136#endif
137 this->errno = EBADFD;
138 return -1;
139 }
140
141 // get file type
142 vfs_inode_type_t type = hal_remote_lw( XPTR( file_cxy , &file_ptr->type ) );
143
144 // action depend on file type
145 if( type == INODE_TYPE_FILE ) // check file readable & read from mapper
146 {
147 // check file readable
148 uint32_t attr = hal_remote_lw( XPTR( file_cxy , &file_ptr->attr ) );
149 if( (attr & FD_ATTR_READ_ENABLE) == 0 )
150 {
151
152#if DEBUG_SYSCALLS_ERROR
153printk("\n[ERROR] in %s : file %d not readable in process %x\n",
154__FUNCTION__ , file_id , process->pid );
155#endif
156 this->errno = EBADFD;
157 return -1;
158 }
159
160 // move count bytes from mapper
161 nbytes = vfs_user_move( true, // from mapper to buffer
162 file_xp,
163 vaddr,
164 count );
165 }
166 else if( type == INODE_TYPE_DEV ) // check ownership & read from from device
167 {
168 // get cluster and pointers on TXT_RX chdev
169 xptr_t chdev_xp = chdev_from_file( file_xp );
170 cxy_t chdev_cxy = GET_CXY( chdev_xp );
171 chdev_t * chdev_ptr = GET_PTR( chdev_xp );
172
173 volatile xptr_t owner_xp;
174
175 while( 1 )
176 {
177 // extended pointer on owner process
178 owner_xp = hal_remote_lwd( XPTR( chdev_cxy , &chdev_ptr->ext.txt.owner_xp ) );
179
180 // check TXT_RX ownership
181 if ( XPTR( local_cxy , process ) != owner_xp )
182 {
183 // deschedule without blocking
184 sched_yield( "wait TXT ownership" );
185 }
186 else
187 {
188 break;
189 }
190 }
191
192 // move count bytes from device
193 nbytes = devfs_user_move( true, // from device to buffer
194 file_xp,
195 vaddr,
196 count );
197
198 }
199 else
200 {
201 nbytes = 0;
202 assert( false , __FUNCTION__ , "file type %d non supported yet\n", type );
203 }
204
205 if( nbytes != count )
206 {
207
208#if DEBUG_SYSCALLS_ERROR
209printk("\n[ERROR] in %s cannot read data from file %d in process %x\n",
210__FUNCTION__ , file_id , process->pid );
211#endif
212 this->errno = error;
213 return -1;
214 }
215
216 // restore IRQs
217 hal_restore_irq( save_sr );
218
219 hal_fence();
220
221#if DEBUG_SYS_READ
222tm_end = hal_get_cycles();
223if( DEBUG_SYS_READ < tm_end )
224printk("\n[DBG] %s : thread %x exit / process %x / cycle %d\n"
225"nbytes = %d / first byte = %c / file_id = %d / cost = %d\n",
226__FUNCTION__ , this, process->pid,
227(uint32_t)tm_start , nbytes , *((char *)(intptr_t)paddr) , file_id ,
228(uint32_t)(tm_end - tm_start) );
229#endif
230
231#if (DEBUG_SYS_READ & 1)
232exit_sys_read = (uint32_t)tm_end;
233
234printk("\n@@@@@@@@@@@@ timing to read character %c\n"
235" - enter_sys_read = %d / delta %d\n"
236" - enter_devfs_read = %d / delta %d\n"
237" - enter_txt_read = %d / delta %d\n"
238" - enter_chdev_cmd_read = %d / delta %d\n"
239" - enter_chdev_server_read = %d / delta %d\n"
240" - enter_tty_cmd_read = %d / delta %d\n"
241" - enter_tty_isr_read = %d / delta %d\n"
242" - exit_tty_isr_read = %d / delta %d\n"
243" - exit_tty_cmd_read = %d / delta %d\n"
244" - exit_chdev_server_read = %d / delta %d\n"
245" - exit_chdev_cmd_read = %d / delta %d\n"
246" - exit_txt_read = %d / delta %d\n"
247" - exit_devfs_read = %d / delta %d\n"
248" - exit_sys_read = %d / delta %d\n",
249*((char *)(intptr_t)paddr) ,
250enter_sys_read , 0 ,
251enter_devfs_read , enter_devfs_read - enter_sys_read ,
252enter_txt_read , enter_txt_read - enter_devfs_read ,
253enter_chdev_cmd_read , enter_chdev_cmd_read - enter_txt_read ,
254enter_chdev_server_read , enter_chdev_server_read - enter_chdev_cmd_read ,
255enter_tty_cmd_read , enter_tty_cmd_read - enter_chdev_server_read ,
256enter_tty_isr_read , enter_tty_isr_read - enter_tty_cmd_read ,
257exit_tty_isr_read , exit_tty_isr_read - enter_tty_isr_read ,
258exit_tty_cmd_read , exit_tty_cmd_read - exit_tty_isr_read ,
259exit_chdev_server_read , exit_chdev_server_read - exit_tty_cmd_read ,
260exit_chdev_cmd_read , exit_chdev_cmd_read - exit_chdev_server_read ,
261exit_txt_read , exit_txt_read - exit_chdev_cmd_read ,
262exit_devfs_read , exit_devfs_read - exit_txt_read ,
263exit_sys_read , exit_sys_read - exit_devfs_read );
264#endif
265
266 return nbytes;
267
268} // end sys_read()
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