source: trunk/kernel/syscalls/sys_read.c@ 492

Last change on this file since 492 was 492, checked in by viala@…, 8 years ago

Refactoring assert calling to conform with new assert macro.

Made with this command for the general case.
find ./kernel/ hal/ -name "*.c" | xargs sed -i -e '/assert(/ s/,[ ]*FUNCTION[ ]*,/,/'

And some done by hand.

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// 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 xptr_t process_owner_xp = process->owner_xp;
68
69#if DEBUG_SYS_READ
70uint64_t tm_start;
71uint64_t tm_end;
72tm_start = hal_get_cycles();
73if( DEBUG_SYS_READ < tm_start )
74printk("\n[DBG] %s : thread %x in process %x enter / vaddr %x / count %d / cycle %d\n",
75__FUNCTION__, this->trdid, process->pid, 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 : illegal file descriptor index = %d\n", __FUNCTION__ , file_id );
88#endif
89 this->errno = EBADFD;
90 return -1;
91 }
92
93 // check user buffer in user space
94 error = vmm_get_vseg( process , (intptr_t)vaddr , &vseg );
95
96 if ( error )
97 {
98
99#if DEBUG_SYSCALLS_ERROR
100printk("\n[ERROR] in %s : user buffer unmapped %x / thread %x / process %x\n",
101__FUNCTION__ , (intptr_t)vaddr, this->trdid, process->pid );
102vmm_display( process , false );
103#endif
104 this->errno = EINVAL;
105 return -1;
106 }
107
108 // enable IRQs
109 hal_enable_irq( &save_sr );
110
111 // get extended pointer on remote file descriptor
112 file_xp = process_fd_get_xptr( process , file_id );
113
114 if( file_xp == XPTR_NULL )
115 {
116
117#if DEBUG_SYSCALLS_ERROR
118printk("\n[ERROR] in %s : undefined fd_id %d in process %x\n",
119__FUNCTION__ , file_id , process->pid );
120#endif
121 this->errno = EBADFD;
122 return -1;
123 }
124
125 // get file descriptor cluster and local pointer
126 vfs_file_t * file_ptr = GET_PTR( file_xp );
127 cxy_t file_cxy = GET_CXY( file_xp );
128
129 // check file readable
130 uint32_t attr = hal_remote_lw( XPTR( file_cxy , &file_ptr->attr ) );
131 if( (attr & FD_ATTR_READ_ENABLE) == 0 )
132 {
133
134#if DEBUG_SYSCALLS_ERROR
135printk("\n[ERROR] in %s : file %d not readable in process %x\n",
136__FUNCTION__ , file_id , process->pid );
137#endif
138 this->errno = EBADFD;
139 return -1;
140 }
141
142 // get file type
143 vfs_inode_type_t type = hal_remote_lw( XPTR( file_cxy , &file_ptr->type ) );
144
145 // action depend on file type
146 if( type == INODE_TYPE_FILE ) // check file readable & read from mapper
147 {
148 // check file readable
149 uint32_t attr = hal_remote_lw( XPTR( file_cxy , &file_ptr->attr ) );
150
151 if( (attr & FD_ATTR_READ_ENABLE) == 0 )
152 {
153
154#if DEBUG_SYSCALLS_ERROR
155printk("\n[ERROR] in %s : file %d not readable in process %x\n",
156__FUNCTION__ , file_id , process->pid );
157#endif
158 this->errno = EBADFD;
159 return -1;
160 }
161
162 // move count bytes from mapper
163 nbytes = vfs_user_move( true, // from mapper to buffer
164 file_xp,
165 vaddr,
166 count );
167 }
168 else if( type == INODE_TYPE_DEV ) // check ownership & read from device
169 {
170 // get cluster and pointers on TXT_RX chdev
171 xptr_t chdev_xp = chdev_from_file( file_xp );
172 cxy_t chdev_cxy = GET_CXY( chdev_xp );
173 chdev_t * chdev_ptr = GET_PTR( chdev_xp );
174
175 volatile xptr_t txt_owner_xp;
176 uint32_t iter = 0;
177
178 while( 1 )
179 {
180 // extended pointer on TXT owner process
181 txt_owner_xp = hal_remote_lwd( XPTR( chdev_cxy , &chdev_ptr->ext.txt.owner_xp ) );
182
183 // check TXT_RX ownership
184 if ( process_owner_xp != txt_owner_xp )
185 {
186 if( (iter & 0xFFF) == 0 )
187 printk("\n[WARNING] in %s : thread %x in process %x wait TXT_RX / cycle %d\n",
188 __FUNCTION__, this->trdid, process->pid, (uint32_t)hal_get_cycles() );
189
190 // deschedule without blocking
191 sched_yield( "wait TXT_RX ownership" );
192
193 iter++;
194 }
195 else
196 {
197 break;
198 }
199 }
200
201 // move count bytes from device
202 nbytes = devfs_user_move( true, // from device to buffer
203 file_xp,
204 vaddr,
205 count );
206
207 }
208 else
209 {
210 nbytes = 0;
211 assert( false , "file type %d non supported yet\n", type );
212 }
213
214 if( nbytes != count )
215 {
216
217#if DEBUG_SYSCALLS_ERROR
218printk("\n[ERROR] in %s cannot read data from file %d in process %x\n",
219__FUNCTION__ , file_id , process->pid );
220#endif
221 this->errno = error;
222 return -1;
223 }
224
225 // restore IRQs
226 hal_restore_irq( save_sr );
227
228 hal_fence();
229
230#if DEBUG_SYS_READ
231tm_end = hal_get_cycles();
232if( DEBUG_SYS_READ < tm_end )
233printk("\n[DBG] %s : thread %x in process %x exit / cycle %d / cost %d\n",
234__FUNCTION__ , this->trdid, process->pid, (uint32_t)tm_start, (uint32_t)(tm_end - tm_start) );
235#endif
236
237#if (DEBUG_SYS_READ & 1)
238exit_sys_read = (uint32_t)tm_end;
239
240printk("\n***** timing to read one character *****\n"
241" - enter_sys_read = %d / delta %d\n"
242" - enter_devfs_read = %d / delta %d\n"
243" - enter_txt_read = %d / delta %d\n"
244" - enter_chdev_cmd_read = %d / delta %d\n"
245" - enter_chdev_server_read = %d / delta %d\n"
246" - enter_tty_cmd_read = %d / delta %d\n"
247" - enter_tty_isr_read = %d / delta %d\n"
248" - exit_tty_isr_read = %d / delta %d\n"
249" - exit_tty_cmd_read = %d / delta %d\n"
250" - exit_chdev_server_read = %d / delta %d\n"
251" - exit_chdev_cmd_read = %d / delta %d\n"
252" - exit_txt_read = %d / delta %d\n"
253" - exit_devfs_read = %d / delta %d\n"
254" - exit_sys_read = %d / delta %d\n",
255enter_sys_read , 0 ,
256enter_devfs_read , enter_devfs_read - enter_sys_read ,
257enter_txt_read , enter_txt_read - enter_devfs_read ,
258enter_chdev_cmd_read , enter_chdev_cmd_read - enter_txt_read ,
259enter_chdev_server_read , enter_chdev_server_read - enter_chdev_cmd_read ,
260enter_tty_cmd_read , enter_tty_cmd_read - enter_chdev_server_read ,
261enter_tty_isr_read , enter_tty_isr_read - enter_tty_cmd_read ,
262exit_tty_isr_read , exit_tty_isr_read - enter_tty_isr_read ,
263exit_tty_cmd_read , exit_tty_cmd_read - exit_tty_isr_read ,
264exit_chdev_server_read , exit_chdev_server_read - exit_tty_cmd_read ,
265exit_chdev_cmd_read , exit_chdev_cmd_read - exit_chdev_server_read ,
266exit_txt_read , exit_txt_read - exit_chdev_cmd_read ,
267exit_devfs_read , exit_devfs_read - exit_txt_read ,
268exit_sys_read , exit_sys_read - exit_devfs_read );
269#endif
270
271 return nbytes;
272
273} // end sys_read()
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