source: trunk/kernel/syscalls/sys_read.c@ 408

Last change on this file since 408 was 408, checked in by alain, 9 years ago

Fix several bugs in the fork() syscall.
File size: 6.5 KB
Line 
1/*
2 * sys_read.c - read bytes from a file
3 *
4 * Author Alain Greiner (2016,2017)
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_special.h>
28#include <errno.h>
29#include <vfs.h>
30#include <vmm.h>
31#include <thread.h>
32#include <printk.h>
33#include <process.h>
34
35// TODO: concurrent user page(s) munmap need to be handled [AG]
36
37// instrumentation
38extern uint32_t enter_sys_read;
39extern uint32_t enter_devfs_move;
40extern uint32_t enter_txt_read;
41extern uint32_t enter_chdev_cmd;
42extern uint32_t enter_chdev_server;
43extern uint32_t enter_tty_cmd;
44extern uint32_t enter_tty_isr;
45extern uint32_t exit_tty_isr;
46extern uint32_t exit_tty_cmd;
47extern uint32_t exit_chdev_server;
48extern uint32_t exit_chdev_cmd;
49extern uint32_t exit_txt_read;
50extern uint32_t exit_devfs_move;
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 paddr_t paddr; // 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 uint32_t tm_start;
65 uint32_t tm_end;
66
67 tm_start = hal_get_cycles();
68
69#if CONFIG_READ_START
70enter_sys_read = tm_start;
71#endif
72
73 thread_t * this = CURRENT_THREAD;
74 process_t * process = this->process;
75
76 // check file_id argument
77 if( file_id >= CONFIG_PROCESS_FILE_MAX_NR )
78 {
79 printk("\n[ERROR] in %s : illegal file descriptor index = %d\n",
80 __FUNCTION__ , file_id );
81 this->errno = EBADFD;
82 return -1;
83 }
84
85 // check user buffer in user space
86 error = vmm_v2p_translate( false , vaddr , &paddr );
87
88 if ( error )
89 {
90 printk("\n[ERROR] in %s : user buffer unmapped = %x\n",
91 __FUNCTION__ , (intptr_t)vaddr );
92 this->errno = EINVAL;
93 return -1;
94 }
95
96 // enable IRQs
97 hal_enable_irq( &save_sr );
98
99 // get extended pointer on remote file descriptor
100 file_xp = process_fd_get_xptr( process , file_id );
101
102 if( file_xp == XPTR_NULL )
103 {
104 printk("\n[ERROR] in %s : undefined file descriptor index = %d in process %x\n",
105 __FUNCTION__ , file_id , process->pid );
106 this->errno = EBADFD;
107 return -1;
108 }
109
110 // get file descriptor cluster and local pointer
111 vfs_file_t * file_ptr = (vfs_file_t *)GET_PTR( file_xp );
112 cxy_t file_cxy = GET_CXY( file_xp );
113
114 // check file readable
115 uint32_t attr = hal_remote_lw( XPTR( file_cxy , &file_ptr->attr ) );
116 if( (attr & FD_ATTR_READ_ENABLE) == 0 )
117 {
118 printk("\n[ERROR] in %s : file %d not readable in process %x\n",
119 __FUNCTION__ , file_id , process->pid );
120 this->errno = EBADFD;
121 return -1;
122 }
123
124 // get file type
125 vfs_inode_type_t type = hal_remote_lw( XPTR( file_cxy , &file_ptr->type ) );
126
127 // action depend on file type
128 if( type == INODE_TYPE_FILE ) // transfer count bytes from file mapper
129 {
130 nbytes = vfs_user_move( true, // from mapper to buffer
131 file_xp,
132 vaddr,
133 count );
134 }
135 else if( type == INODE_TYPE_DEV ) // transfer count bytes from device
136 {
137 nbytes = devfs_user_move( true, // from device to buffer
138 file_xp,
139 vaddr,
140 count );
141 }
142 else
143 {
144 nbytes = 0;
145 panic("file type %d non supported yet", type );
146 }
147
148 if( nbytes != count )
149 {
150 printk("\n[ERROR] in %s cannot read data from file %d in process %x\n",
151 __FUNCTION__ , file_id , process->pid );
152 this->errno = error;
153 return -1;
154 }
155
156 // restore IRQs
157 hal_restore_irq( save_sr );
158
159 hal_fence();
160
161 tm_end = hal_get_cycles();
162
163#if CONFIG_READ_DEBUG
164exit_sys_read = tm_end;
165
166printk("\n@@@@@@@@@@@@ timing ro read character %c\n"
167" - enter_sys_read = %d / delta %d\n"
168" - enter_devfs_move = %d / delta %d\n"
169" - enter_txt_read = %d / delta %d\n"
170" - enter_chdev_cmd = %d / delta %d\n"
171" - enter_chdev_server = %d / delta %d\n"
172" - enter_tty_cmd = %d / delta %d\n"
173" - enter_tty_isr = %d / delta %d\n"
174" - exit_tty_isr = %d / delta %d\n"
175" - exit_tty_cmd = %d / delta %d\n"
176" - exit_chdev_server = %d / delta %d\n"
177" - exit_chdev_cmd = %d / delta %d\n"
178" - exit_txt_read = %d / delta %d\n"
179" - exit_devfs_move = %d / delta %d\n"
180" - exit_sys_read = %d / delta %d\n",
181*((char *)(intptr_t)paddr) ,
182enter_sys_read , 0 ,
183enter_devfs_move , enter_devfs_move - enter_sys_read ,
184enter_txt_read , enter_txt_read - enter_devfs_move ,
185enter_chdev_cmd , enter_chdev_cmd - enter_txt_read ,
186enter_chdev_server , enter_chdev_server - enter_chdev_cmd ,
187enter_tty_cmd , enter_tty_cmd - enter_chdev_server ,
188enter_tty_isr , enter_tty_isr - enter_tty_cmd ,
189exit_tty_isr , exit_tty_isr - enter_tty_isr ,
190exit_tty_cmd , exit_tty_cmd - exit_tty_isr ,
191exit_chdev_server , exit_chdev_server - exit_tty_cmd ,
192exit_chdev_cmd , exit_chdev_cmd - exit_chdev_server ,
193exit_txt_read , exit_txt_read - exit_chdev_cmd ,
194exit_devfs_move , exit_devfs_move - exit_txt_read ,
195exit_sys_read , exit_sys_read - exit_devfs_move );
196#endif
197
198syscall_dmsg("\n[DBG] %s : core[%x,%d] / thread %x in process %x / cycle %d\n"
199"nbytes = %d / first byte = %c / file_id = %d / cost = %d\n",
200__FUNCTION__ , local_cxy , this->core->lid , this->trdid , this->process->pid ,
201tm_start , nbytes , *((char *)(intptr_t)paddr) , file_id , tm_end - tm_start );
202
203 return nbytes;
204
205} // end sys_read()
Note: See TracBrowser for help on using the repository browser.