source: trunk/kernel/syscalls/sys_write.c@ 664

Last change on this file since 664 was 664, checked in by alain, 6 years ago
  • Introduce the sys_socket.c file implementing all socket related syscalls.
  • Improve the non-standard sys_get_config() function.
File size: 8.4 KB
Line 
1/*
2 * sys_write.c - Kernel function implementing the "write" system call.
3 *
4 * Author Alain Greiner (2016,2017,2018,2019)
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_vmm.h>
27#include <hal_uspace.h>
28#include <hal_irqmask.h>
29#include <hal_special.h>
30#include <errno.h>
31#include <vfs.h>
32#include <vmm.h>
33#include <thread.h>
34#include <printk.h>
35#include <process.h>
36
37
38extern uint32_t enter_sys_write;
39extern uint32_t enter_devfs_write;
40extern uint32_t enter_txt_write;
41extern uint32_t enter_chdev_cmd_write;
42extern uint32_t enter_chdev_server_write;
43extern uint32_t enter_tty_cmd_write;
44extern uint32_t enter_tty_isr_write;
45extern uint32_t exit_tty_isr_write;
46extern uint32_t exit_tty_cmd_write;
47extern uint32_t exit_chdev_server_write;
48extern uint32_t exit_chdev_cmd_write;
49extern uint32_t exit_txt_write;
50extern uint32_t exit_devfs_write;
51extern uint32_t exit_sys_write;
52
53//////////////////////////////////
54int sys_write( 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 vfs_file_t * file_ptr; // remote file local pointer
62 cxy_t file_cxy; // remote file cluster identifier
63 uint32_t file_type; // file type
64 uint32_t file_offset; // file offset
65 uint32_t file_attr; // file attributes
66 vfs_inode_t * inode_ptr; // local pointer on associated inode
67 uint32_t nbytes; // number of bytes actually written
68 reg_t save_sr; // required to enable IRQs during syscall
69
70 thread_t * this = CURRENT_THREAD;
71 process_t * process = this->process;
72
73#if (DEBUG_SYS_WRITE || CONFIG_INSTRUMENTATION_SYSCALLS)
74uint64_t tm_start = hal_get_cycles();
75#endif
76
77#if DEBUG_SYS_WRITE
78if( DEBUG_SYS_WRITE < tm_start )
79printk("\n[%s] thread[%x,%x] enter / vaddr %x / %d bytes / cycle %d\n",
80__FUNCTION__, process->pid, this->trdid, vaddr, count, (uint32_t)tm_start );
81#endif
82
83#if (DEBUG_SYS_WRITE & 1)
84if( DEBUG_SYS_WRITE < tm_start )
85enter_sys_write = (uint32_t)tm_start;
86#endif
87
88 // check file_id argument
89 if( file_id >= CONFIG_PROCESS_FILE_MAX_NR )
90 {
91
92#if DEBUG_SYSCALLS_ERROR
93printk("\n[ERROR] in %s : thread[%x,%x] illegal file descriptor index %d\n",
94__FUNCTION__, process->pid, this->trdid, file_id );
95#endif
96 this->errno = EBADFD;
97 return -1;
98 }
99
100 // check user buffer in user space
101 error = vmm_get_vseg( process , (intptr_t)vaddr , &vseg );
102
103 if ( error )
104 {
105
106#if DEBUG_SYSCALLS_ERROR
107printk("\n[ERROR] in %s : thread[%x,%x] user buffer unmapped %x\n",
108__FUNCTION__ , process->pid, this->trdid, (intptr_t)vaddr );
109#endif
110 this->errno = EINVAL;
111 return -1;
112 }
113
114 // get extended pointer on remote file descriptor
115 file_xp = process_fd_get_xptr_from_local( process , file_id );
116
117 if( file_xp == XPTR_NULL )
118 {
119
120#if DEBUG_SYSCALLS_ERROR
121printk("\n[ERROR] in %s : thread[%x,%x] undefined file descriptor = %d\n",
122__FUNCTION__, process->pid, this->trdid, file_id );
123#endif
124 this->errno = EBADFD;
125 return -1;
126 }
127
128 // get file descriptor cluster and local pointer
129 file_ptr = GET_PTR( file_xp );
130 file_cxy = GET_CXY( file_xp );
131
132 // get file type, offset, aatributes, and associated inode
133 file_type = hal_remote_l32( XPTR( file_cxy , &file_ptr->type ) );
134 file_offset = hal_remote_l32( XPTR( file_cxy , &file_ptr->offset ) );
135 inode_ptr = hal_remote_lpt( XPTR( file_cxy , &file_ptr->inode ) );
136 file_attr = hal_remote_l32( XPTR( file_cxy , &file_ptr->attr ) );
137
138 // enable IRQs
139 hal_enable_irq( &save_sr );
140
141 // action depend on file type:
142
143 if( file_type == INODE_TYPE_FILE ) // write to a file mapper
144 {
145 // check file writable
146 if( (file_attr & FD_ATTR_WRITE_ENABLE) == 0 )
147 {
148
149#if DEBUG_SYSCALLS_ERROR
150printk("\n[ERROR] in %s : thread[%x,%x] file %d not writable\n",
151__FUNCTION__ , process->pid, this->trdid, file_id );
152#endif
153 hal_restore_irq( save_sr );
154 this->errno = EBADFD;
155 return -1;
156 }
157
158 // move count bytes to mapper
159 nbytes = vfs_user_move( false, // from buffer to mapper
160 file_xp,
161 vaddr,
162 count );
163 }
164 else if( file_type == INODE_TYPE_DEV ) // write to TXT device
165 {
166 // move count bytes to device
167 nbytes = devfs_user_move( false, // from buffer to device
168 file_xp,
169 vaddr,
170 count );
171 }
172 else // not FILE and not DEV
173 {
174
175#if DEBUG_SYSCALLS_ERROR
176printk("\n[ERROR] in %s : thread[%x,%x] / illegal inode type %\n",
177__FUNCTION__, vfs_inode_type_str( file_type ) );
178#endif
179 hal_restore_irq( save_sr );
180 this->errno = EBADFD;
181 return -1;
182 }
183
184 // chek error
185 if( nbytes == 0xFFFFFFFF )
186 {
187
188#if DEBUG_SYSCALLS_ERROR
189printk("\n[ERROR] in %s : thread[%x,‰x] cannot write data to file %d\n",
190__FUNCTION__ , process->pid, this->trdid, file_id );
191#endif
192 hal_restore_irq( save_sr );
193 this->errno = EIO;
194 return -1;
195 }
196
197 // restore IRQs
198 hal_restore_irq( save_sr );
199
200 hal_fence();
201
202#if (DEBUG_SYS_WRITE || CONFIG_INSTRUMENTATION_SYSCALLS)
203uint64_t tm_end = hal_get_cycles();
204#endif
205
206#if DEBUG_SYS_WRITE
207if( DEBUG_SYS_WRITE < tm_end )
208printk("\n[%s] thread[%x,%x] exit / cycle %d\n",
209__FUNCTION__, process->pid, this->trdid, (uint32_t)tm_end );
210#endif
211
212#if CONFIG_INSTRUMENTATION_SYSCALLS
213hal_atomic_add( &syscalls_cumul_cost[SYS_WRITE] , tm_end - tm_start );
214hal_atomic_add( &syscalls_occurences[SYS_WRITE] , 1 );
215#endif
216
217#if (DEBUG_SYS_WRITE & 1)
218if( DEBUG_SYS_WRITE < tm_start )
219exit_sys_write = (uint32_t)tm_end;
220
221if( DEBUG_SYS_WRITE < tm_start )
222printk("\n***** timing to write a string *****\n"
223" - enter_sys_write = %d / delta %d\n"
224" - enter_devfs_write = %d / delta %d\n"
225" - enter_txt_write = %d / delta %d\n"
226" - enter_chdev_cmd_write = %d / delta %d\n"
227" - enter_chdev_server_write = %d / delta %d\n"
228" - enter_tty_cmd_write = %d / delta %d\n"
229" - enter_tty_isr_write = %d / delta %d\n"
230" - exit_tty_isr_write = %d / delta %d\n"
231" - exit_tty_cmd_write = %d / delta %d\n"
232" - exit_chdev_server_write = %d / delta %d\n"
233" - exit_chdev_cmd_write = %d / delta %d\n"
234" - exit_txt_write = %d / delta %d\n"
235" - exit_devfs_write = %d / delta %d\n"
236" - exit_sys_write = %d / delta %d\n",
237enter_sys_write , 0 ,
238enter_devfs_write , enter_devfs_write - enter_sys_write ,
239enter_txt_write , enter_txt_write - enter_devfs_write ,
240enter_chdev_cmd_write , enter_chdev_cmd_write - enter_txt_write ,
241enter_chdev_server_write , enter_chdev_server_write - enter_chdev_cmd_write ,
242enter_tty_cmd_write , enter_tty_cmd_write - enter_chdev_server_write ,
243enter_tty_isr_write , enter_tty_isr_write - enter_tty_cmd_write ,
244exit_tty_isr_write , exit_tty_isr_write - enter_tty_isr_write ,
245exit_tty_cmd_write , exit_tty_cmd_write - exit_tty_isr_write ,
246exit_chdev_server_write , exit_chdev_server_write - exit_tty_cmd_write ,
247exit_chdev_cmd_write , exit_chdev_cmd_write - exit_chdev_server_write ,
248exit_txt_write , exit_txt_write - exit_chdev_cmd_write ,
249exit_devfs_write , exit_devfs_write - exit_txt_write ,
250exit_sys_write , exit_sys_write - exit_devfs_write );
251#endif
252
253 return nbytes;
254
255} // end sys_write()
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