1 | /* |
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2 | * sys_write.c - Kernel function implementing the "write" system call. |
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3 | * |
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4 | * Author Alain Greiner (2016,2017,2018) |
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5 | * |
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6 | * Copyright (c) UPMC Sorbonne Universites |
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7 | * |
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8 | * This file is part of ALMOS-MKH. |
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9 | * |
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10 | * ALMOS-MKH is free software; you can redistribute it and/or modify it |
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11 | * under the terms of the GNU General Public License as published by |
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12 | * the Free Software Foundation; version 2.0 of the License. |
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13 | * |
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14 | * ALMOS-MKH is distributed in the hope that it will be useful, but |
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15 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
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16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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17 | * General Public License for more details. |
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18 | * |
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19 | * You should have received a copy of the GNU General Public License |
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20 | * along with ALMOS-MKH; if not, write to the Free Software Foundation, |
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21 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
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22 | */ |
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23 | |
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24 | #include <kernel_config.h> |
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25 | #include <hal_kernel_types.h> |
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26 | #include <hal_uspace.h> |
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27 | #include <hal_irqmask.h> |
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28 | #include <hal_special.h> |
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29 | #include <errno.h> |
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30 | #include <vfs.h> |
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31 | #include <vmm.h> |
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32 | #include <thread.h> |
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33 | #include <printk.h> |
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34 | #include <process.h> |
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35 | |
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36 | |
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37 | extern uint32_t enter_sys_write; |
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38 | extern uint32_t enter_devfs_write; |
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39 | extern uint32_t enter_txt_write; |
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40 | extern uint32_t enter_chdev_cmd_write; |
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41 | extern uint32_t enter_chdev_server_write; |
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42 | extern uint32_t enter_tty_cmd_write; |
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43 | extern uint32_t enter_tty_isr_write; |
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44 | extern uint32_t exit_tty_isr_write; |
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45 | extern uint32_t exit_tty_cmd_write; |
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46 | extern uint32_t exit_chdev_server_write; |
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47 | extern uint32_t exit_chdev_cmd_write; |
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48 | extern uint32_t exit_txt_write; |
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49 | extern uint32_t exit_devfs_write; |
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50 | extern uint32_t exit_sys_write; |
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51 | |
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52 | ////////////////////////////////// |
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53 | int sys_write( uint32_t file_id, |
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54 | void * vaddr, |
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55 | uint32_t count ) |
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56 | { |
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57 | error_t error; |
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58 | vseg_t * vseg; // required for user space checking |
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59 | xptr_t file_xp; // remote file extended pointer |
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60 | vfs_file_t * file_ptr; // remote file local pointer |
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61 | cxy_t file_cxy; // remote file cluster identifier |
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62 | uint32_t file_type; // file type |
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63 | uint32_t file_offset; // current file offset |
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64 | uint32_t file_attr; // file_attribute |
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65 | vfs_inode_t * inode_ptr; // local pointer on associated inode |
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66 | uint32_t nbytes; // number of bytes actually written |
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67 | reg_t save_sr; // required to enable IRQs during syscall |
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68 | |
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69 | thread_t * this = CURRENT_THREAD; |
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70 | process_t * process = this->process; |
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71 | |
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72 | #if (DEBUG_SYS_WRITE || CONFIG_INSTRUMENTATION_SYSCALLS) |
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73 | uint64_t tm_start = hal_get_cycles(); |
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74 | #endif |
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75 | |
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76 | #if DEBUG_SYS_WRITE |
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77 | tm_start = hal_get_cycles(); |
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78 | if( DEBUG_SYS_WRITE < tm_start ) |
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79 | printk("\n[%s] thread[%x,%x] enter / vaddr %x / count %d / cycle %d\n", |
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80 | __FUNCTION__, process->pid, this->trdid, vaddr, count, (uint32_t)tm_start ); |
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81 | #endif |
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82 | |
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83 | #if (DEBUG_SYS_WRITE & 1) |
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84 | enter_sys_write = (uint32_t)tm_start; |
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85 | #endif |
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86 | |
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87 | // check file_id argument |
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88 | if( file_id >= CONFIG_PROCESS_FILE_MAX_NR ) |
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89 | { |
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90 | |
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91 | #if DEBUG_SYSCALLS_ERROR |
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92 | printk("\n[ERROR] in %s : thread[%x,%x] illegal file descriptor index %d\n", |
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93 | __FUNCTION__, process->pid, this->trdid, file_id ); |
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94 | #endif |
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95 | this->errno = EBADFD; |
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96 | return -1; |
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97 | } |
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98 | |
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99 | // check user buffer in user space |
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100 | error = vmm_get_vseg( process , (intptr_t)vaddr , &vseg ); |
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101 | |
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102 | if ( error ) |
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103 | { |
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104 | |
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105 | #if DEBUG_SYSCALLS_ERROR |
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106 | printk("\n[ERROR] in %s : thread[%x,%x] user buffer unmapped %x\n", |
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107 | __FUNCTION__ , process->pid, this->trdid, (intptr_t)vaddr ); |
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108 | vmm_display( process , false ); |
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109 | #endif |
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110 | this->errno = EINVAL; |
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111 | return -1; |
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112 | } |
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113 | |
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114 | // get extended pointer on remote file descriptor |
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115 | file_xp = process_fd_get_xptr( process , file_id ); |
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116 | |
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117 | if( file_xp == XPTR_NULL ) |
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118 | { |
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119 | |
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120 | #if DEBUG_SYSCALLS_ERROR |
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121 | printk("\n[ERROR] in %s : thread[%x,%x] undefined file descriptor = %d\n", |
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122 | __FUNCTION__, process->pid, this->trdid, file_id ); |
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123 | #endif |
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124 | this->errno = EBADFD; |
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125 | return -1; |
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126 | } |
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127 | |
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128 | // get file descriptor cluster and local pointer |
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129 | file_ptr = GET_PTR( file_xp ); |
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130 | file_cxy = GET_CXY( file_xp ); |
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131 | |
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132 | // get file type, offset, aatributes, and associated inode |
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133 | file_type = hal_remote_l32( XPTR( file_cxy , &file_ptr->type ) ); |
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134 | file_offset = hal_remote_l32( XPTR( file_cxy , &file_ptr->offset ) ); |
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135 | inode_ptr = hal_remote_lpt( XPTR( file_cxy , &file_ptr->inode ) ); |
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136 | file_attr = hal_remote_l32( XPTR( file_cxy , &file_ptr->attr ) ); |
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137 | |
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138 | // enable IRQs |
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139 | hal_enable_irq( &save_sr ); |
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140 | |
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141 | // action depend on file type |
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142 | if( file_type == INODE_TYPE_FILE ) // write to file mapper |
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143 | { |
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144 | // check file writable |
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145 | if( (file_attr & FD_ATTR_WRITE_ENABLE) == 0 ) |
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146 | { |
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147 | |
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148 | #if DEBUG_SYSCALLS_ERROR |
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149 | printk("\n[ERROR] in %s : thread[%x,%x] file %d not writable\n", |
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150 | __FUNCTION__ , process->pid, this->trdid, file_id ); |
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151 | #endif |
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152 | hal_restore_irq( save_sr ); |
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153 | this->errno = EBADFD; |
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154 | return -1; |
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155 | } |
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156 | |
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157 | // move count bytes to mapper |
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158 | nbytes = vfs_user_move( false, // from buffer to mapper |
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159 | file_xp, |
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160 | vaddr, |
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161 | count ); |
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162 | if ( nbytes != count ) |
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163 | { |
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164 | |
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165 | #if DEBUG_SYSCALLS_ERROR |
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166 | printk("\n[ERROR] in %s : thread[%x,%x] cannot write %d bytes into file %d\n", |
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167 | __FUNCTION__ , process->pid, this->trdid, count, file_id ); |
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168 | #endif |
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169 | hal_restore_irq( save_sr ); |
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170 | this->errno = EIO; |
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171 | return -1; |
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172 | |
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173 | } |
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174 | |
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175 | // update size field in inode if required |
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176 | xptr_t size_xp = XPTR( file_cxy , &inode_ptr->size ); |
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177 | uint32_t inode_size = hal_remote_l32( size_xp ); |
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178 | if ( (file_offset + count) > inode_size ) |
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179 | { |
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180 | hal_remote_s32( size_xp , file_offset + count ); |
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181 | } |
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182 | } |
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183 | else if( file_type == INODE_TYPE_DEV ) // write to TXT device |
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184 | { |
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185 | // move count bytes to device |
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186 | nbytes = devfs_user_move( false, // from buffer to device |
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187 | file_xp, |
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188 | vaddr, |
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189 | count ); |
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190 | if( nbytes != count ) |
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191 | { |
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192 | |
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193 | #if DEBUG_SYSCALLS_ERROR |
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194 | printk("\n[ERROR] in %s : thread[%x,‰x] cannot write data to file %d\n", |
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195 | __FUNCTION__ , process->pid, this->trdid, file_id ); |
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196 | #endif |
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197 | hal_restore_irq( save_sr ); |
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198 | this->errno = EIO; |
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199 | return -1; |
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200 | } |
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201 | } |
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202 | else // not FILE and not DEV |
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203 | { |
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204 | |
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205 | #if DEBUG_SYSCALLS_ERROR |
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206 | printk("\n[ERROR] in %s : thread[%x,%x] / illegal inode type %\n", |
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207 | __FUNCTION__, vfs_inode_type_str( file_type ) ); |
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208 | #endif |
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209 | hal_restore_irq( save_sr ); |
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210 | this->errno = EBADFD; |
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211 | return -1; |
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212 | } |
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213 | |
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214 | // restore IRQs |
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215 | hal_restore_irq( save_sr ); |
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216 | |
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217 | hal_fence(); |
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218 | |
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219 | #if (DEBUG_SYS_WRITE || CONFIG_INSTRUMENTATION_SYSCALLS) |
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220 | uint64_t tm_end = hal_get_cycles(); |
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221 | #endif |
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222 | |
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223 | #if DEBUG_SYS_WRITE |
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224 | if( DEBUG_SYS_WRITE < tm_end ) |
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225 | printk("\n[%s] thread[%x,%x] exit / cycle %d\n", |
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226 | __FUNCTION__, process->pid, this->trdid, (uint32_t)tm_end ); |
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227 | #endif |
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228 | |
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229 | #if CONFIG_INSTRUMENTATION_SYSCALLS |
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230 | hal_atomic_add( &syscalls_cumul_cost[SYS_WRITE] , tm_end - tm_start ); |
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231 | hal_atomic_add( &syscalls_occurences[SYS_WRITE] , 1 ); |
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232 | #endif |
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233 | |
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234 | #if (DEBUG_SYS_WRITE & 1) |
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235 | exit_sys_write = (uint32_t)tm_end; |
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236 | |
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237 | printk("\n***** timing to write a string *****\n" |
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238 | " - enter_sys_write = %d / delta %d\n" |
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239 | " - enter_devfs_write = %d / delta %d\n" |
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240 | " - enter_txt_write = %d / delta %d\n" |
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241 | " - enter_chdev_cmd_write = %d / delta %d\n" |
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242 | " - enter_chdev_server_write = %d / delta %d\n" |
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243 | " - enter_tty_cmd_write = %d / delta %d\n" |
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244 | " - enter_tty_isr_write = %d / delta %d\n" |
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245 | " - exit_tty_isr_write = %d / delta %d\n" |
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246 | " - exit_tty_cmd_write = %d / delta %d\n" |
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247 | " - exit_chdev_server_write = %d / delta %d\n" |
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248 | " - exit_chdev_cmd_write = %d / delta %d\n" |
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249 | " - exit_txt_write = %d / delta %d\n" |
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250 | " - exit_devfs_write = %d / delta %d\n" |
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251 | " - exit_sys_write = %d / delta %d\n", |
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252 | enter_sys_write , 0 , |
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253 | enter_devfs_write , enter_devfs_write - enter_sys_write , |
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254 | enter_txt_write , enter_txt_write - enter_devfs_write , |
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255 | enter_chdev_cmd_write , enter_chdev_cmd_write - enter_txt_write , |
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256 | enter_chdev_server_write , enter_chdev_server_write - enter_chdev_cmd_write , |
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257 | enter_tty_cmd_write , enter_tty_cmd_write - enter_chdev_server_write , |
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258 | enter_tty_isr_write , enter_tty_isr_write - enter_tty_cmd_write , |
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259 | exit_tty_isr_write , exit_tty_isr_write - enter_tty_isr_write , |
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260 | exit_tty_cmd_write , exit_tty_cmd_write - exit_tty_isr_write , |
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261 | exit_chdev_server_write , exit_chdev_server_write - exit_tty_cmd_write , |
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262 | exit_chdev_cmd_write , exit_chdev_cmd_write - exit_chdev_server_write , |
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263 | exit_txt_write , exit_txt_write - exit_chdev_cmd_write , |
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264 | exit_devfs_write , exit_devfs_write - exit_txt_write , |
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265 | exit_sys_write , exit_sys_write - exit_devfs_write ); |
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266 | #endif |
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267 | |
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268 | return nbytes; |
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269 | |
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270 | } // end sys_write() |
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