/* * sys_write.c - Kernel function implementing the "write" system call. * * Author Alain Greiner (2016,2017,2018) * * Copyright (c) UPMC Sorbonne Universites * * This file is part of ALMOS-MKH. * * ALMOS-MKH is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by * the Free Software Foundation; version 2.0 of the License. * * ALMOS-MKH is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with ALMOS-MKH; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #include #include #include #include #include #include #include #include #include #include #include extern uint32_t enter_sys_write; extern uint32_t enter_devfs_write; extern uint32_t enter_txt_write; extern uint32_t enter_chdev_cmd_write; extern uint32_t enter_chdev_server_write; extern uint32_t enter_tty_cmd_write; extern uint32_t enter_tty_isr_write; extern uint32_t exit_tty_isr_write; extern uint32_t exit_tty_cmd_write; extern uint32_t exit_chdev_server_write; extern uint32_t exit_chdev_cmd_write; extern uint32_t exit_txt_write; extern uint32_t exit_devfs_write; extern uint32_t exit_sys_write; ////////////////////////////////// int sys_write( uint32_t file_id, void * vaddr, uint32_t count ) { error_t error; vseg_t * vseg; // required for user space checking xptr_t file_xp; // remote file extended pointer vfs_file_t * file_ptr; // remote file local pointer cxy_t file_cxy; // remote file cluster identifier uint32_t file_type; // file type uint32_t file_offset; // current file offset uint32_t file_attr; // file_attribute vfs_inode_t * inode_ptr; // local pointer on associated inode uint32_t nbytes; // number of bytes actually written reg_t save_sr; // required to enable IRQs during syscall thread_t * this = CURRENT_THREAD; process_t * process = this->process; #if (DEBUG_SYS_WRITE || CONFIG_INSTRUMENTATION_SYSCALLS) uint64_t tm_start = hal_get_cycles(); #endif #if DEBUG_SYS_WRITE tm_start = hal_get_cycles(); if( DEBUG_SYS_WRITE < tm_start ) printk("\n[%s] thread[%x,%x] enter / vaddr %x / count %d / cycle %d\n", __FUNCTION__, process->pid, this->trdid, vaddr, count, (uint32_t)tm_start ); #endif #if (DEBUG_SYS_WRITE & 1) enter_sys_write = (uint32_t)tm_start; #endif // check file_id argument if( file_id >= CONFIG_PROCESS_FILE_MAX_NR ) { #if DEBUG_SYSCALLS_ERROR printk("\n[ERROR] in %s : thread[%x,%x] illegal file descriptor index %d\n", __FUNCTION__, process->pid, this->trdid, file_id ); #endif this->errno = EBADFD; return -1; } // check user buffer in user space error = vmm_get_vseg( process , (intptr_t)vaddr , &vseg ); if ( error ) { #if DEBUG_SYSCALLS_ERROR printk("\n[ERROR] in %s : thread[%x,%x] user buffer unmapped %x\n", __FUNCTION__ , process->pid, this->trdid, (intptr_t)vaddr ); vmm_display( process , false ); #endif this->errno = EINVAL; return -1; } // get extended pointer on remote file descriptor file_xp = process_fd_get_xptr( process , file_id ); if( file_xp == XPTR_NULL ) { #if DEBUG_SYSCALLS_ERROR printk("\n[ERROR] in %s : thread[%x,%x] undefined file descriptor = %d\n", __FUNCTION__, process->pid, this->trdid, file_id ); #endif this->errno = EBADFD; return -1; } // get file descriptor cluster and local pointer file_ptr = GET_PTR( file_xp ); file_cxy = GET_CXY( file_xp ); // get file type, offset, aatributes, and associated inode file_type = hal_remote_l32( XPTR( file_cxy , &file_ptr->type ) ); file_offset = hal_remote_l32( XPTR( file_cxy , &file_ptr->offset ) ); inode_ptr = hal_remote_lpt( XPTR( file_cxy , &file_ptr->inode ) ); file_attr = hal_remote_l32( XPTR( file_cxy , &file_ptr->attr ) ); // enable IRQs hal_enable_irq( &save_sr ); // action depend on file type if( file_type == INODE_TYPE_FILE ) // write to file mapper { // check file writable if( (file_attr & FD_ATTR_WRITE_ENABLE) == 0 ) { #if DEBUG_SYSCALLS_ERROR printk("\n[ERROR] in %s : thread[%x,%x] file %d not writable\n", __FUNCTION__ , process->pid, this->trdid, file_id ); #endif hal_restore_irq( save_sr ); this->errno = EBADFD; return -1; } // move count bytes to mapper nbytes = vfs_user_move( false, // from buffer to mapper file_xp, vaddr, count ); if ( nbytes != count ) { #if DEBUG_SYSCALLS_ERROR printk("\n[ERROR] in %s : thread[%x,%x] cannot write %d bytes into file %d\n", __FUNCTION__ , process->pid, this->trdid, count, file_id ); #endif hal_restore_irq( save_sr ); this->errno = EIO; return -1; } // update size field in inode if required xptr_t size_xp = XPTR( file_cxy , &inode_ptr->size ); uint32_t inode_size = hal_remote_l32( size_xp ); if ( (file_offset + count) > inode_size ) { hal_remote_s32( size_xp , file_offset + count ); } } else if( file_type == INODE_TYPE_DEV ) // write to TXT device { // move count bytes to device nbytes = devfs_user_move( false, // from buffer to device file_xp, vaddr, count ); if( nbytes != count ) { #if DEBUG_SYSCALLS_ERROR printk("\n[ERROR] in %s : thread[%x,‰x] cannot write data to file %d\n", __FUNCTION__ , process->pid, this->trdid, file_id ); #endif hal_restore_irq( save_sr ); this->errno = EIO; return -1; } } else // not FILE and not DEV { #if DEBUG_SYSCALLS_ERROR printk("\n[ERROR] in %s : thread[%x,%x] / illegal inode type %\n", __FUNCTION__, vfs_inode_type_str( file_type ) ); #endif hal_restore_irq( save_sr ); this->errno = EBADFD; return -1; } // restore IRQs hal_restore_irq( save_sr ); hal_fence(); #if (DEBUG_SYS_WRITE || CONFIG_INSTRUMENTATION_SYSCALLS) uint64_t tm_end = hal_get_cycles(); #endif #if DEBUG_SYS_WRITE if( DEBUG_SYS_WRITE < tm_end ) printk("\n[%s] thread[%x,%x] exit / cycle %d\n", __FUNCTION__, process->pid, this->trdid, (uint32_t)tm_end ); #endif #if CONFIG_INSTRUMENTATION_SYSCALLS hal_atomic_add( &syscalls_cumul_cost[SYS_WRITE] , tm_end - tm_start ); hal_atomic_add( &syscalls_occurences[SYS_WRITE] , 1 ); #endif #if (DEBUG_SYS_WRITE & 1) exit_sys_write = (uint32_t)tm_end; printk("\n***** timing to write a string *****\n" " - enter_sys_write = %d / delta %d\n" " - enter_devfs_write = %d / delta %d\n" " - enter_txt_write = %d / delta %d\n" " - enter_chdev_cmd_write = %d / delta %d\n" " - enter_chdev_server_write = %d / delta %d\n" " - enter_tty_cmd_write = %d / delta %d\n" " - enter_tty_isr_write = %d / delta %d\n" " - exit_tty_isr_write = %d / delta %d\n" " - exit_tty_cmd_write = %d / delta %d\n" " - exit_chdev_server_write = %d / delta %d\n" " - exit_chdev_cmd_write = %d / delta %d\n" " - exit_txt_write = %d / delta %d\n" " - exit_devfs_write = %d / delta %d\n" " - exit_sys_write = %d / delta %d\n", enter_sys_write , 0 , enter_devfs_write , enter_devfs_write - enter_sys_write , enter_txt_write , enter_txt_write - enter_devfs_write , enter_chdev_cmd_write , enter_chdev_cmd_write - enter_txt_write , enter_chdev_server_write , enter_chdev_server_write - enter_chdev_cmd_write , enter_tty_cmd_write , enter_tty_cmd_write - enter_chdev_server_write , enter_tty_isr_write , enter_tty_isr_write - enter_tty_cmd_write , exit_tty_isr_write , exit_tty_isr_write - enter_tty_isr_write , exit_tty_cmd_write , exit_tty_cmd_write - exit_tty_isr_write , exit_chdev_server_write , exit_chdev_server_write - exit_tty_cmd_write , exit_chdev_cmd_write , exit_chdev_cmd_write - exit_chdev_server_write , exit_txt_write , exit_txt_write - exit_chdev_cmd_write , exit_devfs_write , exit_devfs_write - exit_txt_write , exit_sys_write , exit_sys_write - exit_devfs_write ); #endif return nbytes; } // end sys_write()