/* * sys_read.c - read bytes from a file * * 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_read; extern uint32_t enter_devfs_read; extern uint32_t enter_txt_read; extern uint32_t enter_chdev_cmd_read; extern uint32_t enter_chdev_server_read; extern uint32_t enter_tty_cmd_read; extern uint32_t enter_tty_isr_read; extern uint32_t exit_tty_isr_read; extern uint32_t exit_tty_cmd_read; extern uint32_t exit_chdev_server_read; extern uint32_t exit_chdev_cmd_read; extern uint32_t exit_txt_read; extern uint32_t exit_devfs_read; extern uint32_t exit_sys_read; ///////////////////////////////// int sys_read( 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 uint32_t nbytes; // number of bytes actually read reg_t save_sr; // required to enable IRQs during syscall thread_t * this = CURRENT_THREAD; process_t * process = this->process; xptr_t process_owner_xp = process->owner_xp; #if (DEBUG_SYS_READ || CONFIG_INSTRUMENTATION_SYSCALLS) uint64_t tm_start = hal_get_cycles(); #endif #if DEBUG_SYS_READ if( DEBUG_SYS_READ < tm_start ) printk("\n[DBG] %s : thread %x in process %x enter / vaddr %x / count %d / cycle %d\n", __FUNCTION__, this->trdid, process->pid, vaddr, count, (uint32_t)tm_start ); #endif #if (DEBUG_SYS_READ & 1) enter_sys_read = (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 : illegal file descriptor index = %d\n", __FUNCTION__ , 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 : user buffer unmapped %x / thread %x / process %x\n", __FUNCTION__ , (intptr_t)vaddr, this->trdid, process->pid ); vmm_display( process , false ); #endif this->errno = EINVAL; return -1; } // enable IRQs hal_enable_irq( &save_sr ); // 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 : undefined fd_id %d in process %x\n", __FUNCTION__ , file_id , process->pid ); #endif this->errno = EBADFD; return -1; } // get file descriptor cluster and local pointer vfs_file_t * file_ptr = GET_PTR( file_xp ); cxy_t file_cxy = GET_CXY( file_xp ); // check file readable uint32_t attr = hal_remote_l32( XPTR( file_cxy , &file_ptr->attr ) ); if( (attr & FD_ATTR_READ_ENABLE) == 0 ) { #if DEBUG_SYSCALLS_ERROR printk("\n[ERROR] in %s : file %d not readable in process %x\n", __FUNCTION__ , file_id , process->pid ); #endif this->errno = EBADFD; return -1; } // get file type vfs_inode_type_t type = hal_remote_l32( XPTR( file_cxy , &file_ptr->type ) ); // action depend on file type if( type == INODE_TYPE_FILE ) // check file readable & read from mapper { // check file readable uint32_t attr = hal_remote_l32( XPTR( file_cxy , &file_ptr->attr ) ); if( (attr & FD_ATTR_READ_ENABLE) == 0 ) { #if DEBUG_SYSCALLS_ERROR printk("\n[ERROR] in %s : file %d not readable in process %x\n", __FUNCTION__ , file_id , process->pid ); #endif this->errno = EBADFD; return -1; } // move count bytes from mapper nbytes = vfs_user_move( true, // from mapper to buffer file_xp, vaddr, count ); } else if( type == INODE_TYPE_DEV ) // check ownership & read from device { // get cluster and pointers on TXT_RX chdev xptr_t chdev_xp = chdev_from_file( file_xp ); cxy_t chdev_cxy = GET_CXY( chdev_xp ); chdev_t * chdev_ptr = GET_PTR( chdev_xp ); volatile xptr_t txt_owner_xp; uint32_t iter = 0; while( 1 ) { // extended pointer on TXT owner process txt_owner_xp = hal_remote_l64( XPTR( chdev_cxy , &chdev_ptr->ext.txt.owner_xp ) ); // check TXT_RX ownership if ( process_owner_xp != txt_owner_xp ) { if( (iter & 0xFFF) == 0 ) printk("\n[WARNING] in %s : thread %x in process %x wait TXT_RX / cycle %d\n", __FUNCTION__, this->trdid, process->pid, (uint32_t)hal_get_cycles() ); // deschedule without blocking sched_yield( "wait TXT_RX ownership" ); iter++; } else { break; } } // move count bytes from device nbytes = devfs_user_move( true, // from device to buffer file_xp, vaddr, count ); } else { nbytes = 0; assert( false , "file type %d non supported yet\n", type ); } if( nbytes != count ) { #if DEBUG_SYSCALLS_ERROR printk("\n[ERROR] in %s cannot read data from file %d in process %x\n", __FUNCTION__ , file_id , process->pid ); #endif this->errno = error; return -1; } // restore IRQs hal_restore_irq( save_sr ); hal_fence(); #if (DEBUG_SYS_READ || CONFIG_INSTRUMENTATION_SYSCALLS) uint64_t tm_end = hal_get_cycles(); #endif #if DEBUG_SYS_READ if( DEBUG_SYS_READ < tm_end ) printk("\n[DBG] %s : thread %x in process %x exit / cycle %d\n", __FUNCTION__ , this->trdid, process->pid, (uint32_t)tm_end ); #endif #if CONFIG_INSTRUMENTATION_SYSCALLS hal_atomic_add( &syscalls_cumul_cost[SYS_READ] , tm_end - tm_start ); hal_atomic_add( &syscalls_occurences[SYS_READ] , 1 ); #endif #if (DEBUG_SYS_READ & 1) exit_sys_read = (uint32_t)tm_end; printk("\n***** timing to read one character *****\n" " - enter_sys_read = %d / delta %d\n" " - enter_devfs_read = %d / delta %d\n" " - enter_txt_read = %d / delta %d\n" " - enter_chdev_cmd_read = %d / delta %d\n" " - enter_chdev_server_read = %d / delta %d\n" " - enter_tty_cmd_read = %d / delta %d\n" " - enter_tty_isr_read = %d / delta %d\n" " - exit_tty_isr_read = %d / delta %d\n" " - exit_tty_cmd_read = %d / delta %d\n" " - exit_chdev_server_read = %d / delta %d\n" " - exit_chdev_cmd_read = %d / delta %d\n" " - exit_txt_read = %d / delta %d\n" " - exit_devfs_read = %d / delta %d\n" " - exit_sys_read = %d / delta %d\n", enter_sys_read , 0 , enter_devfs_read , enter_devfs_read - enter_sys_read , enter_txt_read , enter_txt_read - enter_devfs_read , enter_chdev_cmd_read , enter_chdev_cmd_read - enter_txt_read , enter_chdev_server_read , enter_chdev_server_read - enter_chdev_cmd_read , enter_tty_cmd_read , enter_tty_cmd_read - enter_chdev_server_read , enter_tty_isr_read , enter_tty_isr_read - enter_tty_cmd_read , exit_tty_isr_read , exit_tty_isr_read - enter_tty_isr_read , exit_tty_cmd_read , exit_tty_cmd_read - exit_tty_isr_read , exit_chdev_server_read , exit_chdev_server_read - exit_tty_cmd_read , exit_chdev_cmd_read , exit_chdev_cmd_read - exit_chdev_server_read , exit_txt_read , exit_txt_read - exit_chdev_cmd_read , exit_devfs_read , exit_devfs_read - exit_txt_read , exit_sys_read , exit_sys_read - exit_devfs_read ); #endif return nbytes; } // end sys_read()