| 1 | /* |
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| 2 | * sys_read.c - read bytes from a file |
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| 3 | * |
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| 4 | * Author Alain Greiner (2016,2017) |
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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_types.h> |
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| 26 | #include <hal_uspace.h> |
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| 27 | #include <hal_special.h> |
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| 28 | #include <errno.h> |
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| 29 | #include <vfs.h> |
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| 30 | #include <vmm.h> |
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| 31 | #include <thread.h> |
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| 32 | #include <printk.h> |
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| 33 | #include <process.h> |
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| 34 | |
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| 35 | /* TODO: user page(s) need to be locked [AG] */ |
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| 36 | |
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| 37 | ///////////////////////////////// |
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| 38 | int sys_read( uint32_t file_id, |
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| 39 | void * buf, |
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| 40 | uint32_t count ) |
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| 41 | { |
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| 42 | error_t error; |
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| 43 | paddr_t paddr; // required for user space checking |
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| 44 | xptr_t file_xp; // remote file extended pointer |
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| 45 | |
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| 46 | thread_t * this = CURRENT_THREAD; |
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| 47 | process_t * process = this->process; |
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| 48 | |
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| 49 | // check file_id argument |
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| 50 | if( file_id >= CONFIG_PROCESS_FILE_MAX_NR ) |
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| 51 | { |
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| 52 | printk("\n[ERROR] in %s : illegal file descriptor index = %d\n", |
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| 53 | __FUNCTION__ , file_id ); |
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| 54 | this->errno = EBADFD; |
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| 55 | return -1; |
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| 56 | } |
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| 57 | |
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| 58 | // check user buffer in user space |
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| 59 | error = vmm_v2p_translate( false , buf , &paddr ); |
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| 60 | |
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| 61 | if ( error ) |
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| 62 | { |
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| 63 | printk("\n[ERROR] in %s : user buffer unmapped = %x\n", |
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| 64 | __FUNCTION__ , (intptr_t)buf ); |
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| 65 | this->errno = EINVAL; |
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| 66 | return -1; |
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| 67 | } |
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| 68 | |
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| 69 | // get extended pointer on remote file descriptor |
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| 70 | file_xp = process_fd_get_xptr( process , file_id ); |
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| 71 | |
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| 72 | if( file_xp == XPTR_NULL ) |
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| 73 | { |
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| 74 | printk("\n[ERROR] in %s : undefined file descriptor index = %d\n", |
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| 75 | __FUNCTION__ , file_id ); |
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| 76 | this->errno = EBADFD; |
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| 77 | return -1; |
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| 78 | } |
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| 79 | |
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| 80 | // get file descriptor cluster and local pointer |
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| 81 | vfs_file_t * file_ptr = (vfs_file_t *)GET_PTR( file_xp ); |
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| 82 | cxy_t file_cxy = GET_CXY( file_xp ); |
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| 83 | |
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| 84 | // check file readable |
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| 85 | uint32_t attr = hal_remote_lw( XPTR( file_cxy , &file_ptr->attr ) ); |
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| 86 | if( (attr & FD_ATTR_READ_ENABLE) == 0 ) |
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| 87 | { |
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| 88 | printk("\n[ERROR] in %s : file %d not readable\n", |
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| 89 | __FUNCTION__ , file_id ); |
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| 90 | this->errno = EBADFD; |
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| 91 | return -1; |
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| 92 | } |
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| 93 | |
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| 94 | // transfer count bytes directly from mapper to user buffer |
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| 95 | error = vfs_user_move( true, // to_buffer |
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| 96 | file_xp , |
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| 97 | buf, |
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| 98 | count ); |
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| 99 | |
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| 100 | if( error ) |
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| 101 | { |
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| 102 | printk("\n[ERROR] in %s cannot read data from file %d\n", |
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| 103 | __FUNCTION__ , file_id ); |
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| 104 | this->errno = error; |
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| 105 | return -1; |
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| 106 | } |
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| 107 | |
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| 108 | hal_fence(); |
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| 109 | |
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| 110 | return 0; |
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| 111 | |
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| 112 | } // end sys_read() |
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