source: trunk/kernel/syscalls/sys_chdir.c

Last change on this file was 670, checked in by alain, 3 years ago

1) Introduce up to 4 command lines arguments in the KSH "load" command.
These arguments are transfered to the user process through the
argc/argv mechanism, using the user space "args" vseg.

2) Introduce the named and anonymous "pipes", for inter-process communication
through the pipe() and mkfifo() syscalls.

3) Introduce the "chat" application to validate the two above mechanisms.

4) Improve printk() and assert() fonctions in printk.c.

File size: 4.0 KB
RevLine 
[1]1/*
[610]2 * sys_chdir.c - kernel function implementing the "chdir" syscall.
[301]3 *
[637]4 * Author    Alain Greiner (2016,2017,2018, 2019)
[23]5 *
[610]6 * Copyright (c) UPMC Sorbonne Universites
[1]7 *
[23]8 * This file is part of ALMOS-MKH.
[1]9 *
[23]10 * ALMOS-MKH is free software; you can redistribute it and/or modify it
[1]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 *
[23]14 * ALMOS-MKH is distributed in the hope that it will be useful, but
[1]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
[23]20 * along with ALMOS-MKH; if not, write to the Free Software Foundation,
[1]21 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
[457]24#include <hal_kernel_types.h>
[23]25#include <hal_uspace.h>
[11]26#include <chdev.h>
[1]27#include <rwlock.h>
28#include <vfs.h>
[23]29#include <errno.h>
[1]30#include <thread.h>
[23]31#include <printk.h>
32#include <process.h>
[1]33
[506]34#include <syscalls.h>
35
[23]36/////////////////////////////////
[566]37int sys_chdir ( char * pathname )
[1]38{
[301]39    error_t   error;
[610]40    vseg_t  * vseg; 
41    xptr_t    root_inode_xp;
42
[23]43    char      kbuf[CONFIG_VFS_MAX_PATH_LENGTH];
[1]44
[301]45    thread_t  * this    = CURRENT_THREAD;
[23]46    process_t * process = this->process;
[1]47
[670]48#if DEBUG_SYS_CHDIR || DEBUG_SYSCALLS_ERROR || CONFIG_INSTRUMENTATION_SYSCALLS
[610]49uint64_t     tm_start = hal_get_cycles();
50#endif
51
[407]52    // check pathname length
53    if( hal_strlen_from_uspace( pathname ) >= CONFIG_VFS_MAX_PATH_LENGTH )
[23]54    {
[566]55
56#if DEBUG_SYSCALLS_ERROR
[670]57if( DEBUG_SYSCALLS_ERROR < (uint32_t)tm_start )
[610]58printk("\n[ERROR] in %s : pathname too long / thread[%x,%x]\n",
59__FUNCTION__, process->pid, this->trdid );
[566]60#endif
[610]61        this->errno = EINVAL;
[23]62        return -1;
63    }
64
[610]65    // check pathname in user space
66    if( vmm_get_vseg( process, (intptr_t)pathname , &vseg ) )
67        {
68
69#if DEBUG_SYSCALLS_ERROR
[670]70if( DEBUG_SYSCALLS_ERROR < (uint32_t)tm_start )
[610]71printk("\n[ERROR] in %s : user buffer unmapped %x for thread[%x,%x]\n",
72__FUNCTION__ , (intptr_t)pathname , process->pid, this->trdid );
73#endif
74                this->errno = EINVAL;
75        return -1;
76        }
77
[407]78    // copy pathname in kernel space
[637]79    hal_strcpy_from_uspace( XPTR( local_cxy , kbuf ),
80                            pathname,
81                            CONFIG_VFS_MAX_PATH_LENGTH );
[407]82
[610]83#if DEBUG_SYS_CHDIR
[670]84if( DEBUG_SYS_CHDIR < (uint32_t)tm_start )
[610]85printk("\n[%s] thread[%x,%x] enter for <%s> / cycle %d\n",
86__FUNCTION__, process->pid, this->trdid, kbuf, (uint32_t)tm_start );
87#endif
[566]88
[610]89    // compute root inode for path
90    if( kbuf[0] == '/' )                        // absolute path
91    {
92        // use extended pointer on VFS root inode
93        root_inode_xp = process->vfs_root_xp;
94    }
95    else                                        // relative path
96    {
97        // get cluster and local pointer on reference process
98        xptr_t      ref_xp  = process->ref_xp;
99        process_t * ref_ptr = (process_t *)GET_PTR( ref_xp );
100        cxy_t       ref_cxy = GET_CXY( ref_xp );
[23]101
[610]102        // use extended pointer on CWD inode
103        root_inode_xp = hal_remote_l64( XPTR( ref_cxy , &ref_ptr->cwd_xp ) );
104    }
[23]105
[610]106    // call the relevant VFS function
107    error = vfs_chdir( root_inode_xp , kbuf );
[301]108
109    if( error )
110    {
[610]111
112#if DEBUG_SYSCALLS_ERROR
[670]113if( DEBUG_SYSCALLS_ERROR < (uint32_t)tm_start )
[610]114printk("\n[ERROR] in %s / thread[%x,%x] : cannot change CWD\n",
115__FUNCTION__ , process->pid , this->trdid );
116#endif
[301]117        this->errno = error;
118        return -1;
119    }
120
[610]121    hal_fence();
122
123#if (DEBUG_SYS_CHDIR || CONFIG_INSTRUMENTATION_SYSCALLS)
124uint64_t     tm_end = hal_get_cycles();
125#endif
126
127#if DEBUG_SYS_CHDIR
128if( DEBUG_SYS_CHDIR < tm_end )
129printk("\n[%s] thread[%x,%x] exit  / cycle %d\n",
130__FUNCTION__, process->pid, this->trdid, (uint32_t)tm_end );
131#endif
132 
133#if CONFIG_INSTRUMENTATION_SYSCALLS
134hal_atomic_add( &syscalls_cumul_cost[SYS_CHDIR] , tm_end - tm_start );
135hal_atomic_add( &syscalls_occurences[SYS_CHDIR] , 1 );
136#endif
137
[301]138    return 0;
[1]139}
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