source: trunk/kernel/syscalls/sys_stat.c @ 594

Last change on this file since 594 was 594, checked in by alain, 3 years ago

Fix various bugs in sys_stat() and sys_mmap() functions.
Improve debug in other functions.

File size: 4.9 KB
Line 
1/*
2 * sys_stat.c - Return statistics on a file or directory.
3 *
4 * Author    Alain Greiner  (2016,2017,2018)
5 *
6 * Copyright (c) UPMC Sorbonne Universites
7 *
8 * This file is part of ALMOS-MKH.
9 *
10 * ALMOS-MKH is free software; you can redistribute it and/or modify it
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 *
14 * ALMOS-MKH is distributed in the hope that it will be useful, but
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
20 * along with ALMOS-MKH; if not, write to the Free Software Foundation,
21 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24#include <hal_kernel_types.h>
25#include <hal_uspace.h>
26#include <hal_special.h>
27#include <errno.h>
28#include <thread.h>
29#include <printk.h>
30#include <vfs.h>
31#include <vmm.h>
32#include <process.h>
33
34#include <syscalls.h>
35
36/////////////////////////////////////
37int sys_stat( char        * pathname,
38              struct stat * u_stat )
39{
40    error_t       error;
41    vseg_t      * vseg;                   // for user space checking
42    struct stat   k_stat;                 // in kernel space
43    xptr_t        inode_xp;               // extended pointer on target inode
44
45    char          kbuf[CONFIG_VFS_MAX_PATH_LENGTH];
46       
47        thread_t  * this    = CURRENT_THREAD;
48        process_t * process = this->process;
49
50#if (DEBUG_SYS_STAT || CONFIG_INSTRUMENTATION_SYSCALLS)
51uint64_t     tm_start = hal_get_cycles();
52#endif
53
54    // check stat structure in user space
55    error = vmm_get_vseg( process , (intptr_t)u_stat , &vseg );
56
57        if( error )
58        {
59
60#if DEBUG_SYSCALLS_ERROR
61printk("\n[ERROR] in %s / thread[%x,%x] : stat structure unmapped\n",
62__FUNCTION__ , process->pid , this->trdid );
63vmm_display( process , false );
64#endif
65                this->errno = EINVAL;
66                return -1;
67        }       
68
69    // check pathname length
70    if( hal_strlen_from_uspace( pathname ) >= CONFIG_VFS_MAX_PATH_LENGTH )
71    {
72
73#if DEBUG_SYSCALLS_ERROR
74printk("\n[ERROR] in %s / thread[%x,%x] : pathname too long\n",
75 __FUNCTION__ , process->pid , this->trdid );
76#endif
77        this->errno = ENFILE;
78        return -1;
79    }
80
81    // copy pathname in kernel space
82    hal_strcpy_from_uspace( kbuf , pathname , CONFIG_VFS_MAX_PATH_LENGTH );
83
84#if DEBUG_SYS_STAT
85if( DEBUG_SYS_STAT < tm_start )
86printk("\n[%s] thread[%x,%x] enter for file <%s> / cycle %d\n",
87__FUNCTION__, process->pid, this->trdid, kbuf, (uint32_t)tm_start );
88#endif
89
90    // get cluster and local pointer on reference process
91    xptr_t      ref_xp  = process->ref_xp;
92    process_t * ref_ptr = (process_t *)GET_PTR( ref_xp );
93    cxy_t       ref_cxy = GET_CXY( ref_xp );
94
95    // get extended pointer on cwd inode
96    xptr_t cwd_xp = hal_remote_l64( XPTR( ref_cxy , &ref_ptr->vfs_cwd_xp ) );
97
98    // get the cwd lock in read mode from reference process
99    remote_rwlock_rd_acquire( XPTR( ref_cxy , &ref_ptr->cwd_lock ) );
100
101    // get extended pointer on remote file descriptor
102    error = vfs_lookup( cwd_xp,
103                        kbuf,
104                        0,
105                        &inode_xp );
106
107    // release the cwd lock
108    remote_rwlock_rd_release( XPTR( ref_cxy , &ref_ptr->cwd_lock ) );
109
110    if( error )
111    {
112
113#if DEBUG_SYSCALLS_ERROR
114printk("\n[ERROR] in %s / thread[%x,%x] : cannot found file <%s>\n",
115__FUNCTION__ , process->pid , this->trdid , pathname );
116#endif
117        this->errno = ENFILE;
118        return -1;
119    }
120
121#if (DEBUG_SYS_STAT & 1)
122if( DEBUG_SYS_STAT < tm_start )
123printk("\n[%s] thread[%x,%x] got inode %x in cluster %x for <%s>\n",
124__FUNCTION__, process->pid, this->trdid, GET_PTR(inode_xp), GET_CXY(inode_xp), kbuf );
125#endif
126
127    // call VFS function to get stat info
128    error = vfs_stat( inode_xp,
129                      &k_stat );
130    if( error )
131        {
132
133#if DEBUG_SYSCALLS_ERROR
134printk("\n[ERROR] in %s / thread[%x,%x] : cannot get stats for inode <%s>\n",
135__FUNCTION__ , process->pid , this->trdid , pathname );
136#endif
137                this->errno = ENFILE;
138                return -1;
139        }
140   
141#if (DEBUG_SYS_STAT & 1)
142if( DEBUG_SYS_STAT < tm_start )
143printk("\n[%s] thread[%x,%x] set kstat : inum %d / size %d / mode %d\n",
144__FUNCTION__, process->pid, this->trdid, k_stat.st_ino, k_stat.st_size, k_stat.st_mode );
145#endif
146
147    // copy k_stat to u_stat
148    hal_copy_to_uspace( u_stat , &k_stat , sizeof(struct stat) );
149
150    hal_fence();
151
152#if (DEBUG_SYS_STAT || CONFIG_INSTRUMENTATION_SYSCALLS)
153uint64_t     tm_end = hal_get_cycles();
154#endif
155
156#if DEBUG_SYS_STAT
157if( DEBUG_SYS_STAT < tm_end )
158printk("\n[%s] thread[%x,%x] exit for file <%s> / cycle %d\n",
159__FUNCTION__, process->pid, this->trdid, kbuf, (uint32_t)tm_end );
160#endif
161 
162#if CONFIG_INSTRUMENTATION_SYSCALLS
163hal_atomic_add( &syscalls_cumul_cost[SYS_STAT] , tm_end - tm_start );
164hal_atomic_add( &syscalls_occurences[SYS_STAT] , 1 );
165#endif
166
167        return 0;
168
169}  // end sys_stat()
170
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