source: trunk/kernel/syscalls/sys_munmap.c @ 625

Last change on this file since 625 was 625, checked in by alain, 5 years ago

Fix a bug in the vmm_remove_vseg() function: the physical pages
associated to an user DATA vseg were released to the kernel when
the target process descriptor was in the reference cluster.
This physical pages release should be done only when the page
forks counter value is zero.
All other modifications are cosmetic.

File size: 2.9 KB
Line 
1/*
2 * sys_munmap.c - unmap a mapping from process virtual address space
3 *
4 * Authors       Alain Greiner (2016,2017,2018,2019)
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_vmm.h>
27#include <hal_irqmask.h>
28#include <shared_syscalls.h>
29#include <errno.h>
30#include <thread.h>
31#include <printk.h>
32#include <mapper.h>
33#include <vfs.h>
34#include <process.h>
35#include <vmm.h>
36
37#include <syscalls.h>
38
39////////////////////////////////
40int sys_munmap( void     * vaddr,
41                uint32_t   size )
42{
43    error_t       error;
44    vseg_t      * vseg;
45    reg_t         save_sr;      // required to enable IRQs
46
47        thread_t    * this    = CURRENT_THREAD;
48        process_t   * process = this->process;
49
50#if (DEBUG_SYS_MUNMAP || CONFIG_INSTRUMENTATION_SYSCALLS)
51uint64_t     tm_start = hal_get_cycles();
52#endif
53
54#if DEBUG_SYS_MUNMAP
55if( DEBUG_SYS_MUNMAP < tm_start )
56printk("\n[DBG] %s : thread %x enter / process %x / cycle %d\n",
57__FUNCTION__ , this, process->pid, (uint32_t)tm_start );
58#endif
59
60    // check user buffer is mapped
61    error = vmm_get_vseg( process , (intptr_t)vaddr, &vseg );
62
63    if( error )
64    {
65
66#if DEBUG_SYSCALLS_ERROR
67printk("\n[ERROR] in %s : thread[%x,%x] / user buffer unmapped %x\n",
68__FUNCTION__ , process->pid, this->trdid, (intptr_t)vaddr );
69hal_vmm_display( process , false );
70#endif
71                this->errno = EINVAL;
72                return -1;
73    }
74
75    // enable IRQs
76    hal_enable_irq( &save_sr );
77
78    // call relevant kernel function
79    error = vmm_resize_vseg( process , (intptr_t)vaddr , (intptr_t)size );
80
81    if ( error )
82    {
83
84#if DEBUG_SYSCALLS_ERROR
85printk("\n[ERROR] in %s : cannot remove mapping\n", __FUNCTION__ );
86#endif
87                this->errno = EINVAL;
88                return -1;
89    }
90
91    // restore IRQs
92    hal_restore_irq( save_sr );
93
94#if (DEBUG_SYS_MUNMAP || CONFIG_INSTRUMENTATION_SYSCALLS)
95uint64_t     tm_end = hal_get_cycles();
96#endif
97
98#if CONFIG_INSTRUMENTATION_SYSCALLS
99hal_atomic_add( &syscalls_cumul_cost[SYS_MUNMAP] , tm_end - tm_start );
100hal_atomic_add( &syscalls_occurences[SYS_MUNMAP] , 1 );
101#endif
102
103#if DEBUG_SYS_MUNMAP
104if( DEBUG_SYS_MUNMAP < tm_start )
105printk("\n[DBG] %s : thread %x exit / process %x / cycle %d\n",
106__FUNCTION__ , this, process->pid, (uint32_t)tm_end );
107#endif
108
109    return 0;
110
111}  // end sys_munmap()
112
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