source: trunk/kernel/syscalls/sys_madvise.c @ 459

Last change on this file since 459 was 1, checked in by alain, 5 years ago

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1/*
2 * kern/sys_madvise.c - process memory management related advises
3 *
4 * Copyright (c) 2008,2009,2010,2011,2012 Ghassan Almaless
5 * Copyright (c) 2011,2012 UPMC Sorbonne Universites
6 *
7 * This file is part of ALMOS-kernel.
8 *
9 * ALMOS-kernel is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; version 2.0 of the License.
12 *
13 * ALMOS-kernel is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16 * General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with ALMOS-kernel; if not, write to the Free Software Foundation,
20 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23#include <types.h>
24#include <errno.h>
25#include <bits.h>
26#include <vmm.h>
27#include <thread.h>
28#include <task.h>
29#include <cluster.h>
30#include <page.h>
31#include <ppm.h>
32#include <pmm.h>
33
34/* TODO: don't use locks to lookup region as if address has been accessed it must be in kyesdb */
35static error_t check_args(struct vmm_s *vmm, uint_t start, uint_t len, struct vm_region_s **reg)
36{
37        error_t err;
38        struct vm_region_s *region;
39 
40        err = 0;
41        rwlock_rdlock(&vmm->rwlock);
42
43        region = vmm->last_region;
44 
45        if((start >= region->vm_limit) || (start < region->vm_start))
46        {
47                region = vm_region_find(vmm, start);
48 
49                if((region == NULL) || (start < region->vm_start))
50                        err = EINVAL;
51        }
52
53        if((err == 0) && ((start + len) >= region->vm_limit))
54                err = EINVAL;
55 
56        rwlock_unlock(&vmm->rwlock);
57
58        *reg = region;
59        return 0;
60}
61
62
63/* TODO: compute other advices */
64int sys_madvise(void *start, size_t length, uint_t advice)
65{
66        error_t err;
67        struct vmm_s *vmm;
68        struct vm_region_s *region;
69        struct thread_s *this;
70
71        err = 0;
72        this = current_thread;
73
74        if((start == NULL) || ((uint_t)start & PMM_PAGE_MASK))
75        {
76                err = EINVAL;
77                goto SYS_MADVISE_ERR;
78        }
79
80        if(NOT_IN_USPACE((uint_t)start + length))
81        {
82                err = EPERM;
83                goto SYS_MADVISE_ERR;
84        }
85   
86        vmm = &this->task->vmm;
87        err = check_args(vmm, (uint_t)start, length, &region);
88 
89        if(err) goto SYS_MADVISE_ERR;
90 
91        if((region->vm_flags & VM_REG_DEV) || (region->vm_flags & VM_REG_SHARED))
92                return 0;
93
94        switch(advice)
95        {
96        case MADV_NORMAL:
97        case MADV_RANDOM:
98        case MADV_SEQUENTIAL:
99        case MADV_WILLNEED:
100                err = vmm_madvise_willneed(vmm, (uint_t)start, (uint_t)length);
101                break;
102        case MADV_DONTNEED:
103                return 0;
104   
105        case MADV_MIGRATE:
106                err = vmm_madvise_migrate(vmm, (uint_t)start, (uint_t)length);
107                break;
108 
109        default:
110                err = EINVAL;
111        }
112
113SYS_MADVISE_ERR:
114        this->info.errno = err;
115        return err;
116}
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