source: trunk/kernel/mm/ppm.c @ 236

Last change on this file since 236 was 177, checked in by max@…, 7 years ago

detect use-after-frees

File size: 7.5 KB
RevLine 
[1]1/*
2 * ppm.c - Per-cluster Physical Pages Manager implementation
3 *
4 * Authors  Ghassan Almaless (2008,2009,2010,2011,2012)
[50]5 *          Alain Greiner    (2016,2017)
[1]6 *
7 * Copyright (c) UPMC Sorbonne Universites
8 *
9 * This file is part of ALMOS-MKH.
10 *
11 * ALMOS-MKH.is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; version 2.0 of the License.
14 *
15 * ALMOS-MKH.is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with ALMOS-MKH.; if not, write to the Free Software Foundation,
22 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
23 */
24
[14]25#include <kernel_config.h>
[1]26#include <hal_types.h>
27#include <hal_special.h>
28#include <printk.h>
29#include <list.h>
30#include <bits.h>
31#include <page.h>
32#include <spinlock.h>
33#include <thread.h>
34#include <cluster.h>
35#include <kmem.h>
36#include <process.h>
37#include <dqdt.h>
38#include <ppm.h>
39
40////////////////////////////////////////////////
41inline bool_t ppm_page_is_valid( page_t * page )
42{
[160]43        ppm_t    * ppm  = &LOCAL_CLUSTER->ppm;
[1]44        uint32_t   pgnr = (uint32_t)( page - ppm->pages_tbl );
45        return (pgnr <= ppm->pages_nr);
46}
47
[50]48
49/////////////////////////////////////////////
50inline void * ppm_page2vaddr( page_t * page )
[1]51{
52        ppm_t * ppm = &LOCAL_CLUSTER->ppm;
[50]53        return ppm->vaddr_base + ((page - ppm->pages_tbl) << CONFIG_PPM_PAGE_SHIFT);
[1]54}
55
[50]56//////////////////////////////////////////////
57inline page_t * ppm_vaddr2page( void * vaddr )
[1]58{
59        ppm_t * ppm = &LOCAL_CLUSTER->ppm;
[50]60        return ppm->pages_tbl + (vaddr - ppm->vaddr_base);
[1]61}
62
63//////////////////////////////////////////
64inline ppn_t ppm_page2ppn( page_t * page )
65{
[160]66        ppm_t  * ppm = &LOCAL_CLUSTER->ppm;
[1]67        return (ppn_t)( page - ppm->pages_tbl );
68}
69
70/////////////////////////////////////////
71inline page_t * ppm_ppn2page( ppn_t ppn )
72{
[160]73        ppm_t  * ppm = &LOCAL_CLUSTER->ppm;
[1]74        return &ppm->pages_tbl[ppn];
75}
76
77///////////////////////////////////////
[50]78inline void * ppm_ppn2vaddr( ppn_t ppn )
[1]79{
[50]80        ppm_t  * ppm  = &LOCAL_CLUSTER->ppm;
81        return ppm->vaddr_base + (ppn << CONFIG_PPM_PAGE_SHIFT);
[1]82}
83
[50]84//////////////////////////////////////////
85inline ppn_t ppm_vaddr2ppn( void * vaddr )
[1]86{
[50]87        ppm_t  * ppm  = &LOCAL_CLUSTER->ppm;
[160]88        return ( (ppm->vaddr_base - vaddr) >> CONFIG_PPM_PAGE_SHIFT );
[1]89}
90
[50]91
92///////////////////////////////////////////
93void ppm_free_pages_nolock( page_t * page )
[1]94{
[7]95        page_t   * buddy;            // searched buddy page descriptor
96        uint32_t   buddy_index;      // buddy page index
97        page_t   * current;          // current (merged) page descriptor
98        uint32_t   current_index;    // current (merged) page index
[50]99        uint32_t   current_order;    // current (merged) page order
[7]100
[160]101        ppm_t    * ppm         = &LOCAL_CLUSTER->ppm;
102        page_t   * pages_tbl   = ppm->pages_tbl;
[1]103
[177]104        assert( !page_is_flag( page , PG_FREE ) , __FUNCTION__ , "page already freed" );
105        assert( !page_is_flag( page , PG_RESERVED ) , __FUNCTION__ , "freeing reserved page" );
106
[160]107        // update released page descriptor flags
[1]108        page_set_flag( page , PG_FREE );
109
[160]110        // search the buddy page descriptor
111        // - merge with current page descriptor if found
112        // - exit to release the current page descriptor if not found
113        current       = page ,
114        current_index = (uint32_t)(page - ppm->pages_tbl);
[18]115        for( current_order = page->order ;
[160]116             current_order < CONFIG_PPM_MAX_ORDER ;
117             current_order++ )
118        {
[7]119                buddy_index = current_index ^ (1 << current_order);
120                buddy       = pages_tbl + buddy_index;
[18]121
[7]122                if( !page_is_flag( buddy , PG_FREE ) || (buddy->order != current_order) ) break;
[1]123
[160]124                // remove buddy from free list
[7]125                list_unlink( &buddy->list );
[1]126                ppm->free_pages_nr[current_order] --;
[18]127
[160]128                // merge buddy with current
[7]129                buddy->order = 0;
130                current_index &= buddy_index;
[1]131        }
[18]132
[160]133        // update merged page descriptor order
[7]134        current        = pages_tbl + current_index;
135        current->order = current_order;
[1]136
[160]137        // insert current in free list
[7]138        list_add_first( &ppm->free_pages_root[current_order] , &current->list );
[1]139        ppm->free_pages_nr[current_order] ++;
[160]140}
[1]141
142////////////////////////////////////////////
143page_t * ppm_alloc_pages( uint32_t   order )
144{
[160]145        uint32_t   current_order;
[1]146        page_t   * remaining_block;
147        uint32_t   current_size;
148
[160]149        ppm_t    * ppm = &LOCAL_CLUSTER->ppm;
[1]150
[7]151        assert( (order < CONFIG_PPM_MAX_ORDER) , __FUNCTION__ , "illegal order argument" );
[1]152
153        page_t * block = NULL;
154
[160]155        ppm_dmsg("\n[INFO] %s : enters / order = %d\n",
156                 __FUNCTION__ , order );
[7]157
[160]158        // take lock protecting free lists
[1]159        spinlock_lock( &ppm->free_lock );
160
[160]161        // find a free block equal or larger to requested size
[1]162        for( current_order = order ; current_order < CONFIG_PPM_MAX_ORDER ; current_order ++ )
163        {
164                if( !list_is_empty( &ppm->free_pages_root[current_order] ) )
165                {
166                        block = LIST_FIRST( &ppm->free_pages_root[current_order] , page_t , list );
167                        list_unlink( &block->list );
168                        break;
169                }
170        }
171
172        if( block == NULL ) // return failure
173        {
[160]174                // release lock protecting free lists
175                spinlock_unlock( &ppm->free_lock );
[1]176
[160]177                return NULL;
178        }
[18]179
[160]180        // update free-lists after removing a block
[18]181        ppm->free_pages_nr[current_order] --;
[1]182        current_size = (1 << current_order);
183
[160]184        // split the removed block in smaller sub-blocks if required
185        // and update the free-lists accordingly
[1]186        while( current_order > order )
187        {
188                current_order --;
189                current_size >>= 1;
[18]190
[1]191                remaining_block = block + current_size;
192                remaining_block->order = current_order;
193
194                list_add_first( &ppm->free_pages_root[current_order] , &remaining_block->list );
195                ppm->free_pages_nr[current_order] ++;
196        }
[18]197
[160]198        // update page descriptor
199        page_clear_flag( block , PG_FREE );
[1]200        page_refcount_up( block );
201        block->order = order;
202
[160]203        // release lock protecting free lists
[1]204        spinlock_unlock( &ppm->free_lock );
[18]205
[160]206        ppm_dmsg("\n[INFO] %s : base = %x / order = %d\n",
207                 __FUNCTION__ , (uint32_t)ppm_page2base( block ) , order );
[7]208
[1]209        return block;
[160]210}
[1]211
212
213////////////////////////////////////
214void ppm_free_pages( page_t * page )
215{
216        ppm_t * ppm = &LOCAL_CLUSTER->ppm;
[18]217
[160]218        // get lock protecting free_pages[] array
[1]219        spinlock_lock( &ppm->free_lock );
220
[18]221        ppm_free_pages_nolock( page );
[1]222
[160]223        // release lock protecting free_pages[] array
[1]224        spinlock_unlock( &ppm->free_lock );
225}
226
[7]227////////////////////////////
228void ppm_print( ppm_t * ppm,
229                char  * string )
[1]230{
231        uint32_t       order;
232        list_entry_t * iter;
233        page_t       * page;
234
[160]235        // get lock protecting free lists
[1]236        spinlock_lock( &ppm->free_lock );
237
[50]238        printk("\n***  PPM in cluster %x : %d pages / &pages_tbl = %x / vaddr_base = %x ***\n",
239               local_cxy , ppm->pages_nr , (intptr_t)ppm->pages_tbl , (intptr_t)ppm->vaddr_base );
[18]240
[1]241        for( order = 0 ; order < CONFIG_PPM_MAX_ORDER ; order++ )
242        {
[7]243                printk("- order = %d / free_pages = %d  [",
[160]244                       order , ppm->free_pages_nr[order] );
[18]245
[1]246                LIST_FOREACH( &ppm->free_pages_root[order] , iter )
247                {
248                        page = LIST_ELEMENT( iter , page_t , list );
249                        printk("%d," , page - ppm->pages_tbl );
250                }
[18]251
[1]252                printk("]\n", NULL );
253        }
254
[160]255        // release lock protecting free lists
[1]256        spinlock_unlock( &ppm->free_lock );
[160]257}
[1]258
[53]259///////////////////////////////////////
260error_t ppm_assert_order( ppm_t * ppm )
[1]261{
262        uint32_t       order;
263        list_entry_t * iter;
264        page_t       * page;
[18]265
[1]266        for(order=0; order < CONFIG_PPM_MAX_ORDER; order++)
267        {
268                if( list_is_empty( &ppm->free_pages_root[order] ) ) continue;
[18]269
[1]270                LIST_FOREACH( &ppm->free_pages_root[order] , iter )
271                {
272                        page = LIST_ELEMENT( iter , page_t , list );
273
[160]274                        if( page->order != order )  return -1;
[1]275                }
276        }
277
[160]278        return 0;
279}
[53]280
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