[PATCH] fix Linux kernel ELF core dump privilege elevation
[linux-2.6] / fs / partitions / ibm.c
1 /*
2  * File...........: linux/fs/partitions/ibm.c      
3  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
4  *                  Volker Sameske <sameske@de.ibm.com>
5  * Bugreports.to..: <Linux390@de.ibm.com>
6  * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000
7
8  * History of changes (starts July 2000)
9  * 07/10/00 Fixed detection of CMS formatted disks     
10  * 02/13/00 VTOC partition support added
11  * 12/27/01 fixed PL030593 (CMS reserved minidisk not detected on 64 bit)
12  * 07/24/03 no longer using contents of freed page for CMS label recognition (BZ3611)
13  */
14
15 #include <linux/config.h>
16 #include <linux/buffer_head.h>
17 #include <linux/hdreg.h>
18 #include <linux/slab.h>
19 #include <asm/dasd.h>
20 #include <asm/ebcdic.h>
21 #include <asm/uaccess.h>
22 #include <asm/vtoc.h>
23
24 #include "check.h"
25 #include "ibm.h"
26
27 /*
28  * compute the block number from a 
29  * cyl-cyl-head-head structure
30  */
31 static inline int
32 cchh2blk (cchh_t *ptr, struct hd_geometry *geo) {
33         return ptr->cc * geo->heads * geo->sectors +
34                ptr->hh * geo->sectors;
35 }
36
37
38 /*
39  * compute the block number from a 
40  * cyl-cyl-head-head-block structure
41  */
42 static inline int
43 cchhb2blk (cchhb_t *ptr, struct hd_geometry *geo) {
44         return ptr->cc * geo->heads * geo->sectors +
45                 ptr->hh * geo->sectors +
46                 ptr->b;
47 }
48
49 /*
50  */
51 int 
52 ibm_partition(struct parsed_partitions *state, struct block_device *bdev)
53 {
54         int blocksize, offset, size;
55         dasd_information_t *info;
56         struct hd_geometry *geo;
57         char type[5] = {0,};
58         char name[7] = {0,};
59         volume_label_t *vlabel;
60         unsigned char *data;
61         Sector sect;
62
63         if ((info = kmalloc(sizeof(dasd_information_t), GFP_KERNEL)) == NULL)
64                 goto out_noinfo;
65         if ((geo = kmalloc(sizeof(struct hd_geometry), GFP_KERNEL)) == NULL)
66                 goto out_nogeo;
67         if ((vlabel = kmalloc(sizeof(volume_label_t), GFP_KERNEL)) == NULL)
68                 goto out_novlab;
69         
70         if (ioctl_by_bdev(bdev, BIODASDINFO, (unsigned long)info) != 0 ||
71             ioctl_by_bdev(bdev, HDIO_GETGEO, (unsigned long)geo) != 0)
72                 goto out_noioctl;
73         
74         if ((blocksize = bdev_hardsect_size(bdev)) <= 0)
75                 goto out_badsect;
76
77         /*
78          * Get volume label, extract name and type.
79          */
80         data = read_dev_sector(bdev, info->label_block*(blocksize/512), &sect);
81         if (data == NULL)
82                 goto out_readerr;
83
84         strncpy (type, data, 4);
85         if ((!info->FBA_layout) && (!strcmp(info->type, "ECKD")))
86                 strncpy(name, data + 8, 6);
87         else
88                 strncpy(name, data + 4, 6);
89         memcpy (vlabel, data, sizeof(volume_label_t));
90         put_dev_sector(sect);
91
92         EBCASC(type, 4);
93         EBCASC(name, 6);
94
95         /*
96          * Three different types: CMS1, VOL1 and LNX1/unlabeled
97          */
98         if (strncmp(type, "CMS1", 4) == 0) {
99                 /*
100                  * VM style CMS1 labeled disk
101                  */
102                 int *label = (int *) vlabel;
103
104                 if (label[13] != 0) {
105                         printk("CMS1/%8s(MDSK):", name);
106                         /* disk is reserved minidisk */
107                         blocksize = label[3];
108                         offset = label[13];
109                         size = (label[7] - 1)*(blocksize >> 9);
110                 } else {
111                         printk("CMS1/%8s:", name);
112                         offset = (info->label_block + 1);
113                         size = bdev->bd_inode->i_size >> 9;
114                 }
115                 put_partition(state, 1, offset*(blocksize >> 9),
116                                  size-offset*(blocksize >> 9));
117         } else if ((strncmp(type, "VOL1", 4) == 0) &&
118                 (!info->FBA_layout) && (!strcmp(info->type, "ECKD"))) {
119                 /*
120                  * New style VOL1 labeled disk
121                  */
122                 unsigned int blk;
123                 int counter;
124
125                 printk("VOL1/%8s:", name);
126
127                 /* get block number and read then go through format1 labels */
128                 blk = cchhb2blk(&vlabel->vtoc, geo) + 1;
129                 counter = 0;
130                 while ((data = read_dev_sector(bdev, blk*(blocksize/512),
131                                                &sect)) != NULL) {
132                         format1_label_t f1;
133
134                         memcpy(&f1, data, sizeof(format1_label_t));
135                         put_dev_sector(sect);
136
137                         /* skip FMT4 / FMT5 / FMT7 labels */
138                         if (f1.DS1FMTID == _ascebc['4']
139                             || f1.DS1FMTID == _ascebc['5']
140                             || f1.DS1FMTID == _ascebc['7']) {
141                                 blk++;
142                                 continue;
143                         }
144
145                         /* only FMT1 valid at this point */
146                         if (f1.DS1FMTID != _ascebc['1'])
147                                 break;
148
149                         /* OK, we got valid partition data */
150                         offset = cchh2blk(&f1.DS1EXT1.llimit, geo);
151                         size  = cchh2blk(&f1.DS1EXT1.ulimit, geo) - 
152                                 offset + geo->sectors;
153                         if (counter >= state->limit)
154                                 break;
155                         put_partition(state, counter + 1, 
156                                          offset * (blocksize >> 9),
157                                          size * (blocksize >> 9));
158                         counter++;
159                         blk++;
160                 }
161         } else {
162                 /*
163                  * Old style LNX1 or unlabeled disk
164                  */
165                 if (strncmp(type, "LNX1", 4) == 0)
166                         printk ("LNX1/%8s:", name);
167                 else
168                         printk("(nonl)/%8s:", name);
169                 offset = (info->label_block + 1);
170                 size = (bdev->bd_inode->i_size >> 9);
171                 put_partition(state, 1, offset*(blocksize >> 9),
172                                  size-offset*(blocksize >> 9));
173         }
174
175         printk("\n");
176         kfree(vlabel);
177         kfree(geo);
178         kfree(info);
179         return 1;
180         
181 out_readerr:
182 out_badsect:
183 out_noioctl:
184         kfree(vlabel);
185 out_novlab:
186         kfree(geo);
187 out_nogeo:
188         kfree(info);
189 out_noinfo:
190         return 0;
191 }