Fix for buffer overflow in ldm_frag_add not sufficient
[linux-2.6.git] / fs / partitions / sun.c
1 /*
2  *  fs/partitions/sun.c
3  *
4  *  Code extracted from drivers/block/genhd.c
5  *
6  *  Copyright (C) 1991-1998  Linus Torvalds
7  *  Re-organised Feb 1998 Russell King
8  */
9
10 #include "check.h"
11 #include "sun.h"
12
13 int sun_partition(struct parsed_partitions *state)
14 {
15         int i;
16         __be16 csum;
17         int slot = 1;
18         __be16 *ush;
19         Sector sect;
20         struct sun_disklabel {
21                 unsigned char info[128];   /* Informative text string */
22                 struct sun_vtoc {
23                     __be32 version;     /* Layout version */
24                     char   volume[8];   /* Volume name */
25                     __be16 nparts;      /* Number of partitions */
26                     struct sun_info {           /* Partition hdrs, sec 2 */
27                         __be16 id;
28                         __be16 flags;
29                     } infos[8];
30                     __be16 padding;     /* Alignment padding */
31                     __be32 bootinfo[3];  /* Info needed by mboot */
32                     __be32 sanity;       /* To verify vtoc sanity */
33                     __be32 reserved[10]; /* Free space */
34                     __be32 timestamp[8]; /* Partition timestamp */
35                 } vtoc;
36                 __be32 write_reinstruct; /* sectors to skip, writes */
37                 __be32 read_reinstruct;  /* sectors to skip, reads */
38                 unsigned char spare[148]; /* Padding */
39                 __be16 rspeed;     /* Disk rotational speed */
40                 __be16 pcylcount;  /* Physical cylinder count */
41                 __be16 sparecyl;   /* extra sects per cylinder */
42                 __be16 obs1;       /* gap1 */
43                 __be16 obs2;       /* gap2 */
44                 __be16 ilfact;     /* Interleave factor */
45                 __be16 ncyl;       /* Data cylinder count */
46                 __be16 nacyl;      /* Alt. cylinder count */
47                 __be16 ntrks;      /* Tracks per cylinder */
48                 __be16 nsect;      /* Sectors per track */
49                 __be16 obs3;       /* bhead - Label head offset */
50                 __be16 obs4;       /* ppart - Physical Partition */
51                 struct sun_partition {
52                         __be32 start_cylinder;
53                         __be32 num_sectors;
54                 } partitions[8];
55                 __be16 magic;      /* Magic number */
56                 __be16 csum;       /* Label xor'd checksum */
57         } * label;
58         struct sun_partition *p;
59         unsigned long spc;
60         char b[BDEVNAME_SIZE];
61         int use_vtoc;
62         int nparts;
63
64         label = read_part_sector(state, 0, &sect);
65         if (!label)
66                 return -1;
67
68         p = label->partitions;
69         if (be16_to_cpu(label->magic) != SUN_LABEL_MAGIC) {
70 /*              printk(KERN_INFO "Dev %s Sun disklabel: bad magic %04x\n",
71                        bdevname(bdev, b), be16_to_cpu(label->magic)); */
72                 put_dev_sector(sect);
73                 return 0;
74         }
75         /* Look at the checksum */
76         ush = ((__be16 *) (label+1)) - 1;
77         for (csum = 0; ush >= ((__be16 *) label);)
78                 csum ^= *ush--;
79         if (csum) {
80                 printk("Dev %s Sun disklabel: Csum bad, label corrupted\n",
81                        bdevname(state->bdev, b));
82                 put_dev_sector(sect);
83                 return 0;
84         }
85
86         /* Check to see if we can use the VTOC table */
87         use_vtoc = ((be32_to_cpu(label->vtoc.sanity) == SUN_VTOC_SANITY) &&
88                     (be32_to_cpu(label->vtoc.version) == 1) &&
89                     (be16_to_cpu(label->vtoc.nparts) <= 8));
90
91         /* Use 8 partition entries if not specified in validated VTOC */
92         nparts = (use_vtoc) ? be16_to_cpu(label->vtoc.nparts) : 8;
93
94         /*
95          * So that old Linux-Sun partitions continue to work,
96          * alow the VTOC to be used under the additional condition ...
97          */
98         use_vtoc = use_vtoc || !(label->vtoc.sanity ||
99                                  label->vtoc.version || label->vtoc.nparts);
100         spc = be16_to_cpu(label->ntrks) * be16_to_cpu(label->nsect);
101         for (i = 0; i < nparts; i++, p++) {
102                 unsigned long st_sector;
103                 unsigned int num_sectors;
104
105                 st_sector = be32_to_cpu(p->start_cylinder) * spc;
106                 num_sectors = be32_to_cpu(p->num_sectors);
107                 if (num_sectors) {
108                         put_partition(state, slot, st_sector, num_sectors);
109                         state->parts[slot].flags = 0;
110                         if (use_vtoc) {
111                                 if (be16_to_cpu(label->vtoc.infos[i].id) == LINUX_RAID_PARTITION)
112                                         state->parts[slot].flags |= ADDPART_FLAG_RAID;
113                                 else if (be16_to_cpu(label->vtoc.infos[i].id) == SUN_WHOLE_DISK)
114                                         state->parts[slot].flags |= ADDPART_FLAG_WHOLEDISK;
115                         }
116                 }
117                 slot++;
118         }
119         strlcat(state->pp_buf, "\n", PAGE_SIZE);
120         put_dev_sector(sect);
121         return 1;
122 }