cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

sgi.c (2381B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 *  fs/partitions/sgi.c
      4 *
      5 *  Code extracted from drivers/block/genhd.c
      6 */
      7
      8#include "check.h"
      9
     10#define SGI_LABEL_MAGIC 0x0be5a941
     11
     12enum {
     13	LINUX_RAID_PARTITION = 0xfd,	/* autodetect RAID partition */
     14};
     15
     16struct sgi_disklabel {
     17	__be32 magic_mushroom;		/* Big fat spliff... */
     18	__be16 root_part_num;		/* Root partition number */
     19	__be16 swap_part_num;		/* Swap partition number */
     20	s8 boot_file[16];		/* Name of boot file for ARCS */
     21	u8 _unused0[48];		/* Device parameter useless crapola.. */
     22	struct sgi_volume {
     23		s8 name[8];		/* Name of volume */
     24		__be32 block_num;		/* Logical block number */
     25		__be32 num_bytes;		/* How big, in bytes */
     26	} volume[15];
     27	struct sgi_partition {
     28		__be32 num_blocks;		/* Size in logical blocks */
     29		__be32 first_block;	/* First logical block */
     30		__be32 type;		/* Type of this partition */
     31	} partitions[16];
     32	__be32 csum;			/* Disk label checksum */
     33	__be32 _unused1;			/* Padding */
     34};
     35
     36int sgi_partition(struct parsed_partitions *state)
     37{
     38	int i, csum;
     39	__be32 magic;
     40	int slot = 1;
     41	unsigned int start, blocks;
     42	__be32 *ui, cs;
     43	Sector sect;
     44	struct sgi_disklabel *label;
     45	struct sgi_partition *p;
     46
     47	label = read_part_sector(state, 0, &sect);
     48	if (!label)
     49		return -1;
     50	p = &label->partitions[0];
     51	magic = label->magic_mushroom;
     52	if(be32_to_cpu(magic) != SGI_LABEL_MAGIC) {
     53		/*printk("Dev %s SGI disklabel: bad magic %08x\n",
     54		       state->disk->disk_name, be32_to_cpu(magic));*/
     55		put_dev_sector(sect);
     56		return 0;
     57	}
     58	ui = ((__be32 *) (label + 1)) - 1;
     59	for(csum = 0; ui >= ((__be32 *) label);) {
     60		cs = *ui--;
     61		csum += be32_to_cpu(cs);
     62	}
     63	if(csum) {
     64		printk(KERN_WARNING "Dev %s SGI disklabel: csum bad, label corrupted\n",
     65		       state->disk->disk_name);
     66		put_dev_sector(sect);
     67		return 0;
     68	}
     69	/* All SGI disk labels have 16 partitions, disks under Linux only
     70	 * have 15 minor's.  Luckily there are always a few zero length
     71	 * partitions which we don't care about so we never overflow the
     72	 * current_minor.
     73	 */
     74	for(i = 0; i < 16; i++, p++) {
     75		blocks = be32_to_cpu(p->num_blocks);
     76		start  = be32_to_cpu(p->first_block);
     77		if (blocks) {
     78			put_partition(state, slot, start, blocks);
     79			if (be32_to_cpu(p->type) == LINUX_RAID_PARTITION)
     80				state->parts[slot].flags = ADDPART_FLAG_RAID;
     81		}
     82		slot++;
     83	}
     84	strlcat(state->pp_buf, "\n", PAGE_SIZE);
     85	put_dev_sector(sect);
     86	return 1;
     87}