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// SPDX-License-Identifier: GPL-2.0/* *  linux/fs/hpfs/map.c * *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999 * *  mapping structures to memory with some minimal checks */ #include "hpfs_fn.h" __le32 *hpfs_map_dnode_bitmap(struct super_block *s, struct quad_buffer_head *qbh){	return hpfs_map_4sectors(s, hpfs_sb(s)->sb_dmap, qbh, 0);} __le32 *hpfs_map_bitmap(struct super_block *s, unsigned bmp_block,			 struct quad_buffer_head *qbh, char *id){	secno sec;	__le32 *ret;	unsigned n_bands = (hpfs_sb(s)->sb_fs_size + 0x3fff) >> 14;	if (hpfs_sb(s)->sb_chk) if (bmp_block >= n_bands) {		hpfs_error(s, "hpfs_map_bitmap called with bad parameter: %08x at %s", bmp_block, id);		return NULL;	}	sec = le32_to_cpu(hpfs_sb(s)->sb_bmp_dir[bmp_block]);	if (!sec || sec > hpfs_sb(s)->sb_fs_size-4) {		hpfs_error(s, "invalid bitmap block pointer %08x -> %08x at %s", bmp_block, sec, id);		return NULL;	}	ret = hpfs_map_4sectors(s, sec, qbh, 4);	if (ret) hpfs_prefetch_bitmap(s, bmp_block + 1);	return ret;} void hpfs_prefetch_bitmap(struct super_block *s, unsigned bmp_block){	unsigned to_prefetch, next_prefetch;	unsigned n_bands = (hpfs_sb(s)->sb_fs_size + 0x3fff) >> 14;	if (unlikely(bmp_block >= n_bands))		return;	to_prefetch = le32_to_cpu(hpfs_sb(s)->sb_bmp_dir[bmp_block]);	if (unlikely(bmp_block + 1 >= n_bands))		next_prefetch = 0;	else		next_prefetch = le32_to_cpu(hpfs_sb(s)->sb_bmp_dir[bmp_block + 1]);	hpfs_prefetch_sectors(s, to_prefetch, 4 + 4 * (to_prefetch + 4 == next_prefetch));} /* * Load first code page into kernel memory, return pointer to 256-byte array, * first 128 bytes are uppercasing table for chars 128-255, next 128 bytes are * lowercasing table */ unsigned char *hpfs_load_code_page(struct super_block *s, secno cps){	struct buffer_head *bh;	secno cpds;	unsigned cpi;	unsigned char *ptr;	unsigned char *cp_table;	int i;	struct code_page_data *cpd;	struct code_page_directory *cp = hpfs_map_sector(s, cps, &bh, 0);	if (!cp) return NULL;	if (le32_to_cpu(cp->magic) != CP_DIR_MAGIC) {		pr_err("Code page directory magic doesn't match (magic = %08x)\n",			le32_to_cpu(cp->magic));		brelse(bh);		return NULL;	}	if (!le32_to_cpu(cp->n_code_pages)) {		pr_err("n_code_pages == 0\n");		brelse(bh);		return NULL;	}	cpds = le32_to_cpu(cp->array[0].code_page_data);	cpi = le16_to_cpu(cp->array[0].index);	brelse(bh); 	if (cpi >= 3) {		pr_err("Code page index out of array\n");		return NULL;	}		if (!(cpd = hpfs_map_sector(s, cpds, &bh, 0))) return NULL;	if (le16_to_cpu(cpd->offs[cpi]) > 0x178) {		pr_err("Code page index out of sector\n");		brelse(bh);		return NULL;	}	ptr = (unsigned char *)cpd + le16_to_cpu(cpd->offs[cpi]) + 6;	if (!(cp_table = kmalloc(256, GFP_KERNEL))) {		pr_err("out of memory for code page table\n");		brelse(bh);		return NULL;	}	memcpy(cp_table, ptr, 128);	brelse(bh); 	/* Try to build lowercasing table from uppercasing one */ 	for (i=128; i<256; i++) cp_table[i]=i;	for (i=128; i<256; i++) if (cp_table[i-128]!=i && cp_table[i-128]>=128)		cp_table[cp_table[i-128]] = i;		return cp_table;} __le32 *hpfs_load_bitmap_directory(struct super_block *s, secno bmp){	struct buffer_head *bh;	int n = (hpfs_sb(s)->sb_fs_size + 0x200000 - 1) >> 21;	int i;	__le32 *b;	if (!(b = kmalloc_array(n, 512, GFP_KERNEL))) {		pr_err("can't allocate memory for bitmap directory\n");		return NULL;	}		for (i=0;i<n;i++) {		__le32 *d = hpfs_map_sector(s, bmp+i, &bh, n - i - 1);		if (!d) {			kfree(b);			return NULL;		}		memcpy((char *)b + 512 * i, d, 512);		brelse(bh);	}	return b;} void hpfs_load_hotfix_map(struct super_block *s, struct hpfs_spare_block *spareblock){	struct quad_buffer_head qbh;	__le32 *directory;	u32 n_hotfixes, n_used_hotfixes;	unsigned i; 	n_hotfixes = le32_to_cpu(spareblock->n_spares);	n_used_hotfixes = le32_to_cpu(spareblock->n_spares_used); 	if (n_hotfixes > 256 || n_used_hotfixes > n_hotfixes) {		hpfs_error(s, "invalid number of hotfixes: %u, used: %u", n_hotfixes, n_used_hotfixes);		return;	}	if (!(directory = hpfs_map_4sectors(s, le32_to_cpu(spareblock->hotfix_map), &qbh, 0))) {		hpfs_error(s, "can't load hotfix map");		return;	}	for (i = 0; i < n_used_hotfixes; i++) {		hpfs_sb(s)->hotfix_from[i] = le32_to_cpu(directory[i]);		hpfs_sb(s)->hotfix_to[i] = le32_to_cpu(directory[n_hotfixes + i]);	}	hpfs_sb(s)->n_hotfixes = n_used_hotfixes;	hpfs_brelse4(&qbh);} /* * Load fnode to memory */ struct fnode *hpfs_map_fnode(struct super_block *s, ino_t ino, struct buffer_head **bhp){	struct fnode *fnode;	if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, ino, 1, "fnode")) {		return NULL;	}	if ((fnode = hpfs_map_sector(s, ino, bhp, FNODE_RD_AHEAD))) {		if (hpfs_sb(s)->sb_chk) {			struct extended_attribute *ea;			struct extended_attribute *ea_end;			if (le32_to_cpu(fnode->magic) != FNODE_MAGIC) {				hpfs_error(s, "bad magic on fnode %08lx",					(unsigned long)ino);				goto bail;			}			if (!fnode_is_dir(fnode)) {				if ((unsigned)fnode->btree.n_used_nodes + (unsigned)fnode->btree.n_free_nodes !=				    (bp_internal(GET_BTREE_PTR(&fnode->btree)) ? 12 : 8)) {					hpfs_error(s,					   "bad number of nodes in fnode %08lx",					    (unsigned long)ino);					goto bail;				}				if (le16_to_cpu(fnode->btree.first_free) !=				    8 + fnode->btree.n_used_nodes * (bp_internal(GET_BTREE_PTR(&fnode->btree)) ? 8 : 12)) {					hpfs_error(s,					    "bad first_free pointer in fnode %08lx",					    (unsigned long)ino);					goto bail;				}			}			if (le16_to_cpu(fnode->ea_size_s) && (le16_to_cpu(fnode->ea_offs) < 0xc4 ||			   le16_to_cpu(fnode->ea_offs) + le16_to_cpu(fnode->acl_size_s) + le16_to_cpu(fnode->ea_size_s) > 0x200)) {				hpfs_error(s,					"bad EA info in fnode %08lx: ea_offs == %04x ea_size_s == %04x",					(unsigned long)ino,					le16_to_cpu(fnode->ea_offs), le16_to_cpu(fnode->ea_size_s));				goto bail;			}			ea = fnode_ea(fnode);			ea_end = fnode_end_ea(fnode);			while (ea != ea_end) {				if (ea > ea_end) {					hpfs_error(s, "bad EA in fnode %08lx",						(unsigned long)ino);					goto bail;				}				ea = next_ea(ea);			}		}	}	return fnode;	bail:	brelse(*bhp);	return NULL;} struct anode *hpfs_map_anode(struct super_block *s, anode_secno ano, struct buffer_head **bhp){	struct anode *anode;	if (hpfs_sb(s)->sb_chk) if (hpfs_chk_sectors(s, ano, 1, "anode")) return NULL;	if ((anode = hpfs_map_sector(s, ano, bhp, ANODE_RD_AHEAD)))		if (hpfs_sb(s)->sb_chk) {			if (le32_to_cpu(anode->magic) != ANODE_MAGIC) {				hpfs_error(s, "bad magic on anode %08x", ano);				goto bail;			}			if (le32_to_cpu(anode->self) != ano) {				hpfs_error(s, "self pointer invalid on anode %08x", ano);				goto bail;			}			if ((unsigned)anode->btree.n_used_nodes + (unsigned)anode->btree.n_free_nodes !=			    (bp_internal(GET_BTREE_PTR(&anode->btree)) ? 60 : 40)) {				hpfs_error(s, "bad number of nodes in anode %08x", ano);				goto bail;			}			if (le16_to_cpu(anode->btree.first_free) !=			    8 + anode->btree.n_used_nodes * (bp_internal(GET_BTREE_PTR(&anode->btree)) ? 8 : 12)) {				hpfs_error(s, "bad first_free pointer in anode %08x", ano);				goto bail;			}		}	return anode;	bail:	brelse(*bhp);	return NULL;} /* * Load dnode to memory and do some checks */ struct dnode *hpfs_map_dnode(struct super_block *s, unsigned secno,			     struct quad_buffer_head *qbh){	struct dnode *dnode;	if (hpfs_sb(s)->sb_chk) {		if (hpfs_chk_sectors(s, secno, 4, "dnode")) return NULL;		if (secno & 3) {			hpfs_error(s, "dnode %08x not byte-aligned", secno);			return NULL;		}		}	if ((dnode = hpfs_map_4sectors(s, secno, qbh, DNODE_RD_AHEAD)))		if (hpfs_sb(s)->sb_chk) {			unsigned p, pp = 0;			unsigned char *d = (unsigned char *)dnode;			int b = 0;			if (le32_to_cpu(dnode->magic) != DNODE_MAGIC) {				hpfs_error(s, "bad magic on dnode %08x", secno);				goto bail;			}			if (le32_to_cpu(dnode->self) != secno)				hpfs_error(s, "bad self pointer on dnode %08x self = %08x", secno, le32_to_cpu(dnode->self));			/* Check dirents - bad dirents would cause infinite			   loops or shooting to memory */			if (le32_to_cpu(dnode->first_free) > 2048) {				hpfs_error(s, "dnode %08x has first_free == %08x", secno, le32_to_cpu(dnode->first_free));				goto bail;			}			for (p = 20; p < le32_to_cpu(dnode->first_free); p += d[p] + (d[p+1] << 8)) {				struct hpfs_dirent *de = (struct hpfs_dirent *)((char *)dnode + p);				if (le16_to_cpu(de->length) > 292 || (le16_to_cpu(de->length) < 32) || (le16_to_cpu(de->length) & 3) || p + le16_to_cpu(de->length) > 2048) {					hpfs_error(s, "bad dirent size in dnode %08x, dirent %03x, last %03x", secno, p, pp);					goto bail;				}				if (((31 + de->namelen + de->down*4 + 3) & ~3) != le16_to_cpu(de->length)) {					if (((31 + de->namelen + de->down*4 + 3) & ~3) < le16_to_cpu(de->length) && s->s_flags & SB_RDONLY) goto ok;					hpfs_error(s, "namelen does not match dirent size in dnode %08x, dirent %03x, last %03x", secno, p, pp);					goto bail;				}				ok:				if (hpfs_sb(s)->sb_chk >= 2) b |= 1 << de->down;				if (de->down) if (de_down_pointer(de) < 0x10) {					hpfs_error(s, "bad down pointer in dnode %08x, dirent %03x, last %03x", secno, p, pp);					goto bail;				}				pp = p;							}			if (p != le32_to_cpu(dnode->first_free)) {				hpfs_error(s, "size on last dirent does not match first_free; dnode %08x", secno);				goto bail;			}			if (d[pp + 30] != 1 || d[pp + 31] != 255) {				hpfs_error(s, "dnode %08x does not end with \\377 entry", secno);				goto bail;			}			if (b == 3)				pr_err("unbalanced dnode tree, dnode %08x; see hpfs.txt 4 more info\n",					secno);		}	return dnode;	bail:	hpfs_brelse4(qbh);	return NULL;} dnode_secno hpfs_fnode_dno(struct super_block *s, ino_t ino){	struct buffer_head *bh;	struct fnode *fnode;	dnode_secno dno; 	fnode = hpfs_map_fnode(s, ino, &bh);	if (!fnode)		return 0; 	dno = le32_to_cpu(fnode->u.external[0].disk_secno);	brelse(bh);	return dno;}