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Commit 25d80be8 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'rslib-v4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux 

Pull reed-salomon library updates from Kees Cook:
 "Refactors rslib and callers to provide a per-instance allocation area
  instead of performing VLAs on the stack"

* tag 'rslib-v4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  rslib: Allocate decoder buffers to avoid VLAs
  mtd: rawnand: diskonchip: Allocate rs control per instance
  rslib: Split rs control struct
  rslib: Simplify error path
  rslib: Remove GPL boilerplate
  rslib: Add SPDX identifiers
  rslib: Cleanup top level comments
  rslib: Cleanup whitespace damage
  dm/verity_fec: Use GFP aware reed solomon init
  rslib: Add GFP aware init function
parents a74e0c4c 45888b40

drivers/md/dm-verity-fec.c

+1 −1
Original line number Diff line number Diff line
@@ -570,7 +570,7 @@ static void *fec_rs_alloc(gfp_t gfp_mask, void *pool_data) 
{

	struct dm_verity *v = (struct dm_verity *)pool_data;



	return init_rs(8, 0x11d, 0, 1, v->fec->roots);

	return init_rs_gfp(8, 0x11d, 0, 1, v->fec->roots, gfp_mask);

}



static void fec_rs_free(void *element, void *pool_data)

drivers/mtd/nand/raw/cafe_nand.c

+4 −3
Original line number Diff line number Diff line
@@ -394,8 +394,9 @@ static int cafe_nand_read_page(struct mtd_info *mtd, struct nand_chip *chip, 


		for (i=0; i<8; i+=2) {

			uint32_t tmp = cafe_readl(cafe, NAND_ECC_SYN01 + (i*2));

			syn[i] = cafe->rs->index_of[tmp & 0xfff];

			syn[i+1] = cafe->rs->index_of[(tmp >> 16) & 0xfff];



			syn[i] = cafe->rs->codec->index_of[tmp & 0xfff];

			syn[i+1] = cafe->rs->codec->index_of[(tmp >> 16) & 0xfff];

		}



		n = decode_rs16(cafe->rs, NULL, NULL, 1367, syn, 0, pos, 0,

drivers/mtd/nand/raw/diskonchip.c

+31 −36
Original line number Diff line number Diff line
@@ -66,6 +66,7 @@ struct doc_priv { 
	int curchip;

	int mh0_page;

	int mh1_page;

	struct rs_control *rs_decoder;

	struct mtd_info *nextdoc;



	/* Handle the last stage of initialization (BBT scan, partitioning) */
@@ -123,9 +124,6 @@ MODULE_PARM_DESC(doc_config_location, "Physical memory address at which to probe 
/* Number of symbols */

#define NN 1023



/* the Reed Solomon control structure */

static struct rs_control *rs_decoder;



/*

 * The HW decoder in the DoC ASIC's provides us a error syndrome,

 * which we must convert to a standard syndrome usable by the generic
@@ -140,6 +138,7 @@ static int doc_ecc_decode(struct rs_control *rs, uint8_t *data, uint8_t *ecc) 
	int i, j, nerr, errpos[8];

	uint8_t parity;

	uint16_t ds[4], s[5], tmp, errval[8], syn[4];

	struct rs_codec *cd = rs->codec;



	memset(syn, 0, sizeof(syn));

	/* Convert the ecc bytes into words */
@@ -160,15 +159,15 @@ static int doc_ecc_decode(struct rs_control *rs, uint8_t *data, uint8_t *ecc) 
	for (j = 1; j < NROOTS; j++) {

		if (ds[j] == 0)

			continue;

		tmp = rs->index_of[ds[j]];

		tmp = cd->index_of[ds[j]];

		for (i = 0; i < NROOTS; i++)

			s[i] ^= rs->alpha_to[rs_modnn(rs, tmp + (FCR + i) * j)];

			s[i] ^= cd->alpha_to[rs_modnn(cd, tmp + (FCR + i) * j)];

	}



	/* Calc syn[i] = s[i] / alpha^(v + i) */

	for (i = 0; i < NROOTS; i++) {

		if (s[i])

			syn[i] = rs_modnn(rs, rs->index_of[s[i]] + (NN - FCR - i));

			syn[i] = rs_modnn(cd, cd->index_of[s[i]] + (NN - FCR - i));

	}

	/* Call the decoder library */

	nerr = decode_rs16(rs, NULL, NULL, 1019, syn, 0, errpos, 0, errval);
@@ -930,7 +929,7 @@ static int doc200x_correct_data(struct mtd_info *mtd, u_char *dat, 
				calc_ecc[i] = ReadDOC_(docptr, DoC_ECCSyndrome0 + i);

		}



		ret = doc_ecc_decode(rs_decoder, dat, calc_ecc);

		ret = doc_ecc_decode(doc->rs_decoder, dat, calc_ecc);

		if (ret > 0)

			pr_err("doc200x_correct_data corrected %d errors\n",

			       ret);
@@ -1421,10 +1420,10 @@ static inline int __init doc2001plus_init(struct mtd_info *mtd) 


static int __init doc_probe(unsigned long physadr)

{

	struct nand_chip *nand = NULL;

	struct doc_priv *doc = NULL;

	unsigned char ChipID;

	struct mtd_info *mtd;

	struct nand_chip *nand;

	struct doc_priv *doc;

	void __iomem *virtadr;

	unsigned char save_control;

	unsigned char tmp, tmpb, tmpc;
@@ -1561,8 +1560,25 @@ static int __init doc_probe(unsigned long physadr) 
		goto fail;

	}



	mtd			= nand_to_mtd(nand);



	/*

	 * Allocate a RS codec instance

	 *

	 * Symbolsize is 10 (bits)

	 * Primitve polynomial is x^10+x^3+1

	 * First consecutive root is 510

	 * Primitve element to generate roots = 1

	 * Generator polinomial degree = 4

	 */

	doc = (struct doc_priv *) (nand + 1);

	doc->rs_decoder = init_rs(10, 0x409, FCR, 1, NROOTS);

	if (!doc->rs_decoder) {

		pr_err("DiskOnChip: Could not create a RS codec\n");

		ret = -ENOMEM;

		goto fail;

	}



	mtd			= nand_to_mtd(nand);

	nand->bbt_td		= (struct nand_bbt_descr *) (doc + 1);

	nand->bbt_md		= nand->bbt_td + 1;
@@ -1612,7 +1628,6 @@ static int __init doc_probe(unsigned long physadr) 
		   haven't yet added it.  This is handled without incident by

		   mtd_device_unregister, as far as I can tell. */

		nand_release(mtd);

		kfree(nand);

		goto fail;

	}
@@ -1625,6 +1640,9 @@ static int __init doc_probe(unsigned long physadr) 
	   actually a DiskOnChip.  */

	WriteDOC(save_control, virtadr, DOCControl);

 fail:

	if (doc)

		free_rs(doc->rs_decoder);

	kfree(nand);

	iounmap(virtadr);



error_ioremap:
@@ -1647,6 +1665,7 @@ static void release_nanddoc(void) 
		nand_release(mtd);

		iounmap(doc->virtadr);

		release_mem_region(doc->physadr, DOC_IOREMAP_LEN);

		free_rs(doc->rs_decoder);

		kfree(nand);

	}

}
@@ -1655,27 +1674,12 @@ static int __init init_nanddoc(void) 
{

	int i, ret = 0;



	/* We could create the decoder on demand, if memory is a concern.

	 * This way we have it handy, if an error happens

	 *

	 * Symbolsize is 10 (bits)

	 * Primitve polynomial is x^10+x^3+1

	 * first consecutive root is 510

	 * primitve element to generate roots = 1

	 * generator polinomial degree = 4

	 */

	rs_decoder = init_rs(10, 0x409, FCR, 1, NROOTS);

	if (!rs_decoder) {

		pr_err("DiskOnChip: Could not create a RS decoder\n");

		return -ENOMEM;

	}



	if (doc_config_location) {

		pr_info("Using configured DiskOnChip probe address 0x%lx\n",

			doc_config_location);

		ret = doc_probe(doc_config_location);

		if (ret < 0)

			goto outerr;

			return ret;

	} else {

		for (i = 0; (doc_locations[i] != 0xffffffff); i++) {

			doc_probe(doc_locations[i]);
@@ -1686,11 +1690,7 @@ static int __init init_nanddoc(void) 
	if (!doclist) {

		pr_info("No valid DiskOnChip devices found\n");

		ret = -ENODEV;

		goto outerr;

	}

	return 0;

 outerr:

	free_rs(rs_decoder);

	return ret;

}
@@ -1698,11 +1698,6 @@ static void __exit cleanup_nanddoc(void) 
{

	/* Cleanup the nand/DoC resources */

	release_nanddoc();



	/* Free the reed solomon resources */

	if (rs_decoder) {

		free_rs(rs_decoder);

	}

}



module_init(init_nanddoc);

include/linux/rslib.h

+48 −26
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * include/linux/rslib.h

 *

 * Overview:

 * Generic Reed Solomon encoder / decoder library

 *

 * Copyright (C) 2004 Thomas Gleixner (tglx@linutronix.de)

 *

 * RS code lifted from reed solomon library written by Phil Karn

 * Copyright 2002 Phil Karn, KA9Q

 *

 * $Id: rslib.h,v 1.4 2005/11/07 11:14:52 gleixner Exp $

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 */



#ifndef _RSLIB_H_

#define _RSLIB_H_



#include <linux/list.h>

#include <linux/types.h>	/* for gfp_t */

#include <linux/gfp.h>		/* for GFP_KERNEL */



/**

 * struct rs_control - rs control structure

 * struct rs_codec - rs codec data

 *

 * @mm:		Bits per symbol

 * @nn:		Symbols per block (= (1<<mm)-1)
@@ -36,9 +29,9 @@ 
 * @gfpoly:	The primitive generator polynominal

 * @gffunc:	Function to generate the field, if non-canonical representation

 * @users:	Users of this structure

 * @list:	List entry for the rs control list

 * @list:	List entry for the rs codec list

*/

struct rs_control {

struct rs_codec {

	int		mm;

	int		nn;

	uint16_t	*alpha_to;
@@ -54,6 +47,16 @@ struct rs_control { 
	struct list_head list;

};



/**

 * struct rs_control - rs control structure per instance

 * @codec:	The codec used for this instance

 * @buffers:	Internal scratch buffers used in calls to decode_rs()

 */

struct rs_control {

	struct rs_codec	*codec;

	uint16_t	buffers[0];

};



/* General purpose RS codec, 8-bit data width, symbol width 1-15 bit  */

#ifdef CONFIG_REED_SOLOMON_ENC8

int encode_rs8(struct rs_control *rs, uint8_t *data, int len, uint16_t *par,
@@ -76,9 +79,28 @@ int decode_rs16(struct rs_control *rs, uint16_t *data, uint16_t *par, int len, 
		uint16_t *corr);

#endif



/* Create or get a matching rs control structure */

struct rs_control *init_rs(int symsize, int gfpoly, int fcr, int prim,

			   int nroots);

struct rs_control *init_rs_gfp(int symsize, int gfpoly, int fcr, int prim,

			       int nroots, gfp_t gfp);



/**

 * init_rs - Create a RS control struct and initialize it

 *  @symsize:	the symbol size (number of bits)

 *  @gfpoly:	the extended Galois field generator polynomial coefficients,

 *		with the 0th coefficient in the low order bit. The polynomial

 *		must be primitive;

 *  @fcr:	the first consecutive root of the rs code generator polynomial

 *		in index form

 *  @prim:	primitive element to generate polynomial roots

 *  @nroots:	RS code generator polynomial degree (number of roots)

 *

 * Allocations use GFP_KERNEL.

 */

static inline struct rs_control *init_rs(int symsize, int gfpoly, int fcr,

					 int prim, int nroots)

{

	return init_rs_gfp(symsize, gfpoly, fcr, prim, nroots, GFP_KERNEL);

}



struct rs_control *init_rs_non_canonical(int symsize, int (*func)(int),

					 int fcr, int prim, int nroots);
@@ -87,7 +109,7 @@ void free_rs(struct rs_control *rs); 


/** modulo replacement for galois field arithmetics

 *

 *  @rs:	the rs control structure

 *  @rs:	Pointer to the RS codec

 *  @x:		the value to reduce

 *

 *  where
@@ -97,7 +119,7 @@ void free_rs(struct rs_control *rs); 
 *  Simple arithmetic modulo would return a wrong result for values

 *  >= 3 * rs->nn

*/

static inline int rs_modnn(struct rs_control *rs, int x)

static inline int rs_modnn(struct rs_codec *rs, int x)

{

	while (x >= rs->nn) {

		x -= rs->nn;

lib/reed_solomon/decode_rs.c

+17 −17
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * lib/reed_solomon/decode_rs.c

 *

 * Overview:

 * Generic Reed Solomon encoder / decoder library

 *

 * Copyright 2002, Phil Karn, KA9Q
@@ -9,14 +7,10 @@ 
 *

 * Adaption to the kernel by Thomas Gleixner (tglx@linutronix.de)

 *

 * $Id: decode_rs.c,v 1.7 2005/11/07 11:14:59 gleixner Exp $

 *

 */



/* Generic data width independent code which is included by the

 * wrappers.

 * Generic data width independent code which is included by the wrappers.

 */

{

	struct rs_codec *rs = rsc->codec;

	int deg_lambda, el, deg_omega;

	int i, j, r, k, pad;

	int nn = rs->nn;
@@ -27,16 +21,22 @@ 
	uint16_t *alpha_to = rs->alpha_to;

	uint16_t *index_of = rs->index_of;

	uint16_t u, q, tmp, num1, num2, den, discr_r, syn_error;

	/* Err+Eras Locator poly and syndrome poly The maximum value

	 * of nroots is 8. So the necessary stack size will be about

	 * 220 bytes max.

	 */

	uint16_t lambda[nroots + 1], syn[nroots];

	uint16_t b[nroots + 1], t[nroots + 1], omega[nroots + 1];

	uint16_t root[nroots], reg[nroots + 1], loc[nroots];

	int count = 0;

	uint16_t msk = (uint16_t) rs->nn;



	/*

	 * The decoder buffers are in the rs control struct. They are

	 * arrays sized [nroots + 1]

	 */

	uint16_t *lambda = rsc->buffers + RS_DECODE_LAMBDA * (nroots + 1);

	uint16_t *syn = rsc->buffers + RS_DECODE_SYN * (nroots + 1);

	uint16_t *b = rsc->buffers + RS_DECODE_B * (nroots + 1);

	uint16_t *t = rsc->buffers + RS_DECODE_T * (nroots + 1);

	uint16_t *omega = rsc->buffers + RS_DECODE_OMEGA * (nroots + 1);

	uint16_t *root = rsc->buffers + RS_DECODE_ROOT * (nroots + 1);

	uint16_t *reg = rsc->buffers + RS_DECODE_REG * (nroots + 1);

	uint16_t *loc = rsc->buffers + RS_DECODE_LOC * (nroots + 1);



	/* Check length parameter for validity */

	pad = nn - nroots - len;

	BUG_ON(pad < 0 || pad >= nn);