Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 83a530e1 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Kees Cook
Browse files

rslib: Add GFP aware init function 



The rslib usage in dm/verity_fec is broken because init_rs() can nest in
GFP_NOIO mempool allocations as init_rs() is invoked from the mempool alloc
callback.

Provide a variant which takes gfp_t flags as argument.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Neil Brown <neilb@suse.com>
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
parent 6d08b06e

include/linux/rslib.h

+25 −3
Original line number Diff line number Diff line
@@ -20,6 +20,8 @@ 
#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
@@ -77,8 +79,28 @@ int decode_rs16(struct rs_control *rs, uint16_t *data, uint16_t *par, int len, 
#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);

lib/reed_solomon/reed_solomon.c

+23 −20
Original line number Diff line number Diff line
@@ -59,19 +59,20 @@ static DEFINE_MUTEX(rslistlock); 
 * @fcr:	first root of RS code generator polynomial, index form

 * @prim:	primitive element to generate polynomial roots

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

 * @gfp:	GFP_ flags for allocations

 *

 * Allocate a control structure and the polynom arrays for faster

 * en/decoding. Fill the arrays according to the given parameters.

 */

static struct rs_control *rs_init(int symsize, int gfpoly, int (*gffunc)(int),

                                  int fcr, int prim, int nroots)

				  int fcr, int prim, int nroots, gfp_t gfp)

{

	struct rs_control *rs;

	int i, j, sr, root, iprim;



	/* Allocate the control structure */

	rs = kmalloc(sizeof (struct rs_control), GFP_KERNEL);

	if (rs == NULL)

	rs = kmalloc(sizeof(*rs), gfp);

	if (!rs)

		return NULL;



	INIT_LIST_HEAD(&rs->list);
@@ -85,15 +86,15 @@ static struct rs_control *rs_init(int symsize, int gfpoly, int (*gffunc)(int), 
	rs->gffunc = gffunc;



	/* Allocate the arrays */

	rs->alpha_to = kmalloc(sizeof(uint16_t) * (rs->nn + 1), GFP_KERNEL);

	rs->alpha_to = kmalloc(sizeof(uint16_t) * (rs->nn + 1), gfp);

	if (rs->alpha_to == NULL)

		goto errrs;



	rs->index_of = kmalloc(sizeof(uint16_t) * (rs->nn + 1), GFP_KERNEL);

	rs->index_of = kmalloc(sizeof(uint16_t) * (rs->nn + 1), gfp);

	if (rs->index_of == NULL)

		goto erralp;



	rs->genpoly = kmalloc(sizeof(uint16_t) * (rs->nroots + 1), GFP_KERNEL);

	rs->genpoly = kmalloc(sizeof(uint16_t) * (rs->nroots + 1), gfp);

	if(rs->genpoly == NULL)

		goto erridx;
@@ -181,6 +182,7 @@ void free_rs(struct rs_control *rs) 
	}

	mutex_unlock(&rslistlock);

}

EXPORT_SYMBOL_GPL(free_rs);



/**

 * init_rs_internal - Find a matching or allocate a new rs control structure
@@ -195,10 +197,11 @@ void free_rs(struct rs_control *rs) 
 *		in index form

 *  @prim:	primitive element to generate polynomial roots

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

 *  @gfp:	GFP_ flags for allocations

 */

static struct rs_control *init_rs_internal(int symsize, int gfpoly,

					   int (*gffunc)(int), int fcr,

                                           int prim, int nroots)

					   int prim, int nroots, gfp_t gfp)

{

	struct list_head *tmp;

	struct rs_control *rs;
@@ -236,7 +239,7 @@ static struct rs_control *init_rs_internal(int symsize, int gfpoly, 
	}



	/* Create a new one */

	rs = rs_init(symsize, gfpoly, gffunc, fcr, prim, nroots);

	rs = rs_init(symsize, gfpoly, gffunc, fcr, prim, nroots, gfp);

	if (rs) {

		rs->users = 1;

		list_add(&rs->list, &rslist);
@@ -247,7 +250,7 @@ static struct rs_control *init_rs_internal(int symsize, int gfpoly, 
}



/**

 * init_rs - Find a matching or allocate a new rs control structure

 * init_rs_gfp - Find a matching or allocate a new rs control structure

 *  @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
@@ -256,12 +259,14 @@ static struct rs_control *init_rs_internal(int symsize, int gfpoly, 
 *		in index form

 *  @prim:	primitive element to generate polynomial roots

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

 *  @gfp:	GFP_ flags for allocations

 */

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)

{

	return init_rs_internal(symsize, gfpoly, NULL, fcr, prim, nroots);

	return init_rs_internal(symsize, gfpoly, NULL, fcr, prim, nroots, gfp);

}

EXPORT_SYMBOL_GPL(init_rs_gfp);



/**

 * init_rs_non_canonical - Find a matching or allocate a new rs control
@@ -279,8 +284,10 @@ struct rs_control *init_rs(int symsize, int gfpoly, int fcr, int prim, 
struct rs_control *init_rs_non_canonical(int symsize, int (*gffunc)(int),

                                         int fcr, int prim, int nroots)

{

	return init_rs_internal(symsize, 0, gffunc, fcr, prim, nroots);

	return init_rs_internal(symsize, 0, gffunc, fcr, prim, nroots,

				GFP_KERNEL);

}

EXPORT_SYMBOL_GPL(init_rs_non_canonical);



#ifdef CONFIG_REED_SOLOMON_ENC8

/**
@@ -374,10 +381,6 @@ int decode_rs16(struct rs_control *rs, uint16_t *data, uint16_t *par, int len, 
EXPORT_SYMBOL_GPL(decode_rs16);

#endif



EXPORT_SYMBOL_GPL(init_rs);

EXPORT_SYMBOL_GPL(init_rs_non_canonical);

EXPORT_SYMBOL_GPL(free_rs);



MODULE_LICENSE("GPL");

MODULE_DESCRIPTION("Reed Solomon encoder/decoder");

MODULE_AUTHOR("Phil Karn, Thomas Gleixner");