From 83a530e1610ab996e59c0941db6cc72f763dddbd Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Sun, 22 Apr 2018 18:23:46 +0200
Subject: [PATCH] rslib: Add GFP aware init function
Git-commit: 83a530e1610ab996e59c0941db6cc72f763dddbd
Patch-mainline: v4.18-rc1
References: bsc#1111974
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: Thomas 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: Kees Cook <keescook@chromium.org>
Acked-by: Coly Li <colyli@suse.de>
---
include/linux/rslib.h | 28 ++++++++++++++++++++++++---
lib/reed_solomon/reed_solomon.c | 43 ++++++++++++++++++++++-------------------
2 files changed, 48 insertions(+), 23 deletions(-)
diff --git a/include/linux/rslib.h b/include/linux/rslib.h
index 746580c1939c..2aae7ef987eb 100644
--- a/include/linux/rslib.h
+++ b/include/linux/rslib.h
@@ -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
@@ -77,10 +79,30 @@ 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);
+ int fcr, int prim, int nroots);
/* Release a rs control structure */
void free_rs(struct rs_control *rs);
diff --git a/lib/reed_solomon/reed_solomon.c b/lib/reed_solomon/reed_solomon.c
index 06d04cfa9339..f8ae1f7b3558 100644
--- a/lib/reed_solomon/reed_solomon.c
+++ b/lib/reed_solomon/reed_solomon.c
@@ -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
@@ -195,13 +197,14 @@ 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 (*gffunc)(int), int fcr,
+ int prim, int nroots, gfp_t gfp)
{
- struct list_head *tmp;
- struct rs_control *rs;
+ struct list_head *tmp;
+ struct rs_control *rs;
/* Sanity checks */
if (symsize < 1)
@@ -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");
--
2.16.3