Merge tag 'pstore-v4.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull pstore updates from Kees Cook:
 "This cycle was almost entirely improvements to the pstore compression
  options, noted below:

   - Add lz4hc and 842 to pstore compression options (Geliang Tang)

   - Refactor to use crypto compression API (Geliang Tang)

   - Fix up Kconfig dependencies for compression (Arnd Bergmann)

   - Allow for run-time compression selection

   - Remove stack VLA usage"

* tag 'pstore-v4.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  pstore: fix crypto dependencies
  pstore: Use crypto compress API
  pstore/ram: Do not use stack VLA for parity workspace
  pstore: Select compression at runtime
  pstore: Avoid size casts for 842 compression
  pstore: Add lz4hc and 842 compression support

7 files changed, 226 insertions, 284 deletions

diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig
index b42e5bd6d8ff..09c19ef91526 100644
--- a/fs/pstore/Kconfig
+++ b/fs/pstore/Kconfig
@@ -1,5 +1,6 @@
 config PSTORE
 	tristate "Persistent store support"
+	select CRYPTO if PSTORE_COMPRESS
 	default n
 	help
 	   This option enables generic access to platform level
@@ -12,35 +13,89 @@ config PSTORE
 	   If you don't have a platform persistent store driver,
 	   say N.
 
-choice
-        prompt "Choose compression algorithm"
-        depends on PSTORE
-        default PSTORE_ZLIB_COMPRESS
-        help
-          This option chooses compression algorithm.
-
-config PSTORE_ZLIB_COMPRESS
-        bool "ZLIB"
-        select ZLIB_DEFLATE
-        select ZLIB_INFLATE
-        help
-          This option enables ZLIB compression algorithm support.
+config PSTORE_DEFLATE_COMPRESS
+	tristate "DEFLATE (ZLIB) compression"
+	default y
+	depends on PSTORE
+	select CRYPTO_DEFLATE
+	help
+	  This option enables DEFLATE (also known as ZLIB) compression
+	  algorithm support.
 
 config PSTORE_LZO_COMPRESS
-        bool "LZO"
-        select LZO_COMPRESS
-        select LZO_DECOMPRESS
-        help
-          This option enables LZO compression algorithm support.
+	tristate "LZO compression"
+	depends on PSTORE
+	select CRYPTO_LZO
+	help
+	  This option enables LZO compression algorithm support.
 
 config PSTORE_LZ4_COMPRESS
-        bool "LZ4"
-        select LZ4_COMPRESS
-        select LZ4_DECOMPRESS
-        help
-          This option enables LZ4 compression algorithm support.
+	tristate "LZ4 compression"
+	depends on PSTORE
+	select CRYPTO_LZ4
+	help
+	  This option enables LZ4 compression algorithm support.
+
+config PSTORE_LZ4HC_COMPRESS
+	tristate "LZ4HC compression"
+	depends on PSTORE
+	select CRYPTO_LZ4HC
+	help
+	  This option enables LZ4HC (high compression) mode algorithm.
+
+config PSTORE_842_COMPRESS
+	bool "842 compression"
+	depends on PSTORE
+	select CRYPTO_842
+	help
+	  This option enables 842 compression algorithm support.
+
+config PSTORE_COMPRESS
+	def_bool y
+	depends on PSTORE
+	depends on PSTORE_DEFLATE_COMPRESS || PSTORE_LZO_COMPRESS ||	\
+		   PSTORE_LZ4_COMPRESS || PSTORE_LZ4HC_COMPRESS ||	\
+		   PSTORE_842_COMPRESS
+
+choice
+	prompt "Default pstore compression algorithm"
+	depends on PSTORE_COMPRESS
+	help
+	  This option chooses the default active compression algorithm.
+	  This change be changed at boot with "pstore.compress=..." on
+	  the kernel command line.
+
+	  Currently, pstore has support for 5 compression algorithms:
+	  deflate, lzo, lz4, lz4hc and 842.
+
+	  The default compression algorithm is deflate.
+
+	config PSTORE_DEFLATE_COMPRESS_DEFAULT
+		bool "deflate" if PSTORE_DEFLATE_COMPRESS
+
+	config PSTORE_LZO_COMPRESS_DEFAULT
+		bool "lzo" if PSTORE_LZO_COMPRESS
+
+	config PSTORE_LZ4_COMPRESS_DEFAULT
+		bool "lz4" if PSTORE_LZ4_COMPRESS
+
+	config PSTORE_LZ4HC_COMPRESS_DEFAULT
+		bool "lz4hc" if PSTORE_LZ4HC_COMPRESS
+
+	config PSTORE_842_COMPRESS_DEFAULT
+		bool "842" if PSTORE_842_COMPRESS
+
 endchoice
 
+config PSTORE_COMPRESS_DEFAULT
+	string
+	depends on PSTORE_COMPRESS
+	default "deflate" if PSTORE_DEFLATE_COMPRESS_DEFAULT
+	default "lzo" if PSTORE_LZO_COMPRESS_DEFAULT
+	default "lz4" if PSTORE_LZ4_COMPRESS_DEFAULT
+	default "lz4hc" if PSTORE_LZ4HC_COMPRESS_DEFAULT
+	default "842" if PSTORE_842_COMPRESS_DEFAULT
+
 config PSTORE_CONSOLE
 	bool "Log kernel console messages"
 	depends on PSTORE
diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index d814723fb27d..5fcb845b9fec 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -486,6 +486,8 @@ static int __init init_pstore_fs(void)
 {
 	int err;
 
+	pstore_choose_compression();
+
 	/* Create a convenient mount point for people to access pstore */
 	err = sysfs_create_mount_point(fs_kobj, "pstore");
 	if (err)
diff --git a/fs/pstore/internal.h b/fs/pstore/internal.h
index c029314478fa..fb767e28aeb2 100644
--- a/fs/pstore/internal.h
+++ b/fs/pstore/internal.h
@@ -37,4 +37,7 @@ extern bool	pstore_is_mounted(void);
 extern void	pstore_record_init(struct pstore_record *record,
 				   struct pstore_info *psi);
 
+/* Called during module_init() */
+extern void __init pstore_choose_compression(void);
+
 #endif
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index c3129b131e4d..1143ef351c58 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -28,15 +28,13 @@
 #include <linux/console.h>
 #include <linux/module.h>
 #include <linux/pstore.h>
-#ifdef CONFIG_PSTORE_ZLIB_COMPRESS
-#include <linux/zlib.h>
-#endif
-#ifdef CONFIG_PSTORE_LZO_COMPRESS
+#if IS_ENABLED(CONFIG_PSTORE_LZO_COMPRESS)
 #include <linux/lzo.h>
 #endif
-#ifdef CONFIG_PSTORE_LZ4_COMPRESS
+#if IS_ENABLED(CONFIG_PSTORE_LZ4_COMPRESS) || IS_ENABLED(CONFIG_PSTORE_LZ4HC_COMPRESS)
 #include <linux/lz4.h>
 #endif
+#include <linux/crypto.h>
 #include <linux/string.h>
 #include <linux/timer.h>
 #include <linux/slab.h>
@@ -74,23 +72,18 @@ static DEFINE_SPINLOCK(pstore_lock);
 struct pstore_info *psinfo;
 
 static char *backend;
-
-/* Compression parameters */
-#ifdef CONFIG_PSTORE_ZLIB_COMPRESS
-#define COMPR_LEVEL 6
-#define WINDOW_BITS 12
-#define MEM_LEVEL 4
-static struct z_stream_s stream;
+static char *compress =
+#ifdef CONFIG_PSTORE_COMPRESS_DEFAULT
+		CONFIG_PSTORE_COMPRESS_DEFAULT;
 #else
-static unsigned char *workspace;
+		NULL;
 #endif
 
-struct pstore_zbackend {
-	int (*compress)(const void *in, void *out, size_t inlen, size_t outlen);
-	int (*decompress)(void *in, void *out, size_t inlen, size_t outlen);
-	void (*allocate)(void);
-	void (*free)(void);
+/* Compression parameters */
+static struct crypto_comp *tfm;
 
+struct pstore_zbackend {
+	int (*zbufsize)(size_t size);
 	const char *name;
 };
 
@@ -149,77 +142,12 @@ bool pstore_cannot_block_path(enum kmsg_dump_reason reason)
 }
 EXPORT_SYMBOL_GPL(pstore_cannot_block_path);
 
-#ifdef CONFIG_PSTORE_ZLIB_COMPRESS
-/* Derived from logfs_compress() */
-static int compress_zlib(const void *in, void *out, size_t inlen, size_t outlen)
-{
-	int err, ret;
-
-	ret = -EIO;
-	err = zlib_deflateInit2(&stream, COMPR_LEVEL, Z_DEFLATED, WINDOW_BITS,
-						MEM_LEVEL, Z_DEFAULT_STRATEGY);
-	if (err != Z_OK)
-		goto error;
-
-	stream.next_in = in;
-	stream.avail_in = inlen;
-	stream.total_in = 0;
-	stream.next_out = out;
-	stream.avail_out = outlen;
-	stream.total_out = 0;
-
-	err = zlib_deflate(&stream, Z_FINISH);
-	if (err != Z_STREAM_END)
-		goto error;
-
-	err = zlib_deflateEnd(&stream);
-	if (err != Z_OK)
-		goto error;
-
-	if (stream.total_out >= stream.total_in)
-		goto error;
-
-	ret = stream.total_out;
-error:
-	return ret;
-}
-
-/* Derived from logfs_uncompress */
-static int decompress_zlib(void *in, void *out, size_t inlen, size_t outlen)
+#if IS_ENABLED(CONFIG_PSTORE_DEFLATE_COMPRESS)
+static int zbufsize_deflate(size_t size)
 {
-	int err, ret;
-
-	ret = -EIO;
-	err = zlib_inflateInit2(&stream, WINDOW_BITS);
-	if (err != Z_OK)
-		goto error;
-
-	stream.next_in = in;
-	stream.avail_in = inlen;
-	stream.total_in = 0;
-	stream.next_out = out;
-	stream.avail_out = outlen;
-	stream.total_out = 0;
-
-	err = zlib_inflate(&stream, Z_FINISH);
-	if (err != Z_STREAM_END)
-		goto error;
-
-	err = zlib_inflateEnd(&stream);
-	if (err != Z_OK)
-		goto error;
-
-	ret = stream.total_out;
-error:
-	return ret;
-}
-
-static void allocate_zlib(void)
-{
-	size_t size;
 	size_t cmpr;
 
-	switch (psinfo->bufsize) {
+	switch (size) {
 	/* buffer range for efivars */
 	case 1000 ... 2000:
 		cmpr = 56;
@@ -239,212 +167,131 @@ static void allocate_zlib(void)
 		break;
 	}
 
-	big_oops_buf_sz = (psinfo->bufsize * 100) / cmpr;
-	big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
-	if (big_oops_buf) {
-		size = max(zlib_deflate_workspacesize(WINDOW_BITS, MEM_LEVEL),
-			zlib_inflate_workspacesize());
-		stream.workspace = kmalloc(size, GFP_KERNEL);
-		if (!stream.workspace) {
-			pr_err("No memory for compression workspace; skipping compression\n");
-			kfree(big_oops_buf);
-			big_oops_buf = NULL;
-		}
-	} else {
-		pr_err("No memory for uncompressed data; skipping compression\n");
-		stream.workspace = NULL;
-	}
-
+	return (size * 100) / cmpr;
 }
-
-static void free_zlib(void)
-{
-	kfree(stream.workspace);
-	stream.workspace = NULL;
-	kfree(big_oops_buf);
-	big_oops_buf = NULL;
-	big_oops_buf_sz = 0;
-}
-
-static const struct pstore_zbackend backend_zlib = {
-	.compress	= compress_zlib,
-	.decompress	= decompress_zlib,
-	.allocate	= allocate_zlib,
-	.free		= free_zlib,
-	.name		= "zlib",
-};
 #endif
 
-#ifdef CONFIG_PSTORE_LZO_COMPRESS
-static int compress_lzo(const void *in, void *out, size_t inlen, size_t outlen)
+#if IS_ENABLED(CONFIG_PSTORE_LZO_COMPRESS)
+static int zbufsize_lzo(size_t size)
 {
-	int ret;
-
-	ret = lzo1x_1_compress(in, inlen, out, &outlen, workspace);
-	if (ret != LZO_E_OK) {
-		pr_err("lzo_compress error, ret = %d!\n", ret);
-		return -EIO;
-	}
-
-	return outlen;
+	return lzo1x_worst_compress(size);
 }
+#endif
 
-static int decompress_lzo(void *in, void *out, size_t inlen, size_t outlen)
+#if IS_ENABLED(CONFIG_PSTORE_LZ4_COMPRESS) || IS_ENABLED(CONFIG_PSTORE_LZ4HC_COMPRESS)
+static int zbufsize_lz4(size_t size)
 {
-	int ret;
-
-	ret = lzo1x_decompress_safe(in, inlen, out, &outlen);
-	if (ret != LZO_E_OK) {
-		pr_err("lzo_decompress error, ret = %d!\n", ret);
-		return -EIO;
-	}
-
-	return outlen;
+	return LZ4_compressBound(size);
 }
+#endif
 
-static void allocate_lzo(void)
+#if IS_ENABLED(CONFIG_PSTORE_842_COMPRESS)
+static int zbufsize_842(size_t size)
 {
-	big_oops_buf_sz = lzo1x_worst_compress(psinfo->bufsize);
-	big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
-	if (big_oops_buf) {
-		workspace = kmalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL);
-		if (!workspace) {
-			pr_err("No memory for compression workspace; skipping compression\n");
-			kfree(big_oops_buf);
-			big_oops_buf = NULL;
-		}
-	} else {
-		pr_err("No memory for uncompressed data; skipping compression\n");
-		workspace = NULL;
-	}
+	return size;
 }
+#endif
 
-static void free_lzo(void)
-{
-	kfree(workspace);
-	kfree(big_oops_buf);
-	big_oops_buf = NULL;
-	big_oops_buf_sz = 0;
-}
+static const struct pstore_zbackend *zbackend __ro_after_init;
 
-static const struct pstore_zbackend backend_lzo = {
-	.compress	= compress_lzo,
-	.decompress	= decompress_lzo,
-	.allocate	= allocate_lzo,
-	.free		= free_lzo,
-	.name		= "lzo",
-};
+static const struct pstore_zbackend zbackends[] = {
+#if IS_ENABLED(CONFIG_PSTORE_DEFLATE_COMPRESS)
+	{
+		.zbufsize	= zbufsize_deflate,
+		.name		= "deflate",
+	},
+#endif
+#if IS_ENABLED(CONFIG_PSTORE_LZO_COMPRESS)
+	{
+		.zbufsize	= zbufsize_lzo,
+		.name		= "lzo",
+	},
+#endif
+#if IS_ENABLED(CONFIG_PSTORE_LZ4_COMPRESS)
+	{
+		.zbufsize	= zbufsize_lz4,
+		.name		= "lz4",
+	},
 #endif
+#if IS_ENABLED(CONFIG_PSTORE_LZ4HC_COMPRESS)
+	{
+		.zbufsize	= zbufsize_lz4,
+		.name		= "lz4hc",
+	},
+#endif
+#if IS_ENABLED(CONFIG_PSTORE_842_COMPRESS)
+	{
+		.zbufsize	= zbufsize_842,
+		.name		= "842",
+	},
+#endif
+	{ }
+};
 
-#ifdef CONFIG_PSTORE_LZ4_COMPRESS
-static int compress_lz4(const void *in, void *out, size_t inlen, size_t outlen)
+static int pstore_compress(const void *in, void *out,
+			   unsigned int inlen, unsigned int outlen)
 {
 	int ret;
 
-	ret = LZ4_compress_default(in, out, inlen, outlen, workspace);
-	if (!ret) {
-		pr_err("LZ4_compress_default error; compression failed!\n");
-		return -EIO;
+	ret = crypto_comp_compress(tfm, in, inlen, out, &outlen);
+	if (ret) {
+		pr_err("crypto_comp_compress failed, ret = %d!\n", ret);
+		return ret;
 	}
 
-	return ret;
+	return outlen;
 }
 
-static int decompress_lz4(void *in, void *out, size_t inlen, size_t outlen)
+static int pstore_decompress(void *in, void *out,
+			     unsigned int inlen, unsigned int outlen)
 {
 	int ret;
 
-	ret = LZ4_decompress_safe(in, out, inlen, outlen);
-	if (ret < 0) {
-		/*
-		 * LZ4_decompress_safe will return an error code
-		 * (< 0) if decompression failed
-		 */
-		pr_err("LZ4_decompress_safe error, ret = %d!\n", ret);
-		return -EIO;
+	ret = crypto_comp_decompress(tfm, in, inlen, out, &outlen);
+	if (ret) {
+		pr_err("crypto_comp_decompress failed, ret = %d!\n", ret);
+		return ret;
 	}
 
-	return ret;
-}
-
-static void allocate_lz4(void)
-{
-	big_oops_buf_sz = LZ4_compressBound(psinfo->bufsize);
-	big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
-	if (big_oops_buf) {
-		workspace = kmalloc(LZ4_MEM_COMPRESS, GFP_KERNEL);
-		if (!workspace) {
-			pr_err("No memory for compression workspace; skipping compression\n");
-			kfree(big_oops_buf);
-			big_oops_buf = NULL;
-		}
-	} else {
-		pr_err("No memory for uncompressed data; skipping compression\n");
-		workspace = NULL;
-	}
+	return outlen;
 }
 
-static void free_lz4(void)
+static void allocate_buf_for_compression(void)
 {
-	kfree(workspace);
-	kfree(big_oops_buf);
-	big_oops_buf = NULL;
-	big_oops_buf_sz = 0;
-}
-
-static const struct pstore_zbackend backend_lz4 = {
-	.compress	= compress_lz4,
-	.decompress	= decompress_lz4,
-	.allocate	= allocate_lz4,
-	.free		= free_lz4,
-	.name		= "lz4",
-};
-#endif
-
-static const struct pstore_zbackend *zbackend =
-#if defined(CONFIG_PSTORE_ZLIB_COMPRESS)
-	&backend_zlib;
-#elif defined(CONFIG_PSTORE_LZO_COMPRESS)
-	&backend_lzo;
-#elif defined(CONFIG_PSTORE_LZ4_COMPRESS)
-	&backend_lz4;
-#else
-	NULL;
-#endif
+	if (!zbackend)
+		return;
 
-static int pstore_compress(const void *in, void *out,
-			   size_t inlen, size_t outlen)
-{
-	if (zbackend)
-		return zbackend->compress(in, out, inlen, outlen);
-	else
-		return -EIO;
-}
+	if (!crypto_has_comp(zbackend->name, 0, 0)) {
+		pr_err("No %s compression\n", zbackend->name);
+		return;
+	}
 
-static int pstore_decompress(void *in, void *out, size_t inlen, size_t outlen)
-{
-	if (zbackend)
-		return zbackend->decompress(in, out, inlen, outlen);
-	else
-		return -EIO;
-}
+	big_oops_buf_sz = zbackend->zbufsize(psinfo->bufsize);
+	if (big_oops_buf_sz <= 0)
+		return;
 
-static void allocate_buf_for_compression(void)
-{
-	if (zbackend) {
-		pr_info("using %s compression\n", zbackend->name);
-		zbackend->allocate();
-	} else {
+	big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
+	if (!big_oops_buf) {
 		pr_err("allocate compression buffer error!\n");
+		return;
+	}
+
+	tfm = crypto_alloc_comp(zbackend->name, 0, 0);
+	if (IS_ERR_OR_NULL(tfm)) {
+		kfree(big_oops_buf);
+		big_oops_buf = NULL;
+		pr_err("crypto_alloc_comp() failed!\n");
+		return;
 	}
 }
 
 static void free_buf_for_compression(void)
 {
-	if (zbackend)
-		zbackend->free();
-	else
-		pr_err("free compression buffer error!\n");
+	if (!IS_ERR_OR_NULL(tfm))
+		crypto_free_comp(tfm);
+	kfree(big_oops_buf);
+	big_oops_buf = NULL;
+	big_oops_buf_sz = 0;
 }
 
 /*
@@ -901,5 +748,24 @@ static void pstore_timefunc(struct timer_list *unused)
 			  jiffies + msecs_to_jiffies(pstore_update_ms));
 }
 
+void __init pstore_choose_compression(void)
+{
+	const struct pstore_zbackend *step;
+
+	if (!compress)
+		return;
+
+	for (step = zbackends; step->name; step++) {
+		if (!strcmp(compress, step->name)) {
+			zbackend = step;
+			pr_info("using %s compression\n", zbackend->name);
+			return;
+		}
+	}
+}
+
+module_param(compress, charp, 0444);
+MODULE_PARM_DESC(compress, "Pstore compression to use");
+
 module_param(backend, charp, 0444);
 MODULE_PARM_DESC(backend, "Pstore backend to use");
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 7125b398d312..49b2bc114868 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -938,7 +938,7 @@ static int __init ramoops_init(void)
 	ramoops_register_dummy();
 	return platform_driver_register(&ramoops_driver);
 }
-postcore_initcall(ramoops_init);
+late_initcall(ramoops_init);
 
 static void __exit ramoops_exit(void)
 {
diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
index e11672aa4575..951a14edcf51 100644
--- a/fs/pstore/ram_core.c
+++ b/fs/pstore/ram_core.c
@@ -98,24 +98,23 @@ static void notrace persistent_ram_encode_rs8(struct persistent_ram_zone *prz,
 	uint8_t *data, size_t len, uint8_t *ecc)
 {
 	int i;
-	uint16_t par[prz->ecc_info.ecc_size];
 
 	/* Initialize the parity buffer */
-	memset(par, 0, sizeof(par));
-	encode_rs8(prz->rs_decoder, data, len, par, 0);
+	memset(prz->ecc_info.par, 0,
+	       prz->ecc_info.ecc_size * sizeof(prz->ecc_info.par[0]));
+	encode_rs8(prz->rs_decoder, data, len, prz->ecc_info.par, 0);
 	for (i = 0; i < prz->ecc_info.ecc_size; i++)
-		ecc[i] = par[i];
+		ecc[i] = prz->ecc_info.par[i];
 }
 
 static int persistent_ram_decode_rs8(struct persistent_ram_zone *prz,
 	void *data, size_t len, uint8_t *ecc)
 {
 	int i;
-	uint16_t par[prz->ecc_info.ecc_size];
 
 	for (i = 0; i < prz->ecc_info.ecc_size; i++)
-		par[i] = ecc[i];
-	return decode_rs8(prz->rs_decoder, data, par, len,
+		prz->ecc_info.par[i] = ecc[i];
+	return decode_rs8(prz->rs_decoder, data, prz->ecc_info.par, len,
 				NULL, 0, NULL, 0, NULL);
 }
 
@@ -228,6 +227,15 @@ static int persistent_ram_init_ecc(struct persistent_ram_zone *prz,
 		return -EINVAL;
 	}
 
+	/* allocate workspace instead of using stack VLA */
+	prz->ecc_info.par = kmalloc_array(prz->ecc_info.ecc_size,
+					  sizeof(*prz->ecc_info.par),
+					  GFP_KERNEL);
+	if (!prz->ecc_info.par) {
+		pr_err("cannot allocate ECC parity workspace\n");
+		return -ENOMEM;
+	}
+
 	prz->corrected_bytes = 0;
 	prz->bad_blocks = 0;
 
@@ -514,6 +522,13 @@ void persistent_ram_free(struct persistent_ram_zone *prz)
 		}
 		prz->vaddr = NULL;
 	}
+	if (prz->rs_decoder) {
+		free_rs(prz->rs_decoder);
+		prz->rs_decoder = NULL;
+	}
+	kfree(prz->ecc_info.par);
+	prz->ecc_info.par = NULL;
+
 	persistent_ram_free_old(prz);
 	kfree(prz);
 }
diff --git a/include/linux/pstore_ram.h b/include/linux/pstore_ram.h
index 9395f06e8372..e6d226464838 100644
--- a/include/linux/pstore_ram.h
+++ b/include/linux/pstore_ram.h
@@ -39,6 +39,7 @@ struct persistent_ram_ecc_info {
 	int ecc_size;
 	int symsize;
 	int poly;
+	uint16_t *par;
 };
 
 struct persistent_ram_zone {