pstore: add lzo/lz4 compression support

Like zlib compression in pstore, this patch added lzo and lz4
compression support so that users can have more options and better
compression ratio.

The original code treats the compressed data together with the
uncompressed ECC correction notice by using zlib decompress. The
ECC correction notice is missing in the decompression process. The
treatment also makes lzo and lz4 not working. So I treat them
separately by using pstore_decompress() to treat the compressed
data, and memcpy() to treat the uncompressed ECC correction notice.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Kees Cook <keescook@chromium.org>

1 files changed, 211 insertions, 7 deletions

diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index fe41d8e..16ecca5 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -28,7 +28,15 @@
 #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
+#include <linux/lzo.h>
+#endif
+#ifdef CONFIG_PSTORE_LZ4_COMPRESS
+#include <linux/lz4.h>
+#endif
 #include <linux/string.h>
 #include <linux/timer.h>
 #include <linux/slab.h>
@@ -69,10 +77,23 @@ 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;
+#else
+static unsigned char *workspace;
+#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);
+
+	const char *name;
+};
 
 static char *big_oops_buf;
 static size_t big_oops_buf_sz;
@@ -129,9 +150,9 @@ 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 pstore_compress(const void *in, void *out, size_t inlen,
-							size_t outlen)
+static int compress_zlib(const void *in, void *out, size_t inlen, size_t outlen)
 {
 	int err, ret;
 
@@ -165,7 +186,7 @@ error:
 }
 
 /* Derived from logfs_uncompress */
-static int pstore_decompress(void *in, void *out, size_t inlen, size_t outlen)
+static int decompress_zlib(void *in, void *out, size_t inlen, size_t outlen)
 {
 	int err, ret;
 
@@ -194,7 +215,7 @@ error:
 	return ret;
 }
 
-static void allocate_buf_for_compression(void)
+static void allocate_zlib(void)
 {
 	size_t size;
 	size_t cmpr;
@@ -237,12 +258,190 @@ static void allocate_buf_for_compression(void)
 
 }
 
-static void free_buf_for_compression(void)
+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 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)
+{
+	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;
+}
+
+static int decompress_lzo(void *in, void *out, size_t inlen, size_t outlen)
+{
+	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;
+}
+
+static void allocate_lzo(void)
+{
+	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;
+	}
+}
+
+static void free_lzo(void)
+{
+	kfree(workspace);
+	kfree(big_oops_buf);
+	big_oops_buf = NULL;
+	big_oops_buf_sz = 0;
+}
+
+static struct pstore_zbackend backend_lzo = {
+	.compress	= compress_lzo,
+	.decompress	= decompress_lzo,
+	.allocate	= allocate_lzo,
+	.free		= free_lzo,
+	.name		= "lzo",
+};
+#endif
+
+#ifdef CONFIG_PSTORE_LZ4_COMPRESS
+static int compress_lz4(const void *in, void *out, size_t inlen, size_t outlen)
+{
+	int ret;
+
+	ret = lz4_compress(in, inlen, out, &outlen, workspace);
+	if (ret) {
+		pr_err("lz4_compress error, ret = %d!\n", ret);
+		return -EIO;
+	}
+
+	return outlen;
+}
+
+static int decompress_lz4(void *in, void *out, size_t inlen, size_t outlen)
+{
+	int ret;
+
+	ret = lz4_decompress_unknownoutputsize(in, inlen, out, &outlen);
+	if (ret) {
+		pr_err("lz4_decompress error, ret = %d!\n", ret);
+		return -EIO;
+	}
+
+	return outlen;
+}
+
+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;
+	}
+}
+
+static void free_lz4(void)
+{
+	kfree(workspace);
+	kfree(big_oops_buf);
+	big_oops_buf = NULL;
+	big_oops_buf_sz = 0;
+}
+
+static struct pstore_zbackend backend_lz4 = {
+	.compress	= compress_lz4,
+	.decompress	= decompress_lz4,
+	.allocate	= allocate_lz4,
+	.free		= free_lz4,
+	.name		= "lz4",
+};
+#endif
+
+static 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
+
+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;
+}
+
+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;
+}
+
+static void allocate_buf_for_compression(void)
+{
+	if (zbackend) {
+		pr_info("using %s compression\n", zbackend->name);
+		zbackend->allocate();
+	} else {
+		pr_err("allocate compression buffer error!\n");
+	}
+}
+
+static void free_buf_for_compression(void)
+{
+	if (zbackend)
+		zbackend->free();
+	else
+		pr_err("free compression buffer error!\n");
 }
 
 /*
@@ -522,6 +721,7 @@ void pstore_get_records(int quiet)
 	int			failed = 0, rc;
 	bool			compressed;
 	int			unzipped_len = -1;
+	ssize_t			ecc_notice_size = 0;
 
 	if (!psi)
 		return;
@@ -531,7 +731,7 @@ void pstore_get_records(int quiet)
 		goto out;
 
 	while ((size = psi->read(&id, &type, &count, &time, &buf, &compressed,
-				psi)) > 0) {
+				 &ecc_notice_size, psi)) > 0) {
 		if (compressed && (type == PSTORE_TYPE_DMESG)) {
 			if (big_oops_buf)
 				unzipped_len = pstore_decompress(buf,
@@ -539,6 +739,9 @@ void pstore_get_records(int quiet)
 							big_oops_buf_sz);
 
 			if (unzipped_len > 0) {
+				if (ecc_notice_size)
+					memcpy(big_oops_buf + unzipped_len,
+					       buf + size, ecc_notice_size);
 				kfree(buf);
 				buf = big_oops_buf;
 				size = unzipped_len;
@@ -550,7 +753,8 @@ void pstore_get_records(int quiet)
 			}
 		}
 		rc = pstore_mkfile(type, psi->name, id, count, buf,
-				  compressed, (size_t)size, time, psi);
+				   compressed, size + ecc_notice_size,
+				   time, psi);
 		if (unzipped_len < 0) {
 			/* Free buffer other than big oops */
 			kfree(buf);