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 <[email protected]>
Signed-off-by: Kees Cook <[email protected]>

arch/powerpc/kernel/nvram_64.c

@@ -444,7 +444,8 @@ static int nvram_pstore_write(enum pstore_type_id type,
  */
 static ssize_t nvram_pstore_read(u64 *id, enum pstore_type_id *type,
 				int *count, struct timespec *time, char **buf,
-				bool *compressed, struct pstore_info *psi)
+				bool *compressed, ssize_t *ecc_notice_size,
+				struct pstore_info *psi)
 {
 	struct oops_log_info *oops_hdr;
 	unsigned int err_type, id_no, size = 0;
@@ -545,6 +546,7 @@ static ssize_t nvram_pstore_read(u64 *id, enum pstore_type_id *type,
 			return -ENOMEM;
 		kfree(buff);
 
+		*ecc_notice_size = 0;
 		if (err_type == ERR_TYPE_KERNEL_PANIC_GZ)
 			*compressed = true;
 		else

drivers/acpi/apei/erst.c

@@ -927,7 +927,8 @@ static int erst_open_pstore(struct pstore_info *psi);
 static int erst_close_pstore(struct pstore_info *psi);
 static ssize_t erst_reader(u64 *id, enum pstore_type_id *type, int *count,
 			   struct timespec *time, char **buf,
-			   bool *compressed, struct pstore_info *psi);
+			   bool *compressed, ssize_t *ecc_notice_size,
+			   struct pstore_info *psi);
 static int erst_writer(enum pstore_type_id type, enum kmsg_dump_reason reason,
 		       u64 *id, unsigned int part, int count, bool compressed,
 		       size_t size, struct pstore_info *psi);
@@ -987,7 +988,8 @@ static int erst_close_pstore(struct pstore_info *psi)
 
 static ssize_t erst_reader(u64 *id, enum pstore_type_id *type, int *count,
 			   struct timespec *time, char **buf,
-			   bool *compressed, struct pstore_info *psi)
+			   bool *compressed, ssize_t *ecc_notice_size,
+			   struct pstore_info *psi)
 {
 	int rc;
 	ssize_t len = 0;
@@ -1033,6 +1035,7 @@ static ssize_t erst_reader(u64 *id, enum pstore_type_id *type, int *count,
 	memcpy(*buf, rcd->data, len - sizeof(*rcd));
 	*id = record_id;
 	*compressed = false;
+	*ecc_notice_size = 0;
 	if (uuid_le_cmp(rcd->sec_hdr.section_type,
 			CPER_SECTION_TYPE_DMESG_Z) == 0) {
 		*type = PSTORE_TYPE_DMESG;

drivers/firmware/efi/efi-pstore.c

@@ -34,6 +34,7 @@ struct pstore_read_data {
 	int *count;
 	struct timespec *timespec;
 	bool *compressed;
+	ssize_t *ecc_notice_size;
 	char **buf;
 };
 
@@ -69,13 +70,15 @@ static int efi_pstore_read_func(struct efivar_entry *entry, void *data)
 			*cb_data->compressed = true;
 		else
 			*cb_data->compressed = false;
+		*cb_data->ecc_notice_size = 0;
 	} else if (sscanf(name, "dump-type%u-%u-%d-%lu",
 		   cb_data->type, &part, &cnt, &time) == 4) {
 		*cb_data->id = generic_id(time, part, cnt);
 		*cb_data->count = cnt;
 		cb_data->timespec->tv_sec = time;
 		cb_data->timespec->tv_nsec = 0;
 		*cb_data->compressed = false;
+		*cb_data->ecc_notice_size = 0;
 	} else if (sscanf(name, "dump-type%u-%u-%lu",
 			  cb_data->type, &part, &time) == 3) {
 		/*
@@ -88,6 +91,7 @@ static int efi_pstore_read_func(struct efivar_entry *entry, void *data)
 		cb_data->timespec->tv_sec = time;
 		cb_data->timespec->tv_nsec = 0;
 		*cb_data->compressed = false;
+		*cb_data->ecc_notice_size = 0;
 	} else
 		return 0;
 
@@ -210,6 +214,7 @@ static int efi_pstore_sysfs_entry_iter(void *data, struct efivar_entry **pos)
 static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
 			       int *count, struct timespec *timespec,
 			       char **buf, bool *compressed,
+			       ssize_t *ecc_notice_size,
 			       struct pstore_info *psi)
 {
 	struct pstore_read_data data;
@@ -220,6 +225,7 @@ static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
 	data.count = count;
 	data.timespec = timespec;
 	data.compressed = compressed;
+	data.ecc_notice_size = ecc_notice_size;
 	data.buf = buf;
 
 	*data.buf = kzalloc(EFIVARS_DATA_SIZE_MAX, GFP_KERNEL);

fs/pstore/Kconfig

@@ -1,8 +1,6 @@
 config PSTORE
 	tristate "Persistent store support"
 	default n
-	select ZLIB_DEFLATE
-	select ZLIB_INFLATE
 	help
 	   This option enables generic access to platform level
 	   persistent storage via "pstore" filesystem that can
@@ -14,6 +12,35 @@ 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_LZO_COMPRESS
+        bool "LZO"
+        select LZO_COMPRESS
+        select LZO_DECOMPRESS
+        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.
+endchoice
+
 config PSTORE_CONSOLE
 	bool "Log kernel console messages"
 	depends on PSTORE