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>

2 files changed, 11 insertions, 2 deletions

diff --git a/drivers/acpi/apei/erst.c b/drivers/acpi/apei/erst.c
index 006c3894c6ea..f096ab3cb54d 100644
--- a/drivers/acpi/apei/erst.c
+++ b/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 @@ skip:
 	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;
diff --git a/drivers/firmware/efi/efi-pstore.c b/drivers/firmware/efi/efi-pstore.c
index eac76a79a880..d5903ea77238 100644
--- a/drivers/firmware/efi/efi-pstore.c
+++ b/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;
 };
 
@@ -69,6 +70,7 @@ 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);
@@ -76,6 +78,7 @@ 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 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);