Re: [PATCH v4 13/16] block: sed-opal: check size of shadow mbr
From: David Kozub
Date: Sun Feb 10 2019 - 15:06:21 EST
On Fri, 8 Feb 2019, Derrick, Jonathan wrote:
On Fri, 2019-02-01 at 21:50 +0100, David Kozub wrote:
From: Jonas Rabenstein <jonas.rabenstein@xxxxxxxxxxxxxxxxxxxxxxx>
Check whether the shadow mbr does fit in the provided space on the
target. Also a proper firmware should handle this case and return an
error we may prevent problems or even damage with crappy firmwares.
Signed-off-by: Jonas Rabenstein <jonas.rabenstein@xxxxxxxxxxxxxxxxxxxxxxx>
Reviewed-by: Scott Bauer <sbauer@xxxxxxxxxxxxxx>
---
block/opal_proto.h | 16 ++++++++++++++++
block/sed-opal.c | 39 +++++++++++++++++++++++++++++++++++++++
2 files changed, 55 insertions(+)
diff --git a/block/opal_proto.h b/block/opal_proto.h
index b6e352cfe982..5e8df3245eb0 100644
--- a/block/opal_proto.h
+++ b/block/opal_proto.h
@@ -106,6 +106,7 @@ enum opal_uid {
OPAL_ENTERPRISE_BANDMASTER0_UID,
OPAL_ENTERPRISE_ERASEMASTER_UID,
/* tables */
+ OPAL_TABLE_TABLE,
OPAL_LOCKINGRANGE_GLOBAL,
OPAL_LOCKINGRANGE_ACE_RDLOCKED,
OPAL_LOCKINGRANGE_ACE_WRLOCKED,
@@ -160,6 +161,21 @@ enum opal_token {
OPAL_STARTCOLUMN = 0x03,
OPAL_ENDCOLUMN = 0x04,
OPAL_VALUES = 0x01,
+ /* table table */
+ OPAL_TABLE_UID = 0x00,
+ OPAL_TABLE_NAME = 0x01,
+ OPAL_TABLE_COMMON = 0x02,
+ OPAL_TABLE_TEMPLATE = 0x03,
+ OPAL_TABLE_KIND = 0x04,
+ OPAL_TABLE_COLUMN = 0x05,
+ OPAL_TABLE_COLUMNS = 0x06,
+ OPAL_TABLE_ROWS = 0x07,
+ OPAL_TABLE_ROWS_FREE = 0x08,
+ OPAL_TABLE_ROW_BYTES = 0x09,
+ OPAL_TABLE_LASTID = 0x0A,
+ OPAL_TABLE_MIN = 0x0B,
+ OPAL_TABLE_MAX = 0x0C,
+
/* authority table */
OPAL_PIN = 0x03,
/* locking tokens */
diff --git a/block/sed-opal.c b/block/sed-opal.c
index 2459ac4d523b..3493bb979978 100644
--- a/block/sed-opal.c
+++ b/block/sed-opal.c
@@ -139,6 +139,8 @@ static const u8 opaluid[][OPAL_UID_LENGTH] = {
/* tables */
+ [OPAL_TABLE_TABLE]
+ { 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01 },
[OPAL_LOCKINGRANGE_GLOBAL] =
{ 0x00, 0x00, 0x08, 0x02, 0x00, 0x00, 0x00, 0x01 },
[OPAL_LOCKINGRANGE_ACE_RDLOCKED] =
@@ -1120,6 +1122,29 @@ static int generic_get_column(struct opal_dev *dev, const u8 *table,
return finalize_and_send(dev, parse_and_check_status);
}
+/*
+ * see TCG SAS 5.3.2.3 for a description of the available columns
+ *
+ * the result is provided in dev->resp->tok[4]
+ */
+static int generic_get_table_info(struct opal_dev *dev, enum opal_uid table,
+ u64 column)
+{
+ u8 uid[OPAL_UID_LENGTH];
+ const unsigned int half = OPAL_UID_LENGTH/2;
+
+ /* sed-opal UIDs can be split in two halves:
+ * first: actual table index
+ * second: relative index in the table
+ * so we have to get the first half of the OPAL_TABLE_TABLE and use the
+ * first part of the target table as relative index into that table
+ */
+ memcpy(uid, opaluid[OPAL_TABLE_TABLE], half);
+ memcpy(uid+half, opaluid[table], half);
+
+ return generic_get_column(dev, uid, column);
+}
+
static int gen_key(struct opal_dev *dev, void *data)
{
u8 uid[OPAL_UID_LENGTH];
@@ -1535,6 +1560,20 @@ static int write_shadow_mbr(struct opal_dev *dev, void *data)
u64 len;
int err = 0;
+ /* do we fit in the available shadow mbr space? */
+ err = generic_get_table_info(dev, OPAL_MBR, OPAL_TABLE_ROWS);
Wouldn't you need to multiply this by result from OPAL_TABLE_ROWBYTES?
What does ROWBYTES return for you?
Hi Jon,
reading the spec[1], I think it defines the MBR table to be a "byte table"
(see 5.7.2.6 MBR (Byte Table)). For byte tables, it says (see 3.2.5.1
Kinds of Tables) "A byte table has one unnamed column of type bytes_1." I
think this implies that each row is 1 byte and so number of rows = size of
table in rows.
When I actually try to get OPAL_TABLE_ROWS abd OPAL_TABLE_ROWBYTES of the
MBR table from a Samsung 840 EVO, I get:
* OPAL_TABLE_ROWS 134217728 which is 128 MiB
* OPAL_TABLE_ROWBYTES 0
I'm not sure if I'm doing something wrong here. I just added:
err = generic_get_table_info(dev, OPAL_MBR, OPAL_TABLE_ROW_BYTES);
if (err) {
pr_debug("MBR: could not get shadow row bytes size\n");
return err;
}
row_bytes = response_get_u64(&dev->parsed, 4);
Best regards,
David
[1] https://trustedcomputinggroup.org/wp-content/uploads/TCG_Storage_Architecture_Core_Spec_v2.01_r1.00.pdf