lkml.org 
[lkml]   [2019]   [Feb]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH v4 13/16] block: sed-opal: check size of shadow mbr
    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@studium.uni-erlangen.de>
    >>
    >> 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@studium.uni-erlangen.de>
    >> Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
    >> ---
    >> 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

    \
     
     \ /
      Last update: 2019-02-10 21:07    [W:2.142 / U:0.056 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site