On 29.04.19 15:09, Jason J. Herne wrote:
> Newer versions of zipl have the ability to write signature entries to the boot
> script for secure boot. We don't yet support secure boot, but we need to skip
> over signature entries while reading the boot script in order to maintain our
> ability to boot guest operating systems that have a secure bootloader.
>
> Signed-off-by: Jason J. Herne <jjhe...@linux.ibm.com>
> Reviewed-by: Farhan Ali <al...@linux.ibm.com>
> ---
> pc-bios/s390-ccw/bootmap.c | 19 +++++++++++++++++--
> pc-bios/s390-ccw/bootmap.h | 10 ++++++----
> 2 files changed, 23 insertions(+), 6 deletions(-)
>
> diff --git a/pc-bios/s390-ccw/bootmap.c b/pc-bios/s390-ccw/bootmap.c
> index 7aef65a..d13b7cb 100644
> --- a/pc-bios/s390-ccw/bootmap.c
> +++ b/pc-bios/s390-ccw/bootmap.c
> @@ -254,7 +254,14 @@ static void run_eckd_boot_script(block_number_t
> bmt_block_nr,
> memset(sec, FREE_SPACE_FILLER, sizeof(sec));
> read_block(block_nr, sec, "Cannot read Boot Map Script");
>
> - for (i = 0; bms->entry[i].type == BOOT_SCRIPT_LOAD; i++) {
> + for (i = 0; bms->entry[i].type == BOOT_SCRIPT_LOAD ||
> + bms->entry[i].type == BOOT_SCRIPT_SIGNATURE; i++) {
> +
> + /* We don't support secure boot yet, so we skip signature entries */
> + if (bms->entry[i].type == BOOT_SCRIPT_SIGNATURE) {
> + continue;
> + }
> +
> address = bms->entry[i].address.load_address;
> block_nr = eckd_block_num(&bms->entry[i].blkptr.xeckd.bptr.chs);
>
> @@ -489,7 +496,15 @@ static void zipl_run(ScsiBlockPtr *pte)
>
> /* Load image(s) into RAM */
> entry = (ComponentEntry *)(&header[1]);
> - while (entry->component_type == ZIPL_COMP_ENTRY_LOAD) {
> + while (entry->component_type == ZIPL_COMP_ENTRY_LOAD ||
> + entry->component_type == ZIPL_COMP_ENTRY_SIGNATURE) {
> +
> + /* We don't support secure boot yet, so we skip signature entries */
> + if (entry->component_type == ZIPL_COMP_ENTRY_SIGNATURE) {
> + entry++;
> + continue;
> + }
> +
> zipl_load_segment(entry);
>
> entry++;
> diff --git a/pc-bios/s390-ccw/bootmap.h b/pc-bios/s390-ccw/bootmap.h
> index a085212..94f53a5 100644
> --- a/pc-bios/s390-ccw/bootmap.h
> +++ b/pc-bios/s390-ccw/bootmap.h
> @@ -98,8 +98,9 @@ typedef struct ScsiMbr {
> #define ZIPL_COMP_HEADER_IPL 0x00
> #define ZIPL_COMP_HEADER_DUMP 0x01
>
> -#define ZIPL_COMP_ENTRY_LOAD 0x02
> -#define ZIPL_COMP_ENTRY_EXEC 0x01
> +#define ZIPL_COMP_ENTRY_EXEC 0x01
> +#define ZIPL_COMP_ENTRY_LOAD 0x02
> +#define ZIPL_COMP_ENTRY_SIGNATURE 0x03
>
> typedef struct XEckdMbr {
> uint8_t magic[4]; /* == "xIPL" */
> @@ -117,8 +118,9 @@ typedef struct BootMapScriptEntry {
> BootMapPointer blkptr;
> uint8_t pad[7];
> uint8_t type; /* == BOOT_SCRIPT_* */
> -#define BOOT_SCRIPT_EXEC 0x01
> -#define BOOT_SCRIPT_LOAD 0x02
> +#define BOOT_SCRIPT_EXEC 0x01
> +#define BOOT_SCRIPT_LOAD 0x02
> +#define BOOT_SCRIPT_SIGNATURE 0x03
> union {
> uint64_t load_address;
> uint64_t load_psw;
>
Naive question from me:
Can't we place the signatures somewhere else, and instead associate them
with entries? This avoids breaking backwards compatibility for the sake
of signatures we want unmodified zipl loaders to ignore.
--
Thanks,
David / dhildenb
