Hi, On 21-06-18 09:57, Ard Biesheuvel wrote:
On 21 June 2018 at 09:42, Hans de Goede <hdegoede@xxxxxxxxxx> wrote:Commit 79832f0b5f71 ("efi/libstub/tpm: Initialize pointer variables to zero for mixed mode") fixes a problem with the tpm code on mixed mode (64 bit kernel on 32 bit UEFI), where 64-bit pointer variables are not fully initialized by the 32-bit EFI code. A simlar problem applies to the efi_physical_addr_t variables which are written by the get_event_log EFI call. Even though efi_physical_addr_t is 64 bit everywhere it seems that some 32 bit UEFI implementations only fill in the lower 32 bits when passed a pointer to an efi_physical_addr_t to fill. This commit initializes these to 0 to, to ensure the upper 32 bits are 0 in mixed mode. This fixes recent kernels sometimes hanging during early boot on mixed mode UEFI systems. Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> --- Changes in v2: -Change commit message to reflect that efi_physical_addr_t is 64 bit everywhere and some firmwares only filling the lower 32 bits is somewhat unexpectedThanks Hans Queued in efi/next
Thanks, I just realized I forgot to add a "Cc: stable@xxxxxxxxxxxxxxx", the problem of some BYT machines not booting about 50% of the times was introduced in 4.17. Given that this is a bugfix for this, it would be good to get this added to 4.18-rc# and 4.17.x Regards, Hans
--- drivers/firmware/efi/libstub/tpm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/firmware/efi/libstub/tpm.c b/drivers/firmware/efi/libstub/tpm.c index caa37a6dd9d4..a90b0b8fc69a 100644 --- a/drivers/firmware/efi/libstub/tpm.c +++ b/drivers/firmware/efi/libstub/tpm.c @@ -64,7 +64,7 @@ static void efi_retrieve_tpm2_eventlog_1_2(efi_system_table_t *sys_table_arg) efi_guid_t tcg2_guid = EFI_TCG2_PROTOCOL_GUID; efi_guid_t linux_eventlog_guid = LINUX_EFI_TPM_EVENT_LOG_GUID; efi_status_t status; - efi_physical_addr_t log_location, log_last_entry; + efi_physical_addr_t log_location = 0, log_last_entry = 0; struct linux_efi_tpm_eventlog *log_tbl = NULL; unsigned long first_entry_addr, last_entry_addr; size_t log_size, last_entry_size; -- 2.17.1
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