From 52e1cf2d19c2e62e6a81b8de3f7320d033917dd5 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Fri, 22 Jun 2018 08:42:22 +0200 Subject: [PATCH] efi/libstub/tpm: Initialize efi_physical_addr_t vars to zero for mixed mode 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 similar 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 Signed-off-by: Ard Biesheuvel Cc: # v4.16+ Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20180622064222.11633-2-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar --- 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;