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OvmfPkg: PlatformBdsLib: lock down SMM regardless of S3 

At the moment, the EFI_DXE_SMM_READY_TO_LOCK_PROTOCOL is only installed if
S3 is enabled -- at the end of SaveS3BootScript().

While a runtime OS is never booted with SMM unlocked (because the SMM IPL
locks down SMM as a last resort:

> SMM IPL!  DXE SMM Ready To Lock Protocol not installed before Ready To
> Boot signal
> SmmInstallProtocolInterface: [EfiSmmReadyToLockProtocol] 0
> Patch page table start ...
> Patch page table done!
> SMM IPL locked SMRAM window

), we shouldn't allow UEFI drivers and applications either to mess with
SMM just because S3 is disabled. So install
EFI_DXE_SMM_READY_TO_LOCK_PROTOCOL in PlatformBdsInit() unconditionally.

Cc: Feng Tian <feng.tian@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Acked-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
This commit is contained in:
Laszlo Ersek 2016-04-27 18:01:02 +02:00
parent 70017e4461
commit 84d2070aef
1 changed files with 16 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
OvmfPkg/Library/PlatformBdsLib/BdsPlatform.c
View File

@ -125,6 +125,9 @@ Returns:
--*/ --*/
{ {
EFI_HANDLE Handle;
EFI_STATUS Status;
DEBUG ((EFI_D_INFO, "PlatformBdsInit\n")); DEBUG ((EFI_D_INFO, "PlatformBdsInit\n"));
InstallDevicePathCallback (); InstallDevicePathCallback ();
@ -147,11 +150,20 @@ Returns:
if (QemuFwCfgS3Enabled ()) { if (QemuFwCfgS3Enabled ()) {
// //
// Save the boot script too. Note that this requires/includes emitting the // Save the boot script too. Note that this will require us to emit the
// DxeSmmReadyToLock event, which in turn locks down SMM. // DxeSmmReadyToLock event just below, which in turn locks down SMM.
// //
SaveS3BootScript (); SaveS3BootScript ();
} }
//
// Prevent further changes to LockBoxes or SMRAM.
//
Handle = NULL;
Status = gBS->InstallProtocolInterface (&Handle,
&gEfiDxeSmmReadyToLockProtocolGuid, EFI_NATIVE_INTERFACE,
NULL);
ASSERT_EFI_ERROR (Status);
} }
@ -1206,10 +1218,8 @@ Returns:
/** /**
Save the S3 boot script. Save the S3 boot script.
Note that we trigger DxeSmmReadyToLock here -- otherwise the script wouldn't Note that DxeSmmReadyToLock must be signaled after this function returns;
be saved actually. Triggering this protocol installation event in turn locks otherwise the script wouldn't be saved actually.
down SMM, so no further changes to LockBoxes or SMRAM are possible
afterwards.
**/ **/
STATIC STATIC
VOID VOID
@ -1219,7 +1229,6 @@ SaveS3BootScript (
{ {
EFI_STATUS Status; EFI_STATUS Status;
EFI_S3_SAVE_STATE_PROTOCOL *BootScript; EFI_S3_SAVE_STATE_PROTOCOL *BootScript;
EFI_HANDLE Handle;
STATIC CONST UINT8 Info[] = { 0xDE, 0xAD, 0xBE, 0xEF }; STATIC CONST UINT8 Info[] = { 0xDE, 0xAD, 0xBE, 0xEF };
Status = gBS->LocateProtocol (&gEfiS3SaveStateProtocolGuid, NULL, Status = gBS->LocateProtocol (&gEfiS3SaveStateProtocolGuid, NULL,
@ -1235,12 +1244,6 @@ SaveS3BootScript (
(UINT32) sizeof Info, (UINT32) sizeof Info,
(EFI_PHYSICAL_ADDRESS)(UINTN) &Info); (EFI_PHYSICAL_ADDRESS)(UINTN) &Info);
ASSERT_EFI_ERROR (Status); ASSERT_EFI_ERROR (Status);
Handle = NULL;
Status = gBS->InstallProtocolInterface (&Handle,
&gEfiDxeSmmReadyToLockProtocolGuid, EFI_NATIVE_INTERFACE,
NULL);
ASSERT_EFI_ERROR (Status);
} }