RFC: https://bugzilla.tianocore.org/show_bug.cgi?id=3429
Declare the local variables in SecCoreStartupWithStack that actually
move the data elements as volatile to prevent the optimizer from
replacing this function with the intrinsic memcpy().
Cc: Ard Biesheuvel <ardb+tianoc...@kernel.org>
Cc: Jordan Justen <jordan.l.jus...@intel.com>
Cc: Brijesh Singh <brijesh.si...@amd.com>
Cc: Erdem Aktas <erdemak...@google.com>
Cc: James Bottomley <j...@linux.ibm.com>
Cc: Jiewen Yao <jiewen....@intel.com>
Cc: Tom Lendacky <thomas.lenda...@amd.com>
Cc: Gerd Hoffmann <kra...@redhat.com>
Acked-by: Gerd Hoffmann <kra...@redhat.com>
Signed-off-by: Min Xu <min.m...@intel.com>
---
OvmfPkg/Sec/SecMain.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/OvmfPkg/Sec/SecMain.c b/OvmfPkg/Sec/SecMain.c
index 2c5561661ef3..02520e25ab9a 100644
--- a/OvmfPkg/Sec/SecMain.c
+++ b/OvmfPkg/Sec/SecMain.c
@@ -757,12 +757,17 @@ SecCoreStartupWithStack (
//
IdtTableInStack.PeiService = NULL;
for (Index = 0; Index < SEC_IDT_ENTRY_COUNT; Index++) {
- UINT8 *Src;
- UINT8 *Dst;
- UINTN Byte;
+ //
+ // Declare the local variables that actually move the data elements as
+ // volatile to prevent the optimizer from replacing this function with
+ // the intrinsic memcpy()
+ //
+ CONST UINT8 *Src;
+ volatile UINT8 *Dst;
+ UINTN Byte;
- Src = (UINT8 *)&mIdtEntryTemplate;
- Dst = (UINT8 *)&IdtTableInStack.IdtTable[Index];
+ Src = (CONST UINT8 *)&mIdtEntryTemplate;
+ Dst = (volatile UINT8 *)&IdtTableInStack.IdtTable[Index];
for (Byte = 0; Byte < sizeof (mIdtEntryTemplate); Byte++) {
Dst[Byte] = Src[Byte];
}
--
2.29.2.windows.2
-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#88241): https://edk2.groups.io/g/devel/message/88241
Mute This Topic: https://groups.io/mt/90121243/21656
Group Owner: devel+ow...@edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com]
-=-=-=-=-=-=-=-=-=-=-=-
