sravan/system76-edk2
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

OvmfPkg/Sec: fix stack switch

Browse Source 
The ebp/rbp register can either be used for the frame pointer or
as general purpose register.  With gcc (and clang) this depends
on the -f(no-)omit-frame-pointer switch.

This patch updates tools_def.template to explicitly set the compiler
option and also add a define to allow conditionally compile code.

The new define is used to fix stack switching in TemporaryRamMigration.
The ebp/rbp must not be touched when the compiler can use it as general
purpose register.  With version 12 gcc starts actually using the
register, so changing it leads to firmware crashes in some
configurations.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3934
Reported-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
This commit is contained in:
Gerd Hoffmann
2022-06-08 18:09:36 +08:00
committed by mergify[bot]
parent a81a650da1
commit ff36b2550f
2 changed files with 7 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
OvmfPkg/Sec/SecMain.c
View File

@@ -1052,11 +1052,15 @@ TemporaryRamMigration (
if (SetJump (&JumpBuffer) == 0) {
#if defined (MDE_CPU_IA32)
JumpBuffer.Esp = JumpBuffer.Esp + DebugAgentContext.StackMigrateOffset;
#ifndef OMIT_FRAME_POINTER
JumpBuffer.Ebp = JumpBuffer.Ebp + DebugAgentContext.StackMigrateOffset;
#endif
#endif
#if defined (MDE_CPU_X64)
JumpBuffer.Rsp = JumpBuffer.Rsp + DebugAgentContext.StackMigrateOffset;
#ifndef OMIT_FRAME_POINTER
JumpBuffer.Rbp = JumpBuffer.Rbp + DebugAgentContext.StackMigrateOffset;
#endif
#endif
LongJump (&JumpBuffer, (UINTN)-1);
}