OvmfPkg/Sec: fix stack switch

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>

diff --git a/BaseTools/Conf/tools_def.template b/BaseTools/Conf/tools_def.template
index 5ed19810b7278a7fe8236fe49d49fd50dc5bae55..adcd23f7273fa527522c84959c196e42409eeef1 100755 (executable)
--- a/BaseTools/Conf/tools_def.template
+++ b/BaseTools/Conf/tools_def.template
@@ -1849,9 +1849,9 @@ NOOPT_*_*_OBJCOPY_ADDDEBUGFLAG     = --add-gnu-debuglink=$(DEBUG_DIR)/$(MODULE_N
 *_*_*_DTC_PATH                     = DEF(DTC_BIN)\r
 \r
 DEFINE GCC_ALL_CC_FLAGS            = -g -Os -fshort-wchar -fno-builtin -fno-strict-aliasing -Wall -Werror -Wno-array-bounds -include AutoGen.h -fno-common\r
-DEFINE GCC_IA32_CC_FLAGS           = DEF(GCC_ALL_CC_FLAGS) -m32 -malign-double -freorder-blocks -freorder-blocks-and-partition -O2 -mno-stack-arg-probe\r
-DEFINE GCC_X64_CC_FLAGS            = DEF(GCC_ALL_CC_FLAGS) -mno-red-zone -Wno-address -mno-stack-arg-probe\r
-DEFINE GCC_ARM_CC_FLAGS            = DEF(GCC_ALL_CC_FLAGS) -mlittle-endian -mabi=aapcs -fno-short-enums -funsigned-char -ffunction-sections -fdata-sections -fomit-frame-pointer -Wno-address -mthumb -mfloat-abi=soft -fno-pic -fno-pie\r
+DEFINE GCC_IA32_CC_FLAGS           = DEF(GCC_ALL_CC_FLAGS) -m32 -malign-double -freorder-blocks -freorder-blocks-and-partition -O2 -mno-stack-arg-probe -fno-omit-frame-pointer\r
+DEFINE GCC_X64_CC_FLAGS            = DEF(GCC_ALL_CC_FLAGS) -mno-red-zone -Wno-address -mno-stack-arg-probe -fomit-frame-pointer -DOMIT_FRAME_POINTER=1\r
+DEFINE GCC_ARM_CC_FLAGS            = DEF(GCC_ALL_CC_FLAGS) -mlittle-endian -mabi=aapcs -fno-short-enums -funsigned-char -ffunction-sections -fdata-sections -fomit-frame-pointer -DOMIT_FRAME_POINTER=1 -Wno-address -mthumb -mfloat-abi=soft -fno-pic -fno-pie\r
 DEFINE GCC_ARM_CC_XIPFLAGS         = -mno-unaligned-access\r
 DEFINE GCC_AARCH64_CC_FLAGS        = DEF(GCC_ALL_CC_FLAGS) -mlittle-endian -fno-short-enums -fverbose-asm -funsigned-char  -ffunction-sections -fdata-sections -Wno-address -fno-asynchronous-unwind-tables -fno-unwind-tables -fno-pic -fno-pie -ffixed-x18\r
 DEFINE GCC_AARCH64_CC_XIPFLAGS     = -mstrict-align -mgeneral-regs-only\r

diff --git a/OvmfPkg/Sec/SecMain.c b/OvmfPkg/Sec/SecMain.c
index 1167d22a68cc0e75268fd2f1a4cddfc993592ab2..3ca0dcdfd3ddd513f85566be0692fea2aa5825b3 100644 (file)
--- a/OvmfPkg/Sec/SecMain.c
+++ b/OvmfPkg/Sec/SecMain.c
@@ -1052,11 +1052,15 @@ TemporaryRamMigration (
   if (SetJump (&JumpBuffer) == 0) {\r
  #if defined (MDE_CPU_IA32)\r
     JumpBuffer.Esp = JumpBuffer.Esp + DebugAgentContext.StackMigrateOffset;\r
+ #ifndef OMIT_FRAME_POINTER\r
     JumpBuffer.Ebp = JumpBuffer.Ebp + DebugAgentContext.StackMigrateOffset;\r
  #endif\r
+ #endif\r
  #if defined (MDE_CPU_X64)\r
     JumpBuffer.Rsp = JumpBuffer.Rsp + DebugAgentContext.StackMigrateOffset;\r
+ #ifndef OMIT_FRAME_POINTER\r
     JumpBuffer.Rbp = JumpBuffer.Rbp + DebugAgentContext.StackMigrateOffset;\r
+ #endif\r
  #endif\r
     LongJump (&JumpBuffer, (UINTN)-1);\r
   }\r