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Update transition from EBC function to native IPF function to guarantee that at least 0x40 bytes of stack frame are reserved to prevent stack corruption. 

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@9377 6f19259b-4bc3-4df7-8a09-765794883524
This commit is contained in:
mdkinney 2009-10-27 22:58:55 +00:00
parent ff28420b56
commit 62ba2e4ade
1 changed files with 54 additions and 18 deletions
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72
MdeModulePkg/Universal/EbcDxe/Ipf/EbcLowLevel.s
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@ -121,30 +121,66 @@ PROCEDURE_ENTRY(EbcAsmLLCALLEX)
PROCEDURE_EXIT(EbcAsmLLCALLEX)
//-----------------------------------------------------------------------------
//++
// EbcLLCALLEXNative
//
// This function is called to execute an EBC CALLEX instruction.
// This instruction requires that we thunk out to external native
// code. On return, we restore the stack pointer to its original location.
// Destroys no working registers. For IPF, at least 8 register slots
// must be allocated on the stack frame to support any number of
// arguments beiung passed to the external native function. The
// size of the stack frame is FramePtr - EbcSp. If this size is less
// than 64-bytes, the amount of stack frame allocated is rounded up
// to 64-bytes
//
// Arguments On Entry :
// in0 = CallAddr The function address.
// in1 = EbcSp The new EBC stack pointer.
// in2 = FramePtr The frame pointer.
//
// Return Value:
// None
//
// C Function Prototype:
// VOID
// EFIAPI
// EbcLLCALLEXNative (
// IN UINTN CallAddr,
// IN UINTN EbcSp,
// IN VOID *FramePtr
// );
//--
//---------------------------------------------------------------------------
PROCEDURE_ENTRY(EbcLLCALLEXNative)
NESTED_SETUP (3,6,3,0)
mov loc2 = in2;;
mov loc3 = in1;;
sub loc2 = loc2, loc3
mov loc4 = r12;;
or loc5 = r1, r0
mov loc2 = in2;; // loc2 = in2 = FramePtr
mov loc3 = in1;; // loc3 = in1 = EbcSp
sub loc2 = loc2, loc3;; // loc2 = loc2 - loc3 = FramePtr - EbcSp
mov out2 = loc2;; // out2 = loc2 = FramePtr - EbcSp
mov loc4 = 0x40;; // loc4 = 0x40
cmp.leu p6 = out2, loc4;; // IF out2 < loc4 THEN P6=1 ELSE P6=0; IF (FramePtr - EbcSp) < 0x40 THEN P6 = 1 ELSE P6=0
(p6) mov loc2 = loc4;; // IF P6==1 THEN loc2 = loc4 = 0x40
mov loc4 = r12;; // save sp
or loc5 = r1, r0 // save gp
sub r12 = r12, loc2
mov out2 = loc2;;
sub r12 = r12, loc2;; // sp = sp - loc2 = sp - MAX (0x40, FramePtr - EbcSp)
and r12 = -0x10, r12
mov out1 = in1;;
mov out0 = r12;;
adds r12 = -0x8, r12
(p0) br.call.dptk.many b0 = CopyMem;;
adds r12 = 0x8, r12
and r12 = -0x10, r12 // Round sp down to the nearest 16-byte boundary
mov out1 = in1;; // out1 = EbcSp
mov out0 = r12;; // out0 = sp
adds r12 = -0x8, r12
(p0) br.call.dptk.many b0 = CopyMem;; // CopyMem (sp, EbcSp, (FramePtr - EbcSp))
adds r12 = 0x8, r12
mov out0 = in0;;
mov out1 = r12;;
(p0) br.call.dptk.many b0 = EbcAsmLLCALLEX;;
mov r12 = loc4;;
or r1 = loc5, r0
mov out0 = in0;; // out0 = CallAddr
mov out1 = r12;; // out1 = sp
(p0) br.call.dptk.many b0 = EbcAsmLLCALLEX;; // EbcAsmLLCALLEX (CallAddr, sp)
mov r12 = loc4;; // restore sp
or r1 = loc5, r0 // restore gp
NESTED_RETURN
PROCEDURE_EXIT(EbcLLCALLEXNative)