From ae40c45f2de14e1e670c5af7b0533da838d7cc68 Mon Sep 17 00:00:00 2001
From: clc5q <clc5q@git.zephyr-software.com>
Date: Tue, 14 Jul 2015 02:06:16 +0000
Subject: [PATCH] Move MDFixUseFP() logic earlier, don't depend on IDA Pro
numbers, just compute UseFP or not.
Former-commit-id: e96a39edd1965be394c86ca7a75cc69ac4012773
---
src/base/SMPFunction.cpp | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
diff --git a/src/base/SMPFunction.cpp b/src/base/SMPFunction.cpp
index 5acf6406..00bd3f84 100644
--- a/src/base/SMPFunction.cpp
+++ b/src/base/SMPFunction.cpp
@@ -1780,11 +1780,13 @@ void SMPFunction::FindAllAllocsAndDeallocs(void) {
// we can try to fix incorrect sets of UseFP by IDA.
// NOTE: We might want to extend this in the future to
// handle functions that have no locals. **!!**
+#if 0
bool FixedUseFP = MDFixUseFP();
#if SMP_DEBUG_FRAMEFIXUP
if (FixedUseFP) {
SMP_msg("Fixed UseFP in %s\n", this->GetFuncName());
}
+#endif
#endif
if (this->UsesFramePointer()) { // now that MDFixUseFP() has validated this flag ...
this->FindFramePointerDelta(); // find stack delta that is saved in frame pointer in function prologue
@@ -1874,11 +1876,13 @@ void SMPFunction::FindAllAllocsAndDeallocs(void) {
// we can try to fix incorrect sets of UseFP by IDA.
// NOTE: We might want to extend this in the future to
// handle functions that have no locals. **!!**
+#if 0
bool FixedUseFP = this->MDFixUseFP();
#if SMP_DEBUG_FRAMEFIXUP
if (FixedUseFP) {
SMP_msg("Fixed UseFP in %s\n", this->GetFuncName());
}
+#endif
#endif
if (this->UsesFramePointer()) { // now that MDFixUseFP() has validated this flag ...
this->FindFramePointerDelta(); // find stack delta that is saved in frame pointer in function prologue
@@ -1889,11 +1893,13 @@ void SMPFunction::FindAllAllocsAndDeallocs(void) {
// The x86-64 ABI saves time by not allocating a local frame for some leaf functions,
// and just accesses locations below the stack as if they were allocated local vars.
// We still want the UseFP and FramePointerDelta members to be properly set.
+#if 0
bool FixedUseFP = MDFixUseFP();
#if SMP_DEBUG_FRAMEFIXUP
if (FixedUseFP) {
SMP_msg("Fixed UseFP in %s\n", this->GetFuncName());
}
+#endif
#endif
if (this->UsesFramePointer()) { // now that MDFixUseFP() has validated this flag ...
this->FindFramePointerDelta(); // find stack delta that is saved in frame pointer in function prologue
@@ -2050,6 +2056,8 @@ bool SMPFunction::MDFixFrameInfo(void) {
int NewLocalsSize = 0;
int OldFrameTotal = this->CalleeSavedRegsSize + this->LocalVarsSize;
bool Changed = false;
+ bool EBPSaved = false; // detected push of frame pointer reg
+ bool ESPintoEBP = false; // detected initialization of frame pointer reg with stack pointer reg value
bool DebugFlag = (0 == strcmp("__libc_csu_init", this->GetFuncName()));
// Iterate through the first basic block in the function. If we find
@@ -2088,6 +2096,11 @@ bool SMPFunction::MDFixFrameInfo(void) {
if (DebugFlag) SMP_msg("libc_csu_init OtherPushesSize: %d %s\n", OtherPushesSize,
CurrInstr->GetDisasm());
}
+ if (!EBPSaved) { // still looking for "push ebp"
+ if (CurrInstr->GetOperand(0)->MatchesReg(MD_FRAME_POINTER_REG)) {
+ EBPSaved = true;
+ }
+ }
}
else if (CurrInstr->MDIsFrameAllocInstr()) {
if (DebugFlag) SMP_msg("libc_csu_init allocinstr: %s\n", CurrInstr->GetDisasm());
@@ -2149,6 +2162,13 @@ bool SMPFunction::MDFixFrameInfo(void) {
SMP_msg("INFO: Miscellaneous stack pointer delta of %d found at %lx in MDFixFrameInfo\n", (unsigned long) CurrInstr->GetAddr());
}
}
+ else if (EBPSaved && (!ESPintoEBP)) { // found "push ebp", looking for "mov ebp,esp"
+ if ((CurrInstr->GetIDAOpcode() == STARS_NN_mov)
+ && (CurrInstr->GetFirstDef()->GetOp()->MatchesReg(MD_FRAME_POINTER_REG))
+ && (CurrInstr->GetFirstUse()->GetOp()->MatchesReg(MD_STACK_POINTER_REG))) {
+ ESPintoEBP = true;
+ }
+ }
} // end for all instructions in the first basic block
// If we did not find an allocating instruction, see if it would keep
@@ -2193,6 +2213,10 @@ bool SMPFunction::MDFixFrameInfo(void) {
}
#endif
+ // If we found ESPintoEBP, we also found EBPSaved first, and we need to set
+ // this->UseFP to true.
+ this->UseFP = ESPintoEBP;
+
return Changed;
} // end of SMPFunction::MDFixFrameInfo()
--
GitLab