Fix bug in Platform_Set/ClearHardwareBreakpoint()

adamgreen · facchinm · commit 9c2fca69186c · 2020-03-17T09:09:27.000+01:00
I hit this bug when attempting to use temporary breakpoints on setup()
in ThreadMRI but it is bad enough that I fixed it in the kernel mode
version of MRI at the same time rather than wait for my backprop of
core MRI changes.
diff --git a/libraries/MRI/src/architectures/armv7-m/armv7-m.c b/libraries/MRI/src/architectures/armv7-m/armv7-m.c
@@ -938,16 +938,16 @@ static int doesKindIndicate32BitInstruction(uint32_t kind)
 void Platform_SetHardwareBreakpoint(uint32_t address)
 {
     uint32_t* pFPBBreakpointComparator;
-    uint16_t  currentInstructionWord;
+    uint16_t  firstInstructionWord;
 
      __try
     {
-        currentInstructionWord = getFirstHalfWordOfCurrentInstruction();
+        firstInstructionWord = throwingMemRead16(address);
     }
     __catch
         __rethrow;
 
-    pFPBBreakpointComparator = enableFPBBreakpoint(address, isInstruction32Bit(currentInstructionWord));
+    pFPBBreakpointComparator = enableFPBBreakpoint(address, isInstruction32Bit(firstInstructionWord));
     if (!pFPBBreakpointComparator)
         __throw(exceededHardwareResourcesException);
 }
@@ -968,16 +968,16 @@ void Platform_ClearHardwareBreakpointOfGdbKind(uint32_t address, uint32_t kind)
 
 void Platform_ClearHardwareBreakpoint(uint32_t address)
 {
-    uint16_t  currentInstructionWord;
+    uint16_t  firstInstructionWord;
 
      __try
     {
-        currentInstructionWord = getFirstHalfWordOfCurrentInstruction();
+        firstInstructionWord = throwingMemRead16(address);
     }
     __catch
         __rethrow;
 
-    disableFPBBreakpointComparator(address, isInstruction32Bit(currentInstructionWord));
+    disableFPBBreakpointComparator(address, isInstruction32Bit(firstInstructionWord));
 }
 
 
diff --git a/libraries/ThreadMRI/src/architectures/armv7-m/armv7-m.c b/libraries/ThreadMRI/src/architectures/armv7-m/armv7-m.c
@@ -975,16 +975,16 @@ static int doesKindIndicate32BitInstruction(uint32_t kind)
 void Platform_SetHardwareBreakpoint(uint32_t address)
 {
     uint32_t* pFPBBreakpointComparator;
-    uint16_t  currentInstructionWord;
+    uint16_t  firstInstructionWord;
 
      __try
     {
-        currentInstructionWord = getFirstHalfWordOfCurrentInstruction();
+        firstInstructionWord = throwingMemRead16(address);
     }
     __catch
         __rethrow;
 
-    pFPBBreakpointComparator = enableFPBBreakpoint(address, isInstruction32Bit(currentInstructionWord));
+    pFPBBreakpointComparator = enableFPBBreakpoint(address, isInstruction32Bit(firstInstructionWord));
     if (!pFPBBreakpointComparator)
         __throw(exceededHardwareResourcesException);
 }
@@ -1005,16 +1005,16 @@ void Platform_ClearHardwareBreakpointOfGdbKind(uint32_t address, uint32_t kind)
 
 void Platform_ClearHardwareBreakpoint(uint32_t address)
 {
-    uint16_t  currentInstructionWord;
+    uint16_t  firstInstructionWord;
 
      __try
     {
-        currentInstructionWord = getFirstHalfWordOfCurrentInstruction();
+        firstInstructionWord = throwingMemRead16(address);
     }
     __catch
         __rethrow;
 
-    disableFPBBreakpointComparator(address, isInstruction32Bit(currentInstructionWord));
+    disableFPBBreakpointComparator(address, isInstruction32Bit(firstInstructionWord));
 }
 
 

Original file line number	Diff line number	Diff line change
`@@ -938,16 +938,16 @@ static int doesKindIndicate32BitInstruction(uint32_t kind)`
`938`	`938`	`void Platform_SetHardwareBreakpoint(uint32_t address)`
`939`	`939`	`{`
`940`	`940`	`uint32_t* pFPBBreakpointComparator;`
`941`		`- uint16_t currentInstructionWord;`
	`941`	`+ uint16_t firstInstructionWord;`
`942`	`942`
`943`	`943`	`__try`
`944`	`944`	`{`
`945`		`- currentInstructionWord = getFirstHalfWordOfCurrentInstruction();`
	`945`	`+ firstInstructionWord = throwingMemRead16(address);`
`946`	`946`	`}`
`947`	`947`	`__catch`
`948`	`948`	`__rethrow;`
`949`	`949`
`950`		`- pFPBBreakpointComparator = enableFPBBreakpoint(address, isInstruction32Bit(currentInstructionWord));`
	`950`	`+ pFPBBreakpointComparator = enableFPBBreakpoint(address, isInstruction32Bit(firstInstructionWord));`
`951`	`951`	`if (!pFPBBreakpointComparator)`
`952`	`952`	`__throw(exceededHardwareResourcesException);`
`953`	`953`	`}`
`@@ -968,16 +968,16 @@ void Platform_ClearHardwareBreakpointOfGdbKind(uint32_t address, uint32_t kind)`
`968`	`968`
`969`	`969`	`void Platform_ClearHardwareBreakpoint(uint32_t address)`
`970`	`970`	`{`
`971`		`- uint16_t currentInstructionWord;`
	`971`	`+ uint16_t firstInstructionWord;`
`972`	`972`
`973`	`973`	`__try`
`974`	`974`	`{`
`975`		`- currentInstructionWord = getFirstHalfWordOfCurrentInstruction();`
	`975`	`+ firstInstructionWord = throwingMemRead16(address);`
`976`	`976`	`}`
`977`	`977`	`__catch`
`978`	`978`	`__rethrow;`
`979`	`979`
`980`		`- disableFPBBreakpointComparator(address, isInstruction32Bit(currentInstructionWord));`
	`980`	`+ disableFPBBreakpointComparator(address, isInstruction32Bit(firstInstructionWord));`
`981`	`981`	`}`
`982`	`982`
`983`	`983`
Original file line number	Diff line number	Diff line change
`@@ -975,16 +975,16 @@ static int doesKindIndicate32BitInstruction(uint32_t kind)`
`975`	`975`	`void Platform_SetHardwareBreakpoint(uint32_t address)`
`976`	`976`	`{`
`977`	`977`	`uint32_t* pFPBBreakpointComparator;`
`978`		`- uint16_t currentInstructionWord;`
	`978`	`+ uint16_t firstInstructionWord;`
`979`	`979`
`980`	`980`	`__try`
`981`	`981`	`{`
`982`		`- currentInstructionWord = getFirstHalfWordOfCurrentInstruction();`
	`982`	`+ firstInstructionWord = throwingMemRead16(address);`
`983`	`983`	`}`
`984`	`984`	`__catch`
`985`	`985`	`__rethrow;`
`986`	`986`
`987`		`- pFPBBreakpointComparator = enableFPBBreakpoint(address, isInstruction32Bit(currentInstructionWord));`
	`987`	`+ pFPBBreakpointComparator = enableFPBBreakpoint(address, isInstruction32Bit(firstInstructionWord));`
`988`	`988`	`if (!pFPBBreakpointComparator)`
`989`	`989`	`__throw(exceededHardwareResourcesException);`
`990`	`990`	`}`
`@@ -1005,16 +1005,16 @@ void Platform_ClearHardwareBreakpointOfGdbKind(uint32_t address, uint32_t kind)`
`1005`	`1005`
`1006`	`1006`	`void Platform_ClearHardwareBreakpoint(uint32_t address)`
`1007`	`1007`	`{`
`1008`		`- uint16_t currentInstructionWord;`
	`1008`	`+ uint16_t firstInstructionWord;`
`1009`	`1009`
`1010`	`1010`	`__try`
`1011`	`1011`	`{`
`1012`		`- currentInstructionWord = getFirstHalfWordOfCurrentInstruction();`
	`1012`	`+ firstInstructionWord = throwingMemRead16(address);`
`1013`	`1013`	`}`
`1014`	`1014`	`__catch`
`1015`	`1015`	`__rethrow;`
`1016`	`1016`
`1017`		`- disableFPBBreakpointComparator(address, isInstruction32Bit(currentInstructionWord));`
	`1017`	`+ disableFPBBreakpointComparator(address, isInstruction32Bit(firstInstructionWord));`
`1018`	`1018`	`}`
`1019`	`1019`
`1020`	`1020`