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-rw-r--r--util/statetrace/arch/tracechild_arm.cc49
-rw-r--r--util/statetrace/arch/tracechild_arm.hh21
-rw-r--r--util/statetrace/statetrace.cc13
3 files changed, 68 insertions, 15 deletions
diff --git a/util/statetrace/arch/tracechild_arm.cc b/util/statetrace/arch/tracechild_arm.cc
index b52c0694a..b03cb208b 100644
--- a/util/statetrace/arch/tracechild_arm.cc
+++ b/util/statetrace/arch/tracechild_arm.cc
@@ -1,4 +1,16 @@
/*
+ * Copyright (c) 2010 ARM Limited
+ * All rights reserved
+ *
+ * The license below extends only to copyright in the software and shall
+ * not be construed as granting a license to any other intellectual
+ * property including but not limited to intellectual property relating
+ * to a hardware implementation of the functionality of the software
+ * licensed hereunder. You may use the software subject to the license
+ * terms below provided that you ensure that this notice is replicated
+ * unmodified and in its entirety in all distributions of the software,
+ * modified or unmodified, in source code or in binary form.
+ *
* Copyright (c) 2006-2009 The Regents of The University of Michigan
* All rights reserved.
*
@@ -33,6 +45,7 @@
#include <errno.h>
#include <stdint.h>
#include <cstring>
+#include <cstdio>
#include "tracechild_arm.hh"
@@ -46,6 +59,8 @@ const char* ARMTraceChild::regNames[numregs] = {
ARMTraceChild::ARMTraceChild()
{
+ foundMvn = false;
+
for (int x = 0; x < numregs; x++) {
memset(&regs, 0, sizeof(regs));
memset(&oldregs, 0, sizeof(regs));
@@ -79,7 +94,7 @@ bool ARMTraceChild::sendState(int socket)
toSend -= sent;
messagePtr += sent;
}
-
+
return true;
}
@@ -97,7 +112,7 @@ bool ARMTraceChild::update(int pid)
cerr << "update: " << strerror(errno) << endl;
return false;
}
-
+
for(unsigned int x = 0; x < numregs; x++)
regDiffSinceUpdate[x] = (getRegVal(x) != getOldRegVal(x));
return true;
@@ -207,25 +222,39 @@ bool ARMTraceChild::step()
uint32_t lr = getRegVal(14);
uint32_t pc = getPC();
- uint32_t lrOp;
+ uint32_t lrOp, subsOp;
+ char obuf[128];
+ bool patch = false;
// Since ARM uses software breakpoints behind the scenes, they don't work
// in read only areas like the page of routines provided by the kernel. The
// link register generally holds the address the process wants to the
// kernel to return to after it's done, so we'll install a software
- // breakpoint there. If the lr happens to point to the next instruction
- // we'll leave out our breakpoint to avoid an infinite loop. This isn't a
- // fool proof strategy, but it should work well in all the reasonable
- // scenarios I can think of right now.
+ // breakpoint there.
+ //
+ // Calls into the kernel user page always follow the form:
+ // MVN ...
+ // <possible MOV lr,...>
+ // SUB PC, ...
+ //
+ // So we look for this pattern and set a breakpoint on the LR at the SUB
+ // instruction.
- if (pc != lr) {
+
+ subsOp = ptrace(PTRACE_PEEKDATA, pid, pc, 0);
+ if ((subsOp & 0xFFFF0FFF) == 0xe3e00a0f)
+ foundMvn = true;
+
+ if (foundMvn && ((subsOp & 0xFFF0F000) == 0xe240f000)) {
+ foundMvn = false;
lrOp = ptrace(PTRACE_PEEKDATA, pid, lr, 0);
ptrace(PTRACE_POKEDATA, pid, lr, bkpt_inst);
+ patch = true;
}
ptraceSingleStep();
- if (pc != lr) {
+
+ if (patch)
ptrace(PTRACE_POKEDATA, pid, lr, lrOp);
- }
}
diff --git a/util/statetrace/arch/tracechild_arm.hh b/util/statetrace/arch/tracechild_arm.hh
index 9e1af6a8d..79eccd891 100644
--- a/util/statetrace/arch/tracechild_arm.hh
+++ b/util/statetrace/arch/tracechild_arm.hh
@@ -1,4 +1,16 @@
/*
+ * Copyright (c) 2010 ARM Limited
+ * All rights reserved
+ *
+ * The license below extends only to copyright in the software and shall
+ * not be construed as granting a license to any other intellectual
+ * property including but not limited to intellectual property relating
+ * to a hardware implementation of the functionality of the software
+ * licensed hereunder. You may use the software subject to the license
+ * terms below provided that you ensure that this notice is replicated
+ * unmodified and in its entirety in all distributions of the software,
+ * modified or unmodified, in source code or in binary form.
+ *
* Copyright (c) 2009 The Regents of The University of Michigan
* All rights reserved.
*
@@ -63,15 +75,16 @@ class ARMTraceChild : public TraceChild
user_regs regs;
user_regs oldregs;
bool regDiffSinceUpdate[numregs];
-
+ bool foundMvn;
+
protected:
bool update(int pid);
-
+
public:
ARMTraceChild();
bool sendState(int socket);
- int getNumRegs()
+ int getNumRegs()
{
return numregs;
}
@@ -90,7 +103,7 @@ class ARMTraceChild : public TraceChild
int64_t getRegVal(int num);
int64_t getOldRegVal(int num);
-
+
bool step();
uint64_t getPC()
diff --git a/util/statetrace/statetrace.cc b/util/statetrace/statetrace.cc
index e2762ac2c..d50c24f59 100644
--- a/util/statetrace/statetrace.cc
+++ b/util/statetrace/statetrace.cc
@@ -49,7 +49,13 @@ using namespace std;
void printUsage(const char * execName)
{
- cout << execName << " -h | -r -- <command> <arguments>" << endl;
+ cout << execName << " <options> -- <command> <arguments>" << endl;
+ cout << "options:" << endl;
+ cout << " -h print this help" << endl;
+ cout << " --host remote m5 host to connect to" << endl;
+ cout << " -r print register names" << endl;
+ cout << " -i print initial stack state" << endl;
+ cout << " -nt don't print an instruction trace" << endl;
}
int main(int argc, char * argv[], char * envp[])
@@ -62,6 +68,11 @@ int main(int argc, char * argv[], char * envp[])
bool printInitial = false;
bool printTrace = true;
string host = "localhost";
+
+ if (argc == 1) {
+ printUsage(argv[0]);
+ return 0;
+ }
for(int x = 1; x < argc; x++)
{
if(!strcmp(argv[x], "-h"))