Allow insert call with more than 8 parameters on aarch64

Fix bug on insert call to local function on rewrite mode
dyninst · Oct 28, 2020 · 56c0989 · 56c0989
1 parent 4311e94
commit 56c0989
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Showing 2 changed files with 49 additions and 6 deletions.
diff --git a/dyninstAPI/src/inst-aarch64.C b/dyninstAPI/src/inst-aarch64.C
@@ -620,6 +620,8 @@ Register EmitterAARCH64::emitCall(opCode op,
         assert(0);
     }
 
+    inst_printf("emitCall to: %s\n", callee->name().c_str());
+
     vector<int> savedRegs;
 
     // save r0-r7
@@ -641,7 +643,8 @@ Register EmitterAARCH64::emitCall(opCode op,
     }
 
     // Passing operands to registers
-    for(size_t id = 0; id < operands.size(); id++)
+    // first 8 put into registers r0-r7
+    for(size_t id = 0; id < operands.size() && id < 8; id++)
     {
         Register reg = REG_NULL;
         if (gen.rs()->allocateSpecificRegister(gen, registerSpace::r0 + id, true))
@@ -653,19 +656,47 @@ Register EmitterAARCH64::emitCall(opCode op,
         assert(reg!=REG_NULL);
     }
 
+    // remaining parameters put into the stack
+    auto num_operands = operands.size();
+    if( num_operands > 8 ){
+        // adjust stack
+        insnCodeGen::generateAddSubImmediate(gen, insnCodeGen::Sub, 0,
+               ALIGN_QUADWORD( (num_operands-8)*8 ), REG_SP, REG_SP, true);
+
+        // generate parameter code and load into the stack
+        for(size_t id = 8; id < num_operands; id++)
+        {
+            Register scratch = gen.rs()->getScratchRegister(gen);
+            Address unnecessary = ADDR_NULL;
+            if (!operands[id]->generateCode_phase2(gen, false, unnecessary, scratch))
+                assert(0);
+
+            // move scratch to stack
+            int offset_from_sp = 8 * (id-8);
+            insnCodeGen::saveRegister(gen, scratch, offset_from_sp);
+
+        }
+    }
+
     assert(gen.rs());
 
     //Address of function to call in scratch register
     Register scratch = gen.rs()->getScratchRegister(gen);
     assert(scratch != REG_NULL && "cannot get a scratch register");
     gen.markRegDefined(scratch);
 
-    if (gen.addrSpace()->edit() != NULL) {
-        // gen.as.edit() checks if we are in rewriter mode
-        Address dest = getInterModuleFuncAddr(callee, gen);
+    // prepare register with address to call
+    // if ( rewrite mode )
+    //     - if ( callee in different module ) call getInterModuleFunc
+    // else (attach or create mode)
+    //     - use the scratch register to load calle address
+    //
+    if (gen.addrSpace()->edit() != NULL) { // rewriter mode
+        Address dest = callee->addr();
+        if( gen.func()->obj() != callee->obj() )
+            dest = getInterModuleFuncAddr(callee, gen);
 
         // emit ADR instruction
-
         long disp = dest - gen.currAddr();
         instruction insn;
         insn.clear();
@@ -676,11 +707,13 @@ Register EmitterAARCH64::emitCall(opCode op,
         INSN_SET(insn, 0, 4, scratch);
         insnCodeGen::generate(gen, insn);
 
-        insnCodeGen::generateMemAccess(gen, insnCodeGen::Load, scratch, scratch, 0, 8, insnCodeGen::Offset);
+        if( gen.func()->obj() != callee->obj() )
+            insnCodeGen::generateMemAccess(gen, insnCodeGen::Load, scratch, scratch, 0, 8, insnCodeGen::Offset);
     } else {
         insnCodeGen::loadImmIntoReg<Address>(gen, scratch, callee->addr());
     }
 
+    // emit BL instruction
     instruction branchInsn;
     branchInsn.clear();
 
@@ -697,6 +730,13 @@ Register EmitterAARCH64::emitCall(opCode op,
     INSN_SET(branchInsn, 21, 21, 1);
     insnCodeGen::generate(gen, branchInsn);
 
+    // reset stack pointer if used for parameters
+    if( num_operands > 8 ){
+        // re-adjust stack
+        insnCodeGen::generateAddSubImmediate(gen, insnCodeGen::Add, 0,
+               ALIGN_QUADWORD( (num_operands-8)*8 ), REG_SP, REG_SP, true);
+    }
+
     /*
      * Restoring registers
      */
@@ -1739,6 +1779,7 @@ Address Emitter::getInterModuleFuncAddr(func_instance *func, codeGen &gen) {
     if (!binEdit || !func) {
         assert(!"Invalid function call (function info is missing)");
     }
+    inst_printf("getInterModuleFuncAddr to %s\n", func->get_name().c_str());
 
     // find the Symbol corresponding to the func_instance
     std::vector<SymtabAPI::Symbol *> syms;

diff --git a/symtabAPI/src/emitElf.C b/symtabAPI/src/emitElf.C
@@ -1744,13 +1744,15 @@ bool emitElf<ElfTypes>::createSymbolTables(set<Symbol *> &allSymbols) {
         }
     }
 
+    rewrite_printf("dynamic symbols: \n");
     for (auto sym_iter = allSymbols.begin(); sym_iter != allSymbols.end(); ++sym_iter) {
         if ((*sym_iter)->isInSymtab()) {
             allSymSymbols.push_back(*sym_iter);
         }
         if (!obj->isStaticBinary()) {
             if ((*sym_iter)->isInDynSymtab()) {
                 allDynSymbols.push_back(*sym_iter);
+                rewrite_printf("\t%s\n", (*sym_iter)->getMangledName().c_str());
             }
         }
     }