From 3e6cfdb5739d8f7bc901771408c9f988b9365ba2 Mon Sep 17 00:00:00 2001
From: Jason Hiser <jdhiser@gmail.com>
Date: Fri, 17 May 2019 12:56:58 +0000
Subject: [PATCH] added support for WRT objects in pc-rel addressing
---
unpin_arm32.cpp | 68 ++++++++++++++++++++-----------------------------
1 file changed, 28 insertions(+), 40 deletions(-)
diff --git a/unpin_arm32.cpp b/unpin_arm32.cpp
index 1035111..56aa56e 100644
--- a/unpin_arm32.cpp
+++ b/unpin_arm32.cpp
@@ -36,6 +36,7 @@
#include <inttypes.h>
#include <stdint.h>
#include <limits.h>
+#include <irdb-util>
using namespace IRDB_SDK;
@@ -87,34 +88,23 @@ void UnpinArm32_t::HandlePcrelReloc(Instruction_t* from_insn, Relocation_t* relo
assert(0);
};
-
-
// get the new insn addr
- const auto from_insn_location=(VirtualOffset_t)locMap[from_insn];
+ const auto from_insn_location = VirtualOffset_t(locMap[from_insn]);
// get WRT info
- auto to_addr=VirtualOffset_t(0xdeadbeef); // noteable value that shouldn't be used.
- auto convert_string=string();
+ const auto to_addr =
+ (scoop_wrt != nullptr) ? scoop_wrt->getStart()->getVirtualOffset() : // is scoop
+ (insn_wrt != nullptr) ? locMap[insn_wrt] : // is instruction
+ (bo_wrt == nullptr) ? VirtualOffset_t(0u) : // no WRT obj
+ throw invalid_argument("Cannot map pcrel relocation WRT object to address");
+ const auto addend = reloc -> getAddend();
+ const auto reloc_offset = to_addr + addend;
- if(scoop_wrt)
- {
- to_addr=scoop_wrt->getStart()->getVirtualOffset();
- convert_string=string("scoop ")+scoop_wrt->getName();
- }
- else if(insn_wrt)
- {
- to_addr=locMap[insn_wrt];
- convert_string=string("insn ")+to_string(insn_wrt->getBaseID())+
- ":"+insn_wrt->getDisassembly();
- }
- else
- {
- assert(bo_wrt==nullptr);
- to_addr=0; /* no WRT obj */
- convert_string=string("no-object");
- }
- assert(bo_wrt==nullptr); // not yet imp'd WRT offsetting.
- assert(to_addr==0); // not yet imp'd WRT offsetting.
+ const auto to_object_id =
+ (scoop_wrt != nullptr) ? scoop_wrt->getName() +"@"+to_hex_string(scoop_wrt->getStart() ->getVirtualOffset()) : // scoop
+ (insn_wrt != nullptr) ? insn_wrt ->getDisassembly()+"@"+to_hex_string(insn_wrt ->getAddress()->getVirtualOffset()) : // instruction
+ (bo_wrt == nullptr) ? string("No-object") :
+ throw invalid_argument("Cannot map pcrel relocation WRT object to address");
// so far, only handling ldr and ldrb
@@ -216,12 +206,12 @@ void UnpinArm32_t::HandlePcrelReloc(Instruction_t* from_insn, Relocation_t* relo
zo->applyPatch(L5,FT);
// put the calculated pc-rel offset at L3
- const auto new_offset = int32_t(orig_insn_addr - L2);
+ const auto new_offset = int32_t(orig_insn_addr - L2 + reloc_offset);
ms.plopBytes(L6,reinterpret_cast<const char*>(&new_offset),4); // endianness of host must match target
// should be few enough of these to always print
cout<< "Had to trampoline " << disasm->getDisassembly() << " @"<<FA<<" to "
- << hex << L0 << "-" << L0+tramp_size-1 << endl;
+ << hex << L0 << "-" << L0+tramp_size-1 << " WRT=" << to_object_id << endl;
}
else if( is_ldr_type && !is_rd_pc && !I_bit_set) /* ldr <not pc>, [pc, imm] */
@@ -289,13 +279,13 @@ void UnpinArm32_t::HandlePcrelReloc(Instruction_t* from_insn, Relocation_t* relo
// put the calculated pc-rel offset at L3
const auto ldr_imm_field = int32_t(full_insn & mask12);
const auto ldr_imm = is_pos_imm ? ldr_imm_field : - ldr_imm_field;
- const auto orig_target = orig_insn_addr + 8 + to_addr + ldr_imm;
- const auto new_offset = int32_t(orig_target - (L1+8));
+ const auto new_addend = bo_wrt == nullptr ? 8 + ldr_imm : reloc_offset;
+ const auto new_offset = int32_t(orig_insn_addr - L3 + new_addend);
ms.plopBytes(L3,reinterpret_cast<const char*>(&new_offset),4); // endianness of host must match target
// should be few enough of these to always print
cout<< "Had to trampoline " << disasm->getDisassembly() << " @"<<FA<<" to "
- << hex << L0 << "-" << L0+tramp_size-1 << " ldr_imm = " << ldr_imm << endl;
+ << hex << L0 << "-" << L0+tramp_size-1 << " ldr_imm = " << ldr_imm << " WRT=" << to_object_id << endl;
}
else if( is_ldr_type && !is_rd_pc && I_bit_set) /* ldr <not pc>, [pc, reg/shift] */
{
@@ -379,14 +369,13 @@ void UnpinArm32_t::HandlePcrelReloc(Instruction_t* from_insn, Relocation_t* relo
zo->applyPatch(L5,FT);
// put the calculated pc-rel offset at L6
- const auto new_offset = orig_insn_addr - L2;
+ const auto new_offset = int32_t(orig_insn_addr - L2 + reloc_offset);
ms.plopBytes(L6,reinterpret_cast<const char*>(&new_offset),4); // endianness of host must match target
// should be few enough of these to always print
cout << "Had to trampoline " << disasm->getDisassembly() << " @" << hex << FA
- << " to " << L0 << "-" << L0+tramp_size-1 << endl;
+ << " to " << L0 << "-" << L0+tramp_size-1 << " WRT=" << to_object_id << endl;
-
}
else if((is_ldrls_type || is_addne_type || is_addls_type) && is_rd_pc && is_rn_pc)
{
@@ -477,13 +466,12 @@ void UnpinArm32_t::HandlePcrelReloc(Instruction_t* from_insn, Relocation_t* relo
ms.plopBytes(L6,xfer_insn.c_str(),4);
// put the calculated pc-rel offset at L7
- const auto new_offset = orig_insn_addr - L2;
+ const auto new_offset = int32_t(orig_insn_addr - L2 + reloc_offset);
ms.plopBytes(L7,reinterpret_cast<const char*>(&new_offset),4); // endianness of host must match target
// should be few enough of these to always print
cout<< "Had to trampoline " << disasm->getDisassembly() << " @"<<FA<<" to "
- << hex << L0 << "-" << L0+tramp_size-1 << endl;
-
+ << hex << L0 << "-" << L0+tramp_size-1 << " WRT=" << to_object_id << endl;
}
else if(is_add_type && I_bit_set)
{
@@ -549,13 +537,13 @@ void UnpinArm32_t::HandlePcrelReloc(Instruction_t* from_insn, Relocation_t* relo
const auto add_imm_field = int32_t(full_insn & mask8);
const auto add_ror_field = int32_t((full_insn>>8) & mask4);
const auto add_imm = rotr32(add_imm_field,add_ror_field*2);
- const auto orig_target = orig_insn_addr + 8 + to_addr + add_imm;
- const auto new_offset = int32_t(orig_target - (L1+8));
+ const auto orig_target = orig_insn_addr + 8 + add_imm;
+ const auto new_offset = int32_t(orig_target - L3 + reloc_offset);
ms.plopBytes(L3,reinterpret_cast<const char*>(&new_offset),4); // endianness of host must match target
// should be few enough of these to always print
cout<< "Had to trampoline " << disasm->getDisassembly() << " @"<<FA<<" to "
- << hex << L0 << "-" << L0+tramp_size-1 << " add_imm = " << add_imm << endl;
+ << hex << L0 << "-" << L0+tramp_size-1 << " add_imm = " << add_imm << " WRT=" << to_object_id << endl;
}
else if(is_add_type && !I_bit_set)
{
@@ -655,12 +643,12 @@ void UnpinArm32_t::HandlePcrelReloc(Instruction_t* from_insn, Relocation_t* relo
zo->applyPatch(L5,FT);
// put the calculated pc-rel offset at L3
- const auto new_offset = int32_t(orig_insn_addr - L1);
+ const auto new_offset = int32_t(orig_insn_addr - L1 + reloc_offset);
ms.plopBytes(L6,reinterpret_cast<const char*>(&new_offset),4); // endianness of host must match target
// should be few enough of these to always print
cout<< "Had to trampoline " << disasm->getDisassembly() << " @"<<FA<<" to "
- << hex << L0 << "-" << L0+tramp_size-1 << endl;
+ << hex << L0 << "-" << L0+tramp_size-1 << " WRT=" << to_object_id << endl;
}
else
{
--
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