From c312c9ac152be8b4ed1cd1455a1e7e2565a55ced Mon Sep 17 00:00:00 2001
From: Christopher Ferris <cferris@google.com>
Date: Mon, 1 Apr 2019 16:53:56 -0700
Subject: [PATCH] Add minimal support for Dwarf 5.

This is not full support for dwarf 5, this merely treats a Dwarf 5
version as Dwarf 4. There are new dwarf ops that are not supported yet,
but this minimally support should allow unwinding to work if those
ops are not present.

Bug: 127355724

Test: New Unit tests pass.
Change-Id: I35b24fbcb15a64acd49e1e0b6890dff4456ee6fd
---
 libunwindstack/DwarfSection.cpp              |  4 +--
 libunwindstack/tests/DwarfDebugFrameTest.cpp | 27 ++++++++++++++++----
 2 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/libunwindstack/DwarfSection.cpp b/libunwindstack/DwarfSection.cpp
index 57a780ece..849a31a90 100644
--- a/libunwindstack/DwarfSection.cpp
+++ b/libunwindstack/DwarfSection.cpp
@@ -138,7 +138,7 @@ bool DwarfSectionImpl<AddressType>::FillInCie(DwarfCie* cie) {
     return false;
   }
 
-  if (cie->version != 1 && cie->version != 3 && cie->version != 4) {
+  if (cie->version != 1 && cie->version != 3 && cie->version != 4 && cie->version != 5) {
     // Unrecognized version.
     last_error_.code = DWARF_ERROR_UNSUPPORTED_VERSION;
     return false;
@@ -155,7 +155,7 @@ bool DwarfSectionImpl<AddressType>::FillInCie(DwarfCie* cie) {
     cie->augmentation_string.push_back(aug_value);
   } while (aug_value != '\0');
 
-  if (cie->version == 4) {
+  if (cie->version == 4 || cie->version == 5) {
     // Skip the Address Size field since we only use it for validation.
     memory_.set_cur_offset(memory_.cur_offset() + 1);
 
diff --git a/libunwindstack/tests/DwarfDebugFrameTest.cpp b/libunwindstack/tests/DwarfDebugFrameTest.cpp
index d62093404..120bd73b5 100644
--- a/libunwindstack/tests/DwarfDebugFrameTest.cpp
+++ b/libunwindstack/tests/DwarfDebugFrameTest.cpp
@@ -550,6 +550,22 @@ TYPED_TEST_P(DwarfDebugFrameTest, GetCieFromOffset64_version4) {
   VerifyCieVersion(cie, 4, 10, DW_EH_PE_sdata8, 0x181, 0x1c, 0x10c);
 }
 
+TYPED_TEST_P(DwarfDebugFrameTest, GetCieFromOffset32_version5) {
+  SetCie32(&this->memory_, 0x5000, 0x100, std::vector<uint8_t>{5, '\0', 0, 10, 4, 8, 0x81, 3});
+  const DwarfCie* cie = this->debug_frame_->GetCieFromOffset(0x5000);
+  EXPECT_EQ(DWARF_ERROR_NONE, this->debug_frame_->LastErrorCode());
+  ASSERT_TRUE(cie != nullptr);
+  VerifyCieVersion(cie, 5, 10, DW_EH_PE_sdata4, 0x181, 0x10, 0x104);
+}
+
+TYPED_TEST_P(DwarfDebugFrameTest, GetCieFromOffset64_version5) {
+  SetCie64(&this->memory_, 0x5000, 0x100, std::vector<uint8_t>{5, '\0', 0, 10, 4, 8, 0x81, 3});
+  const DwarfCie* cie = this->debug_frame_->GetCieFromOffset(0x5000);
+  EXPECT_EQ(DWARF_ERROR_NONE, this->debug_frame_->LastErrorCode());
+  ASSERT_TRUE(cie != nullptr);
+  VerifyCieVersion(cie, 5, 10, DW_EH_PE_sdata8, 0x181, 0x1c, 0x10c);
+}
+
 TYPED_TEST_P(DwarfDebugFrameTest, GetCieFromOffset_version_invalid) {
   SetCie32(&this->memory_, 0x5000, 0x100, std::vector<uint8_t>{0, '\0', 1, 2, 3, 4, 5, 6, 7});
   ASSERT_TRUE(this->debug_frame_->GetCieFromOffset(0x5000) == nullptr);
@@ -558,10 +574,10 @@ TYPED_TEST_P(DwarfDebugFrameTest, GetCieFromOffset_version_invalid) {
   ASSERT_TRUE(this->debug_frame_->GetCieFromOffset(0x6000) == nullptr);
   EXPECT_EQ(DWARF_ERROR_UNSUPPORTED_VERSION, this->debug_frame_->LastErrorCode());
 
-  SetCie32(&this->memory_, 0x7000, 0x100, std::vector<uint8_t>{5, '\0', 1, 2, 3, 4, 5, 6, 7});
+  SetCie32(&this->memory_, 0x7000, 0x100, std::vector<uint8_t>{6, '\0', 1, 2, 3, 4, 5, 6, 7});
   ASSERT_TRUE(this->debug_frame_->GetCieFromOffset(0x7000) == nullptr);
   EXPECT_EQ(DWARF_ERROR_UNSUPPORTED_VERSION, this->debug_frame_->LastErrorCode());
-  SetCie64(&this->memory_, 0x8000, 0x100, std::vector<uint8_t>{5, '\0', 1, 2, 3, 4, 5, 6, 7});
+  SetCie64(&this->memory_, 0x8000, 0x100, std::vector<uint8_t>{6, '\0', 1, 2, 3, 4, 5, 6, 7});
   ASSERT_TRUE(this->debug_frame_->GetCieFromOffset(0x8000) == nullptr);
   EXPECT_EQ(DWARF_ERROR_UNSUPPORTED_VERSION, this->debug_frame_->LastErrorCode());
 }
@@ -803,9 +819,10 @@ REGISTER_TYPED_TEST_CASE_P(
     GetFdeFromPc64_not_in_section, GetCieFde32, GetCieFde64, GetCieFromOffset32_cie_cached,
     GetCieFromOffset64_cie_cached, GetCieFromOffset32_version1, GetCieFromOffset64_version1,
     GetCieFromOffset32_version3, GetCieFromOffset64_version3, GetCieFromOffset32_version4,
-    GetCieFromOffset64_version4, GetCieFromOffset_version_invalid, GetCieFromOffset32_augment,
-    GetCieFromOffset64_augment, GetFdeFromOffset32_augment, GetFdeFromOffset64_augment,
-    GetFdeFromOffset32_lsda_address, GetFdeFromOffset64_lsda_address, GetFdeFromPc_interleaved);
+    GetCieFromOffset64_version4, GetCieFromOffset32_version5, GetCieFromOffset64_version5,
+    GetCieFromOffset_version_invalid, GetCieFromOffset32_augment, GetCieFromOffset64_augment,
+    GetFdeFromOffset32_augment, GetFdeFromOffset64_augment, GetFdeFromOffset32_lsda_address,
+    GetFdeFromOffset64_lsda_address, GetFdeFromPc_interleaved);
 
 typedef ::testing::Types<uint32_t, uint64_t> DwarfDebugFrameTestTypes;
 INSTANTIATE_TYPED_TEST_CASE_P(, DwarfDebugFrameTest, DwarfDebugFrameTestTypes);