This revision was automatically updated to reflect the committed changes.
Closed by commit rLLDB360574: Breakpad: Generate unwind plans from STACK CFI
records (authored by labath, committed by ).
Herald added a subscriber: abidh.
Herald added a project: LLDB.
Changed prior to commit:
https://reviews.llvm.org/D61733?vs=198993&id=199246#toc
Repository:
rLLDB LLDB
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D61733/new/
https://reviews.llvm.org/D61733
Files:
lit/SymbolFile/Breakpad/Inputs/stack-cfi-parsing.syms
lit/SymbolFile/Breakpad/Inputs/stack-cfi-parsing.yaml
lit/SymbolFile/Breakpad/stack-cfi-parsing.test
source/Plugins/SymbolFile/Breakpad/SymbolFileBreakpad.cpp
source/Plugins/SymbolFile/Breakpad/SymbolFileBreakpad.h
Index: source/Plugins/SymbolFile/Breakpad/SymbolFileBreakpad.cpp
===================================================================
--- source/Plugins/SymbolFile/Breakpad/SymbolFileBreakpad.cpp
+++ source/Plugins/SymbolFile/Breakpad/SymbolFileBreakpad.cpp
@@ -15,9 +15,11 @@
#include "lldb/Host/FileSystem.h"
#include "lldb/Symbol/CompileUnit.h"
#include "lldb/Symbol/ObjectFile.h"
+#include "lldb/Symbol/PostfixExpression.h"
#include "lldb/Symbol/SymbolVendor.h"
#include "lldb/Symbol/TypeMap.h"
#include "lldb/Utility/Log.h"
+#include "lldb/Utility/StreamString.h"
#include "llvm/ADT/StringExtras.h"
using namespace lldb;
@@ -370,6 +372,155 @@
symtab.CalculateSymbolSizes();
}
+static llvm::Optional<std::pair<llvm::StringRef, llvm::StringRef>>
+GetRule(llvm::StringRef &unwind_rules) {
+ // Unwind rules are of the form
+ // register1: expression1 register2: expression2 ...
+ // We assume none of the tokens in expression<n> end with a colon.
+
+ llvm::StringRef lhs, rest;
+ std::tie(lhs, rest) = getToken(unwind_rules);
+ if (!lhs.consume_back(":"))
+ return llvm::None;
+
+ // Seek forward to the next register: expression pair
+ llvm::StringRef::size_type pos = rest.find(": ");
+ if (pos == llvm::StringRef::npos) {
+ // No pair found, this means the rest of the string is a single expression.
+ unwind_rules = llvm::StringRef();
+ return std::make_pair(lhs, rest);
+ }
+
+ // Go back one token to find the end of the current rule.
+ pos = rest.rfind(' ', pos);
+ if (pos == llvm::StringRef::npos)
+ return llvm::None;
+
+ llvm::StringRef rhs = rest.take_front(pos);
+ unwind_rules = rest.drop_front(pos);
+ return std::make_pair(lhs, rhs);
+}
+
+static const RegisterInfo *
+ResolveRegister(const SymbolFile::RegisterInfoResolver &resolver,
+ llvm::StringRef name) {
+ if (name.consume_front("$"))
+ return resolver.ResolveName(name);
+
+ return nullptr;
+}
+
+static const RegisterInfo *
+ResolveRegisterOrRA(const SymbolFile::RegisterInfoResolver &resolver,
+ llvm::StringRef name) {
+ if (name == ".ra")
+ return resolver.ResolveNumber(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC);
+ return ResolveRegister(resolver, name);
+}
+
+bool SymbolFileBreakpad::ParseUnwindRow(llvm::StringRef unwind_rules,
+ const RegisterInfoResolver &resolver,
+ UnwindPlan::Row &row) {
+ Log *log = GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYMBOLS);
+
+ llvm::BumpPtrAllocator node_alloc;
+ while (auto rule = GetRule(unwind_rules)) {
+ node_alloc.Reset();
+ llvm::StringRef lhs = rule->first;
+ postfix::Node *rhs = postfix::Parse(rule->second, node_alloc);
+ if (!rhs) {
+ LLDB_LOG(log, "Could not parse `{0}` as unwind rhs.", rule->second);
+ return false;
+ }
+
+ bool success = postfix::ResolveSymbols(
+ rhs, [&](postfix::SymbolNode &symbol) -> postfix::Node * {
+ llvm::StringRef name = symbol.GetName();
+ if (name == ".cfa" && lhs != ".cfa")
+ return postfix::MakeNode<postfix::InitialValueNode>(node_alloc);
+
+ if (const RegisterInfo *info = ResolveRegister(resolver, name)) {
+ return postfix::MakeNode<postfix::RegisterNode>(
+ node_alloc, info->kinds[eRegisterKindLLDB]);
+ }
+ return nullptr;
+ });
+
+ if (!success) {
+ LLDB_LOG(log, "Resolving symbols in `{0}` failed.", rule->second);
+ return false;
+ }
+
+ ArchSpec arch = m_obj_file->GetArchitecture();
+ StreamString dwarf(Stream::eBinary, arch.GetAddressByteSize(),
+ arch.GetByteOrder());
+ ToDWARF(*rhs, dwarf);
+ uint8_t *saved = m_allocator.Allocate<uint8_t>(dwarf.GetSize());
+ std::memcpy(saved, dwarf.GetData(), dwarf.GetSize());
+
+ if (lhs == ".cfa") {
+ row.GetCFAValue().SetIsDWARFExpression(saved, dwarf.GetSize());
+ } else if (const RegisterInfo *info = ResolveRegisterOrRA(resolver, lhs)) {
+ UnwindPlan::Row::RegisterLocation loc;
+ loc.SetIsDWARFExpression(saved, dwarf.GetSize());
+ row.SetRegisterInfo(info->kinds[eRegisterKindLLDB], loc);
+ } else
+ LLDB_LOG(log, "Invalid register `{0}` in unwind rule.", lhs);
+ }
+ if (unwind_rules.empty())
+ return true;
+
+ LLDB_LOG(log, "Could not parse `{0}` as an unwind rule.", unwind_rules);
+ return false;
+}
+
+UnwindPlanSP
+SymbolFileBreakpad::GetUnwindPlan(const Address &address,
+ const RegisterInfoResolver &resolver) {
+ ParseUnwindData();
+ const UnwindMap::Entry *entry =
+ m_unwind_data->FindEntryThatContains(address.GetFileAddress());
+ if (!entry)
+ return nullptr;
+
+ addr_t base = GetBaseFileAddress();
+ if (base == LLDB_INVALID_ADDRESS)
+ return nullptr;
+
+ LineIterator It(*m_obj_file, Record::StackCFI, entry->data), End(*m_obj_file);
+ llvm::Optional<StackCFIRecord> init_record = StackCFIRecord::parse(*It);
+ assert(init_record.hasValue());
+ assert(init_record->Size.hasValue());
+
+ auto plan_sp = std::make_shared<UnwindPlan>(lldb::eRegisterKindLLDB);
+ plan_sp->SetSourceName("breakpad STACK CFI");
+ plan_sp->SetUnwindPlanValidAtAllInstructions(eLazyBoolNo);
+ plan_sp->SetSourcedFromCompiler(eLazyBoolYes);
+ plan_sp->SetPlanValidAddressRange(
+ AddressRange(base + init_record->Address, *init_record->Size,
+ m_obj_file->GetModule()->GetSectionList()));
+
+ auto row_sp = std::make_shared<UnwindPlan::Row>();
+ row_sp->SetOffset(0);
+ if (!ParseUnwindRow(init_record->UnwindRules, resolver, *row_sp))
+ return nullptr;
+ plan_sp->AppendRow(row_sp);
+ for (++It; It != End; ++It) {
+ llvm::Optional<StackCFIRecord> record = StackCFIRecord::parse(*It);
+ if (!record.hasValue())
+ return nullptr;
+ if (record->Size.hasValue())
+ break;
+
+ row_sp = std::make_shared<UnwindPlan::Row>(*row_sp);
+ row_sp->SetOffset(record->Address - init_record->Address);
+ if (!ParseUnwindRow(record->UnwindRules, resolver, *row_sp))
+ return nullptr;
+ plan_sp->AppendRow(row_sp);
+ }
+ return plan_sp;
+}
+
SymbolVendor &SymbolFileBreakpad::GetSymbolVendor() {
return *m_obj_file->GetModule()->GetSymbolVendor();
}
@@ -476,3 +627,27 @@
finish_sequence();
data.support_files = map.translate(cu, *m_files);
}
+
+void SymbolFileBreakpad::ParseUnwindData() {
+ if (m_unwind_data)
+ return;
+
+ m_unwind_data.emplace();
+ Log *log = GetLogIfAllCategoriesSet(LIBLLDB_LOG_SYMBOLS);
+ addr_t base = GetBaseFileAddress();
+ if (base == LLDB_INVALID_ADDRESS) {
+ LLDB_LOG(log, "SymbolFile parsing failed: Unable to fetch the base address "
+ "of object file.");
+ }
+
+ for (LineIterator It(*m_obj_file, Record::StackCFI), End(*m_obj_file);
+ It != End; ++It) {
+ if (auto record = StackCFIRecord::parse(*It)) {
+ if (record->Size)
+ m_unwind_data->Append(UnwindMap::Entry(
+ base + record->Address, *record->Size, It.GetBookmark()));
+ } else
+ LLDB_LOG(log, "Failed to parse: {0}. Skipping record.", *It);
+ }
+ m_unwind_data->Sort();
+}
Index: source/Plugins/SymbolFile/Breakpad/SymbolFileBreakpad.h
===================================================================
--- source/Plugins/SymbolFile/Breakpad/SymbolFileBreakpad.h
+++ source/Plugins/SymbolFile/Breakpad/SymbolFileBreakpad.h
@@ -13,6 +13,7 @@
#include "lldb/Core/FileSpecList.h"
#include "lldb/Symbol/LineTable.h"
#include "lldb/Symbol/SymbolFile.h"
+#include "lldb/Symbol/UnwindPlan.h"
namespace lldb_private {
@@ -133,6 +134,10 @@
void AddSymbols(Symtab &symtab) override;
+ lldb::UnwindPlanSP
+ GetUnwindPlan(const Address &address,
+ const RegisterInfoResolver &resolver) override;
+
ConstString GetPluginName() override { return GetPluginNameStatic(); }
uint32_t GetPluginVersion() override { return 1; }
@@ -144,6 +149,11 @@
struct Bookmark {
uint32_t section;
size_t offset;
+
+ friend bool operator<(const Bookmark &lhs, const Bookmark &rhs) {
+ return std::tie(lhs.section, lhs.offset) <
+ std::tie(rhs.section, rhs.offset);
+ }
};
// At iterator class for simplifying algorithms reading data from the breakpad
@@ -177,8 +187,7 @@
return *this;
}
friend bool operator<(const CompUnitData &lhs, const CompUnitData &rhs) {
- return std::tie(lhs.bookmark.section, lhs.bookmark.offset) <
- std::tie(rhs.bookmark.section, rhs.bookmark.offset);
+ return lhs.bookmark < rhs.bookmark;
}
Bookmark bookmark;
@@ -192,11 +201,19 @@
void ParseFileRecords();
void ParseCUData();
void ParseLineTableAndSupportFiles(CompileUnit &cu, CompUnitData &data);
+ void ParseUnwindData();
+ bool ParseUnwindRow(llvm::StringRef unwind_rules,
+ const RegisterInfoResolver &resolver,
+ UnwindPlan::Row &row);
using CompUnitMap = RangeDataVector<lldb::addr_t, lldb::addr_t, CompUnitData>;
llvm::Optional<std::vector<FileSpec>> m_files;
llvm::Optional<CompUnitMap> m_cu_data;
+
+ using UnwindMap = RangeDataVector<lldb::addr_t, lldb::addr_t, Bookmark>;
+ llvm::Optional<UnwindMap> m_unwind_data;
+ llvm::BumpPtrAllocator m_allocator;
};
} // namespace breakpad
Index: lit/SymbolFile/Breakpad/stack-cfi-parsing.test
===================================================================
--- lit/SymbolFile/Breakpad/stack-cfi-parsing.test
+++ lit/SymbolFile/Breakpad/stack-cfi-parsing.test
@@ -0,0 +1,48 @@
+# RUN: yaml2obj %S/Inputs/stack-cfi-parsing.yaml > %t
+# RUN: %lldb -c %t -o "target symbols add %S/Inputs/stack-cfi-parsing.syms" \
+# RUN: -s %s -b | FileCheck %s
+
+image show-unwind -n func0
+# CHECK-LABEL: image show-unwind -n func0
+# CHECK: Symbol file UnwindPlan:
+# CHECK-NEXT: This UnwindPlan originally sourced from breakpad STACK CFI
+# CHECK-NEXT: This UnwindPlan is sourced from the compiler: yes.
+# CHECK-NEXT: This UnwindPlan is valid at all instruction locations: no.
+# CHECK-NEXT: Address range of this UnwindPlan: [stack-cfi-parsing.out..module_image + 0-0x0000000000000002)
+# CHECK-NEXT: row[0]: 0: CFA=DW_OP_breg7 +0 => rbp=DW_OP_breg7 +0 rip=DW_OP_pick 0x00
+# CHECK-NEXT: row[1]: 1: CFA=DW_OP_breg7 +0 => rbx=DW_OP_breg2 +0 rbp=DW_OP_breg0 +0 rip=DW_OP_pick 0x00
+
+# The following plans are all (syntactically) invalid for various reasons.
+# Processing those should not cause a crash.
+
+image show-unwind -n func2
+# CHECK-LABEL: image show-unwind -n func2
+# CHECK-NOT: Symbol file
+
+image show-unwind -n func3
+# CHECK-LABEL: image show-unwind -n func3
+# CHECK-NOT: Symbol file
+
+image show-unwind -n func4
+# CHECK-LABEL: image show-unwind -n func4
+# CHECK-NOT: Symbol file
+
+image show-unwind -n func5
+# CHECK-LABEL: image show-unwind -n func5
+# CHECK-NOT: Symbol file
+
+image show-unwind -n func6
+# CHECK-LABEL: image show-unwind -n func6
+# CHECK-NOT: Symbol file
+
+image show-unwind -n func7
+# CHECK-LABEL: image show-unwind -n func7
+# CHECK-NOT: Symbol file
+
+# Finally, try an unwind plan with just a single row
+image show-unwind -n func9
+# CHECK-LABEL: image show-unwind -n func9
+# CHECK: Symbol file UnwindPlan:
+# CHECK: Address range of this UnwindPlan: [stack-cfi-parsing.out..module_image + 9-0x000000000000000a)
+# CHECK: row[0]: 0: CFA=DW_OP_breg6 +0 => rip=DW_OP_breg0 +0
+
Index: lit/SymbolFile/Breakpad/Inputs/stack-cfi-parsing.syms
===================================================================
--- lit/SymbolFile/Breakpad/Inputs/stack-cfi-parsing.syms
+++ lit/SymbolFile/Breakpad/Inputs/stack-cfi-parsing.syms
@@ -0,0 +1,20 @@
+MODULE Linux x86_64 E5894855C35DCCCCCCCCCCCCCCCCCCCC0 linux.out
+INFO CODE_ID E35C283BC327C28762DB788BF5A4078BE2351448
+FUNC 0 2 0 func0
+FUNC 2 1 0 func2
+FUNC 3 1 0 func3
+FUNC 4 1 0 func4
+FUNC 5 1 0 func5
+FUNC 6 1 0 func6
+FUNC 7 2 0 func7
+FUNC 9 1 0 func9
+STACK CFI INIT 0 2 .cfa: $rsp .ra: .cfa $rbp: $rsp
+STACK CFI 1 $rbp: $rax $rbx: $rcx
+STACK CFI INIT 2 1 $r47: $r42
+STACK CFI INIT 3 1 $rbp:
+STACK CFI INIT 4 1 $rbp
+STACK CFI INIT 5 1 $rbp: $rbx $rsp:
+STACK CFI INIT 6 1 $rbp: $rsp:
+STACK CFI INIT 7 1 .cfa: $rsp
+STACK CFI bogus
+STACK CFI INIT 9 1 .cfa: $rbp .ra: $rax
Index: lit/SymbolFile/Breakpad/Inputs/stack-cfi-parsing.yaml
===================================================================
--- lit/SymbolFile/Breakpad/Inputs/stack-cfi-parsing.yaml
+++ lit/SymbolFile/Breakpad/Inputs/stack-cfi-parsing.yaml
@@ -0,0 +1,36 @@
+--- !minidump
+Streams:
+ - Type: ThreadList
+ Threads:
+ - Thread Id: 0x00003E81
+ Context: DEAD
+ Stack:
+ Start of Memory Range: 0x00007FFCEB34A000
+ Content: DEAD
+ - Type: ModuleList
+ Modules:
+ - Base of Image: 0x0000000000400000
+ Size of Image: 0x00001000
+ Module Name: '/tmp/stack-cfi-parsing.out'
+ CodeView Record: 4C457042E35C283BC327C28762DB788BF5A4078BE2351448
+ - Type: SystemInfo
+ Processor Arch: AMD64
+ Processor Level: 6
+ Processor Revision: 15876
+ Number of Processors: 40
+ Platform ID: Linux
+ CSD Version: 'Linux 3.13.0-91-generic'
+ CPU:
+ Vendor ID: GenuineIntel
+ Version Info: 0x00000000
+ Feature Info: 0x00000000
+ - Type: LinuxProcStatus
+ Text: |
+ Name: linux-x86_64
+ State: t (tracing stop)
+ Tgid: 29917
+ Ngid: 0
+ Pid: 29917
+ PPid: 29370
+
+...
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