LibCoredump: Copy out the FooInfo structs to an aligned address

We were handing out unaligned pointers to these, which made UBSAN super
mad, copy them out to avoid that.

Userland/Applications/CrashReporter/main.cpp

@@ -153,7 +153,7 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
 
     Vector<String> memory_regions;
     coredump->for_each_memory_region_info([&](auto& memory_region_info) {
-        memory_regions.append(String::formatted("{:p} - {:p}: {}", memory_region_info.region_start, memory_region_info.region_end, (const char*)memory_region_info.region_name));
+        memory_regions.append(String::formatted("{:p} - {:p}: {}", memory_region_info.region_start, memory_region_info.region_end, memory_region_info.region_name));
         return IterationDecision::Continue;
     });
 

Userland/Libraries/LibCoredump/Backtrace.cpp

@@ -17,7 +17,7 @@
 
 namespace Coredump {
 
-ELFObjectInfo const* Backtrace::object_info_for_region(ELF::Core::MemoryRegionInfo const& region)
+ELFObjectInfo const* Backtrace::object_info_for_region(MemoryRegionInfo const& region)
 {
     auto path = region.object_name();
     if (!path.starts_with('/') && Core::File::looks_like_shared_library(path))
@@ -99,8 +99,8 @@ Backtrace::~Backtrace()
 
 void Backtrace::add_entry(const Reader& coredump, FlatPtr ip)
 {
-    auto* ip_region = coredump.region_containing(ip);
-    if (!ip_region) {
+    auto ip_region = coredump.region_containing(ip);
+    if (!ip_region.has_value()) {
         m_entries.append({ ip, {}, {}, {} });
         return;
     }
@@ -116,7 +116,7 @@ void Backtrace::add_entry(const Reader& coredump, FlatPtr ip)
     // the PT_LOAD header for the .text segment isn't the first one
     // in the object file.
     auto region = coredump.first_region_for_object(object_name);
-    auto* object_info = object_info_for_region(*region);
+    auto object_info = object_info_for_region(*region);
     if (!object_info)
         return;
 

Userland/Libraries/LibCoredump/Backtrace.h

@@ -45,7 +45,7 @@ public:
 
 private:
     void add_entry(const Reader&, FlatPtr ip);
-    ELFObjectInfo const* object_info_for_region(ELF::Core::MemoryRegionInfo const&);
+    ELFObjectInfo const* object_info_for_region(MemoryRegionInfo const&);
 
     bool m_skip_loader_so { false };
     ELF::Core::ThreadInfo m_thread_info;

Userland/Libraries/LibCoredump/Reader.cpp

@@ -135,8 +135,8 @@ bool Reader::NotesEntryIterator::at_end() const
 
 Optional<FlatPtr> Reader::peek_memory(FlatPtr address) const
 {
-    const auto* region = region_containing(address);
-    if (!region)
+    auto region = region_containing(address);
+    if (!region.has_value())
         return {};
 
     FlatPtr offset_in_region = address - region->region_start;
@@ -167,12 +167,12 @@ const JsonObject Reader::process_info() const
     // FIXME: Maybe just cache this on the Reader instance after first access.
 }
 
-ELF::Core::MemoryRegionInfo const* Reader::first_region_for_object(StringView object_name) const
+Optional<MemoryRegionInfo> Reader::first_region_for_object(StringView object_name) const
 {
-    ELF::Core::MemoryRegionInfo const* ret = nullptr;
+    Optional<MemoryRegionInfo> ret;
     for_each_memory_region_info([&ret, &object_name](auto& region_info) {
         if (region_info.object_name() == object_name) {
-            ret = &region_info;
+            ret = region_info;
             return IterationDecision::Break;
         }
         return IterationDecision::Continue;
@@ -180,12 +180,12 @@ ELF::Core::MemoryRegionInfo const* Reader::first_region_for_object(StringView ob
     return ret;
 }
 
-const ELF::Core::MemoryRegionInfo* Reader::region_containing(FlatPtr address) const
+Optional<MemoryRegionInfo> Reader::region_containing(FlatPtr address) const
 {
-    const ELF::Core::MemoryRegionInfo* ret = nullptr;
-    for_each_memory_region_info([&ret, address](const ELF::Core::MemoryRegionInfo& region_info) {
+    Optional<MemoryRegionInfo> ret;
+    for_each_memory_region_info([&ret, address](const auto& region_info) {
         if (region_info.region_start <= address && region_info.region_end >= address) {
-            ret = &region_info;
+            ret = region_info;
             return IterationDecision::Break;
         }
         return IterationDecision::Continue;
@@ -272,8 +272,8 @@ HashMap<String, String> Reader::metadata() const
 const Reader::LibraryData* Reader::library_containing(FlatPtr address) const
 {
     static HashMap<String, OwnPtr<LibraryData>> cached_libs;
-    auto* region = region_containing(address);
-    if (!region)
+    auto region = region_containing(address);
+    if (!region.has_value())
         return {};
 
     auto name = region->object_name();
@@ -300,7 +300,7 @@ const Reader::LibraryData* Reader::library_containing(FlatPtr address) const
 void Reader::for_each_library(Function<void(LibraryInfo)> func) const
 {
     HashTable<String> libraries;
-    for_each_memory_region_info([&](ELF::Core::MemoryRegionInfo const& region) {
+    for_each_memory_region_info([&](auto const& region) {
         auto name = region.object_name();
         if (name.is_null() || libraries.contains(name))
             return IterationDecision::Continue;

Userland/Libraries/LibCoredump/Reader.h

@@ -6,6 +6,7 @@
 
 #pragma once
 
+#include <AK/ByteReader.h>
 #include <AK/HashMap.h>
 #include <AK/Noncopyable.h>
 #include <AK/OwnPtr.h>
@@ -15,6 +16,24 @@
 
 namespace Coredump {
 
+struct MemoryRegionInfo {
+    ELF::Core::NotesEntryHeader header;
+    uint64_t region_start;
+    uint64_t region_end;
+    uint16_t program_header_index;
+    StringView region_name;
+
+    StringView object_name() const
+    {
+        if (region_name.contains("Loader.so"))
+            return "Loader.so"sv;
+        auto maybe_colon_index = region_name.find(':');
+        if (!maybe_colon_index.has_value())
+            return {};
+        return region_name.substring_view(0, *maybe_colon_index);
+    }
+};
+
 class Reader {
     AK_MAKE_NONCOPYABLE(Reader);
     AK_MAKE_NONMOVABLE(Reader);
@@ -40,8 +59,8 @@ public:
     const ELF::Image& image() const { return m_coredump_image; }
 
     Optional<FlatPtr> peek_memory(FlatPtr address) const;
-    ELF::Core::MemoryRegionInfo const* first_region_for_object(StringView object_name) const;
-    const ELF::Core::MemoryRegionInfo* region_containing(FlatPtr address) const;
+    Optional<MemoryRegionInfo> first_region_for_object(StringView object_name) const;
+    Optional<MemoryRegionInfo> region_containing(FlatPtr address) const;
 
     struct LibraryData {
         String name;
@@ -104,7 +123,20 @@ void Reader::for_each_memory_region_info(Func func) const
     for (; !it.at_end(); it.next()) {
         if (it.type() != ELF::Core::NotesEntryHeader::Type::MemoryRegionInfo)
             continue;
-        auto& memory_region_info = *bit_cast<const ELF::Core::MemoryRegionInfo*>(it.current());
+        ELF::Core::MemoryRegionInfo raw_memory_region_info;
+        ReadonlyBytes raw_data {
+            it.current(),
+            sizeof(raw_memory_region_info),
+        };
+        ByteReader::load(raw_data.data(), raw_memory_region_info);
+
+        MemoryRegionInfo memory_region_info {
+            raw_memory_region_info.header,
+            raw_memory_region_info.region_start,
+            raw_memory_region_info.region_end,
+            raw_memory_region_info.program_header_index,
+            { bit_cast<const char*>(raw_data.offset_pointer(raw_data.size())) },
+        };
         IterationDecision decision = func(memory_region_info);
         if (decision == IterationDecision::Break)
             return;
@@ -118,7 +150,9 @@ void Reader::for_each_thread_info(Func func) const
     for (; !it.at_end(); it.next()) {
         if (it.type() != ELF::Core::NotesEntryHeader::Type::ThreadInfo)
             continue;
-        auto& thread_info = *bit_cast<const ELF::Core::ThreadInfo*>(it.current());
+        ELF::Core::ThreadInfo thread_info;
+        ByteReader::load(bit_cast<const u8*>(it.current()), thread_info);
+
         IterationDecision decision = func(thread_info);
         if (decision == IterationDecision::Break)
             return;