Fix test compilation issues with from FLAGS_disable_dwarf_parsing. Add elf_reader_max_file_size flag to prevent huge allocations for large binaries

Signed-off-by: Dom Del Nano <ddelnano@gmail.com>

Author: ddelnano

src/stirling/obj_tools/dwarf_reader.cc

@@ -34,7 +34,8 @@
 #include "src/stirling/obj_tools/dwarf_utils.h"
 #include "src/stirling/obj_tools/init.h"
 
-DECLARE_bool(disable_dwarf_parsing);
+DEFINE_bool(disable_dwarf_parsing, true,
+            "Disable parsing of DWARF info for symbol offsets and uprobes");
 
 namespace px {
 namespace stirling {

src/stirling/obj_tools/dwarf_reader.h

@@ -36,6 +36,8 @@
 #include "src/stirling/obj_tools/abi_model.h"
 #include "src/stirling/obj_tools/utils.h"
 
+DECLARE_bool(disable_dwarf_parsing);
+
 namespace px {
 namespace stirling {
 namespace obj_tools {

src/stirling/obj_tools/elf_reader.cc

@@ -32,6 +32,8 @@
 #include "src/common/fs/fs_wrapper.h"
 #include "src/stirling/obj_tools/init.h"
 
+DEFINE_uint64(elf_reader_max_file_size, 30 << 20, "Maximum file size for ELF files. Value of 0 means no limit. Default is 30MB.");
+
 namespace px {
 namespace stirling {
 namespace obj_tools {
@@ -167,6 +169,11 @@ StatusOr<std::unique_ptr<ElfReader>> ElfReader::Create(
 
   elf_reader->binary_path_ = binary_path;
 
+  PX_ASSIGN_OR_RETURN(auto stat, fs::Stat(binary_path));
+  uint64_t file_size = stat.st_size;
+  if (file_size > FLAGS_elf_reader_max_file_size) {
+    return error::Internal("File size $0 exceeds ElfReader's max file size $1. Refusing to process file", file_size, FLAGS_elf_reader_max_file_size);
+  }
   if (!elf_reader->elf_reader_.load_header_and_sections(binary_path)) {
     return error::Internal("Can't find or process ELF file $0", binary_path);
   }

src/stirling/obj_tools/elf_reader.h

@@ -33,6 +33,8 @@
 
 using ::px::utils::u8string;
 
+DECLARE_uint64(elf_reader_max_file_size);
+
 namespace px {
 namespace stirling {
 namespace obj_tools {

src/stirling/source_connectors/socket_tracer/socket_trace_bpf_tables.cc

@@ -53,7 +53,7 @@ ConnInfoMapManager::ConnInfoMapManager(bpf_tools::BCCWrapper* bcc)
   std::filesystem::path self_path = GetSelfPath().ValueOrDie();
   auto elf_reader_or_s = obj_tools::ElfReader::Create(self_path.string());
   if (!elf_reader_or_s.ok()) {
-    LOG(FATAL) << "Failed to create ElfReader for self probe";
+    LOG(FATAL) << "Failed to create ElfReader for self probe: " << elf_reader_or_s.status();
   }
   auto elf_reader = elf_reader_or_s.ConsumeValueOrDie();
 

src/stirling/source_connectors/socket_tracer/uprobe_manager.cc

@@ -650,6 +650,7 @@ StatusOr<int> UProbeManager::AttachOpenSSLUProbesOnStaticBinary(
     const uint32_t pid, const std::filesystem::path& proc_exe) {
   const auto host_proc_exe = ProcPidRootPath(pid, proc_exe);
 
+  VLOG(1) << absl::Substitute("Attaching OpenSSL probes on static binary: $0", host_proc_exe.string());
   PX_ASSIGN_OR_RETURN(auto elf_reader, ElfReader::Create(host_proc_exe));
   auto statusor = elf_reader->SearchTheOnlySymbol("SSL_write");
 
@@ -663,6 +664,8 @@ StatusOr<int> UProbeManager::AttachOpenSSLUProbesOnStaticBinary(
     spec.probe_fn = absl::StrCat(spec.probe_fn, "_syscall_fd_access");
     PX_RETURN_IF_ERROR(LogAndAttachUProbe(spec));
   }
+  VLOG(1) << absl::Substitute("Successfully attached OpenSSL probes on static binary: $0",
+                              host_proc_exe.string());
   return kOpenSSLUProbes.size();
 }
 

src/stirling/source_connectors/socket_tracer/uprobe_symaddrs.cc

@@ -47,9 +47,6 @@ DEFINE_bool(openssl_raw_fptrs_enabled, false,
             "If true, allows the openssl tracing implementation to fall back to function pointers "
             "if dlopen/dlsym is unable to find symbols");
 
-DEFINE_bool(disable_dwarf_parsing, true,
-            "Disable parsing of DWARF info for symbol offsets and uprobes");
-
 std::map<std::string, std::map<std::string, std::map<std::string, int32_t>>> g_structsOffsetMap;
 
 std::map<std::string, std::map<std::string, std::map<std::string, std::unique_ptr<location_t>>>>