Add option to disable symbolization (#380)

include/ddprof_cli.hpp

@@ -68,6 +68,7 @@ struct DDProfCLI {
   bool fault_info{true};
   bool help_extended{false};
   bool remote_symbolization{false};
+  bool disable_symbolization{false};
 
   std::string socket_path;
   int pipefd_to_library{-1};

include/ddprof_context.hpp

@@ -33,6 +33,7 @@ struct DDProfContext {
     bool show_samples{false};
     bool timeline{false};
     bool remote_symbolization{false};
+    bool disable_symbolization{false};
 
     cpu_set_t cpu_affinity{};
     std::string switch_user;

include/dwfl_symbol_lookup.hpp

@@ -43,7 +43,7 @@ struct DwflSymbolLookupStats {
 class DwflSymbolLookup {
 public:
   // build and check env var to know check setting
-  DwflSymbolLookup();
+  explicit DwflSymbolLookup(bool disable_symbolization = false);
 
   // Get symbol from internal cache or fetch through dwarf
   SymbolIdx_t get_or_insert(const DDProfMod &ddprof_mod, SymbolTable &table,
@@ -85,6 +85,7 @@ class DwflSymbolLookup {
   // unordered map of DSO elements
   FileInfo2SymbolMap _file_info_map;
   DwflSymbolLookupStats _stats;
+  bool _disable_symbolization{false};
 };
 
 } // namespace ddprof

include/symbol_hdr.hpp

@@ -19,8 +19,10 @@
 
 namespace ddprof {
 struct SymbolHdr {
-  explicit SymbolHdr(std::string_view path_to_proc = "")
-      : _runtime_symbol_lookup(path_to_proc) {}
+  explicit SymbolHdr(bool disable_symbolization = false,
+                     std::string_view path_to_proc = "")
+      : _dwfl_symbol_lookup(disable_symbolization),
+        _runtime_symbol_lookup(path_to_proc) {}
   void display_stats() const {
     _dwfl_symbol_lookup.stats().display(_dwfl_symbol_lookup.size());
     _dso_symbol_lookup.stats_display();

include/unwind_state.hpp

@@ -41,8 +41,10 @@ struct UnwindRegisters {
 /// Single structure with everything necessary in unwinding. The structure is
 /// given through callbacks
 struct UnwindState {
-  explicit UnwindState(UniqueElf ref_elf, int dd_profiling_fd = -1)
-      : dso_hdr("", dd_profiling_fd), ref_elf(std::move(ref_elf)) {
+  explicit UnwindState(UniqueElf ref_elf, int dd_profiling_fd = -1,
+                       bool disable_symbolization = false)
+      : dso_hdr("", dd_profiling_fd), symbol_hdr(disable_symbolization),
+        ref_elf(std::move(ref_elf)) {
     output.clear();
     output.locs.reserve(kMaxStackDepth);
   }
@@ -65,7 +67,9 @@ struct UnwindState {
   UniqueElf ref_elf; // reference elf object used to initialize dwfl
 };
 
-std::optional<UnwindState> create_unwind_state(int dd_profiling_fd = -1);
+std::optional<UnwindState>
+create_unwind_state(int dd_profiling_fd = -1,
+                    bool disable_symbolization = false);
 
 static inline bool unwind_registers_equal(const UnwindRegisters *lhs,
                                           const UnwindRegisters *rhs) {

src/ddprof_cli.cc

@@ -347,6 +347,13 @@ int DDProfCLI::parse(int argc, const char *argv[]) {
                                  ->envname("DD_PROFILING_REMOTE_SYMBOLIZATION")
                                  ->group(""));
 
+  extended_options.push_back(app.add_flag("--disable-symbolization",
+                                          disable_symbolization,
+                                          "Disable symbolization")
+                                 ->default_val(false)
+                                 ->envname("DD_PROFILING_DISABLE_SYMBOLIZATION")
+                                 ->group(""));
+
   // Parse
   CLI11_PARSE(app, argc, argv);
 

src/ddprof_context_lib.cc

@@ -90,6 +90,7 @@ void copy_cli_values(const DDProfCLI &ddprof_cli, DDProfContext &ctx) {
   ctx.params.timeline = ddprof_cli.timeline;
   ctx.params.fault_info = ddprof_cli.fault_info;
   ctx.params.remote_symbolization = ddprof_cli.remote_symbolization;
+  ctx.params.disable_symbolization = ddprof_cli.disable_symbolization;
 
   ctx.params.initial_loaded_libs_check_delay =
       ddprof_cli.initial_loaded_libs_check_delay;

src/ddprof_worker.cc

@@ -339,7 +339,8 @@ DDRes worker_library_init(DDProfContext &ctx,
     // Make sure worker index is initialized correctly
     ctx.worker_ctx.i_current_pprof = 0;
     ctx.worker_ctx.exp_tid = {0};
-    auto unwind_state = create_unwind_state(ctx.params.dd_profiling_fd);
+    auto unwind_state = create_unwind_state(ctx.params.dd_profiling_fd,
+                                            ctx.params.disable_symbolization);
     if (!unwind_state) {
       LG_ERR("Failed to create unwind state");
       return ddres_error(DD_WHAT_UW_ERROR);

src/dwfl_symbol_lookup.cc

@@ -18,7 +18,8 @@
 
 namespace ddprof {
 
-DwflSymbolLookup::DwflSymbolLookup() {
+DwflSymbolLookup::DwflSymbolLookup(bool disable_symbolization)
+    : _disable_symbolization(disable_symbolization) {
   if (const char *env_p = std::getenv("DDPROF_CACHE_SETTING")) {
     if (strcmp(env_p, "VALIDATE") == 0) {
       // Allows to compare the accuracy of the cache
@@ -93,7 +94,8 @@ SymbolIdx_t DwflSymbolLookup::insert(const DDProfMod &ddprof_mod,
 
   ElfAddress_t const elf_pc = process_pc - ddprof_mod._sym_bias;
 
-  if (!symbol_get_from_dwfl(ddprof_mod._mod, process_pc, symbol, elf_sym,
+  if (_disable_symbolization ||
+      !symbol_get_from_dwfl(ddprof_mod._mod, process_pc, symbol, elf_sym,
                             lbias)) {
     ++_stats._no_dwfl_symbols;
     // Override with info from dso

src/unwind_state.cc

@@ -9,12 +9,13 @@
 #include "logger.hpp"
 
 namespace ddprof {
-std::optional<UnwindState> create_unwind_state(int dd_profiling_fd) {
+std::optional<UnwindState> create_unwind_state(int dd_profiling_fd,
+                                               bool disable_symbolization) {
   auto elf = create_elf_from_self();
   if (!elf) {
     return std::nullopt;
   }
 
-  return UnwindState(std::move(elf), dd_profiling_fd);
+  return UnwindState(std::move(elf), dd_profiling_fd, disable_symbolization);
 }
 } // namespace ddprof

test/ddprof_exporter-ut.cc

@@ -20,7 +20,9 @@
 
 namespace ddprof {
 // todo : cut this dependency
-DwflSymbolLookup::DwflSymbolLookup() : _lookup_setting(K_CACHE_ON) {}
+DwflSymbolLookup::DwflSymbolLookup(bool disable_symbolization)
+    : _lookup_setting(K_CACHE_ON),
+      _disable_symbolization(disable_symbolization) {}
 
 // Mock
 int get_nb_hw_thread() { return 2; }

test/ddprof_pprof-ut.cc

@@ -22,7 +22,9 @@
 
 namespace ddprof {
 // todo : cut this dependency
-DwflSymbolLookup::DwflSymbolLookup() : _lookup_setting(K_CACHE_ON) {}
+DwflSymbolLookup::DwflSymbolLookup(bool disable_symbolization)
+    : _lookup_setting(K_CACHE_ON),
+      _disable_symbolization(disable_symbolization) {}
 
 TEST(DDProfPProf, init_profiles) {
   DDProfPProf pprof;