Merge pull request #3660 from davemarchevsky/davemarchevsky_sections

bcc internals: Keep track of BPF progs using function instead of section
iovisor · Feb 22, 2022 · 678197b · 678197b
2 parents f96fed0 + 8323d74
commit 678197b
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Showing 8 changed files with 314 additions and 231 deletions.
diff --git a/src/cc/bcc_debug.cc b/src/cc/bcc_debug.cc
@@ -196,68 +196,67 @@ void SourceDebugger::dump() {
   vector<string> LineCache = buildLineCache();
 
   // Start to disassemble with source code annotation section by section
-  for (auto section : sections_)
-    if (!strncmp(fn_prefix_.c_str(), section.first.c_str(),
-                 fn_prefix_.size())) {
-      MCDisassembler::DecodeStatus S;
-      MCInst Inst;
-      uint64_t Size;
-      uint8_t *FuncStart = get<0>(section.second);
-      uint64_t FuncSize = get<1>(section.second);
+  prog_func_info_.for_each_func([&](std::string func_name, FuncInfo &info) {
+    MCDisassembler::DecodeStatus S;
+    MCInst Inst;
+    uint64_t Size;
+    uint8_t *FuncStart = info.start_;
+    uint64_t FuncSize = info.size_;
 #if LLVM_MAJOR_VERSION >= 9
-      unsigned SectionID = get<2>(section.second);
+    auto section = sections_.find(info.section_);
+    if (section == sections_.end()) {
+      errs() << "Debug Error: no section entry for section " << info.section_
+             << '\n';
+      return;
+    }
+    unsigned SectionID = get<2>(section->second);
 #endif
-      ArrayRef<uint8_t> Data(FuncStart, FuncSize);
-      uint32_t CurrentSrcLine = 0;
-      string func_name = section.first.substr(fn_prefix_.size());
+    ArrayRef<uint8_t> Data(FuncStart, FuncSize);
+    uint32_t CurrentSrcLine = 0;
 
-      errs() << "Disassembly of section " << section.first << ":\n"
-             << func_name << ":\n";
+    errs() << "Disassembly of function " << func_name << "\n";
 
-      string src_dbg_str;
-      llvm::raw_string_ostream os(src_dbg_str);
-      for (uint64_t Index = 0; Index < FuncSize; Index += Size) {
+    string src_dbg_str;
+    llvm::raw_string_ostream os(src_dbg_str);
+    for (uint64_t Index = 0; Index < FuncSize; Index += Size) {
 #if LLVM_MAJOR_VERSION >= 10
-        S = DisAsm->getInstruction(Inst, Size, Data.slice(Index), Index,
-                                   nulls());
+      S = DisAsm->getInstruction(Inst, Size, Data.slice(Index), Index, nulls());
 #else
-        S = DisAsm->getInstruction(Inst, Size, Data.slice(Index), Index,
-                                   nulls(), nulls());
+      S = DisAsm->getInstruction(Inst, Size, Data.slice(Index), Index, nulls(),
+                                 nulls());
 #endif
-        if (S != MCDisassembler::Success) {
-          os << "Debug Error: disassembler failed: " << std::to_string(S)
-             << '\n';
-          break;
-        } else {
-          DILineInfo LineInfo;
+      if (S != MCDisassembler::Success) {
+        os << "Debug Error: disassembler failed: " << std::to_string(S) << '\n';
+        break;
+      } else {
+        DILineInfo LineInfo;
 
-          LineTable->getFileLineInfoForAddress(
+        LineTable->getFileLineInfoForAddress(
 #if LLVM_MAJOR_VERSION >= 9
-              {(uint64_t)FuncStart + Index, SectionID},
+            {(uint64_t)FuncStart + Index, SectionID},
 #else
-              (uint64_t)FuncStart + Index,
+            (uint64_t)FuncStart + Index,
 #endif
-              CU->getCompilationDir(),
-              DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath,
-              LineInfo);
+            CU->getCompilationDir(),
+            DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath, LineInfo);
 
-          adjustInstSize(Size, Data[Index], Data[Index + 1]);
-          dumpSrcLine(LineCache, LineInfo.FileName, LineInfo.Line,
-                      CurrentSrcLine, os);
-          os << format("%4" PRIu64 ":", Index >> 3) << '\t';
-          dumpBytes(Data.slice(Index, Size), os);
+        adjustInstSize(Size, Data[Index], Data[Index + 1]);
+        dumpSrcLine(LineCache, LineInfo.FileName, LineInfo.Line, CurrentSrcLine,
+                    os);
+        os << format("%4" PRIu64 ":", Index >> 3) << '\t';
+        dumpBytes(Data.slice(Index, Size), os);
 #if LLVM_MAJOR_VERSION >= 10
-          IP->printInst(&Inst, 0, "", *STI, os);
+        IP->printInst(&Inst, 0, "", *STI, os);
 #else
-          IP->printInst(&Inst, os, "", *STI);
+        IP->printInst(&Inst, os, "", *STI);
 #endif
-          os << '\n';
-        }
+        os << '\n';
       }
-      os.flush();
-      errs() << src_dbg_str << '\n';
-      src_dbg_fmap_[func_name] = src_dbg_str;
     }
+    os.flush();
+    errs() << src_dbg_str << '\n';
+    src_dbg_fmap_[func_name] = src_dbg_str;
+  });
 }
 
 }  // namespace ebpf
diff --git a/src/cc/bcc_debug.h b/src/cc/bcc_debug.h
@@ -15,19 +15,18 @@
  */
 
 #include "bpf_module.h"
+#include "frontends/clang/loader.h"
 
 namespace ebpf {
 
 class SourceDebugger {
  public:
-  SourceDebugger(
-      llvm::Module *mod,
-      sec_map_def &sections,
-      const std::string &fn_prefix, const std::string &mod_src,
-      std::map<std::string, std::string> &src_dbg_fmap)
+  SourceDebugger(llvm::Module *mod, sec_map_def &sections,
+                 ProgFuncInfo &prog_func_info, const std::string &mod_src,
+                 std::map<std::string, std::string> &src_dbg_fmap)
       : mod_(mod),
         sections_(sections),
-        fn_prefix_(fn_prefix),
+        prog_func_info_(prog_func_info),
         mod_src_(mod_src),
         src_dbg_fmap_(src_dbg_fmap) {}
 // Only support dump for llvm 6.x and later.
@@ -56,7 +55,7 @@ class SourceDebugger {
  private:
   llvm::Module *mod_;
   const sec_map_def &sections_;
-  const std::string &fn_prefix_;
+  ProgFuncInfo &prog_func_info_;
   const std::string &mod_src_;
   std::map<std::string, std::string> &src_dbg_fmap_;
 };