Add support for zstd compressed sections to dump_syms

Support for zstd must be enabled by passing --enable-zstd to configure.

Change-Id: I57d0196552284de86575d979d673ac20a3fc4d64
Reviewed-on: https://chromium-review.googlesource.com/c/breakpad/breakpad/+/4722191
Reviewed-by: Joshua Peraza <jperaza@chromium.org>

Makefile.am

@@ -694,9 +694,11 @@ src_tools_linux_dump_syms_dump_syms_SOURCES = \
 	src/common/linux/safe_readlink.cc \
 	src/tools/linux/dump_syms/dump_syms.cc
 src_tools_linux_dump_syms_dump_syms_CXXFLAGS = \
-	$(RUSTC_DEMANGLE_CFLAGS)
+	$(RUSTC_DEMANGLE_CFLAGS) \
+	$(ZSTD_CFLAGS)
 src_tools_linux_dump_syms_dump_syms_LDADD = \
 	$(RUSTC_DEMANGLE_LIBS) \
+	$(ZSTD_CFLAGS) \
 	-lz
 
 src_tools_linux_md2core_minidump_2_core_SOURCES = \
@@ -821,11 +823,13 @@ src_common_dumper_unittest_SOURCES = \
 src_common_dumper_unittest_CPPFLAGS = \
 	$(AM_CPPFLAGS) $(TEST_CFLAGS) \
 	$(RUSTC_DEMANGLE_CFLAGS) \
-	$(PTHREAD_CFLAGS)
+	$(PTHREAD_CFLAGS) \
+	$(ZSTD_CFLAGS)
 src_common_dumper_unittest_LDADD = \
 	$(TEST_LIBS) \
 	$(RUSTC_DEMANGLE_LIBS) \
 	$(PTHREAD_CFLAGS) $(PTHREAD_LIBS) \
+	$(ZSTD_LIBS) \
 	-lz
 
 src_common_mac_macho_reader_unittest_SOURCES = \

Makefile.in

@@ -2695,7 +2695,7 @@ src_tools_linux_dump_syms_dump_syms_CXXFLAGS = \
 
 src_tools_linux_dump_syms_dump_syms_LDADD = \
 	$(RUSTC_DEMANGLE_LIBS) \
-	-lz
+	-lz -lzstd
 
 src_tools_linux_md2core_minidump_2_core_SOURCES = \
 	src/common/linux/memory_mapped_file.cc \
@@ -2828,7 +2828,7 @@ src_common_dumper_unittest_LDADD = \
 	$(TEST_LIBS) \
 	$(RUSTC_DEMANGLE_LIBS) \
 	$(PTHREAD_CFLAGS) $(PTHREAD_LIBS) \
-	-lz
+	-lz -lzstd
 
 src_common_mac_macho_reader_unittest_SOURCES = \
 	src/common/dwarf_cfi_to_module.cc \

configure

@@ -810,6 +810,7 @@ enable_system_test_libs
 enable_selftest
 with_rustc_demangle
 enable_system_rustc_demangle
+enable_zstd
 with_tests_as_root
 '
       ac_precious_vars='build_alias
@@ -1483,6 +1484,7 @@ Optional Features:
                           is no). This assumes that rustc-demangle is
                           installed in your sysroot, and all headers from it
                           are available in your standard include path
+  --enable-zstd           Enable decompression of ELF sections with zstd
 
 Optional Packages:
   --with-PACKAGE[=ARG]    use PACKAGE [ARG=yes]
@@ -6594,11 +6596,11 @@ if test x$ac_prog_cxx_stdcxx = xno
 then :
   { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $CXX option to enable C++11 features" >&5
 printf %s "checking for $CXX option to enable C++11 features... " >&6; }
-if test ${ac_cv_prog_cxx_11+y}
+if test ${ac_cv_prog_cxx_cxx11+y}
 then :
   printf %s "(cached) " >&6
 else $as_nop
-  ac_cv_prog_cxx_11=no
+  ac_cv_prog_cxx_cxx11=no
 ac_save_CXX=$CXX
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
@@ -6640,11 +6642,11 @@ if test x$ac_prog_cxx_stdcxx = xno
 then :
   { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $CXX option to enable C++98 features" >&5
 printf %s "checking for $CXX option to enable C++98 features... " >&6; }
-if test ${ac_cv_prog_cxx_98+y}
+if test ${ac_cv_prog_cxx_cxx98+y}
 then :
   printf %s "(cached) " >&6
 else $as_nop
-  ac_cv_prog_cxx_98=no
+  ac_cv_prog_cxx_cxx98=no
 ac_save_CXX=$CXX
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
@@ -10504,6 +10506,70 @@ fi
 
 
 
+# Check whether --enable-zstd was given.
+if test ${enable_zstd+y}
+then :
+  enableval=$enable_zstd;
+else $as_nop
+  enable_zstd=no
+fi
+
+if test "x${enable_zstd}" != xno; then
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for ZSTD_decompress in -lzstd" >&5
+printf %s "checking for ZSTD_decompress in -lzstd... " >&6; }
+if test ${ac_cv_lib_zstd_ZSTD_decompress+y}
+then :
+  printf %s "(cached) " >&6
+else $as_nop
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-lzstd  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+char ZSTD_decompress ();
+int
+main (void)
+{
+return ZSTD_decompress ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"
+then :
+  ac_cv_lib_zstd_ZSTD_decompress=yes
+else $as_nop
+  ac_cv_lib_zstd_ZSTD_decompress=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_zstd_ZSTD_decompress" >&5
+printf "%s\n" "$ac_cv_lib_zstd_ZSTD_decompress" >&6; }
+if test "x$ac_cv_lib_zstd_ZSTD_decompress" = xyes
+then :
+  printf "%s\n" "#define HAVE_LIBZSTD 1" >>confdefs.h
+
+  LIBS="-lzstd $LIBS"
+
+else $as_nop
+  as_fn_error $? "zstd library not found." "$LINENO" 5
+fi
+
+  ac_fn_c_check_header_compile "$LINENO" "zstd.h" "ac_cv_header_zstd_h" "$ac_includes_default"
+if test "x$ac_cv_header_zstd_h" = xyes
+then :
+
+else $as_nop
+  as_fn_error $? "zstd header not found." "$LINENO" 5
+fi
+
+fi
+
 
 # Check whether --with-tests-as-root was given.
 if test ${with_tests_as_root+y}

configure.ac

@@ -212,6 +212,17 @@ fi
 AC_ARG_VAR([RUSTC_DEMANGLE_CFLAGS], [Compiler flags for rustc-demangle])
 AC_ARG_VAR([RUSTC_DEMANGLE_LIBS], [Linker flags for rustc-demangle])
 
+AC_ARG_ENABLE(zstd,
+              AS_HELP_STRING([--enable-zstd],
+                             [Enable decompression of ELF sections with zstd]),,
+              [enable_zstd=no])
+if test "x${enable_zstd}" != xno; then
+  AC_CHECK_LIB(zstd, ZSTD_decompress, [],
+               [AC_MSG_ERROR([zstd library not found.])])
+  AC_CHECK_HEADER(zstd.h, [],
+                  [AC_MSG_ERROR([zstd header not found.])])
+fi
+
 AC_ARG_WITH(tests-as-root,
             AS_HELP_STRING([--with-tests-as-root],
                            [Run the tests as root. Use this on platforms]

src/common/linux/dump_symbols.cc

@@ -51,6 +51,9 @@
 #include <sys/stat.h>
 #include <unistd.h>
 #include <zlib.h>
+#ifdef HAVE_LIBZSTD
+#include <zstd.h>
+#endif
 
 #include <set>
 #include <string>
@@ -108,6 +111,11 @@ using google_breakpad::wasteful_vector;
 #define EM_AARCH64      183
 #endif
 
+// Define ZStd compression if host machine does not include this define.
+#ifndef ELFCOMPRESS_ZSTD
+#define ELFCOMPRESS_ZSTD 2
+#endif
+
 //
 // FDWrapper
 //
@@ -305,7 +313,7 @@ uint32_t GetCompressionHeader(
   return sizeof (*header);
 }
 
-std::pair<uint8_t *, uint64_t> UncompressSectionContents(
+std::pair<uint8_t *, uint64_t> UncompressZlibSectionContents(
     const uint8_t* compressed_buffer, uint64_t compressed_size, uint64_t uncompressed_size) {
   z_stream stream;
   memset(&stream, 0, sizeof stream);
@@ -334,6 +342,37 @@ std::pair<uint8_t *, uint64_t> UncompressSectionContents(
     : std::make_pair(uncompressed_buffer.release(), uncompressed_size);
 }
 
+#ifdef HAVE_LIBZSTD
+std::pair<uint8_t *, uint64_t> UncompressZstdSectionContents(
+    const uint8_t* compressed_buffer, uint64_t compressed_size,uint64_t uncompressed_size) {
+
+  google_breakpad::scoped_array<uint8_t> uncompressed_buffer(new uint8_t[uncompressed_size]);
+  size_t out_size = ZSTD_decompress(uncompressed_buffer.get(), uncompressed_size,
+    compressed_buffer, compressed_size);
+  if (ZSTD_isError(out_size)) {
+    return std::make_pair(nullptr, 0);
+  }
+  assert(out_size == uncompressed_size);
+  return std::make_pair(uncompressed_buffer.release(), uncompressed_size);
+}
+#endif
+
+std::pair<uint8_t *, uint64_t> UncompressSectionContents(
+    uint64_t compression_type, const uint8_t* compressed_buffer,
+    uint64_t compressed_size, uint64_t uncompressed_size) {
+  if (compression_type == ELFCOMPRESS_ZLIB) {
+    return UncompressZlibSectionContents(compressed_buffer, compressed_size, uncompressed_size);
+  }
+
+#ifdef HAVE_LIBZSTD
+  if (compression_type == ELFCOMPRESS_ZSTD) {
+    return UncompressZstdSectionContents(compressed_buffer, compressed_size, uncompressed_size);
+  }
+#endif
+
+  return std::make_pair(nullptr, 0);
+}
+
 void StartProcessSplitDwarf(google_breakpad::CompilationUnit* reader,
                             Module* module,
                             google_breakpad::Endianness endianness,
@@ -437,7 +476,7 @@ bool LoadDwarf(const string& dwarf_filename,
     size -= compression_header_size;
 
     std::pair<uint8_t *, uint64_t> uncompressed =
-      UncompressSectionContents(contents, size, chdr.ch_size);
+      UncompressSectionContents(chdr.ch_type, contents, size, chdr.ch_size);
 
     if (uncompressed.first != nullptr && uncompressed.second != 0) {
       file_context.AddManagedSectionToSectionMap(name, uncompressed.first, uncompressed.second);
@@ -587,7 +626,7 @@ bool LoadDwarfCFI(const string& dwarf_filename,
   cfi_size -= compression_header_size;
 
   std::pair<uint8_t *, uint64_t> uncompressed =
-    UncompressSectionContents(cfi, cfi_size, chdr.ch_size);
+    UncompressSectionContents(chdr.ch_type, cfi, cfi_size, chdr.ch_size);
 
   if (uncompressed.first == nullptr || uncompressed.second == 0) {
     fprintf(stderr, "%s: decompression failed\n", dwarf_filename.c_str());

src/config.h.in

@@ -21,6 +21,9 @@
 /* Define to 1 if you have the `rustc_demangle' library (-lrustc_demangle). */
 #undef HAVE_LIBRUSTC_DEMANGLE
 
+/* Define to 1 if you have the `zstd' library (-lzstd). */
+#undef HAVE_LIBZSTD
+
 /* Define to 1 if you have the `memfd_create' function. */
 #undef HAVE_MEMFD_CREATE