re PR sanitizer/77631 (no symbols in backtrace shown by ASan when debug info is split)

	PR sanitizer/77631
	Support for external debug info.
	* elf.c: Include <errno.h>, <sys/stat.h>, <unistd.h>.
	(S_ISLNK): Define if not defined.
	(xstrnlen): Define if strnlen is not available.
	(b_elf_note): Define type.
	(NT_GNU_BUILD_ID): Define macro.
	(elf_crc32, elf_crc32_file): New static functions.
	(elf_is_symlink, elf_readlink): New static functions.
	(elf_open_debugfile_by_buildid): New static function.
	(elf_try_debugfile): New static function.
	(elf_find_debugfile_by_debuglink): New static function.
	(elf_open_debugfile_by_debuglink): New static function.
	(elf_add): Add filename and debuginfo parameters.  Adjust all
	callers.  Look for external debug info notes, and try to fetch
	debug info from external file.
	(struct phdr_data): Add exe_filename field.
	(phdr_callback): Pass filename to elf_add.
	(backtrace_initialize): Add filename parameter.
	* internal.h (backtrace_initialize): Add filename parameter.
	* fileline.c (fileline_initialize): Pass filename to
	backtrace_initialize.
	* pecoff.c (fileline_initialize): Add unused filename parameter.
	* unknown.c (fileline_initialize): Likewise.
	* xcoff.c (fileline_initialize): Likewise.
	* configure.ac: Check for objcopy --add-gnu-debuglink.
	* Makefile.am (dtest): New test target.
	* configure, Makefile.in: Rebuild.

Co-Authored-By: Denis Khalikov <d.khalikov@partner.samsung.com>

From-SVN: r253032

libbacktrace/ChangeLog

+2017-09-20  Ian Lance Taylor  <iant@golang.org>
+	    Denis Khalikov  <d.khalikov@partner.samsung.com>
+
+	PR sanitizer/77631
+	Support for external debug info.
+	* elf.c: Include <errno.h>, <sys/stat.h>, <unistd.h>.
+	(S_ISLNK): Define if not defined.
+	(xstrnlen): Define if strnlen is not available.
+	(b_elf_note): Define type.
+	(NT_GNU_BUILD_ID): Define macro.
+	(elf_crc32, elf_crc32_file): New static functions.
+	(elf_is_symlink, elf_readlink): New static functions.
+	(elf_open_debugfile_by_buildid): New static function.
+	(elf_try_debugfile): New static function.
+	(elf_find_debugfile_by_debuglink): New static function.
+	(elf_open_debugfile_by_debuglink): New static function.
+	(elf_add): Add filename and debuginfo parameters.  Adjust all
+	callers.  Look for external debug info notes, and try to fetch
+	debug info from external file.
+	(struct phdr_data): Add exe_filename field.
+	(phdr_callback): Pass filename to elf_add.
+	(backtrace_initialize): Add filename parameter.
+	* internal.h (backtrace_initialize): Add filename parameter.
+	* fileline.c (fileline_initialize): Pass filename to
+	backtrace_initialize.
+	* pecoff.c (fileline_initialize): Add unused filename parameter.
+	* unknown.c (fileline_initialize): Likewise.
+	* xcoff.c (fileline_initialize): Likewise.
+	* configure.ac: Check for objcopy --add-gnu-debuglink.
+	* Makefile.am (dtest): New test target.
+	* configure, Makefile.in: Rebuild.
+
 2017-09-12  Steve Ellcey  <sellcey@cavium.com>
 
 	PR other/81096

libbacktrace/Makefile.am

@@ -122,6 +122,16 @@ ttest_LDADD = libbacktrace.la
 
 endif HAVE_PTHREAD
 
+if HAVE_OBJCOPY_DEBUGLINK
+
+TESTS += dtest
+
+dtest: btest
+	$(OBJCOPY) --only-keep-debug btest btest.debug
+	$(OBJCOPY) --strip-debug --add-gnu-debuglink=btest.debug btest dtest
+
+endif HAVE_OBJCOPY_DEBUGLINK
+
 endif NATIVE
 
 # We can't use automake's automatic dependency tracking, because it

libbacktrace/Makefile.in

@@ -86,6 +86,7 @@ target_triplet = @target@
 check_PROGRAMS = $(am__EXEEXT_1) $(am__EXEEXT_2)
 @NATIVE_TRUE@am__append_1 = btest stest edtest
 @HAVE_PTHREAD_TRUE@@NATIVE_TRUE@am__append_2 = ttest
+@HAVE_OBJCOPY_DEBUGLINK_TRUE@@NATIVE_TRUE@am__append_3 = dtest
 subdir = .
 DIST_COMMON = README ChangeLog $(srcdir)/Makefile.in \
 	$(srcdir)/Makefile.am $(top_srcdir)/configure \
@@ -217,6 +218,7 @@ MAKEINFO = @MAKEINFO@
 MKDIR_P = @MKDIR_P@
 NM = @NM@
 NMEDIT = @NMEDIT@
+OBJCOPY = @OBJCOPY@
 OBJDUMP = @OBJDUMP@
 OBJEXT = @OBJEXT@
 OTOOL = @OTOOL@
@@ -343,7 +345,7 @@ libbacktrace_la_LIBADD = \
 	$(ALLOC_FILE)
 
 libbacktrace_la_DEPENDENCIES = $(libbacktrace_la_LIBADD)
-TESTS = $(check_PROGRAMS)
+TESTS = $(check_PROGRAMS) $(am__append_3)
 @NATIVE_TRUE@btest_SOURCES = btest.c testlib.c
 @NATIVE_TRUE@btest_CFLAGS = $(AM_CFLAGS) -g -O
 @NATIVE_TRUE@btest_LDADD = libbacktrace.la
@@ -799,6 +801,10 @@ uninstall-am:
 @NATIVE_TRUE@	cat $(srcdir)/edtest2.c > tmp-edtest2_build.c
 @NATIVE_TRUE@	$(SHELL) $(srcdir)/../move-if-change tmp-edtest2_build.c edtest2_build.c
 @NATIVE_TRUE@	echo timestamp > $@
+
+@HAVE_OBJCOPY_DEBUGLINK_TRUE@@NATIVE_TRUE@dtest: btest
+@HAVE_OBJCOPY_DEBUGLINK_TRUE@@NATIVE_TRUE@	$(OBJCOPY) --only-keep-debug btest btest.debug
+@HAVE_OBJCOPY_DEBUGLINK_TRUE@@NATIVE_TRUE@	$(OBJCOPY) --strip-debug --add-gnu-debuglink=btest.debug btest dtest
 alloc.lo: config.h backtrace.h internal.h
 backtrace.lo: config.h backtrace.h internal.h
 btest.lo: (INCDIR)/filenames.h backtrace.h backtrace-supported.h

libbacktrace/configure

@@ -604,6 +604,9 @@ LTLIBOBJS
 LIBOBJS
 NATIVE_FALSE
 NATIVE_TRUE
+HAVE_OBJCOPY_DEBUGLINK_FALSE
+HAVE_OBJCOPY_DEBUGLINK_TRUE
+OBJCOPY
 HAVE_PTHREAD_FALSE
 HAVE_PTHREAD_TRUE
 PTHREAD_CFLAGS
@@ -746,7 +749,8 @@ CFLAGS
 LDFLAGS
 LIBS
 CPPFLAGS
-CPP'
+CPP
+OBJCOPY'
 
 
 # Initialize some variables set by options.
@@ -1396,6 +1400,7 @@ Some influential environment variables:
   CPPFLAGS    C/C++/Objective C preprocessor flags, e.g. -I<include dir> if
               you have headers in a nonstandard directory <include dir>
   CPP         C preprocessor
+  OBJCOPY     location of objcopy
 
 Use these variables to override the choices made by `configure' or to help
 it to find libraries and programs with nonstandard names/locations.
@@ -11136,7 +11141,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11139 "configure"
+#line 11144 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -11242,7 +11247,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11245 "configure"
+#line 11250 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -12761,6 +12766,69 @@ else
 fi
 
 
+
+# Extract the first word of "objcopy", so it can be a program name with args.
+set dummy objcopy; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if test "${ac_cv_prog_OBJCOPY+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test -n "$OBJCOPY"; then
+  ac_cv_prog_OBJCOPY="$OBJCOPY" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
+    ac_cv_prog_OBJCOPY="objcopy"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+fi
+fi
+OBJCOPY=$ac_cv_prog_OBJCOPY
+if test -n "$OBJCOPY"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $OBJCOPY" >&5
+$as_echo "$OBJCOPY" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether objcopy supports debuglink" >&5
+$as_echo_n "checking whether objcopy supports debuglink... " >&6; }
+if test "${libbacktrace_cv_objcopy_debuglink+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test -n "${with_target_subdir}"; then
+  libbacktrace_cv_objcopy_debuglink=no
+elif ${OBJCOPY} --add-gnu-debuglink=x /bin/ls /tmp/ls$$; then
+  rm -f /tmp/ls$$
+  libbacktrace_cv_objcopy_debuglink=yes
+else
+  libbacktrace_cv_objcopy_debuglink=no
+fi
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libbacktrace_cv_objcopy_debuglink" >&5
+$as_echo "$libbacktrace_cv_objcopy_debuglink" >&6; }
+ if test "$libbacktrace_cv_objcopy_debuglink" = yes; then
+  HAVE_OBJCOPY_DEBUGLINK_TRUE=
+  HAVE_OBJCOPY_DEBUGLINK_FALSE='#'
+else
+  HAVE_OBJCOPY_DEBUGLINK_TRUE='#'
+  HAVE_OBJCOPY_DEBUGLINK_FALSE=
+fi
+
+
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether tests can run" >&5
 $as_echo_n "checking whether tests can run... " >&6; }
 if test "${libbacktrace_cv_sys_native+set}" = set; then :
@@ -12927,6 +12995,10 @@ if test -z "${HAVE_PTHREAD_TRUE}" && test -z "${HAVE_PTHREAD_FALSE}"; then
   as_fn_error "conditional \"HAVE_PTHREAD\" was never defined.
 Usually this means the macro was only invoked conditionally." "$LINENO" 5
 fi
+if test -z "${HAVE_OBJCOPY_DEBUGLINK_TRUE}" && test -z "${HAVE_OBJCOPY_DEBUGLINK_FALSE}"; then
+  as_fn_error "conditional \"HAVE_OBJCOPY_DEBUGLINK\" was never defined.
+Usually this means the macro was only invoked conditionally." "$LINENO" 5
+fi
 if test -z "${NATIVE_TRUE}" && test -z "${NATIVE_FALSE}"; then
   as_fn_error "conditional \"NATIVE\" was never defined.
 Usually this means the macro was only invoked conditionally." "$LINENO" 5

libbacktrace/configure.ac

@@ -404,6 +404,20 @@ AC_SUBST(PTHREAD_CFLAGS)
 
 AM_CONDITIONAL(HAVE_PTHREAD, test "$libgo_cv_lib_pthread" = yes)
 
+AC_ARG_VAR(OBJCOPY, [location of objcopy])
+AC_CHECK_PROG(OBJCOPY, objcopy, objcopy,)
+AC_CACHE_CHECK([whether objcopy supports debuglink],
+[libbacktrace_cv_objcopy_debuglink],
+[if test -n "${with_target_subdir}"; then
+  libbacktrace_cv_objcopy_debuglink=no
+elif ${OBJCOPY} --add-gnu-debuglink=x /bin/ls /tmp/ls$$; then
+  rm -f /tmp/ls$$
+  libbacktrace_cv_objcopy_debuglink=yes
+else
+  libbacktrace_cv_objcopy_debuglink=no
+fi])
+AM_CONDITIONAL(HAVE_OBJCOPY_DEBUGLINK, test "$libbacktrace_cv_objcopy_debuglink" = yes)
+
 AC_CACHE_CHECK([whether tests can run],
   [libbacktrace_cv_sys_native],
   [AC_RUN_IFELSE([AC_LANG_PROGRAM([], [return 0;])],

libbacktrace/fileline.c

@@ -58,6 +58,7 @@ fileline_initialize (struct backtrace_state *state,
   int pass;
   int called_error_callback;
   int descriptor;
+  const char *filename;
   char buf[64];
 
   if (!state->threaded)
@@ -84,7 +85,6 @@ fileline_initialize (struct backtrace_state *state,
   called_error_callback = 0;
   for (pass = 0; pass < 5; ++pass)
     {
-      const char *filename;
       int does_not_exist;
 
       switch (pass)
@@ -140,8 +140,8 @@ fileline_initialize (struct backtrace_state *state,
 
   if (!failed)
     {
-      if (!backtrace_initialize (state, descriptor, error_callback, data,
-				 &fileline_fn))
+      if (!backtrace_initialize (state, filename, descriptor, error_callback,
+				 data, &fileline_fn))
 	failed = 1;
     }
 

libbacktrace/internal.h

@@ -268,6 +268,7 @@ extern int backtrace_vector_release (struct backtrace_state *state,
    appropriate one.  */
 
 extern int backtrace_initialize (struct backtrace_state *state,
+				 const char *filename,
 				 int descriptor,
 				 backtrace_error_callback error_callback,
 				 void *data,

libbacktrace/pecoff.c

@@ -890,7 +890,8 @@ coff_add (struct backtrace_state *state, int descriptor,
    sections.  */
 
 int
-backtrace_initialize (struct backtrace_state *state, int descriptor,
+backtrace_initialize (struct backtrace_state *state,
+		      const char *filename ATTRIBUTE_UNUSED, int descriptor,
 		      backtrace_error_callback error_callback,
 		      void *data, fileline *fileline_fn)
 {

libbacktrace/unknown.c

@@ -54,6 +54,7 @@ unknown_fileline (struct backtrace_state *state ATTRIBUTE_UNUSED,
 
 int
 backtrace_initialize (struct backtrace_state *state ATTRIBUTE_UNUSED,
+		      const char *filename ATTRIBUTE_UNUSED,
 		      int descriptor ATTRIBUTE_UNUSED,
 		      backtrace_error_callback error_callback ATTRIBUTE_UNUSED,
 		      void *data ATTRIBUTE_UNUSED, fileline *fileline_fn)

libbacktrace/xcoff.c

@@ -1434,7 +1434,8 @@ xcoff_add_shared_libs (struct backtrace_state *state,
    Returns 1 on success, 0 on failure.  */
 
 int
-backtrace_initialize (struct backtrace_state *state, int descriptor,
+backtrace_initialize (struct backtrace_state *state,
+		      const char *filename ATTRIBUTE_UNUSED, int descriptor,
 		      backtrace_error_callback error_callback,
 		      void *data, fileline *fileline_fn)
 {