btrace, vdso: add vdso target sections

When loading symbols for the vdso, also add its sections to target_sections.

This fixes an issue with record btrace where vdso instructions could not be
disassembled during replay.

	* symfile-mem.c (symbol_file_add_from_memory): Add BFD sections.

testsuite/
	* gdb.btrace/vdso.c: New.
	* gdb.btrace/vdso.exp: New.

1 files changed, 18 insertions, 0 deletions

diff --git a/gdb/symfile-mem.c b/gdb/symfile-mem.c
index 3f09c4d..b29421e 100644
--- a/gdb/symfile-mem.c
+++ b/gdb/symfile-mem.c
@@ -92,6 +92,7 @@ symbol_file_add_from_memory (struct bfd *templ, CORE_ADDR addr,
   struct section_addr_info *sai;
   unsigned int i;
   struct cleanup *cleanup;
+  struct target_section *sections, *sections_end, *tsec;
 
   if (bfd_get_flavour (templ) != bfd_target_elf_flavour)
     error (_("add-symbol-file-from-memory not supported for this target"));
@@ -131,6 +132,23 @@ symbol_file_add_from_memory (struct bfd *templ, CORE_ADDR addr,
 				   from_tty ? SYMFILE_VERBOSE : 0,
                                    sai, OBJF_SHARED, NULL);
 
+  sections = NULL;
+  sections_end = NULL;
+
+  if (build_section_table (nbfd, &sections, &sections_end) == 0)
+    {
+      make_cleanup (xfree, sections);
+
+      /* Adjust the target section addresses by the load address.  */
+      for (tsec = sections; tsec != sections_end; ++tsec)
+	{
+	  tsec->addr += loadbase;
+	  tsec->endaddr += loadbase;
+	}
+
+      add_target_sections (&nbfd, sections, sections_end);
+    }
+
   /* This might change our ideas about frames already looked at.  */
   reinit_frame_cache ();