1 files changed, 13 insertions, 5 deletions

diff --git a/src/coredump/_UCD_find_proc_info.c b/src/coredump/_UCD_find_proc_info.c
index 35e1624c..fae61d9f 100644
--- a/src/coredump/_UCD_find_proc_info.c
+++ b/src/coredump/_UCD_find_proc_info.c
@@ -53,6 +53,9 @@ get_unwind_info(struct UCD_info *ui, unw_addr_space_t as, unw_word_t ip)
        && ip >= ui->edi.di_debug.start_ip && ip < ui->edi.di_debug.end_ip))
     return 0;
 
+  /* The invalidate_edi call unmaps memory it doesn't own, so just null it out
+     instead. */
+  ui->edi.ei.image = NULL;
   invalidate_edi (&ui->edi);
 
   /* Used to be tdep_get_elf_image() in ptrace unwinding code */
@@ -62,17 +65,22 @@ get_unwind_info(struct UCD_info *ui, unw_addr_space_t as, unw_word_t ip)
       Debug(1, "returns error: _UCD_get_elf_image failed\n");
       return -UNW_ENOINFO;
     }
+
+  ucd_file_t *ucd_file = ucd_file_table_at(&ui->ucd_file_table, phdr->p_backing_file_index);
+  if (ucd_file == NULL)
+    {
+      Debug(0, "no backing file for index %d\n", phdr->p_backing_file_index);
+      return -UNW_ENOINFO;
+    }
+
   /* segbase: where it is mapped in virtual memory */
-  /* mapoff: offset in the file */
   segbase = phdr->p_vaddr;
-  /*mapoff  = phdr->p_offset; WRONG! phdr->p_offset is the offset in COREDUMP file */
+  /* mapoff doesn't matter since the entire file is loaded */
   mapoff  = 0;
-///FIXME. text segment is USUALLY, not always, at offset 0 in the binary/.so file.
-// ensure that at initialization.
 
   /* Here, SEGBASE is the starting-address of the (mmap'ped) segment
      which covers the IP we're looking for.  */
-  if (tdep_find_unwind_table(&ui->edi, as, phdr->backing_filename, segbase, mapoff, ip) < 0)
+  if (tdep_find_unwind_table(&ui->edi, as, ucd_file->filename, segbase, mapoff, ip) < 0)
     {
       Debug(1, "returns error: tdep_find_unwind_table failed\n");
       return -UNW_ENOINFO;