arc: Fix potential invalid pointer access when fixing got symbols.

When statically linking, it can arrive to an undefined weak symbol of
which its value cannot be determined. However, we are having pieces of
code which doesn't take this situation into account, leading to access
a structure which may not be initialized. Fix this situation and add a
test.

bfd/
xxxx-xx-xx  Cupertino Miranda  <cmiranda@synopsys.com>
            Claudiu Zissulescu  <claziss@synopsys.com>

	* arc-got.h (arc_static_sym_data): New structure.
	(get_static_sym_data): New function.
	(relocate_fix_got_relocs_for_got_info): Move the computation fo
	symbol value and section to above introduced function, and use
	this new function.

ld/testsuite/
xxxx-xx-xx  Claudiu Zissulescu  <claziss@synopsys.com>

	* ld-arc/got-weak.d: New file.
	* ld-arc/got-weak.s: Likewise.

Signed-off-by: Claudiu Zissulescu <claziss@synopsys.com>
fix

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index d878d0512173328a603c910eecf65a508898c01a..a69b50c6199217146075e46de2d35c75ee86b042 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,12 @@
+2021-09-014  Cupertino Miranda  <cmiranda@synopsys.com>
+           Claudiu Zissulescu  <claziss@synopsys.com>
+
+       * arc-got.h (arc_static_sym_data): New structure.
+       (get_static_sym_data): New function.
+       (relocate_fix_got_relocs_for_got_info): Move the computation fo
+       symbol value and section to above introduced function, and use
+       this new function.
+
 2021-09-07  Luis Machado  <luis.machado@linaro.org>
 
        Revert: [AArch64] MTE corefile support

diff --git a/bfd/arc-got.h b/bfd/arc-got.h
index 76fc761a8cf20c56226ff554a03860793575d616..c45d981b50474060d20f872aa29fb67bb49faed4 100644 (file)
--- a/bfd/arc-got.h
+++ b/bfd/arc-got.h
@@ -262,6 +262,48 @@ arc_fill_got_info_for_reloc (enum tls_type_e type,
   return true;
 }
 
+struct arc_static_sym_data {
+  bfd_vma sym_value;
+  const char *symbol_name;
+};
+
+static struct arc_static_sym_data
+get_static_sym_data (unsigned long  r_symndx,
+                    Elf_Internal_Sym  *local_syms,
+                    asection **local_sections,
+                    struct elf_link_hash_entry *h,
+                    struct arc_relocation_data *reloc_data)
+{
+  static const char local_name[] = "(local)";
+  struct arc_static_sym_data ret = { 0, NULL };
+
+  if (h != NULL)
+    {
+      BFD_ASSERT (h->root.type != bfd_link_hash_undefweak
+                 && h->root.type != bfd_link_hash_undefined);
+      /* TODO: This should not be here.  */
+      reloc_data->sym_value = h->root.u.def.value;
+      reloc_data->sym_section = h->root.u.def.section;
+
+      ret.sym_value = h->root.u.def.value
+       + h->root.u.def.section->output_section->vma
+       + h->root.u.def.section->output_offset;
+
+      ret.symbol_name = h->root.root.string;
+    }
+  else
+  {
+    Elf_Internal_Sym *sym = local_syms + r_symndx;
+    asection *sec = local_sections[r_symndx];
+
+    ret.sym_value = sym->st_value
+      + sec->output_section->vma
+      + sec->output_offset;
+
+    ret.symbol_name = local_name;
+  }
+  return ret;
+}
 
 static bfd_vma
 relocate_fix_got_relocs_for_got_info (struct got_entry **         list_p,
@@ -290,38 +332,7 @@ relocate_fix_got_relocs_for_got_info (struct got_entry **     list_p,
              && SYMBOL_REFERENCES_LOCAL (info, h))))
     {
       const char ATTRIBUTE_UNUSED *symbol_name;
-      static const char local_name[] = "(local)";
-      asection *tls_sec = NULL;
-      bfd_vma sym_value = 0;
-
-      if (h != NULL)
-       {
-         /* TODO: This should not be here.  */
-         reloc_data->sym_value = h->root.u.def.value;
-         reloc_data->sym_section = h->root.u.def.section;
-
-         sym_value = h->root.u.def.value
-           + h->root.u.def.section->output_section->vma
-           + h->root.u.def.section->output_offset;
-
-         tls_sec = elf_hash_table (info)->tls_sec;
-
-         symbol_name = h->root.root.string;
-       }
-      else
-       {
-         Elf_Internal_Sym *sym = local_syms + r_symndx;
-         asection *sec = local_sections[r_symndx];
-
-         sym_value = sym->st_value
-           + sec->output_section->vma
-           + sec->output_offset;
-
-         tls_sec = elf_hash_table (info)->tls_sec;
-
-         symbol_name = local_name;
-       }
-
+      asection *tls_sec = elf_hash_table (info)->tls_sec;
 
       if (entry && !entry->processed)
        {
@@ -335,8 +346,12 @@ relocate_fix_got_relocs_for_got_info (struct got_entry **     list_p,
                if (h == NULL || h->forced_local
                   || !elf_hash_table (info)->dynamic_sections_created)
                  {
+                   struct arc_static_sym_data tmp =
+                     get_static_sym_data (r_symndx, local_syms, local_sections,
+                                          h, reloc_data);
+
                    bfd_put_32 (output_bfd,
-                           sym_value - sec_vma
+                           tmp.sym_value - sec_vma
                            + (elf_hash_table (info)->dynamic_sections_created
                               ? 0
                               : (align_power (0,
@@ -355,7 +370,7 @@ relocate_fix_got_relocs_for_got_info (struct got_entry **      list_p,
                             + entry->offset
                             + (entry->existing_entries == TLS_GOT_MOD_AND_OFF
                                ? 4 : 0)),
-                         symbol_name);
+                         tmp.symbol_name);
                  }
              }
              break;
@@ -366,8 +381,12 @@ relocate_fix_got_relocs_for_got_info (struct got_entry **     list_p,
                bfd_vma ATTRIBUTE_UNUSED sec_vma
                  = tls_sec->output_section->vma;
 
+               struct arc_static_sym_data tmp =
+                 get_static_sym_data (r_symndx, local_syms, local_sections,
+                                      h, reloc_data);
+
                bfd_put_32 (output_bfd,
-                           sym_value - sec_vma
+                           tmp.sym_value - sec_vma
                            + (elf_hash_table (info)->dynamic_sections_created
                               ? 0
                               : (align_power (TCB_SIZE,
@@ -386,7 +405,7 @@ relocate_fix_got_relocs_for_got_info (struct got_entry **      list_p,
                              + entry->offset
                              + (entry->existing_entries == TLS_GOT_MOD_AND_OFF
                                 ? 4 : 0)),
-                          symbol_name);
+                          tmp.symbol_name);
              }
              break;
 
@@ -415,7 +434,8 @@ relocate_fix_got_relocs_for_got_info (struct got_entry **      list_p,
                               "@ %#08lx for sym %s in got offset %#lx\n",
                               (long) (reloc_data->sym_value + sec_vma),
                               (long) (htab->sgot->output_section->vma
-                                      + htab->sgot->output_offset + entry->offset),
+                                      + htab->sgot->output_offset
+                                      + entry->offset),
                               symbol_name,
                               (long) entry->offset);
                  }

diff --git a/ld/ChangeLog b/ld/ChangeLog
index 28deefc93fb56d36d2a250ec30d87ef572cac065..ebcd4cd9e932d35b7fe1f3f0a499ad08aef8da29 100644 (file)
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,8 @@
+2021-09-14  Claudiu Zissulescu  <claziss@synopsys.com>
+
+       * ld-arc/got-weak.d: New file.
+       * ld-arc/got-weak.s: Likewise.
+
 2021-07-26  Roland McGrath  <mcgrathr@google.com>
 
        * testsuite/ld-x86-64/x86-64.exp (Build textrel-1): Use --warn-textrel.

diff --git a/ld/testsuite/ld-arc/got-weak.d b/ld/testsuite/ld-arc/got-weak.d
new file mode 100644 (file)
index 0000000..cf15069
--- /dev/null
+++ b/ld/testsuite/ld-arc/got-weak.d
@@ -0,0 +1,12 @@
+#source: got-weak.s
+#as:
+#ld: -Bstatic
+#objdump: -d
+
+[^:]*:     file format elf32-.*arc
+
+
+Disassembly of section \.text:
+
+00000100 <.*>:
+ 100:  2730 7f80 0000 2014     ld      r0,\[pcl,0x2014\].*

diff --git a/ld/testsuite/ld-arc/got-weak.s b/ld/testsuite/ld-arc/got-weak.s
new file mode 100644 (file)
index 0000000..8ea18be
--- /dev/null
+++ b/ld/testsuite/ld-arc/got-weak.s
@@ -0,0 +1,7 @@
+       .cpu archs
+
+       .weak symb
+       .global __start
+       .text
+__start:
+       ld      r0,[pcl,@symb@gotpc]