Support for dedicated stub section with padding

	2016-03-29  Thomas Preud'homme  <thomas.preudhomme@arm.com>

	bfd/
	* elf32-arm.c (arm_dedicated_stub_section_padding): New function.
	(elf32_arm_size_stubs): Declare stub_type in a more outer scope and
	account for padding for stub section requiring one.
	(elf32_arm_build_stubs): Add comment to stress the importance of
	zeroing veneer section content.

diff --git a/bfd/ChangeLog.arm b/bfd/ChangeLog.arm
index 8d353e2bd9fddc2cef6e79d44feb1499214fcb90..fec9d2d2cd4af01bd5aa4f3bb1508dbbf00d590d 100644 (file)
--- a/bfd/ChangeLog.arm
+++ b/bfd/ChangeLog.arm
@@ -1,3 +1,11 @@
+2016-03-29  Thomas Preud'homme  <thomas.preudhomme@arm.com>
+
+       * elf32-arm.c (arm_dedicated_stub_section_padding): New function.
+       (elf32_arm_size_stubs): Declare stub_type in a more outer scope and
+       account for padding for stub section requiring one.
+       (elf32_arm_build_stubs): Add comment to stress the importance of
+       zeroing veneer section content.
+
 2016-03-29  Thomas Preud'homme  <thomas.preudhomme@arm.com>
 
        * bfd-in.h (bfd_elf32_arm_keep_private_stub_output_sections): Declare

diff --git a/bfd/elf32-arm.c b/bfd/elf32-arm.c
index a871dcd752e98cb65f9dbed6d9788e1237e32f7e..874ff6b73d1cbb2fe1958923ec83218a02f9b82a 100644 (file)
--- a/bfd/elf32-arm.c
+++ b/bfd/elf32-arm.c
@@ -4402,6 +4402,24 @@ arm_stub_sym_claimed (enum elf32_arm_stub_type stub_type)
   abort ();  /* Should be unreachable.  */
 }
 
+/* Returns the padding needed for the dedicated section used stubs of type
+   STUB_TYPE.  */
+
+static int
+arm_dedicated_stub_section_padding (enum elf32_arm_stub_type stub_type)
+{
+  if (stub_type >= max_stub_type)
+    abort ();  /* Should be unreachable.  */
+
+  switch (stub_type)
+    {
+    default:
+      return 0;
+    }
+
+  abort ();  /* Should be unreachable.  */
+}
+
 static bfd_boolean
 arm_build_one_stub (struct bfd_hash_entry *gen_entry,
                    void * in_arg)
@@ -5378,6 +5396,7 @@ elf32_arm_size_stubs (bfd *output_bfd,
       bfd *input_bfd;
       unsigned int bfd_indx;
       asection *stub_sec;
+      enum elf32_arm_stub_type stub_type;
       bfd_boolean stub_changed = FALSE;
       unsigned prev_num_a8_fixes = num_a8_fixes;
 
@@ -5433,7 +5452,6 @@ elf32_arm_size_stubs (bfd *output_bfd,
              for (; irela < irelaend; irela++)
                {
                  unsigned int r_type, r_indx;
-                 enum elf32_arm_stub_type stub_type;
                  asection *sym_sec;
                  bfd_vma sym_value;
                  bfd_vma destination;
@@ -5733,7 +5751,27 @@ elf32_arm_size_stubs (bfd *output_bfd,
          stub_sec->size = 0;
        }
 
+      /* Compute stub section size, considering padding.  */
       bfd_hash_traverse (&htab->stub_hash_table, arm_size_one_stub, htab);
+      for (stub_type = arm_stub_none + 1; stub_type < max_stub_type;
+          stub_type++)
+       {
+         int size, padding;
+         asection **stub_sec_p;
+
+         padding = arm_dedicated_stub_section_padding (stub_type);
+         stub_sec_p = arm_dedicated_stub_input_section_ptr (htab, stub_type);
+         /* Skip if no stub input section or no stub section padding
+            required.  */
+         if ((stub_sec_p != NULL && *stub_sec_p == NULL) || padding == 0)
+           continue;
+         /* Stub section padding required but no dedicated section.  */
+         BFD_ASSERT (stub_sec_p);
+
+         size = (*stub_sec_p)->size;
+         size = (size + padding - 1) & ~(padding - 1);
+         (*stub_sec_p)->size = size;
+       }
 
       /* Add Cortex-A8 erratum veneers to stub section sizes too.  */
       if (htab->fix_cortex_a8)
@@ -5841,7 +5879,8 @@ elf32_arm_build_stubs (struct bfd_link_info *info)
       if (!strstr (stub_sec->name, STUB_SUFFIX))
        continue;
 
-      /* Allocate memory to hold the linker stubs.  */
+      /* Allocate memory to hold the linker stubs.  Zeroing the stub sections
+        must at least be done for stub section requiring padding.  */
       size = stub_sec->size;
       stub_sec->contents = (unsigned char *) bfd_zalloc (htab->stub_bfd, size);
       if (stub_sec->contents == NULL && size != 0)