re PR middle-end/60281 (Address Sanitizer triggers alignment fault in ARM machines)

	PR middle-end/60281
	* asan.c (asan_emit_stack_protection): Force the base to align to
	appropriate bits if STRICT_ALIGNMENT.  Set shadow_mem align to
	appropriate bits if STRICT_ALIGNMENT.
	* cfgexpand.c (expand_stack_vars): Set base_align appropriately
	when asan is on.
	(expand_used_vars): Leave a space in the stack frame for alignment
	if STRICT_ALIGNMENT.

From-SVN: r209554

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index b40f008de8333b0a8d4d5ecb462f6155d6729212..577f4bdf9f8da3f69ef23d02e1d20742da1862d3 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,14 @@
+2014-04-22  Lin Zuojian  <manjian2006@gmail.com>
+
+       PR middle-end/60281
+       * asan.c (asan_emit_stack_protection): Force the base to align to
+       appropriate bits if STRICT_ALIGNMENT.  Set shadow_mem align to
+       appropriate bits if STRICT_ALIGNMENT.
+       * cfgexpand.c (expand_stack_vars): Set base_align appropriately
+       when asan is on.
+       (expand_used_vars): Leave a space in the stack frame for alignment
+       if STRICT_ALIGNMENT.
+
 2014-04-21  David Malcolm  <dmalcolm@redhat.com>
 
        * gimple.h (gimple_assign_single_p): Accept a const_gimple rather

diff --git a/gcc/asan.c b/gcc/asan.c
index 9f298079d6b89a8ba1cd797c1ae7ef5e197a1361..d7c282e312e4d79c922a3f527c84e20143d096f5 100644 (file)
--- a/gcc/asan.c
+++ b/gcc/asan.c
@@ -1017,8 +1017,17 @@ asan_emit_stack_protection (rtx base, rtx pbase, unsigned int alignb,
        base_align_bias = ((asan_frame_size + alignb - 1)
                           & ~(alignb - HOST_WIDE_INT_1)) - asan_frame_size;
     }
+  /* Align base if target is STRICT_ALIGNMENT.  */
+  if (STRICT_ALIGNMENT)
+    base = expand_binop (Pmode, and_optab, base,
+                        gen_int_mode (-((GET_MODE_ALIGNMENT (SImode)
+                                         << ASAN_SHADOW_SHIFT)
+                                        / BITS_PER_UNIT), Pmode), NULL_RTX,
+                        1, OPTAB_DIRECT);
+
   if (use_after_return_class == -1 && pbase)
     emit_move_insn (pbase, base);
+
   base = expand_binop (Pmode, add_optab, base,
                       gen_int_mode (base_offset - base_align_bias, Pmode),
                       NULL_RTX, 1, OPTAB_DIRECT);
@@ -1097,6 +1106,8 @@ asan_emit_stack_protection (rtx base, rtx pbase, unsigned int alignb,
              && (ASAN_RED_ZONE_SIZE >> ASAN_SHADOW_SHIFT) == 4);
   shadow_mem = gen_rtx_MEM (SImode, shadow_base);
   set_mem_alias_set (shadow_mem, asan_shadow_set);
+  if (STRICT_ALIGNMENT)
+    set_mem_align (shadow_mem, (GET_MODE_ALIGNMENT (SImode)));
   prev_offset = base_offset;
   for (l = length; l; l -= 2)
     {
@@ -1186,6 +1197,10 @@ asan_emit_stack_protection (rtx base, rtx pbase, unsigned int alignb,
 
   shadow_mem = gen_rtx_MEM (BLKmode, shadow_base);
   set_mem_alias_set (shadow_mem, asan_shadow_set);
+
+  if (STRICT_ALIGNMENT)
+    set_mem_align (shadow_mem, (GET_MODE_ALIGNMENT (SImode)));
+
   prev_offset = base_offset;
   last_offset = base_offset;
   last_size = 0;

diff --git a/gcc/cfgexpand.c b/gcc/cfgexpand.c
index f2fd5fc92a9bce4958192a40be79efeadce036fd..78eca25f493776f2a85248875188e734175323a1 100644 (file)
--- a/gcc/cfgexpand.c
+++ b/gcc/cfgexpand.c
@@ -1013,10 +1013,19 @@ expand_stack_vars (bool (*pred) (size_t), struct stack_vars_data *data)
              if (data->asan_base == NULL)
                data->asan_base = gen_reg_rtx (Pmode);
              base = data->asan_base;
+
+             if (!STRICT_ALIGNMENT)
+               base_align = crtl->max_used_stack_slot_alignment;
+             else
+               base_align = MAX (crtl->max_used_stack_slot_alignment,
+                                 GET_MODE_ALIGNMENT (SImode)
+                                 << ASAN_SHADOW_SHIFT);
            }
          else
-           offset = alloc_stack_frame_space (stack_vars[i].size, alignb);
-         base_align = crtl->max_used_stack_slot_alignment;
+           {
+             offset = alloc_stack_frame_space (stack_vars[i].size, alignb);
+             base_align = crtl->max_used_stack_slot_alignment;
+           }
        }
       else
        {
@@ -1845,6 +1854,11 @@ expand_used_vars (void)
            = alloc_stack_frame_space (redzonesz, ASAN_RED_ZONE_SIZE);
          data.asan_vec.safe_push (prev_offset);
          data.asan_vec.safe_push (offset);
+         /* Leave space for alignment if STRICT_ALIGNMENT.  */
+         if (STRICT_ALIGNMENT)
+           alloc_stack_frame_space ((GET_MODE_ALIGNMENT (SImode)
+                                     << ASAN_SHADOW_SHIFT)
+                                    / BITS_PER_UNIT, 1);
 
          var_end_seq
            = asan_emit_stack_protection (virtual_stack_vars_rtx,