--- UTC
--- gcc/cfgexpand.c.orig
+++ gcc/cfgexpand.c
@@ -1291,6 +1291,12 @@
clear_tree_used (t);
}
+ enum {
+ SPCT_FLAG_DEFAULT = 1,
+ SPCT_FLAG_ALL = 2,
+ SPCT_FLAG_STRONG = 3
+ };
+
/* Examine TYPE and determine a bit mask of the following features. */
#define SPCT_HAS_LARGE_CHAR_ARRAY 1
@@ -1360,7 +1366,8 @@
if (bits & SPCT_HAS_SMALL_CHAR_ARRAY)
has_short_buffer = true;
- if (flag_stack_protect == 2)
+ if (flag_stack_protect == SPCT_FLAG_ALL
+ || flag_stack_protect == SPCT_FLAG_STRONG)
{
if ((bits & (SPCT_HAS_SMALL_CHAR_ARRAY | SPCT_HAS_LARGE_CHAR_ARRAY))
&& !(bits & SPCT_HAS_AGGREGATE))
@@ -1514,6 +1521,27 @@
return size;
}
+/* Helper routine to check if a record or union contains an array field. */
+
+static int
+record_or_union_type_has_array_p (const_tree tree_type)
+{
+ tree fields = TYPE_FIELDS (tree_type);
+ tree f;
+
+ for (f = fields; f; f = DECL_CHAIN (f))
+ if (TREE_CODE (f) == FIELD_DECL)
+ {
+ tree field_type = TREE_TYPE (f);
+ if (RECORD_OR_UNION_TYPE_P (field_type)
+ && record_or_union_type_has_array_p (field_type))
+ return 1;
+ if (TREE_CODE (field_type) == ARRAY_TYPE)
+ return 1;
+ }
+ return 0;
+}
+
/* Expand all variables used in the function. */
static rtx
@@ -1525,6 +1553,7 @@
struct pointer_map_t *ssa_name_decls;
unsigned i;
unsigned len;
+ bool gen_stack_protect_signal = false;
/* Compute the phase of the stack frame for this function. */
{
@@ -1575,6 +1604,24 @@
}
}
pointer_map_destroy (ssa_name_decls);
+
+ if (flag_stack_protect == SPCT_FLAG_STRONG)
+ FOR_EACH_LOCAL_DECL (cfun, i, var)
+ if (!is_global_var (var))
+ {
+ tree var_type = TREE_TYPE (var);
+ /* Examine local referenced variables that have their addresses taken,
+ contain an array, or are arrays. */
+ if (TREE_CODE (var) == VAR_DECL
+ && (TREE_CODE (var_type) == ARRAY_TYPE
+ || TREE_ADDRESSABLE (var)
+ || (RECORD_OR_UNION_TYPE_P (var_type)
+ && record_or_union_type_has_array_p (var_type))))
+ {
+ gen_stack_protect_signal = true;
+ break;
+ }
+ }
/* At this point all variables on the local_decls with TREE_USED
set are not associated with any block scope. Lay them out. */
@@ -1662,12 +1709,32 @@
dump_stack_var_partition ();
}
- /* There are several conditions under which we should create a
- stack guard: protect-all, alloca used, protected decls present. */
- if (flag_stack_protect == 2
- || (flag_stack_protect
- && (cfun->calls_alloca || has_protected_decls)))
- create_stack_guard ();
+ /* Create stack guard, if
+ a) "-fstack-protector-all" - always;
+ b) "-fstack-protector-strong" - if there are arrays, memory
+ references to local variables, alloca used, or protected decls present;
+ c) "-fstack-protector" - if alloca used, or protected decls present */
+
+ switch (flag_stack_protect)
+ {
+ case SPCT_FLAG_ALL:
+ create_stack_guard ();
+ break;
+
+ case SPCT_FLAG_STRONG:
+ if (gen_stack_protect_signal
+ || cfun->calls_alloca || has_protected_decls)
+ create_stack_guard ();
+ break;
+
+ case SPCT_FLAG_DEFAULT:
+ if (cfun->calls_alloca || has_protected_decls)
+ create_stack_guard ();
+ break;
+
+ default:
+ ;
+ }
/* Assign rtl to each variable based on these partitions. */
if (stack_vars_num > 0)
@@ -1688,7 +1755,7 @@
expand_stack_vars (stack_protect_decl_phase_1, &data);
/* Phase 2 contains other kinds of arrays. */
- if (flag_stack_protect == 2)
+ if (flag_stack_protect == SPCT_FLAG_ALL)
expand_stack_vars (stack_protect_decl_phase_2, &data);
}
--- gcc/common.opt.orig
+++ gcc/common.opt
@@ -1942,6 +1942,10 @@ fstack-protector-all
Common Report RejectNegative Var(flag_stack_protect, 2)
Use a stack protection method for every function
+fstack-protector-strong
+Common Report RejectNegative Var(flag_stack_protect, 3)
+Use a smart stack protection method for certain functions
+
fstack-usage
Common RejectNegative Var(flag_stack_usage)
Output stack usage information on a per-function basis
--- gcc/gcc.c.orig
+++ gcc/gcc.c
@@ -655,7 +655,7 @@ proper position among the other output files. */
#ifdef TARGET_LIBC_PROVIDES_SSP
#define LINK_SSP_SPEC "%{fstack-protector:}"
#else
-#define LINK_SSP_SPEC "%{fstack-protector|fstack-protector-all:-lssp_nonshared -lssp}"
+#define LINK_SSP_SPEC "%{fstack-protector|fstack-protector-strong|fstack-protector-all:-lssp_nonshared -lssp}"
#endif
#endif
