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| author | Eric Botcazou <ebotcazou@adacore.com> | 2024-05-27 16:46:03 +0200 |
|---|---|---|
| committer | Marc Poulhiès <poulhies@adacore.com> | 2024-06-21 10:34:23 +0200 |
| commit | 2b510ac3aa521c6984495c63547914f271f1f51c (patch) | |
| tree | c0824a3b35c487868fde29f83987a16281395c4d /gcc/ada | |
| parent | d69c53f73dae181c79f6ec6c7276a172476a2728 (diff) | |
| download | gcc-2b510ac3aa521c6984495c63547914f271f1f51c.zip gcc-2b510ac3aa521c6984495c63547914f271f1f51c.tar.gz gcc-2b510ac3aa521c6984495c63547914f271f1f51c.tar.bz2 | |
ada: Fix bogus Address Sanitizer stack-buffer-overflow on packed array copy
The Address Sanitizer considers that the padding at the end of a justified
modular type may be accessed through the object, but it is never accessed
and therefore can always be reused.
gcc/ada/
* gcc-interface/decl.cc (gnat_to_gnu_entity) <discrete_type>: Set
the TYPE_JUSTIFIED_MODULAR_P flag earlier.
* gcc-interface/misc.cc (gnat_unit_size_without_reusable_padding):
New function.
(LANG_HOOKS_UNIT_SIZE_WITHOUT_REUSABLE_PADDING): Redefine to above
function.
Diffstat (limited to 'gcc/ada')
| -rw-r--r-- | gcc/ada/gcc-interface/decl.cc | 2 | ||||
| -rw-r--r-- | gcc/ada/gcc-interface/misc.cc | 17 |
2 files changed, 17 insertions, 2 deletions
diff --git a/gcc/ada/gcc-interface/decl.cc b/gcc/ada/gcc-interface/decl.cc index aa31a88..5b3a3b4 100644 --- a/gcc/ada/gcc-interface/decl.cc +++ b/gcc/ada/gcc-interface/decl.cc @@ -1976,6 +1976,7 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, bool definition) gnu_type = make_node (RECORD_TYPE); TYPE_NAME (gnu_type) = create_concat_name (gnat_entity, "JM"); + TYPE_JUSTIFIED_MODULAR_P (gnu_type) = 1; TYPE_PACKED (gnu_type) = 1; TYPE_SIZE (gnu_type) = TYPE_SIZE (gnu_field_type); TYPE_SIZE_UNIT (gnu_type) = TYPE_SIZE_UNIT (gnu_field_type); @@ -2006,7 +2007,6 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, bool definition) /* We will output additional debug info manually below. */ finish_record_type (gnu_type, gnu_field, 2, false); - TYPE_JUSTIFIED_MODULAR_P (gnu_type) = 1; /* Make the original array type a parallel/debug type. Note that gnat_get_array_descr_info needs a TYPE_IMPL_PACKED_ARRAY_P type diff --git a/gcc/ada/gcc-interface/misc.cc b/gcc/ada/gcc-interface/misc.cc index b703f00..4f6f677 100644 --- a/gcc/ada/gcc-interface/misc.cc +++ b/gcc/ada/gcc-interface/misc.cc @@ -760,6 +760,19 @@ gnat_type_max_size (const_tree gnu_type) return max_size_unit; } +/* Return the unit size of TYPE without reusable tail padding. */ + +static tree +gnat_unit_size_without_reusable_padding (tree type) +{ + /* The padding of justified modular types can always be reused. */ + if (TYPE_JUSTIFIED_MODULAR_P (type)) + return fold_convert (sizetype, + size_binop (CEIL_DIV_EXPR, + TYPE_ADA_SIZE (type), bitsize_unit_node)); + return TYPE_SIZE_UNIT (type); +} + static tree get_array_bit_stride (tree); /* Provide information in INFO for debug output about the TYPE array type. @@ -1407,6 +1420,8 @@ const struct scoped_attribute_specs *const gnat_attribute_table[] = #define LANG_HOOKS_TYPE_FOR_SIZE gnat_type_for_size #undef LANG_HOOKS_TYPES_COMPATIBLE_P #define LANG_HOOKS_TYPES_COMPATIBLE_P gnat_types_compatible_p +#undef LANG_HOOKS_UNIT_SIZE_WITHOUT_REUSABLE_PADDING +#define LANG_HOOKS_UNIT_SIZE_WITHOUT_REUSABLE_PADDING gnat_unit_size_without_reusable_padding #undef LANG_HOOKS_GET_ARRAY_DESCR_INFO #define LANG_HOOKS_GET_ARRAY_DESCR_INFO gnat_get_array_descr_info #undef LANG_HOOKS_GET_SUBRANGE_BOUNDS @@ -1433,7 +1448,7 @@ const struct scoped_attribute_specs *const gnat_attribute_table[] = #define LANG_HOOKS_DEEP_UNSHARING true #undef LANG_HOOKS_CUSTOM_FUNCTION_DESCRIPTORS #define LANG_HOOKS_CUSTOM_FUNCTION_DESCRIPTORS true -#undef LANG_HOOKS_GET_SARIF_SOURCE_LANGUAGE +#undef LANG_HOOKS_GET_SARIF_SOURCE_LANGUAGE #define LANG_HOOKS_GET_SARIF_SOURCE_LANGUAGE gnat_get_sarif_source_language struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER; |