The __attribute__((__copy__)) functionality was crashing when copying
sanitizer-related attributes because these attributes violated the standard
GCC attribute infrastructure by storing INTEGER_CST values directly instead
of wrapping them in TREE_LIST like all other attributes.
Wrap sanitizer attributes INTEGER_CST values in TREE_LIST structures
to follow the same pattern as other attributes. This eliminates the
copy_list() crashes when copying sanitizer attributes:
test.c:4:1: internal compiler error: tree check: expected tree that contains
‘common’ structure, have ‘integer_cst’ in copy_list, at tree.cc:1427
4 | __attribute__((__copy__(__tanh)));
| ^~~~~~~~~~~~~
0x859d06 tree_contains_struct_check_failed(tree_node const*,
tree_node_structure_enum, char const*, int, char const*)
../../gcc/gcc/tree.cc:9126
0x860f78 contains_struct_check(tree_node*, tree_node_structure_enum, char
const*, int, char const*)
../../gcc/gcc/tree.h:3748
0x860f78 copy_list(tree_node*)
../../gcc/gcc/tree.cc:1427
0xa755a5 handle_copy_attribute
../../gcc/gcc/c-family/c-attribs.cc:3077
gcc/c-family/ChangeLog:
PR c/113264
* c-attribs.cc (add_no_sanitize_value): Store INTEGER_CST values
wrapped in TREE_LIST following standard attribute conventions.
(handle_no_sanitize_attribute): Handle both original string
arguments and copied INTEGER_CST values from TREE_LIST format.
gcc/ChangeLog:
PR c/113264
* asan.h (sanitize_flags_p): Extract sanitizer flags from
TREE_LIST wrapper instead of directly from INTEGER_CST.
gcc/d/ChangeLog:
PR c/113264
* d-attribs.cc (d_handle_no_sanitize_attribute): Store INTEGER_CST
values wrapped in TREE_LIST following standard conventions.
gcc/testsuite/ChangeLog:
PR c/113264
* gcc.dg/pr113264.c: New test.
* gcc.dg/pr113264-asan-no-instrumentation.c: New test validating
that copied sanitizer attributes prevent ASAN instrumentation.
Signed-off-by: Kees Cook <[email protected]>
---
v2: Rebased on to latest upstream, which has sanitize_code_type now.
Cc: Indu Bhagat <[email protected]>
Cc: Claudiu Zissulescu <[email protected]>
Cc: Andrew Pinski <[email protected]>
---
gcc/asan.h | 8 ++++++-
gcc/c-family/c-attribs.cc | 49 +++++++++++++++++++++++++++------------
gcc/d/d-attribs.cc | 17 ++++++++++----
3 files changed, 54 insertions(+), 20 deletions(-)
diff --git a/gcc/asan.h b/gcc/asan.h
index a24562f67a29..f5dc3d7ceb8d 100644
--- a/gcc/asan.h
+++ b/gcc/asan.h
@@ -253,7 +253,13 @@ sanitize_flags_p (sanitize_code_type flag,
{
tree value = lookup_attribute ("no_sanitize", DECL_ATTRIBUTES (fn));
if (value)
- result_flags &= ~tree_to_uhwi (TREE_VALUE (value));
+ {
+ /* Extract the INTEGER_CST from the TREE_LIST wrapper. */
+ tree attr_args = TREE_VALUE (value);
+ gcc_assert (attr_args && TREE_CODE (attr_args) == TREE_LIST);
+ sanitize_code_type no_sanitize_flags = tree_to_sanitize_code_type
(TREE_VALUE (attr_args));
+ result_flags &= ~no_sanitize_flags;
+ }
}
return result_flags;
diff --git a/gcc/c-family/c-attribs.cc b/gcc/c-family/c-attribs.cc
index 1e3a94ed9493..e629601579ef 100644
--- a/gcc/c-family/c-attribs.cc
+++ b/gcc/c-family/c-attribs.cc
@@ -1425,20 +1425,27 @@ add_no_sanitize_value (tree node, sanitize_code_type
flags)
tree attr = lookup_attribute ("no_sanitize", DECL_ATTRIBUTES (node));
if (attr)
{
- sanitize_code_type old_value =
- tree_to_sanitize_code_type (TREE_VALUE (attr));
+ /* Extract the INTEGER_CST from the TREE_LIST wrapper. */
+ tree attr_args = TREE_VALUE (attr);
+ gcc_assert (attr_args && TREE_CODE (attr_args) == TREE_LIST);
+ sanitize_code_type old_value = tree_to_sanitize_code_type (TREE_VALUE
(attr_args));
+
flags |= old_value;
if (flags == old_value)
return;
- TREE_VALUE (attr) = build_int_cst (uint64_type_node, flags);
+ tree new_value = build_tree_list (NULL_TREE,
+ build_int_cst (uint64_type_node,
flags));
+ TREE_VALUE (attr) = new_value;
}
else
- DECL_ATTRIBUTES (node)
- = tree_cons (get_identifier ("no_sanitize"),
- build_int_cst (uint64_type_node, flags),
- DECL_ATTRIBUTES (node));
+ {
+ tree attr_value = build_tree_list (NULL_TREE,
+ build_int_cst (uint64_type_node,
flags));
+ DECL_ATTRIBUTES (node) = tree_cons (get_identifier ("no_sanitize"),
attr_value,
+ DECL_ATTRIBUTES (node));
+ }
}
/* Handle a "no_sanitize" attribute; arguments as in
@@ -1456,17 +1463,29 @@ handle_no_sanitize_attribute (tree *node, tree name,
tree args, int,
return NULL_TREE;
}
- for (; args; args = TREE_CHAIN (args))
+ /* Handle both original string arguments and copied attributes that
+ have already been processed into INTEGER_CST wrapped in TREE_LIST. */
+ if (args && TREE_CODE (args) == TREE_LIST
+ && TREE_VALUE (args) && TREE_CODE (TREE_VALUE (args)) == INTEGER_CST)
{
- tree id = TREE_VALUE (args);
- if (TREE_CODE (id) != STRING_CST)
+ /* This is a copied attribute with the flags already processed. */
+ flags = tree_to_sanitize_code_type (TREE_VALUE (args));
+ }
+ else
+ {
+ /* Process original string arguments. */
+ for (; args; args = TREE_CHAIN (args))
{
- error ("%qE argument not a string", name);
- return NULL_TREE;
- }
+ tree id = TREE_VALUE (args);
+ if (TREE_CODE (id) != STRING_CST)
+ {
+ error ("%qE argument not a string", name);
+ return NULL_TREE;
+ }
- char *string = ASTRDUP (TREE_STRING_POINTER (id));
- flags |= parse_no_sanitize_attribute (string);
+ char *string = ASTRDUP (TREE_STRING_POINTER (id));
+ flags |= parse_no_sanitize_attribute (string);
+ }
}
add_no_sanitize_value (*node, flags);
diff --git a/gcc/d/d-attribs.cc b/gcc/d/d-attribs.cc
index 53aea5e2e904..342702b05acb 100644
--- a/gcc/d/d-attribs.cc
+++ b/gcc/d/d-attribs.cc
@@ -1424,17 +1424,26 @@ d_handle_no_sanitize_attribute (tree *node, tree name,
tree args, int,
merge existing flags if no_sanitize was previously handled. */
if (tree attr = lookup_attribute ("no_sanitize", DECL_ATTRIBUTES (*node)))
{
- sanitize_code_type old_value =
- tree_to_sanitize_code_type (TREE_VALUE (attr));
+ /* Extract the INTEGER_CST from the TREE_LIST wrapper. */
+ tree attr_args = TREE_VALUE (attr);
+ gcc_assert (attr_args && TREE_CODE (attr_args) == TREE_LIST);
+ sanitize_code_type old_value = tree_to_sanitize_code_type (TREE_VALUE
(attr_args));
+
flags |= old_value;
if (flags != old_value)
- TREE_VALUE (attr) = build_int_cst (d_ulong_type, flags);
+ {
+ tree new_value = build_tree_list (NULL_TREE,
+ build_int_cst (d_ulong_type,
flags));
+ TREE_VALUE (attr) = new_value;
+ }
}
else
{
+ tree attr_value = build_tree_list (NULL_TREE,
+ build_int_cst (d_ulong_type, flags));
DECL_ATTRIBUTES (*node) = tree_cons (get_identifier ("no_sanitize"),
- build_int_cst (d_ulong_type, flags),
+ attr_value,
DECL_ATTRIBUTES (*node));
}
--
2.34.1
