On Sat, 21 Aug 2021, Qing Zhao wrote:
> Hi,
>
> This is the 8th version of the patch for the new security feature for GCC.
> I have tested it with bootstrap on both x86 and aarch64, regression testing
> on both x86 and aarch64.
> Also tested it with the kernel testing case provided by Kees.
> Also compile CPU2017 (running is ongoing), without any issue.
>
> Please take a look at this patch and let me know any issues.
+ /* If this DECL is a VLA, a temporary address variable for it has been
+ created, the replacement for DECL is recorded in DECL_VALUE_EXPR
(decl),
+ we should use it as the LHS of the call. */
+
+ tree lhs_call
+ = is_vla ? DECL_VALUE_EXPR (decl) : decl;
+ gimplify_assign (lhs_call, call, seq_p);
you shouldn't need to replace the lhs with DECL_VALUE_EXPR of it
here, gimplify_assign should take care of that.
+/* Return true if the DECL need to be automaticly initialized by the
+ compiler. */
+static bool
+is_var_need_auto_init (tree decl)
+{
+ if (auto_var_p (decl)
+ && (opt_for_fn (current_function_decl, flag_auto_var_init)
maybe I said otherwise at some point but you can test 'flag_auto_var_init'
directly when not in an IPA pass, no need to use 'opt_for_fn'
+ > AUTO_INIT_UNINITIALIZED)
+ && (!lookup_attribute ("uninitialized", DECL_ATTRIBUTES (decl))))
+ return true;
+ return false;
diff --git a/gcc/tree.c b/gcc/tree.c
index e923e67b6942..23d7b17774ce 100644
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -9508,6 +9508,22 @@ build_common_builtin_nodes (void)
tree tmp, ftype;
int ecf_flags;
+ /* If user requests automatic variables initialization, the builtin
+ BUILT_IN_CLEAR_PADDING is needed. */
+ if (flag_auto_var_init > AUTO_INIT_UNINITIALIZED
+ && !builtin_decl_explicit_p (BUILT_IN_CLEAR_PADDING))
I think this is prone to fail with LTO and auto-var-init setting
different in different TUs. Just build the builtin unconditionally
when it's not available.
+ {
+ ftype = build_function_type_list (void_type_node,
+ ptr_type_node,
+ ptr_type_node,
+ integer_type_node,
+ NULL_TREE);
+ local_define_builtin ("__builtin_clear_padding", ftype,
+ BUILT_IN_CLEAR_PADDING,
+ "__builtin_clear_padding",
+ ECF_LEAF | ECF_NOTHROW);
+ }
With these changes the patch looks OK to me, so please go ahead
after fixing the above.
Thanks,
Ricahrd.
> thanks.
>
> Qing
>
> In this version:
>
> *****Fix all issues raised by Richard B on 8/9: (compared with version 7)
>
> 1. in "handle_uninitialized_attribute", exclude globals with additional
> checking and warning message. Update corresponding testing cases for this
> change c-c++-common/auto-init-9/10.c
> 2. add more clarification on the new argument "for_auto_init" for
> "BUILT_IN_CLEAR_PADDING" in the comments part.
> 3. use auto_var_p to replace "VAR_P && !DECL_EXTERNAL && !TREE_STATIC";
> add a new helper routine "is_var_need_auto_init" to check whether a
> variable need to be initialized.
> 4. move the "gimple_add_padding_init_for_auto_var" inside the routine
> "gimplify_init_constructor";
> 5. restrict gimple_add_padding_init_for_auto_var only for INIT_EXPR;
> 6. in "gimplify.c" phase, generate a GENERIC call to DEFERRED_INIT +
> gimplfiy_assign instead of a gimple call to fully gimplify the call to the
> .DEFERRED_INIT to avoid some potential issues.
> 7. in "internal-fn.c" phase, use helper routines "lang_hooks.types,
> type_for_mode", "can_native_interpret_type_p", "native_interpret_expr" to
> simplify the implementation for pattern generation.
> 8. move "generating tree node for __BUILTIN_CLEAR_PADDING" in tree.c;
> 9. cleanup tree-cfg.c.
> 10. testing cases updates.
> for address taken variable -Wuninitialized warnings, add "xfail" for C
> testing cases; deleting C++ testing cases since "xfail" does not work.
> (FIXME, add them back if something like "xfail" works for C++.)
>
> ******Known issue:
>
> 1. -Wuninitialized warnings migh not be issued for address taken auto
> variables.
> please see https://gcc.gnu.org/pipermail/gcc-patches/2021-August/577431.html
> for details.
>
> Plan: add a separate patch to improve -Wuninitialized on address taken
> auto variables.
>
> ******NOTE:
>
> 1. Changes in tree-sra.c have been reviewed and approved by Martin Jambor.
> 2. the code changes should be very clean now;
> 3. The testing cases might need more review, I need comments and
> suggestions on testing cases part. (Not feel very comfortable especially on
> the testing cases for checking pattern initializations).
>
> ******Please see version 7 at:
> https://gcc.gnu.org/pipermail/gcc-patches/2021-July/576341.html
>
> ******ChangeLog is:
> gcc/ChangeLog:
>
> 2021-08-21 qing zhao <qing.z...@oracle.com>
>
> * builtins.c (expand_builtin_memset): Make external visible.
> * builtins.h (expand_builtin_memset): Declare extern.
> * common.opt (ftrivial-auto-var-init=): New option.
> * doc/extend.texi: Document the uninitialized attribute.
> * doc/invoke.texi: Document -ftrivial-auto-var-init.
> * flag-types.h (enum auto_init_type): New enumerated type
> auto_init_type.
> * gimple-fold.c (clear_padding_type): Add one new parameter.
> (clear_padding_union): Likewise.
> (clear_padding_emit_loop): Likewise.
> (clear_type_padding_in_mask): Likewise.
> (gimple_fold_builtin_clear_padding): Handle this new parameter.
> * gimplify.c (gimple_add_init_for_auto_var): New function.
> (gimple_add_padding_init_for_auto_var): New function.
> (is_var_need_auto_init): New function.
> (gimplify_decl_expr): Add initialization to automatic variables per
> users' requests.
> (gimplify_call_expr): Add one new parameter for call to
> __builtin_clear_padding.
> (gimplify_init_constructor): Add padding initialization in the end.
> * internal-fn.c (INIT_PATTERN_VALUE): New macro.
> (expand_DEFERRED_INIT): New function.
> * internal-fn.def (DEFERRED_INIT): New internal function.
> * tree-cfg.c (verify_gimple_call): Verify calls to .DEFERRED_INIT.
> * tree-sra.c (generate_subtree_deferred_init): New function.
> (scan_function): Avoid setting cannot_scalarize_away_bitmap for
> calls to .DEFERRED_INIT.
> (sra_modify_deferred_init): New function.
> (sra_modify_function_body): Handle calls to DEFERRED_INIT specially.
> * tree-ssa-structalias.c (find_func_aliases_for_call): Likewise.
> * tree-ssa-uninit.c (warn_uninit): Handle calls to DEFERRED_INIT
> specially.
> (check_defs): Likewise.
> (warn_uninitialized_vars): Likewise.
> * tree-ssa.c (ssa_undefined_value_p): Likewise.
> * tree.c (build_common_builtin_nodes): Build tree node for
> BUILT_IN_CLEAR_PADDING when needed.
>
> gcc/c-family/ChangeLog:
>
> 2021-08-21 qing zhao <qing.z...@oracle.com>
>
> * c-attribs.c (handle_uninitialized_attribute): New function.
> (c_common_attribute_table): Add "uninitialized" attribute.
>
> gcc/testsuite/ChangeLog:
>
>
> 2021-08-20 qing zhao <qing.z...@oracle.com>
>
> * c-c++-common/auto-init-1.c: New test.
> * c-c++-common/auto-init-10.c: New test.
> * c-c++-common/auto-init-11.c: New test.
> * c-c++-common/auto-init-12.c: New test.
> * c-c++-common/auto-init-13.c: New test.
> * c-c++-common/auto-init-14.c: New test.
> * c-c++-common/auto-init-15.c: New test.
> * c-c++-common/auto-init-16.c: New test.
> * c-c++-common/auto-init-2.c: New test.
> * c-c++-common/auto-init-3.c: New test.
> * c-c++-common/auto-init-4.c: New test.
> * c-c++-common/auto-init-5.c: New test.
> * c-c++-common/auto-init-6.c: New test.
> * c-c++-common/auto-init-7.c: New test.
> * c-c++-common/auto-init-8.c: New test.
> * c-c++-common/auto-init-9.c: New test.
> * c-c++-common/auto-init-esra.c: New test.
> * c-c++-common/auto-init-padding-1.c: New test.
> * c-c++-common/auto-init-padding-2.c: New test.
> * c-c++-common/auto-init-padding-3.c: New test.
> * g++.dg/auto-init-uninit-pred-1_a.C: New test.
> * g++.dg/auto-init-uninit-pred-2_a.C: New test.
> * g++.dg/auto-init-uninit-pred-3_a.C: New test.
> * g++.dg/auto-init-uninit-pred-4.C: New test.
> * gcc.dg/auto-init-sra-1.c: New test.
> * gcc.dg/auto-init-sra-2.c: New test.
> * gcc.dg/auto-init-uninit-1.c: New test.
> * gcc.dg/auto-init-uninit-12.c: New test.
> * gcc.dg/auto-init-uninit-13.c: New test.
> * gcc.dg/auto-init-uninit-14.c: New test.
> * gcc.dg/auto-init-uninit-15.c: New test.
> * gcc.dg/auto-init-uninit-16.c: New test.
> * gcc.dg/auto-init-uninit-17.c: New test.
> * gcc.dg/auto-init-uninit-18.c: New test.
> * gcc.dg/auto-init-uninit-19.c: New test.
> * gcc.dg/auto-init-uninit-2.c: New test.
> * gcc.dg/auto-init-uninit-20.c: New test.
> * gcc.dg/auto-init-uninit-21.c: New test.
> * gcc.dg/auto-init-uninit-22.c: New test.
> * gcc.dg/auto-init-uninit-23.c: New test.
> * gcc.dg/auto-init-uninit-24.c: New test.
> * gcc.dg/auto-init-uninit-25.c: New test.
> * gcc.dg/auto-init-uninit-26.c: New test.
> * gcc.dg/auto-init-uninit-3.c: New test.
> * gcc.dg/auto-init-uninit-34.c: New test.
> * gcc.dg/auto-init-uninit-36.c: New test.
> * gcc.dg/auto-init-uninit-37.c: New test.
> * gcc.dg/auto-init-uninit-4.c: New test.
> * gcc.dg/auto-init-uninit-5.c: New test.
> * gcc.dg/auto-init-uninit-6.c: New test.
> * gcc.dg/auto-init-uninit-8.c: New test.
> * gcc.dg/auto-init-uninit-9.c: New test.
> * gcc.dg/auto-init-uninit-A.c: New test.
> * gcc.dg/auto-init-uninit-B.c: New test.
> * gcc.dg/auto-init-uninit-C.c: New test.
> * gcc.dg/auto-init-uninit-H.c: New test.
> * gcc.dg/auto-init-uninit-I.c: New test.
> * gcc.target/aarch64/auto-init-1.c: New test.
> * gcc.target/aarch64/auto-init-2.c: New test.
> * gcc.target/aarch64/auto-init-3.c: New test.
> * gcc.target/aarch64/auto-init-4.c: New test.
> * gcc.target/aarch64/auto-init-5.c: New test.
> * gcc.target/aarch64/auto-init-6.c: New test.
> * gcc.target/aarch64/auto-init-7.c: New test.
> * gcc.target/aarch64/auto-init-8.c: New test.
> * gcc.target/aarch64/auto-init-padding-1.c: New test.
> * gcc.target/aarch64/auto-init-padding-10.c: New test.
> * gcc.target/aarch64/auto-init-padding-11.c: New test.
> * gcc.target/aarch64/auto-init-padding-12.c: New test.
> * gcc.target/aarch64/auto-init-padding-2.c: New test.
> * gcc.target/aarch64/auto-init-padding-3.c: New test.
> * gcc.target/aarch64/auto-init-padding-4.c: New test.
> * gcc.target/aarch64/auto-init-padding-5.c: New test.
> * gcc.target/aarch64/auto-init-padding-6.c: New test.
> * gcc.target/aarch64/auto-init-padding-7.c: New test.
> * gcc.target/aarch64/auto-init-padding-8.c: New test.
> * gcc.target/aarch64/auto-init-padding-9.c: New test.
> * gcc.target/i386/auto-init-1.c: New test.
> * gcc.target/i386/auto-init-2.c: New test.
> * gcc.target/i386/auto-init-21.c: New test.
> * gcc.target/i386/auto-init-22.c: New test.
> * gcc.target/i386/auto-init-23.c: New test.
> * gcc.target/i386/auto-init-24.c: New test.
> * gcc.target/i386/auto-init-3.c: New test.
> * gcc.target/i386/auto-init-4.c: New test.
> * gcc.target/i386/auto-init-5.c: New test.
> * gcc.target/i386/auto-init-6.c: New test.
> * gcc.target/i386/auto-init-7.c: New test.
> * gcc.target/i386/auto-init-8.c: New test.
> * gcc.target/i386/auto-init-padding-1.c: New test.
> * gcc.target/i386/auto-init-padding-10.c: New test.
> * gcc.target/i386/auto-init-padding-11.c: New test.
> * gcc.target/i386/auto-init-padding-12.c: New test.
> * gcc.target/i386/auto-init-padding-2.c: New test.
> * gcc.target/i386/auto-init-padding-3.c: New test.
> * gcc.target/i386/auto-init-padding-4.c: New test.
> * gcc.target/i386/auto-init-padding-5.c: New test.
> * gcc.target/i386/auto-init-padding-6.c: New test.
> * gcc.target/i386/auto-init-padding-7.c: New test.
> * gcc.target/i386/auto-init-padding-8.c: New test.
> * gcc.target/i386/auto-init-padding-9.c: New test.
>
> ****** The patch against the 7th patch:
>
>
> ******The complete 8th patch:
>
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)
