Hi, FYI I just committed the following patch to gcc upstream:
https://gcc.gnu.org/pipermail/gcc-cvs/2021-September/353195.html Thanks. Qing > On Sep 6, 2021, at 5:16 AM, Richard Biener <rguent...@suse.de> wrote: > > 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)
