Marek, Sorry for the late comment (I was just back from a long vacation immediate after Cauldron).
One question: Is the option “-fhandened” for production build or for development build? If it’s for development build, then adding -ftrivial-auto-var-init=pattern is reasonable since the major purpose for -ftrivial-auto-var-init=pattern is for debugging, the runtime overhead of -ftrivial-auto-var-init=pattern is higher then -ftrivial-auto-var-init=zero. However, if it’s for production build, then adding -ftrivial-auto-var-init=zero is better since the major purpose for -ftrivial-auto-var-init=zero is for production build to eliminate all uninitialization. And the runtime overhead of =zero is smaller than =pattern. Qing > On Oct 11, 2023, at 4:48 PM, Marek Polacek <pola...@redhat.com> wrote: > > On Tue, Sep 19, 2023 at 10:58:19AM -0400, Marek Polacek wrote: >> On Mon, Sep 18, 2023 at 08:57:39AM +0200, Richard Biener wrote: >>> On Fri, Sep 15, 2023 at 5:09 PM Marek Polacek via Gcc-patches >>> <gcc-patches@gcc.gnu.org> wrote: >>>> >>>> Bootstrapped/regtested on x86_64-pc-linux-gnu, >>>> powerpc64le-unknown-linux-gnu, >>>> and aarch64-unknown-linux-gnu; ok for trunk? >>>> >>>> -- >8 -- >>>> In <https://gcc.gnu.org/pipermail/gcc-patches/2023-August/628748.html> >>>> I proposed -fhardened, a new umbrella option that enables a reasonable set >>>> of hardening flags. The read of the room seems to be that the option >>>> would be useful. So here's a patch implementing that option. >>>> >>>> Currently, -fhardened enables: >>>> >>>> -D_FORTIFY_SOURCE=3 (or =2 for older glibcs) >>>> -D_GLIBCXX_ASSERTIONS >>>> -ftrivial-auto-var-init=pattern >>>> -fPIE -pie -Wl,-z,relro,-z,now >>>> -fstack-protector-strong >>>> -fstack-clash-protection >>>> -fcf-protection=full (x86 GNU/Linux only) >>>> >>>> -fhardened will not override options that were specified on the command >>>> line >>>> (before or after -fhardened). For example, >>>> >>>> -D_FORTIFY_SOURCE=1 -fhardened >>>> >>>> means that _FORTIFY_SOURCE=1 will be used. Similarly, >>>> >>>> -fhardened -fstack-protector >>>> >>>> will not enable -fstack-protector-strong. >>>> >>>> In DW_AT_producer it is reflected only as -fhardened; it doesn't expand >>>> to anything. I think we need a better way to show what it actually >>>> enables. >>> >>> I do think we need to find a solution here to solve asserting compliance. >> >> Fair enough. >> >>> Maybe we can have -Whardened that will diagnose any altering of >>> -fhardened by other options on the command-line or by missed target >>> implementations? People might for example use -fstack-protector >>> but don't really want to make protection lower than requested with >>> -fhardened. >>> >>> Any such conflict is much less appearant than when you use the >>> flags -fhardened composes. >> >> How about: --help=hardened says which options -fhardened attempts to >> enable, and -Whardened warns when it didn't enable an option? E.g., >> >> -fstack-protector -fhardened -Whardened >> >> would say that it didn't enable -fstack-protector-strong because >> -fstack-protector was specified on the command line? >> >> If !HAVE_LD_NOW_SUPPORT, --help=hardened probably doesn't even have to >> list -z now, likewise for -z relro. >> >> Unclear if -Whardened should be enabled by default, but probably yes? > > Here's v2 which adds -Whardened (enabled by default). > > Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk? > > -- >8 -- > In <https://gcc.gnu.org/pipermail/gcc-patches/2023-August/628748.html> > I proposed -fhardened, a new umbrella option that enables a reasonable set > of hardening flags. The read of the room seems to be that the option > would be useful. So here's a patch implementing that option. > > Currently, -fhardened enables: > > -D_FORTIFY_SOURCE=3 (or =2 for older glibcs) > -D_GLIBCXX_ASSERTIONS > -ftrivial-auto-var-init=pattern > -fPIE -pie -Wl,-z,relro,-z,now > -fstack-protector-strong > -fstack-clash-protection > -fcf-protection=full (x86 GNU/Linux only) > > -fhardened will not override options that were specified on the command line > (before or after -fhardened). For example, > > -D_FORTIFY_SOURCE=1 -fhardened > > means that _FORTIFY_SOURCE=1 will be used. Similarly, > > -fhardened -fstack-protector > > will not enable -fstack-protector-strong. > > In DW_AT_producer it is reflected only as -fhardened; it doesn't expand > to anything. This patch provides -Whardened, enabled by default, which > warns when -fhardened couldn't enable a particular option. I think most > often it will say that _FORTIFY_SOURCE wasn't enabled because optimization > were not enabled. > > gcc/c-family/ChangeLog: > > * c-opts.cc (c_finish_options): Maybe cpp_define _FORTIFY_SOURCE > and _GLIBCXX_ASSERTIONS. > > gcc/ChangeLog: > > * common.opt (Whardened, fhardened): New options. > * config.in: Regenerate. > * config/bpf/bpf.cc: Include "opts.h". > (bpf_option_override): If flag_stack_protector_set_by_fhardened_p, do > not inform that -fstack-protector does not work. > * config/i386/i386-options.cc (ix86_option_override_internal): When > -fhardened, maybe enable -fcf-protection=full. > * configure: Regenerate. > * configure.ac: Check if the linker supports '-z now' and '-z relro'. > * doc/invoke.texi: Document -fhardened and -Whardened. > * gcc.cc (driver_handle_option): Remember if any link options or -static > were specified on the command line. > (process_command): When -fhardened, maybe enable -pie and > -Wl,-z,relro,-z,now. > * opts.cc (flag_stack_protector_set_by_fhardened_p): New global. > (finish_options): When -fhardened, enable > -ftrivial-auto-var-init=pattern and -fstack-protector-strong. > (print_help_hardened): New. > (print_help): Call it. > * toplev.cc (process_options): When -fhardened, enable > -fstack-clash-protection. If flag_stack_protector_set_by_fhardened_p, > do not warn that -fstack-protector not supported for this target. > > gcc/testsuite/ChangeLog: > > * gcc.misc-tests/help.exp: Test -fhardened. > * c-c++-common/fhardened-1.S: New test. > * c-c++-common/fhardened-1.c: New test. > * c-c++-common/fhardened-10.c: New test. > * c-c++-common/fhardened-11.c: New test. > * c-c++-common/fhardened-12.c: New test. > * c-c++-common/fhardened-13.c: New test. > * c-c++-common/fhardened-14.c: New test. > * c-c++-common/fhardened-15.c: New test. > * c-c++-common/fhardened-2.c: New test. > * c-c++-common/fhardened-3.c: New test. > * c-c++-common/fhardened-4.c: New test. > * c-c++-common/fhardened-5.c: New test. > * c-c++-common/fhardened-6.c: New test. > * c-c++-common/fhardened-7.c: New test. > * c-c++-common/fhardened-8.c: New test. > * c-c++-common/fhardened-9.c: New test. > * gcc.target/i386/cf_check-6.c: New test. > --- > gcc/c-family/c-opts.cc | 42 ++++++++++++++ > gcc/common.opt | 8 +++ > gcc/config.in | 12 ++++ > gcc/config/bpf/bpf.cc | 8 ++- > gcc/config/i386/i386-options.cc | 17 +++++- > gcc/configure | 50 +++++++++++++++- > gcc/configure.ac | 42 +++++++++++++- > gcc/doc/invoke.texi | 44 +++++++++++++- > gcc/gcc.cc | 48 +++++++++++++++- > gcc/opts.cc | 67 +++++++++++++++++++++- > gcc/opts.h | 1 + > gcc/testsuite/c-c++-common/fhardened-1.S | 6 ++ > gcc/testsuite/c-c++-common/fhardened-1.c | 14 +++++ > gcc/testsuite/c-c++-common/fhardened-10.c | 12 ++++ > gcc/testsuite/c-c++-common/fhardened-11.c | 10 ++++ > gcc/testsuite/c-c++-common/fhardened-12.c | 11 ++++ > gcc/testsuite/c-c++-common/fhardened-13.c | 6 ++ > gcc/testsuite/c-c++-common/fhardened-14.c | 6 ++ > gcc/testsuite/c-c++-common/fhardened-15.c | 5 ++ > gcc/testsuite/c-c++-common/fhardened-2.c | 12 ++++ > gcc/testsuite/c-c++-common/fhardened-3.c | 14 +++++ > gcc/testsuite/c-c++-common/fhardened-4.c | 4 ++ > gcc/testsuite/c-c++-common/fhardened-5.c | 11 ++++ > gcc/testsuite/c-c++-common/fhardened-6.c | 12 ++++ > gcc/testsuite/c-c++-common/fhardened-7.c | 7 +++ > gcc/testsuite/c-c++-common/fhardened-8.c | 7 +++ > gcc/testsuite/c-c++-common/fhardened-9.c | 9 +++ > gcc/testsuite/gcc.misc-tests/help.exp | 2 + > gcc/testsuite/gcc.target/i386/cf_check-6.c | 12 ++++ > gcc/toplev.cc | 18 +++++- > 30 files changed, 503 insertions(+), 14 deletions(-) > create mode 100644 gcc/testsuite/c-c++-common/fhardened-1.S > create mode 100644 gcc/testsuite/c-c++-common/fhardened-1.c > create mode 100644 gcc/testsuite/c-c++-common/fhardened-10.c > create mode 100644 gcc/testsuite/c-c++-common/fhardened-11.c > create mode 100644 gcc/testsuite/c-c++-common/fhardened-12.c > create mode 100644 gcc/testsuite/c-c++-common/fhardened-13.c > create mode 100644 gcc/testsuite/c-c++-common/fhardened-14.c > create mode 100644 gcc/testsuite/c-c++-common/fhardened-15.c > create mode 100644 gcc/testsuite/c-c++-common/fhardened-2.c > create mode 100644 gcc/testsuite/c-c++-common/fhardened-3.c > create mode 100644 gcc/testsuite/c-c++-common/fhardened-4.c > create mode 100644 gcc/testsuite/c-c++-common/fhardened-5.c > create mode 100644 gcc/testsuite/c-c++-common/fhardened-6.c > create mode 100644 gcc/testsuite/c-c++-common/fhardened-7.c > create mode 100644 gcc/testsuite/c-c++-common/fhardened-8.c > create mode 100644 gcc/testsuite/c-c++-common/fhardened-9.c > create mode 100644 gcc/testsuite/gcc.target/i386/cf_check-6.c > > diff --git a/gcc/c-family/c-opts.cc b/gcc/c-family/c-opts.cc > index ce2e021e69d..f5f6ba24290 100644 > --- a/gcc/c-family/c-opts.cc > +++ b/gcc/c-family/c-opts.cc > @@ -1556,6 +1556,9 @@ c_finish_options (void) > cb_file_change (parse_in, cmd_map); > linemap_line_start (line_table, 0, 1); > > + bool fortify_seen_p = false; > + bool cxx_assert_seen_p = false; > + > /* All command line defines must have the same location. */ > cpp_force_token_locations (parse_in, line_table->highest_line); > for (size_t i = 0; i < deferred_count; i++) > @@ -1573,6 +1576,45 @@ c_finish_options (void) > else > cpp_assert (parse_in, opt->arg); > } > + > + if (UNLIKELY (flag_hardened) > + && (opt->code == OPT_D || opt->code == OPT_U)) > + { > + if (!fortify_seen_p) > + fortify_seen_p > + = (!strncmp (opt->arg, "_FORTIFY_SOURCE", 15) > + && (opt->arg[15] == '\0' || opt->arg[15] == '=')); > + if (!cxx_assert_seen_p) > + cxx_assert_seen_p > + = (!strncmp (opt->arg, "_GLIBCXX_ASSERTIONS", 19) > + && (opt->arg[19] == '\0' || opt->arg[19] == '=')); > + } > + } > + > + if (flag_hardened) > + { > + if (!fortify_seen_p && optimize > 0) > + { > + if (TARGET_GLIBC_MAJOR == 2 && TARGET_GLIBC_MINOR >= 35) > + cpp_define (parse_in, "_FORTIFY_SOURCE=3"); > + else > + cpp_define (parse_in, "_FORTIFY_SOURCE=2"); > + } > + else if (optimize == 0) > + warning_at (UNKNOWN_LOCATION, OPT_Whardened, > + "%<_FORTIFY_SOURCE%> is not enabled by %<-fhardened%> " > + "because optimizations are turned off"); > + else > + warning_at (UNKNOWN_LOCATION, OPT_Whardened, > + "%<_FORTIFY_SOURCE%> is not enabled by %<-fhardened%> " > + "because it was specified in %<-D%> or %<-U%>"); > + if (!cxx_assert_seen_p) > + cpp_define (parse_in, "_GLIBCXX_ASSERTIONS"); > + else > + warning_at (UNKNOWN_LOCATION, OPT_Whardened, > + "%<_GLIBCXX_ASSERTIONS%> is not enabled by " > + "%<-fhardened%> because it was specified in %<-D%> " > + "or %<-U%>"); > } > > cpp_stop_forcing_token_locations (parse_in); > diff --git a/gcc/common.opt b/gcc/common.opt > index f137a1f81ac..60c13b9ffd2 100644 > --- a/gcc/common.opt > +++ b/gcc/common.opt > @@ -634,6 +634,10 @@ Wfree-nonheap-object > Common Var(warn_free_nonheap_object) Init(1) Warning > Warn when attempting to free a non-heap object. > > +Whardened > +Common Var(warn_hardened) Init(1) Warning > +Warn when -fhardened did not enable an option from its set. > + > Whsa > Common Ignore Warning > Does nothing. Preserved for backward compatibility. > @@ -1827,6 +1831,10 @@ fharden-conditional-branches > Common Var(flag_harden_conditional_branches) Optimization > Harden conditional branches by checking reversed conditions. > > +fhardened > +Common Driver Var(flag_hardened) > +Enable various security-relevant flags. > + > ; Nonzero means ignore `#ident' directives. 0 means handle them. > ; Generate position-independent code for executables if possible > ; On SVR4 targets, it also controls whether or not to emit a > diff --git a/gcc/config.in b/gcc/config.in > index d04718ad128..faa941c1385 100644 > --- a/gcc/config.in > +++ b/gcc/config.in > @@ -1676,6 +1676,12 @@ > #endif > > > +/* Define 0/1 if your linker supports -z now */ > +#ifndef USED_FOR_TARGET > +#undef HAVE_LD_NOW_SUPPORT > +#endif > + > + > /* Define if your PowerPC64 linker only needs function descriptor syms. */ > #ifndef USED_FOR_TARGET > #undef HAVE_LD_NO_DOT_SYMS > @@ -1719,6 +1725,12 @@ > #endif > > > +/* Define 0/1 if your linker supports -z relro */ > +#ifndef USED_FOR_TARGET > +#undef HAVE_LD_RELRO_SUPPORT > +#endif > + > + > /* Define if your linker links a mix of read-only and read-write sections into > a read-write section. */ > #ifndef USED_FOR_TARGET > diff --git a/gcc/config/bpf/bpf.cc b/gcc/config/bpf/bpf.cc > index 437bd652de3..41dc7fd3dae 100644 > --- a/gcc/config/bpf/bpf.cc > +++ b/gcc/config/bpf/bpf.cc > @@ -70,6 +70,7 @@ along with GCC; see the file COPYING3. If not see > #include "gimplify-me.h" > > #include "core-builtins.h" > +#include "opts.h" > > /* Per-function machine data. */ > struct GTY(()) machine_function > @@ -250,9 +251,10 @@ bpf_option_override (void) > /* Disable -fstack-protector as it is not supported in BPF. */ > if (flag_stack_protect) > { > - inform (input_location, > - "%<-fstack-protector%> does not work " > - "on this architecture"); > + if (!flag_stack_protector_set_by_fhardened_p) > + inform (input_location, > + "%<-fstack-protector%> does not work " > + "on this architecture"); > flag_stack_protect = 0; > } > > diff --git a/gcc/config/i386/i386-options.cc b/gcc/config/i386/i386-options.cc > index 06af373ca57..22ede9e15b5 100644 > --- a/gcc/config/i386/i386-options.cc > +++ b/gcc/config/i386/i386-options.cc > @@ -3061,10 +3061,25 @@ ix86_option_override_internal (bool main_args_p, > = build_target_option_node (opts, opts_set); > } > > + const bool cf_okay_p = (TARGET_64BIT || TARGET_CMOV); > + /* When -fhardened, enable -fcf-protection=full, but only when it's > + compatible with this target, and when it wasn't already specified > + on the command line. */ > + if (opts->x_flag_hardened && cf_okay_p) > + { > + if (opts->x_flag_cf_protection == CF_NONE) > + opts->x_flag_cf_protection = CF_FULL; > + else if (opts->x_flag_cf_protection != CF_FULL) > + warning_at (UNKNOWN_LOCATION, OPT_Whardened, > + "%<-fcf-protection=full%> is not enabled by " > + "%<-fhardened%> because it was specified on the command " > + "line"); > + } > + > if (opts->x_flag_cf_protection != CF_NONE) > { > if ((opts->x_flag_cf_protection & CF_BRANCH) == CF_BRANCH > - && !TARGET_64BIT && !TARGET_CMOV) > + && !cf_okay_p) > error ("%<-fcf-protection%> is not compatible with this target"); > > opts->x_flag_cf_protection > diff --git a/gcc/configure b/gcc/configure > index c43bde8174b..e2aac56edf6 100755 > --- a/gcc/configure > +++ b/gcc/configure > @@ -32713,7 +32713,7 @@ if test x"$ld_is_gold" = xno; then > ld_bndplt_support=yes > fi > elif test x$gcc_cv_ld != x; then > - # Check if linker supports -a bndplt option > + # Check if linker supports -z bndplt option > if $gcc_cv_ld --help 2>&1 | grep -- '-z bndplt' > /dev/null; then > ld_bndplt_support=yes > fi > @@ -32842,6 +32842,54 @@ $as_echo "#define ENABLE_S390_EXCESS_FLOAT_PRECISION > 1" >>confdefs.h > ;; > esac > > +# Check if the linker supports '-z now' > +ld_now_support=no > +{ $as_echo "$as_me:${as_lineno-$LINENO}: checking linker -z now option" >&5 > +$as_echo_n "checking linker -z now option... " >&6; } > +if test x"$ld_is_gold" = xyes; then > + ld_now_support=yes > +elif test $in_tree_ld = yes ; then > + if test "$gcc_cv_gld_major_version" -eq 2 -a "$gcc_cv_gld_minor_version" > -ge 14 -o "$gcc_cv_gld_major_version" -gt 2; then > + ld_now_support=yes > + fi > +elif test x$gcc_cv_ld != x; then > + # Check if linker supports -z now > + if $gcc_cv_ld --help 2>&1 | grep -- '-z now' > /dev/null; then > + ld_now_support=yes > + fi > +fi > + > +cat >>confdefs.h <<_ACEOF > +#define HAVE_LD_NOW_SUPPORT `if test x"$ld_now_support" = xyes; then echo 1; > else echo 0; fi` > +_ACEOF > + > +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ld_now_support" >&5 > +$as_echo "$ld_now_support" >&6; } > + > +# Check if the linker supports '-z relro' > +ld_relro_support=no > +{ $as_echo "$as_me:${as_lineno-$LINENO}: checking linker -z relro option" >&5 > +$as_echo_n "checking linker -z relro option... " >&6; } > +if test x"$ld_is_gold" = xyes; then > + ld_relro_support=yes > +elif test $in_tree_ld = yes ; then > + if test "$gcc_cv_gld_major_version" -eq 2 -a "$gcc_cv_gld_minor_version" > -ge 15 -o "$gcc_cv_gld_major_version" -gt 2; then > + ld_relro_support=yes > + fi > +elif test x$gcc_cv_ld != x; then > + # Check if linker supports -z relro > + if $gcc_cv_ld --help 2>&1 | grep -- '-z relro' > /dev/null; then > + ld_relro_support=yes > + fi > +fi > + > +cat >>confdefs.h <<_ACEOF > +#define HAVE_LD_RELRO_SUPPORT `if test x"$ld_relro_support" = xyes; then > echo 1; else echo 0; fi` > +_ACEOF > + > +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ld_relro_support" >&5 > +$as_echo "$ld_relro_support" >&6; } > + > # Configure the subdirectories > # AC_CONFIG_SUBDIRS($subdirs) > > diff --git a/gcc/configure.ac b/gcc/configure.ac > index fb8e32f8ee5..6a090ccf3bd 100644 > --- a/gcc/configure.ac > +++ b/gcc/configure.ac > @@ -7678,7 +7678,7 @@ if test x"$ld_is_gold" = xno; then > ld_bndplt_support=yes > fi > elif test x$gcc_cv_ld != x; then > - # Check if linker supports -a bndplt option > + # Check if linker supports -z bndplt option > if $gcc_cv_ld --help 2>&1 | grep -- '-z bndplt' > /dev/null; then > ld_bndplt_support=yes > fi > @@ -7779,6 +7779,46 @@ standards-compatible mode on s390 targets.]) > ;; > esac > > +# Check if the linker supports '-z now' > +ld_now_support=no > +AC_MSG_CHECKING(linker -z now option) > +if test x"$ld_is_gold" = xyes; then > + ld_now_support=yes > +elif test $in_tree_ld = yes ; then > + if test "$gcc_cv_gld_major_version" -eq 2 -a "$gcc_cv_gld_minor_version" > -ge 14 -o "$gcc_cv_gld_major_version" -gt 2; then > + ld_now_support=yes > + fi > +elif test x$gcc_cv_ld != x; then > + # Check if linker supports -z now > + if $gcc_cv_ld --help 2>&1 | grep -- '-z now' > /dev/null; then > + ld_now_support=yes > + fi > +fi > +AC_DEFINE_UNQUOTED(HAVE_LD_NOW_SUPPORT, > + [`if test x"$ld_now_support" = xyes; then echo 1; else echo 0; fi`], > + [Define 0/1 if your linker supports -z now]) > +AC_MSG_RESULT($ld_now_support) > + > +# Check if the linker supports '-z relro' > +ld_relro_support=no > +AC_MSG_CHECKING(linker -z relro option) > +if test x"$ld_is_gold" = xyes; then > + ld_relro_support=yes > +elif test $in_tree_ld = yes ; then > + if test "$gcc_cv_gld_major_version" -eq 2 -a "$gcc_cv_gld_minor_version" > -ge 15 -o "$gcc_cv_gld_major_version" -gt 2; then > + ld_relro_support=yes > + fi > +elif test x$gcc_cv_ld != x; then > + # Check if linker supports -z relro > + if $gcc_cv_ld --help 2>&1 | grep -- '-z relro' > /dev/null; then > + ld_relro_support=yes > + fi > +fi > +AC_DEFINE_UNQUOTED(HAVE_LD_RELRO_SUPPORT, > + [`if test x"$ld_relro_support" = xyes; then echo 1; else echo 0; fi`], > + [Define 0/1 if your linker supports -z relro]) > +AC_MSG_RESULT($ld_relro_support) > + > # Configure the subdirectories > # AC_CONFIG_SUBDIRS($subdirs) > > diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi > index 7c5f81d9783..48e6a3f433c 100644 > --- a/gcc/doc/invoke.texi > +++ b/gcc/doc/invoke.texi > @@ -366,7 +366,7 @@ Objective-C and Objective-C++ Dialects}. > -Wformat-y2k -Wframe-address > -Wframe-larger-than=@var{byte-size} -Wno-free-nonheap-object > -Wno-if-not-aligned -Wno-ignored-attributes > --Wignored-qualifiers -Wno-incompatible-pointer-types > +-Wignored-qualifiers -Wno-incompatible-pointer-types -Whardened > -Wimplicit -Wimplicit-fallthrough -Wimplicit-fallthrough=@var{n} > -Wno-implicit-function-declaration -Wno-implicit-int > -Winfinite-recursion > @@ -640,7 +640,7 @@ Objective-C and Objective-C++ Dialects}. > -fasan-shadow-offset=@var{number} -fsanitize-sections=@var{s1},@var{s2},... > -fsanitize-undefined-trap-on-error -fbounds-check > -fcf-protection=@r{[}full@r{|}branch@r{|}return@r{|}none@r{|}check@r{]} > --fharden-compares -fharden-conditional-branches > +-fharden-compares -fharden-conditional-branches -fhardened > -fstack-protector -fstack-protector-all -fstack-protector-strong > -fstack-protector-explicit -fstack-check > -fstack-limit-register=@var{reg} -fstack-limit-symbol=@var{sym} > @@ -6842,6 +6842,18 @@ This warning is upgraded to an error by > @option{-pedantic-errors}. > Same as @option{-Wimplicit-int} and @option{-Wimplicit-function-declaration}. > This warning is enabled by @option{-Wall}. > > +@opindex Whardened > +@opindex Wno-hardened > +@item -Whardened > +Warn when @option{-fhardened} did not enable an option from its set (for > +which see @option{-fhardened}). For instance, using @option{-fhardened} > +and @option{-fstack-protector} at the same time on the command line causes > +@option{-Whardened} to warn because @option{-fstack-protector-strong} is > +not enabled by @option{-fhardened}. > + > +This warning is enabled by default and has effect only when > @option{-fhardened} > +is enabled. > + > @opindex Wimplicit-fallthrough > @opindex Wno-implicit-fallthrough > @item -Wimplicit-fallthrough > @@ -17427,6 +17439,34 @@ condition, and to call @code{__builtin_trap} if the > result is > unexpected. Use with @samp{-fharden-compares} to cover all > conditionals. > > +@opindex fhardened > +@item -fhardened > +Enable a set of flags for C and C++ that improve the security of the > +generated code without affecting its ABI. The precise flags enabled > +may change between major releases of GCC, but are currently: > + > +@c Keep this in sync with print_help_hardened! > +@gccoptlist{ > +-D_FORTIFY_SOURCE=3 > +-D_GLIBCXX_ASSERTIONS > +-ftrivial-auto-var-init=pattern > +-fPIE -pie -Wl,-z,relro,-z,now > +-fstack-protector-strong > +-fstack-clash-protection > +-fcf-protection=full @r{(x86 GNU/Linux only)} > +} > + > +The list of options enabled by @option{-fhardened} can be generated using > +the @option{--help=hardened} option. > + > +When the system glibc is older than 2.35, @option{-D_FORTIFY_SOURCE=2} > +is used instead. > + > +@option{-fhardened} only enables a particular option if it wasn't > +already specified anywhere on the command line. For instance, > +@option{-fhardened} @option{-fstack-protector} will only enable > +@option{-fstack-protector}, but not @option{-fstack-protector-strong}. > + > @opindex fstack-protector > @item -fstack-protector > Emit extra code to check for buffer overflows, such as stack smashing > diff --git a/gcc/gcc.cc b/gcc/gcc.cc > index c6e600fa0d3..ed4e2400e91 100644 > --- a/gcc/gcc.cc > +++ b/gcc/gcc.cc > @@ -302,6 +302,13 @@ static size_t dumpdir_length = 0; > driver added to dumpdir after dumpbase or linker output name. */ > static bool dumpdir_trailing_dash_added = false; > > +/* True if -r, -shared, -pie, or -no-pie were specified on the command > + line. */ > +static bool any_link_options_p; > + > +/* True if -static was specified on the command line. */ > +static bool static_p; > + > /* Basename of dump and aux outputs, computed from dumpbase (given or > derived from output name), to override input_basename in non-%w %b > et al. */ > @@ -4601,10 +4608,20 @@ driver_handle_option (struct gcc_options *opts, > save_switch ("-o", 1, &arg, validated, true); > return true; > > -#ifdef ENABLE_DEFAULT_PIE > case OPT_pie: > +#ifdef ENABLE_DEFAULT_PIE > /* -pie is turned on by default. */ > + validated = true; > #endif > + case OPT_r: > + case OPT_shared: > + case OPT_no_pie: > + any_link_options_p = true; > + break; > + > + case OPT_static: > + static_p = true; > + break; > > case OPT_static_libgcc: > case OPT_shared_libgcc: > @@ -4980,6 +4997,35 @@ process_command (unsigned int decoded_options_count, > #endif > } > > + /* TODO: check if -static -pie works and maybe use it. */ > + if (flag_hardened) > + { > + if (!any_link_options_p && !static_p) > + { > +#ifdef HAVE_LD_PIE > + save_switch (LD_PIE_SPEC, 0, NULL, /*validated=*/true, > /*known=*/false); > +#endif > + /* These are passed straight down to collect2 so we have to break > + it up like this. */ > + if (HAVE_LD_NOW_SUPPORT) > + { > + add_infile ("-z", "*"); > + add_infile ("now", "*"); > + } > + if (HAVE_LD_RELRO_SUPPORT) > + { > + add_infile ("-z", "*"); > + add_infile ("relro", "*"); > + } > + } > + /* We can't use OPT_Whardened yet. Sigh. */ > + else if (warn_hardened) > + warning_at (UNKNOWN_LOCATION, 0, > + "linker hardening options not enabled by %<-fhardened%> " > + "because other link options were specified on the command " > + "line"); > + } > + > /* Handle -gtoggle as it would later in toplev.cc:process_options to > make the debug-level-gt spec function work as expected. */ > if (flag_gtoggle) > diff --git a/gcc/opts.cc b/gcc/opts.cc > index 573dcf8e497..8265c5b3c1b 100644 > --- a/gcc/opts.cc > +++ b/gcc/opts.cc > @@ -43,6 +43,10 @@ along with GCC; see the file COPYING3. If not see > /* Set by -fcanon-prefix-map. */ > bool flag_canon_prefix_map; > > +/* Set by finish_options when flag_stack_protector was set only because of > + -fhardened. Yuck. */ > +bool flag_stack_protector_set_by_fhardened_p; > + > static void set_Wstrict_aliasing (struct gcc_options *opts, int onoff); > > /* Names of fundamental debug info formats indexed by enum > @@ -1093,6 +1097,17 @@ finish_options (struct gcc_options *opts, struct > gcc_options *opts_set, > opts->x_flag_section_anchors = 0; > } > > + if (opts->x_flag_hardened) > + { > + if (!opts_set->x_flag_auto_var_init) > + opts->x_flag_auto_var_init = AUTO_INIT_PATTERN; > + else if (opts->x_flag_auto_var_init != AUTO_INIT_PATTERN) > + warning_at (loc, OPT_Whardened, > + "%<-ftrivial-auto-var-init=pattern%> is not enabled by " > + "%<-fhardened%> because it was specified on the command " > + "line"); > + } > + > if (!opts->x_flag_opts_finished) > { > /* We initialize opts->x_flag_pie to -1 so that targets can set a > @@ -1102,7 +1117,8 @@ finish_options (struct gcc_options *opts, struct > gcc_options *opts_set, > /* We initialize opts->x_flag_pic to -1 so that we can tell if > -fpic, -fPIC, -fno-pic or -fno-PIC is used. */ > if (opts->x_flag_pic == -1) > - opts->x_flag_pie = DEFAULT_FLAG_PIE; > + opts->x_flag_pie = (opts->x_flag_hardened > + ? /*-fPIE*/ 2 : DEFAULT_FLAG_PIE); > else > opts->x_flag_pie = 0; > } > @@ -1117,9 +1133,29 @@ finish_options (struct gcc_options *opts, struct > gcc_options *opts_set, > } > > /* We initialize opts->x_flag_stack_protect to -1 so that targets > - can set a default value. */ > + can set a default value. With --enable-default-ssp or -fhardened > + the default is -fstack-protector-strong. */ > if (opts->x_flag_stack_protect == -1) > - opts->x_flag_stack_protect = DEFAULT_FLAG_SSP; > + { > + /* This should check FRAME_GROWS_DOWNWARD, but on some targets it's > + defined in such a way that it uses flag_stack_protect which can't > + be used here. Moreover, some targets like BPF don't support > + -fstack-protector at all but we don't know that here. So remember > + that flag_stack_protect was set at the behest of -fhardened. */ > + if (opts->x_flag_hardened) > + { > + opts->x_flag_stack_protect = SPCT_FLAG_STRONG; > + flag_stack_protector_set_by_fhardened_p = true; > + } > + else > + opts->x_flag_stack_protect = DEFAULT_FLAG_SSP; > + } > + else if (opts->x_flag_hardened > + && opts->x_flag_stack_protect != SPCT_FLAG_STRONG) > + warning_at (UNKNOWN_LOCATION, OPT_Whardened, > + "%<-fstack-protector-strong%> is not enabled by " > + "%<-fhardened%> because it was specified on the command " > + "line"); > > if (opts->x_optimize == 0) > { > @@ -2461,6 +2497,29 @@ parse_and_check_patch_area (const char *arg, bool > report_error, > free (patch_area_arg); > } > > +/* Print options enabled by -fhardened. Keep this in sync with the manual! > */ > + > +static void > +print_help_hardened () > +{ > + printf ("%s\n", "The following options are enabled by -fhardened:"); > + printf (" %s=%d\n", "-D_FORTIFY_SOURCE", > + (TARGET_GLIBC_MAJOR == 2 && TARGET_GLIBC_MINOR >= 35) ? 3 : 2); > + printf (" %s\n", "-D_GLIBCXX_ASSERTIONS"); > + printf (" %s\n", "-ftrivial-auto-var-init=pattern"); > +#ifdef HAVE_LD_PIE > + printf (" %s %s\n", "-fPIE", "-pie"); > +#endif > + if (HAVE_LD_NOW_SUPPORT) > + printf (" %s\n", "-Wl,-z,now"); > + if (HAVE_LD_RELRO_SUPPORT) > + printf (" %s\n", "-Wl,-z,relro"); > + printf (" %s\n", "-fstack-protector-strong"); > + printf (" %s\n", "-fstack-clash-protection"); > + printf (" %s\n", "-fcf-protection=full"); > + putchar ('\n'); > +} > + > /* Print help when OPT__help_ is set. */ > > void > @@ -2576,6 +2635,8 @@ print_help (struct gcc_options *opts, unsigned int > lang_mask, > } > else if (lang_flag != 0) > *pflags |= lang_flag; > + else if (strncasecmp (a, "hardened", len) == 0) > + print_help_hardened (); > else > warning (0, > "unrecognized argument to %<--help=%> option: %q.*s", > diff --git a/gcc/opts.h b/gcc/opts.h > index 00f377f9ca7..d89c5de8114 100644 > --- a/gcc/opts.h > +++ b/gcc/opts.h > @@ -344,6 +344,7 @@ struct cl_option_handlers > /* Hold command-line options associated with stack limitation. */ > extern const char *opt_fstack_limit_symbol_arg; > extern int opt_fstack_limit_register_no; > +extern bool flag_stack_protector_set_by_fhardened_p; > > /* Input file names. */ > > diff --git a/gcc/testsuite/c-c++-common/fhardened-1.S > b/gcc/testsuite/c-c++-common/fhardened-1.S > new file mode 100644 > index 00000000000..4dd22cdfe45 > --- /dev/null > +++ b/gcc/testsuite/c-c++-common/fhardened-1.S > @@ -0,0 +1,6 @@ > +/* { dg-do preprocess { target pie } } */ > +/* { dg-options "-fhardened -O" } */ > + > +#if __PIE__ != 2 > +# error "-fPIE not enabled" > +#endif > diff --git a/gcc/testsuite/c-c++-common/fhardened-1.c > b/gcc/testsuite/c-c++-common/fhardened-1.c > new file mode 100644 > index 00000000000..dd3cde93805 > --- /dev/null > +++ b/gcc/testsuite/c-c++-common/fhardened-1.c > @@ -0,0 +1,14 @@ > +/* { dg-do compile } */ > +/* { dg-options "-fhardened -O" } */ > + > +#ifndef __SSP_STRONG__ > +# error "-fstack-protector-strong not enabled" > +#endif > + > +#if _FORTIFY_SOURCE < 2 > +# error "_FORTIFY_SOURCE not enabled" > +#endif > + > +#ifndef _GLIBCXX_ASSERTIONS > +# error "_GLIBCXX_ASSERTIONS not enabled" > +#endif > diff --git a/gcc/testsuite/c-c++-common/fhardened-10.c > b/gcc/testsuite/c-c++-common/fhardened-10.c > new file mode 100644 > index 00000000000..8242530bc4d > --- /dev/null > +++ b/gcc/testsuite/c-c++-common/fhardened-10.c > @@ -0,0 +1,12 @@ > +/* { dg-do compile } */ > +/* { dg-options "-fhardened -D_FORTIFY_SOURCE=1" } */ > + > +#if _FORTIFY_SOURCE != 1 > +# error "_FORTIFY_SOURCE != 1" > +#endif > + > +#ifndef _GLIBCXX_ASSERTIONS > +# error "_GLIBCXX_ASSERTIONS disabled when it should not be" > +#endif > + > +/* { dg-warning "._FORTIFY_SOURCE. is not enabled" "" { target *-*-* } 0 } */ > diff --git a/gcc/testsuite/c-c++-common/fhardened-11.c > b/gcc/testsuite/c-c++-common/fhardened-11.c > new file mode 100644 > index 00000000000..b8fd65a960c > --- /dev/null > +++ b/gcc/testsuite/c-c++-common/fhardened-11.c > @@ -0,0 +1,10 @@ > +/* { dg-do compile } */ > +/* { dg-options "-fhardened -O -D_FORTIFY_SOURCE_ -D_GLIBCXX_ASSERTIONS_" } > */ > + > +#ifndef _FORTIFY_SOURCE > +# error "_FORTIFY_SOURCE disabled when it should not be" > +#endif > + > +#ifndef _GLIBCXX_ASSERTIONS > +# error "_GLIBCXX_ASSERTIONS disabled when it should not be" > +#endif > diff --git a/gcc/testsuite/c-c++-common/fhardened-12.c > b/gcc/testsuite/c-c++-common/fhardened-12.c > new file mode 100644 > index 00000000000..42594e4c0e0 > --- /dev/null > +++ b/gcc/testsuite/c-c++-common/fhardened-12.c > @@ -0,0 +1,11 @@ > +/* { dg-do compile } */ > +/* { dg-options "-fhardened -O -fdump-tree-gimple" } */ > + > +int > +foo () > +{ > + int i; > + return i; > +} > + > +/* { dg-final { scan-tree-dump ".DEFERRED_INIT" "gimple" } } */ > diff --git a/gcc/testsuite/c-c++-common/fhardened-13.c > b/gcc/testsuite/c-c++-common/fhardened-13.c > new file mode 100644 > index 00000000000..6945a6391a9 > --- /dev/null > +++ b/gcc/testsuite/c-c++-common/fhardened-13.c > @@ -0,0 +1,6 @@ > +/* { dg-do compile { target pie } } */ > +/* { dg-options "-fhardened -O" } */ > + > +#if __PIE__ != 2 > +# error "-fPIE not enabled" > +#endif > diff --git a/gcc/testsuite/c-c++-common/fhardened-14.c > b/gcc/testsuite/c-c++-common/fhardened-14.c > new file mode 100644 > index 00000000000..652ece3d4c4 > --- /dev/null > +++ b/gcc/testsuite/c-c++-common/fhardened-14.c > @@ -0,0 +1,6 @@ > +/* { dg-do compile { target pie } } */ > +/* { dg-options "-fhardened -O -fno-PIE" } */ > + > +#ifdef __PIE__ > +# error "PIE enabled when it should not be" > +#endif > diff --git a/gcc/testsuite/c-c++-common/fhardened-15.c > b/gcc/testsuite/c-c++-common/fhardened-15.c > new file mode 100644 > index 00000000000..c6202754bf5 > --- /dev/null > +++ b/gcc/testsuite/c-c++-common/fhardened-15.c > @@ -0,0 +1,5 @@ > +/* { dg-do compile } */ > +/* { dg-require-stack-check "specific" } */ > +/* { dg-options "-fhardened -O -fstack-check" } */ > + > +/* { dg-warning ".-fstack-clash-protection. is not enabled by .-fhardened. > because .-fstack-check. was specified" "" { target *-*-* } 0 } */ > diff --git a/gcc/testsuite/c-c++-common/fhardened-2.c > b/gcc/testsuite/c-c++-common/fhardened-2.c > new file mode 100644 > index 00000000000..283867ca806 > --- /dev/null > +++ b/gcc/testsuite/c-c++-common/fhardened-2.c > @@ -0,0 +1,12 @@ > +/* { dg-do compile } */ > +/* { dg-options "-fhardened -fstack-protector" } */ > + > +#ifdef __SSP_STRONG__ > +# error "-fstack-protector-strong enabled when it should not be" > +#endif > +#ifndef __SSP__ > +# error "-fstack-protector not enabled" > +#endif > + > +/* { dg-warning ".-fstack-protector-strong. is not enabled" "" { target > *-*-* } 0 } */ > +/* { dg-warning "._FORTIFY_SOURCE. is not enabled" "" { target *-*-* } 0 } */ > diff --git a/gcc/testsuite/c-c++-common/fhardened-3.c > b/gcc/testsuite/c-c++-common/fhardened-3.c > new file mode 100644 > index 00000000000..6924ba242f0 > --- /dev/null > +++ b/gcc/testsuite/c-c++-common/fhardened-3.c > @@ -0,0 +1,14 @@ > +/* { dg-do compile } */ > +/* { dg-options "-fhardened -O0" } */ > +/* Test that we don't get any diagnostic coming from libc headers. */ > + > +#include <stdio.h> > + > +/* The most useful C program known to man. */ > + > +int > +main () > +{ > +} > + > +/* { dg-warning "._FORTIFY_SOURCE. is not enabled" "" { target *-*-* } 0 } */ > diff --git a/gcc/testsuite/c-c++-common/fhardened-4.c > b/gcc/testsuite/c-c++-common/fhardened-4.c > new file mode 100644 > index 00000000000..7d44d299f19 > --- /dev/null > +++ b/gcc/testsuite/c-c++-common/fhardened-4.c > @@ -0,0 +1,4 @@ > +/* { dg-do compile } */ > +/* { dg-options "-fhardened -O0 -Wno-hardened" } */ > + > +/* { dg-bogus "._FORTIFY_SOURCE. is not enabled" "" { target *-*-* } 0 } */ > diff --git a/gcc/testsuite/c-c++-common/fhardened-5.c > b/gcc/testsuite/c-c++-common/fhardened-5.c > new file mode 100644 > index 00000000000..42594e4c0e0 > --- /dev/null > +++ b/gcc/testsuite/c-c++-common/fhardened-5.c > @@ -0,0 +1,11 @@ > +/* { dg-do compile } */ > +/* { dg-options "-fhardened -O -fdump-tree-gimple" } */ > + > +int > +foo () > +{ > + int i; > + return i; > +} > + > +/* { dg-final { scan-tree-dump ".DEFERRED_INIT" "gimple" } } */ > diff --git a/gcc/testsuite/c-c++-common/fhardened-6.c > b/gcc/testsuite/c-c++-common/fhardened-6.c > new file mode 100644 > index 00000000000..a757cbf0d12 > --- /dev/null > +++ b/gcc/testsuite/c-c++-common/fhardened-6.c > @@ -0,0 +1,12 @@ > +/* { dg-do compile } */ > +/* { dg-options "-fhardened -O -ftrivial-auto-var-init=uninitialized > -fdump-tree-gimple" } */ > + > +int > +foo () > +{ > + int i; > + return i; > +} > + > +/* { dg-final { scan-tree-dump-not ".DEFERRED_INIT" "gimple" } } */ > +/* { dg-warning ".-ftrivial-auto-var-init=pattern. is not enabled" "" { > target *-*-* } 0 } */ > diff --git a/gcc/testsuite/c-c++-common/fhardened-7.c > b/gcc/testsuite/c-c++-common/fhardened-7.c > new file mode 100644 > index 00000000000..32f35eb2595 > --- /dev/null > +++ b/gcc/testsuite/c-c++-common/fhardened-7.c > @@ -0,0 +1,7 @@ > +/* { dg-do compile { target pie } } */ > +/* { dg-options "-fhardened -O -fpie" } */ > + > +/* -fpie takes precedence over -fhardened */ > +#if __PIE__ != 1 > +# error "__PIE__ != 1" > +#endif > diff --git a/gcc/testsuite/c-c++-common/fhardened-8.c > b/gcc/testsuite/c-c++-common/fhardened-8.c > new file mode 100644 > index 00000000000..5b3162b4d1f > --- /dev/null > +++ b/gcc/testsuite/c-c++-common/fhardened-8.c > @@ -0,0 +1,7 @@ > +/* { dg-do compile { target pie } } */ > +/* { dg-options "-fhardened -O -fPIC" } */ > + > +/* -fPIC takes precedence over -fhardened */ > +#ifdef __PIE__ > +# error "PIE enabled when it should not be" > +#endif > diff --git a/gcc/testsuite/c-c++-common/fhardened-9.c > b/gcc/testsuite/c-c++-common/fhardened-9.c > new file mode 100644 > index 00000000000..d3b9e79b9b6 > --- /dev/null > +++ b/gcc/testsuite/c-c++-common/fhardened-9.c > @@ -0,0 +1,9 @@ > +/* { dg-do compile } */ > +/* { dg-options "-fhardened -U_FORTIFY_SOURCE -U_GLIBCXX_ASSERTIONS" } */ > + > +#if defined(_FORTIFY_SOURCE) || defined(_GLIBCXX_ASSERTIONS) > +# error "hardening enabled when it should not be" > +#endif > + > +/* { dg-warning "._FORTIFY_SOURCE. is not enabled" "" { target *-*-* } 0 } */ > +/* { dg-warning "._GLIBCXX_ASSERTIONS. is not enabled" "" { target *-*-* } 0 > } */ > diff --git a/gcc/testsuite/gcc.misc-tests/help.exp > b/gcc/testsuite/gcc.misc-tests/help.exp > index 52b9cb0ab90..15d618a2528 100644 > --- a/gcc/testsuite/gcc.misc-tests/help.exp > +++ b/gcc/testsuite/gcc.misc-tests/help.exp > @@ -151,6 +151,8 @@ foreach cls { "ada" "c" "c++" "d" "fortran" "go" \ > # Listing only excludes gives empty results. > check_for_options c "--help=^joined,^separate" "" "" "" > > +check_for_options c "--help=hardened" "The following options are enabled by > -fhardened" "" "" > + > if [ info exists prev_columns ] { > # Reset the enviroment variable to its oriuginal value. > set env(COLUMNS) $prev_columns > diff --git a/gcc/testsuite/gcc.target/i386/cf_check-6.c > b/gcc/testsuite/gcc.target/i386/cf_check-6.c > new file mode 100644 > index 00000000000..73b78dce889 > --- /dev/null > +++ b/gcc/testsuite/gcc.target/i386/cf_check-6.c > @@ -0,0 +1,12 @@ > +/* { dg-do compile } */ > +/* { dg-options "-O2 -fhardened -mno-manual-endbr" } */ > +/* { dg-final { scan-assembler-times {\mendbr} 1 } } */ > +/* Test that -fhardened enables CET. */ > + > +extern void bar (void) __attribute__((__cf_check__)); > + > +void > +foo (void) > +{ > + bar (); > +} > diff --git a/gcc/toplev.cc b/gcc/toplev.cc > index 8af9bf5090e..743a3a91684 100644 > --- a/gcc/toplev.cc > +++ b/gcc/toplev.cc > @@ -1575,6 +1575,19 @@ process_options (bool no_backend) > "where the stack grows from lower to higher addresses"); > flag_stack_clash_protection = 0; > } > + else if (flag_hardened) > + { > + if (!flag_stack_clash_protection > + /* Don't enable -fstack-clash-protection when -fstack-check= > + is used: it would result in confusing errors. */ > + && flag_stack_check == NO_STACK_CHECK) > + flag_stack_clash_protection = 1; > + else if (flag_stack_check != NO_STACK_CHECK) > + warning_at (UNKNOWN_LOCATION, OPT_Whardened, > + "%<-fstack-clash-protection%> is not enabled by " > + "%<-fhardened%> because %<-fstack-check%> was " > + "specified on the command line"); > + } > > /* We cannot support -fstack-check= and -fstack-clash-protection at > the same time. */ > @@ -1590,8 +1603,9 @@ process_options (bool no_backend) > target already uses a soft frame pointer, the transition is trivial. */ > if (!FRAME_GROWS_DOWNWARD && flag_stack_protect) > { > - warning_at (UNKNOWN_LOCATION, 0, > - "%<-fstack-protector%> not supported for this target"); > + if (!flag_stack_protector_set_by_fhardened_p) > + warning_at (UNKNOWN_LOCATION, 0, > + "%<-fstack-protector%> not supported for this target"); > flag_stack_protect = 0; > } > if (!flag_stack_protect) > > base-commit: e8d418df3dc609f27487deece796d4aa69004b8c > -- > 2.41.0 >
