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
