[v3] gcc: Introduce -fhardened
Checks
Commit Message
On Thu, Oct 19, 2023 at 02:24:11PM +0200, Richard Biener wrote:
> On Wed, Oct 11, 2023 at 10:48 PM Marek Polacek <polacek@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
>
> I think =zero is much better here given the overhead is way
> cheaper and pointers get a more reliable behavior.
Ok, changed now.
> > > > > -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?
>
> I think it's OK but I'd like to see a second ACK here.
Thanks!
> Can you see how our
> primary and secondary targets (+ host OS) behave here?
That's very reasonable. I tried to build gcc on Compile Farm 119 (AIX) but
that fails with:
ar -X64 x ../ppc64/libgcc/libgcc_s.a shr.o
ar: 0707-100 ../ppc64/libgcc/libgcc_s.a does not exist.
make[2]: *** [/home/polacek/gcc/libgcc/config/rs6000/t-slibgcc-aix:98: all] Error 1
make[2]: Leaving directory '/home/polacek/x/trunk/powerpc-ibm-aix7.3.1.0/libgcc'
and I tried Darwin (104) and that fails with
*** Configuration aarch64-apple-darwin21.6.0 not supported
Is anyone else able to build gcc on those machines, or test the attached
patch?
> I think the
> documentation should elaborate a bit on expectations for non-Linux/GNU
> targets, specifically I think the default configuration for a target should
> with -fhardened _not_ have any -Whardened diagnostics. Maybe we can
> have a testcase for this?
Sorry, I'm not sure how to test that. I suppose if -fhardened enables
something not supported on those systems, and it's something for which
we have a configure test, then we shouldn't warn. This is already the
case for -pie, -z relro, and -z now.
Should the docs say something like the following for features without
configure checks?
@option{-fhardened} can, on certain systems, attempt to enable features
not supported on that particular system. In that case, it's possible to
prevent the warning using the @option{-Wno-hardened} option.
I've added a line saying:
+This option is intended to be used in production builds, not merely
+in debug builds.
-- >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=zero
-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=zero 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 | 47 ++++++++++++++-
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, 506 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
base-commit: 32b74c9e1d46932a4bbb1f46353bfc43c702c20a
Comments
On Mon, Oct 23, 2023 at 9:26 PM Marek Polacek <polacek@redhat.com> wrote:
>
> On Thu, Oct 19, 2023 at 02:24:11PM +0200, Richard Biener wrote:
> > On Wed, Oct 11, 2023 at 10:48 PM Marek Polacek <polacek@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
> >
> > I think =zero is much better here given the overhead is way
> > cheaper and pointers get a more reliable behavior.
>
> Ok, changed now.
>
> > > > > > -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?
> >
> > I think it's OK but I'd like to see a second ACK here.
>
> Thanks!
>
> > Can you see how our
> > primary and secondary targets (+ host OS) behave here?
>
> That's very reasonable. I tried to build gcc on Compile Farm 119 (AIX) but
> that fails with:
>
> ar -X64 x ../ppc64/libgcc/libgcc_s.a shr.o
> ar: 0707-100 ../ppc64/libgcc/libgcc_s.a does not exist.
> make[2]: *** [/home/polacek/gcc/libgcc/config/rs6000/t-slibgcc-aix:98: all] Error 1
> make[2]: Leaving directory '/home/polacek/x/trunk/powerpc-ibm-aix7.3.1.0/libgcc'
>
> and I tried Darwin (104) and that fails with
>
> *** Configuration aarch64-apple-darwin21.6.0 not supported
>
> Is anyone else able to build gcc on those machines, or test the attached
> patch?
>
> > I think the
> > documentation should elaborate a bit on expectations for non-Linux/GNU
> > targets, specifically I think the default configuration for a target should
> > with -fhardened _not_ have any -Whardened diagnostics. Maybe we can
> > have a testcase for this?
>
> Sorry, I'm not sure how to test that. I suppose if -fhardened enables
> something not supported on those systems, and it's something for which
> we have a configure test, then we shouldn't warn. This is already the
> case for -pie, -z relro, and -z now.
I was thinking of
/* { dg-do compile } */
/* { dg-additional-options "-fhardened -Whardened" } */
int main () {}
and excess errors should catch "misconfigurations"?
> Should the docs say something like the following for features without
> configure checks?
>
> @option{-fhardened} can, on certain systems, attempt to enable features
> not supported on that particular system. In that case, it's possible to
> prevent the warning using the @option{-Wno-hardened} option.
Yeah, but ideally
@option{-fhardened} can, on certain systems, not enable features not
available on those systems and @option{-Whardened} will not diagnose
those as missing.
But I understand it doesn't work like that?
> I've added a line saying:
>
> +This option is intended to be used in production builds, not merely
> +in debug builds.
>
> -- >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=zero
> -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=zero 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 | 47 ++++++++++++++-
> 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, 506 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 1cf3bdd3b51..48a15f077ef 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.
> @@ -1823,6 +1827,10 @@ fguess-branch-probability
> Common Var(flag_guess_branch_prob) Optimization
> Enable guessing of branch probabilities.
>
> +fhardened
> +Common Driver Var(flag_hardened)
> +Enable various security-relevant flags.
> +
> fharden-compares
> Common Var(flag_harden_compares) Optimization
> Harden conditionals not used in branches, checking reversed conditions.
> diff --git a/gcc/config.in b/gcc/config.in
> index 03faee1c6ac..327b1e3e2ee 100644
> --- a/gcc/config.in
> +++ b/gcc/config.in
> @@ -1695,6 +1695,12 @@
> #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
> @@ -1738,6 +1744,12 @@
> #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 072bbc628e2..8b31ee5b80c 100644
> --- a/gcc/config/i386/i386-options.cc
> +++ b/gcc/config/i386/i386-options.cc
> @@ -3069,10 +3069,25 @@ 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 77f33ee4df6..00ffc82ced8 100755
> --- a/gcc/configure
> +++ b/gcc/configure
> @@ -32883,7 +32883,7 @@ 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
> @@ -33012,6 +33012,54 @@ $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 10982cdfc09..fd845308a24 100644
> --- a/gcc/configure.ac
> +++ b/gcc/configure.ac
> @@ -7701,7 +7701,7 @@ 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 $gcc_cv_ld --help 2>&1 | grep -- '-z bndplt' > /dev/null; then
> ld_bndplt_support=yes
> fi
> @@ -7802,6 +7802,46 @@ standards-compatible mode on s390 targets.])
> ;;
> esac
>
> +# Check if the linker supports '-z now'
> +ld_now_support=no
> +AC_MSG_CHECKING(linker -z now option)
> +if test x"$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 5a9284d635c..e4237c28608 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
> @@ -641,7 +641,7 @@ 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
> -fharden-control-flow-redundancy -fhardcfr-skip-leaf
> -fhardcfr-check-exceptions -fhardcfr-check-returning-calls
> -fhardcfr-check-noreturn-calls=@r{[}always@r{|}no-xthrow@r{|}nothrow@r{|}never@r{]}
> @@ -6860,6 +6860,18 @@ 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
> @@ -17542,6 +17554,37 @@ made @option{no-xthrow} the default setting for this option: it excludes
> from the @code{noreturn} treatment only internal functions used to
> (re)raise exceptions, that are not affected by these optimizations.
>
> +@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=zero
> +-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.
> +
> +This option is intended to be used in production builds, not merely
> +in debug builds.
> +
> +@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 884284e66b4..a7e5774dcfa 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. */
> @@ -4606,10 +4613,20 @@ 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:
> @@ -4985,6 +5002,35 @@ 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..c5fc065ce68 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_ZERO;
> + else if (opts->x_flag_auto_var_init != AUTO_INIT_ZERO)
> + warning_at (loc, OPT_Whardened,
> + "%<-ftrivial-auto-var-init=zero%> 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=zero");
> +#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..744384f317f
> --- /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=zero. 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: 32b74c9e1d46932a4bbb1f46353bfc43c702c20a
> --
> 2.41.0
>
Hi Marek,
> On 23 Oct 2023, at 20:25, Marek Polacek <polacek@redhat.com> wrote:
>
> On Thu, Oct 19, 2023 at 02:24:11PM +0200, Richard Biener wrote:
>> On Wed, Oct 11, 2023 at 10:48 PM Marek Polacek <polacek@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:
>
> and I tried Darwin (104) and that fails with
>
> *** Configuration aarch64-apple-darwin21.6.0 not supported
>
> Is anyone else able to build gcc on those machines, or test the attached
> patch?
We’re still working on upstreaming the aarch64 Darwin port - the devt. branch
is here; https://github.com/iains/gcc-darwin-arm64 (but it will be rebased soon
because we just upstreamed some dependencies).
In the meantime, I will put your patch into my test queue - hopefully before
next week.
Iain
hi Marek,
> On 24 Oct 2023, at 08:44, Iain Sandoe <iain@sandoe.co.uk> wrote:
> On 23 Oct 2023, at 20:25, Marek Polacek <polacek@redhat.com> wrote:
>>
>> On Thu, Oct 19, 2023 at 02:24:11PM +0200, Richard Biener wrote:
>>> On Wed, Oct 11, 2023 at 10:48 PM Marek Polacek <polacek@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:
>>
>
>> and I tried Darwin (104) and that fails with
>>
>> *** Configuration aarch64-apple-darwin21.6.0 not supported
>>
>> Is anyone else able to build gcc on those machines, or test the attached
>> patch?
>
> We’re still working on upstreaming the aarch64 Darwin port - the devt. branch
> is here; https://github.com/iains/gcc-darwin-arm64 (but it will be rebased soon
> because we just upstreamed some dependencies).
>
> In the meantime, I will put your patch into my test queue - hopefully before
> next week.
actually, I rebased already .. (but not pushed yet, pending testing).
aarch64-darwin21 bootstrapped fine with your patch (as did x86_64-darwin19)
===
$ /opt/iains/aarch64-apple-darwin21/gcc-14-0-0/bin/gcc /source/test/hello.c -o hc -fhardened -Whardened
cc1: warning: ‘_FORTIFY_SOURCE’ is not enabled by ‘-fhardened’ because optimizations are turned off [-Whardened]
$ /opt/iains/aarch64-apple-darwin21/gcc-14-0-0/bin/gcc /source/test/hello.c -o hc -fhardened -Whardened -O
<no output>
I’m about to run the testsuite, but if there’s something else to be tested please let me know (NOTE: I have not read the patch, just applied it and built).
thanks,
Iain
On Tue, Oct 24, 2023 at 10:34:22AM +0100, Iain Sandoe wrote:
> hi Marek,
>
> > On 24 Oct 2023, at 08:44, Iain Sandoe <iain@sandoe.co.uk> wrote:
> > On 23 Oct 2023, at 20:25, Marek Polacek <polacek@redhat.com> wrote:
> >>
> >> On Thu, Oct 19, 2023 at 02:24:11PM +0200, Richard Biener wrote:
> >>> On Wed, Oct 11, 2023 at 10:48 PM Marek Polacek <polacek@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:
> >>
> >
> >> and I tried Darwin (104) and that fails with
> >>
> >> *** Configuration aarch64-apple-darwin21.6.0 not supported
> >>
> >> Is anyone else able to build gcc on those machines, or test the attached
> >> patch?
> >
> > We’re still working on upstreaming the aarch64 Darwin port - the devt. branch
> > is here; https://github.com/iains/gcc-darwin-arm64 (but it will be rebased soon
> > because we just upstreamed some dependencies).
> >
> > In the meantime, I will put your patch into my test queue - hopefully before
> > next week.
>
> actually, I rebased already .. (but not pushed yet, pending testing).
>
> aarch64-darwin21 bootstrapped fine with your patch (as did x86_64-darwin19)
Thank you so much Iain!
> ===
>
> $ /opt/iains/aarch64-apple-darwin21/gcc-14-0-0/bin/gcc /source/test/hello.c -o hc -fhardened -Whardened
> cc1: warning: ‘_FORTIFY_SOURCE’ is not enabled by ‘-fhardened’ because optimizations are turned off [-Whardened]
>
> $ /opt/iains/aarch64-apple-darwin21/gcc-14-0-0/bin/gcc /source/test/hello.c -o hc -fhardened -Whardened -O
> <no output>
That looks correct.
> I’m about to run the testsuite, but if there’s something else to be tested please let me know (NOTE: I have not read the patch, just applied it and built).
I am mostly curious about the fhardened* tests, if they all pass.
Thanks,
Marek
On Tue, Oct 24, 2023 at 09:22:25AM +0200, Richard Biener wrote:
> On Mon, Oct 23, 2023 at 9:26 PM Marek Polacek <polacek@redhat.com> wrote:
> >
> > On Thu, Oct 19, 2023 at 02:24:11PM +0200, Richard Biener wrote:
> > > On Wed, Oct 11, 2023 at 10:48 PM Marek Polacek <polacek@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
> > >
> > > I think =zero is much better here given the overhead is way
> > > cheaper and pointers get a more reliable behavior.
> >
> > Ok, changed now.
> >
> > > > > > > -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?
> > >
> > > I think it's OK but I'd like to see a second ACK here.
> >
> > Thanks!
> >
> > > Can you see how our
> > > primary and secondary targets (+ host OS) behave here?
> >
> > That's very reasonable. I tried to build gcc on Compile Farm 119 (AIX) but
> > that fails with:
> >
> > ar -X64 x ../ppc64/libgcc/libgcc_s.a shr.o
> > ar: 0707-100 ../ppc64/libgcc/libgcc_s.a does not exist.
> > make[2]: *** [/home/polacek/gcc/libgcc/config/rs6000/t-slibgcc-aix:98: all] Error 1
> > make[2]: Leaving directory '/home/polacek/x/trunk/powerpc-ibm-aix7.3.1.0/libgcc'
> >
> > and I tried Darwin (104) and that fails with
> >
> > *** Configuration aarch64-apple-darwin21.6.0 not supported
> >
> > Is anyone else able to build gcc on those machines, or test the attached
> > patch?
> >
> > > I think the
> > > documentation should elaborate a bit on expectations for non-Linux/GNU
> > > targets, specifically I think the default configuration for a target should
> > > with -fhardened _not_ have any -Whardened diagnostics. Maybe we can
> > > have a testcase for this?
> >
> > Sorry, I'm not sure how to test that. I suppose if -fhardened enables
> > something not supported on those systems, and it's something for which
> > we have a configure test, then we shouldn't warn. This is already the
> > case for -pie, -z relro, and -z now.
>
> I was thinking of
>
> /* { dg-do compile } */
> /* { dg-additional-options "-fhardened -Whardened" } */
>
> int main () {}
>
> and excess errors should catch "misconfigurations"?
I see. fhardened-3.c is basically just like this (-Whardened is on by default).
> > Should the docs say something like the following for features without
> > configure checks?
> >
> > @option{-fhardened} can, on certain systems, attempt to enable features
> > not supported on that particular system. In that case, it's possible to
> > prevent the warning using the @option{-Wno-hardened} option.
>
> Yeah, but ideally
>
> @option{-fhardened} can, on certain systems, not enable features not
> available on those systems and @option{-Whardened} will not diagnose
> those as missing.
>
> But I understand it doesn't work like that?
Right. It will not diagnose missing features if they have a configure
check, otherwise it will. And I don't know if we want a configure check
for every feature. Maybe we can add them in the future if the current
patch turns out to be problematical in practice?
Thanks,
Marek
> On 24 Oct 2023, at 20:03, Marek Polacek <polacek@redhat.com> wrote:
>
> On Tue, Oct 24, 2023 at 10:34:22AM +0100, Iain Sandoe wrote:
>> hi Marek,
>>
>>> On 24 Oct 2023, at 08:44, Iain Sandoe <iain@sandoe.co.uk> wrote:
>>> On 23 Oct 2023, at 20:25, Marek Polacek <polacek@redhat.com> wrote:
>>>>
>>>> On Thu, Oct 19, 2023 at 02:24:11PM +0200, Richard Biener wrote:
>>>>> On Wed, Oct 11, 2023 at 10:48 PM Marek Polacek <polacek@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:
>>>>
>>>
>>>> and I tried Darwin (104) and that fails with
>>>>
>>>> *** Configuration aarch64-apple-darwin21.6.0 not supported
>>>>
>>>> Is anyone else able to build gcc on those machines, or test the attached
>>>> patch?
>>>
>>> We’re still working on upstreaming the aarch64 Darwin port - the devt. branch
>>> is here; https://github.com/iains/gcc-darwin-arm64 (but it will be rebased soon
>>> because we just upstreamed some dependencies).
>>>
>>> In the meantime, I will put your patch into my test queue - hopefully before
>>> next week.
>>
>> actually, I rebased already .. (but not pushed yet, pending testing).
>>
>> aarch64-darwin21 bootstrapped fine with your patch (as did x86_64-darwin19)
>
> Thank you so much Iain!
>
>> ===
>>
>> $ /opt/iains/aarch64-apple-darwin21/gcc-14-0-0/bin/gcc /source/test/hello.c -o hc -fhardened -Whardened
>> cc1: warning: ‘_FORTIFY_SOURCE’ is not enabled by ‘-fhardened’ because optimizations are turned off [-Whardened]
>>
>> $ /opt/iains/aarch64-apple-darwin21/gcc-14-0-0/bin/gcc /source/test/hello.c -o hc -fhardened -Whardened -O
>> <no output>
>
> That looks correct.
>
>> I’m about to run the testsuite, but if there’s something else to be tested please let me know (NOTE: I have not read the patch, just applied it and built).
>
> I am mostly curious about the fhardened* tests, if they all pass.
No, some that require __PIE__=2 fail.
That is because Darwin has to handle PIE and PIC locally, because the way in which those options interact is different from Linux. I need to amend Darwin’s handling to work together with fhardening on platform versions tor which that’s relevant (but do not expect that to be too tricky).
For aarch64-darwin, PIE is mandatory so we had not even been considering it [we basically ignore the flag, because all it does is to create tool warnings] (I need to fix the ouput of the pp define tho).
For all x86_64 Darwin>=20 warns about no-PIE so we are also defaulting it on there.
Of course, none of this should affect these tests (it just means that fhardening will be a NOP for PIE on later Darwin).
I’ll look into these changes over the next few days, if I have a chance, in any case, they do not need to be relevant to your patch.
Iain
>
> Thanks,
> Marek
> Am 24.10.2023 um 21:09 schrieb Marek Polacek <polacek@redhat.com>:
>
> On Tue, Oct 24, 2023 at 09:22:25AM +0200, Richard Biener wrote:
>>> On Mon, Oct 23, 2023 at 9:26 PM Marek Polacek <polacek@redhat.com> wrote:
>>>
>>> On Thu, Oct 19, 2023 at 02:24:11PM +0200, Richard Biener wrote:
>>>> On Wed, Oct 11, 2023 at 10:48 PM Marek Polacek <polacek@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
>>>>
>>>> I think =zero is much better here given the overhead is way
>>>> cheaper and pointers get a more reliable behavior.
>>>
>>> Ok, changed now.
>>>
>>>>>>>> -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?
>>>>
>>>> I think it's OK but I'd like to see a second ACK here.
>>>
>>> Thanks!
>>>
>>>> Can you see how our
>>>> primary and secondary targets (+ host OS) behave here?
>>>
>>> That's very reasonable. I tried to build gcc on Compile Farm 119 (AIX) but
>>> that fails with:
>>>
>>> ar -X64 x ../ppc64/libgcc/libgcc_s.a shr.o
>>> ar: 0707-100 ../ppc64/libgcc/libgcc_s.a does not exist.
>>> make[2]: *** [/home/polacek/gcc/libgcc/config/rs6000/t-slibgcc-aix:98: all] Error 1
>>> make[2]: Leaving directory '/home/polacek/x/trunk/powerpc-ibm-aix7.3.1.0/libgcc'
>>>
>>> and I tried Darwin (104) and that fails with
>>>
>>> *** Configuration aarch64-apple-darwin21.6.0 not supported
>>>
>>> Is anyone else able to build gcc on those machines, or test the attached
>>> patch?
>>>
>>>> I think the
>>>> documentation should elaborate a bit on expectations for non-Linux/GNU
>>>> targets, specifically I think the default configuration for a target should
>>>> with -fhardened _not_ have any -Whardened diagnostics. Maybe we can
>>>> have a testcase for this?
>>>
>>> Sorry, I'm not sure how to test that. I suppose if -fhardened enables
>>> something not supported on those systems, and it's something for which
>>> we have a configure test, then we shouldn't warn. This is already the
>>> case for -pie, -z relro, and -z now.
>>
>> I was thinking of
>>
>> /* { dg-do compile } */
>> /* { dg-additional-options "-fhardened -Whardened" } */
>>
>> int main () {}
>>
>> and excess errors should catch "misconfigurations"?
>
> I see. fhardened-3.c is basically just like this (-Whardened is on by default).
>
>>> Should the docs say something like the following for features without
>>> configure checks?
>>>
>>> @option{-fhardened} can, on certain systems, attempt to enable features
>>> not supported on that particular system. In that case, it's possible to
>>> prevent the warning using the @option{-Wno-hardened} option.
>>
>> Yeah, but ideally
>>
>> @option{-fhardened} can, on certain systems, not enable features not
>> available on those systems and @option{-Whardened} will not diagnose
>> those as missing.
>>
>> But I understand it doesn't work like that?
>
> Right. It will not diagnose missing features if they have a configure
> check, otherwise it will. And I don't know if we want a configure check
> for every feature. Maybe we can add them in the future if the current
> patch turns out to be problematical in practice?
Maybe we can have a switch on known target triples and statically configure based
On that, eventually even not support -fhardened for targets not listed. That’s certainly easier than detecting the target system features (think of cross compilers)
> Thanks,
>
> Marek
>
@@ -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);
@@ -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.
@@ -1823,6 +1827,10 @@ fguess-branch-probability
Common Var(flag_guess_branch_prob) Optimization
Enable guessing of branch probabilities.
+fhardened
+Common Driver Var(flag_hardened)
+Enable various security-relevant flags.
+
fharden-compares
Common Var(flag_harden_compares) Optimization
Harden conditionals not used in branches, checking reversed conditions.
@@ -1695,6 +1695,12 @@
#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
@@ -1738,6 +1744,12 @@
#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
@@ -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;
}
@@ -3069,10 +3069,25 @@ 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
@@ -32883,7 +32883,7 @@ 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
@@ -33012,6 +33012,54 @@ $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)
@@ -7701,7 +7701,7 @@ 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 $gcc_cv_ld --help 2>&1 | grep -- '-z bndplt' > /dev/null; then
ld_bndplt_support=yes
fi
@@ -7802,6 +7802,46 @@ standards-compatible mode on s390 targets.])
;;
esac
+# Check if the linker supports '-z now'
+ld_now_support=no
+AC_MSG_CHECKING(linker -z now option)
+if test x"$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)
@@ -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
@@ -641,7 +641,7 @@ 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
-fharden-control-flow-redundancy -fhardcfr-skip-leaf
-fhardcfr-check-exceptions -fhardcfr-check-returning-calls
-fhardcfr-check-noreturn-calls=@r{[}always@r{|}no-xthrow@r{|}nothrow@r{|}never@r{]}
@@ -6860,6 +6860,18 @@ 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
@@ -17542,6 +17554,37 @@ made @option{no-xthrow} the default setting for this option: it excludes
from the @code{noreturn} treatment only internal functions used to
(re)raise exceptions, that are not affected by these optimizations.
+@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=zero
+-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.
+
+This option is intended to be used in production builds, not merely
+in debug builds.
+
+@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
@@ -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. */
@@ -4606,10 +4613,20 @@ 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:
@@ -4985,6 +5002,35 @@ 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)
@@ -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_ZERO;
+ else if (opts->x_flag_auto_var_init != AUTO_INIT_ZERO)
+ warning_at (loc, OPT_Whardened,
+ "%<-ftrivial-auto-var-init=zero%> 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=zero");
+#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",
@@ -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. */
new file mode 100644
@@ -0,0 +1,6 @@
+/* { dg-do preprocess { target pie } } */
+/* { dg-options "-fhardened -O" } */
+
+#if __PIE__ != 2
+# error "-fPIE not enabled"
+#endif
new file mode 100644
@@ -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
new file mode 100644
@@ -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 } */
new file mode 100644
@@ -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
new file mode 100644
@@ -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" } } */
new file mode 100644
@@ -0,0 +1,6 @@
+/* { dg-do compile { target pie } } */
+/* { dg-options "-fhardened -O" } */
+
+#if __PIE__ != 2
+# error "-fPIE not enabled"
+#endif
new file mode 100644
@@ -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
new file mode 100644
@@ -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 } */
new file mode 100644
@@ -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 } */
new file mode 100644
@@ -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 } */
new file mode 100644
@@ -0,0 +1,4 @@
+/* { dg-do compile } */
+/* { dg-options "-fhardened -O0 -Wno-hardened" } */
+
+/* { dg-bogus "._FORTIFY_SOURCE. is not enabled" "" { target *-*-* } 0 } */
new file mode 100644
@@ -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" } } */
new file mode 100644
@@ -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=zero. is not enabled" "" { target *-*-* } 0 } */
new file mode 100644
@@ -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
new file mode 100644
@@ -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
new file mode 100644
@@ -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 } */
@@ -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
new file mode 100644
@@ -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 ();
+}
@@ -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)