| Message ID | 20220130181616.420092-1-keescook@chromium.org (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 818ab43fc56ad978cbb7c0ffdc9a332fd2f23a23 |
| Headers | show |
| Series | fortify: Update compile-time tests for Clang 14 | expand |
On Sun, Jan 30, 2022 at 10:16:16AM -0800, Kees Cook wrote: > Clang 14 introduces support for compiletime_assert(). Update the > compile-time warning regex to catch Clang's variant of the warning text > in preparation for Clang supporting CONFIG_FORTIFY_SOURCE. > > Cc: Nathan Chancellor <nathan@kernel.org> > Cc: Nick Desaulniers <ndesaulniers@google.com> > Cc: linux-hardening@vger.kernel.org > Cc: llvm@lists.linux.dev > Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org> > --- > I'm splitting this patch out of the main Clang FORTIFY enabling patch. > --- > scripts/test_fortify.sh | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/scripts/test_fortify.sh b/scripts/test_fortify.sh > index a4da365508f0..c2688ab8281d 100644 > --- a/scripts/test_fortify.sh > +++ b/scripts/test_fortify.sh > @@ -46,8 +46,12 @@ if "$@" -Werror -c "$IN" -o "$OUT".o 2> "$TMP" ; then > status="warning: unsafe ${FUNC}() usage lacked '$WANT' symbol in $IN" > fi > else > - # If the build failed, check for the warning in the stderr (gcc). > - if ! grep -q -m1 "error: call to .\b${WANT}\b." "$TMP" ; then > + # If the build failed, check for the warning in the stderr. > + # GCC: > + # ./include/linux/fortify-string.h:316:25: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning] > + # Clang 14: > + # ./include/linux/fortify-string.h:316:4: error: call to __write_overflow_field declared with 'warning' attribute: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror,-Wattribute-warning] > + if ! grep -Eq -m1 "error: call to .?\b${WANT}\b.?" "$TMP" ; then > status="warning: unsafe ${FUNC}() usage lacked '$WANT' warning in $IN" > fi > fi > -- > 2.30.2 >
On Sun, Jan 30, 2022 at 10:16 AM Kees Cook <keescook@chromium.org> wrote: > > Clang 14 introduces support for compiletime_assert(). Update the > compile-time warning regex to catch Clang's variant of the warning text > in preparation for Clang supporting CONFIG_FORTIFY_SOURCE. https://twitter.com/ifosteve/status/1190348262500421634?lang=en error messages can change over time. More thoughts below. > > Cc: Nathan Chancellor <nathan@kernel.org> > Cc: Nick Desaulniers <ndesaulniers@google.com> > Cc: linux-hardening@vger.kernel.org > Cc: llvm@lists.linux.dev > Signed-off-by: Kees Cook <keescook@chromium.org> > --- > I'm splitting this patch out of the main Clang FORTIFY enabling patch. > --- > scripts/test_fortify.sh | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/scripts/test_fortify.sh b/scripts/test_fortify.sh > index a4da365508f0..c2688ab8281d 100644 > --- a/scripts/test_fortify.sh > +++ b/scripts/test_fortify.sh > @@ -46,8 +46,12 @@ if "$@" -Werror -c "$IN" -o "$OUT".o 2> "$TMP" ; then > status="warning: unsafe ${FUNC}() usage lacked '$WANT' symbol in $IN" > fi > else > - # If the build failed, check for the warning in the stderr (gcc). > - if ! grep -q -m1 "error: call to .\b${WANT}\b." "$TMP" ; then > + # If the build failed, check for the warning in the stderr. > + # GCC: > + # ./include/linux/fortify-string.h:316:25: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning] > + # Clang 14: > + # ./include/linux/fortify-string.h:316:4: error: call to __write_overflow_field declared with 'warning' attribute: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror,-Wattribute-warning] > + if ! grep -Eq -m1 "error: call to .?\b${WANT}\b.?" "$TMP" ; then Doesn't this depend on -Werror being set? I guess it did so before hand, too, but couldn't I unset CONFIG_WERROR then this check would still fail (since instead of `error:` we'd have `warning:`)? If we used __attribute__((error(""))) then this would always be an error. Right now, it is only because -Werror is set promoting the warning diagnostic to an error. > status="warning: unsafe ${FUNC}() usage lacked '$WANT' warning in $IN" > fi > fi > -- > 2.30.2 >
On Mon, Jan 31, 2022 at 11:09:27AM -0800, Nick Desaulniers wrote: > On Sun, Jan 30, 2022 at 10:16 AM Kees Cook <keescook@chromium.org> wrote: > > > > Clang 14 introduces support for compiletime_assert(). Update the > > compile-time warning regex to catch Clang's variant of the warning text > > in preparation for Clang supporting CONFIG_FORTIFY_SOURCE. > > https://twitter.com/ifosteve/status/1190348262500421634?lang=en > error messages can change over time. More thoughts below. Sure, but I don't want the compile-time checks to silently regress, which requires looking specifically for the error. > > Cc: Nathan Chancellor <nathan@kernel.org> > > Cc: Nick Desaulniers <ndesaulniers@google.com> > > Cc: linux-hardening@vger.kernel.org > > Cc: llvm@lists.linux.dev > > Signed-off-by: Kees Cook <keescook@chromium.org> > > --- > > I'm splitting this patch out of the main Clang FORTIFY enabling patch. > > --- > > scripts/test_fortify.sh | 8 ++++++-- > > 1 file changed, 6 insertions(+), 2 deletions(-) > > > > diff --git a/scripts/test_fortify.sh b/scripts/test_fortify.sh > > index a4da365508f0..c2688ab8281d 100644 > > --- a/scripts/test_fortify.sh > > +++ b/scripts/test_fortify.sh > > @@ -46,8 +46,12 @@ if "$@" -Werror -c "$IN" -o "$OUT".o 2> "$TMP" ; then > > status="warning: unsafe ${FUNC}() usage lacked '$WANT' symbol in $IN" > > fi > > else > > - # If the build failed, check for the warning in the stderr (gcc). > > - if ! grep -q -m1 "error: call to .\b${WANT}\b." "$TMP" ; then > > + # If the build failed, check for the warning in the stderr. > > + # GCC: > > + # ./include/linux/fortify-string.h:316:25: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning] > > + # Clang 14: > > + # ./include/linux/fortify-string.h:316:4: error: call to __write_overflow_field declared with 'warning' attribute: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror,-Wattribute-warning] > > + if ! grep -Eq -m1 "error: call to .?\b${WANT}\b.?" "$TMP" ; then > > Doesn't this depend on -Werror being set? I guess it did so before > hand, too, but couldn't I unset CONFIG_WERROR then this check would > still fail (since instead of `error:` we'd have `warning:`)? If we > used __attribute__((error(""))) then this would always be an error. > Right now, it is only because -Werror is set promoting the warning > diagnostic to an error. Right, see earlier up in the script. "-Werror" is explicitly set: line 40: if "$@" -Werror -c "$IN" -o "$OUT".o 2> "$TMP" ; then
On Mon, Jan 31, 2022 at 1:09 PM Kees Cook <keescook@chromium.org> wrote: > > On Mon, Jan 31, 2022 at 11:09:27AM -0800, Nick Desaulniers wrote: > > On Sun, Jan 30, 2022 at 10:16 AM Kees Cook <keescook@chromium.org> wrote: > > > > > > Clang 14 introduces support for compiletime_assert(). Update the > > > compile-time warning regex to catch Clang's variant of the warning text > > > in preparation for Clang supporting CONFIG_FORTIFY_SOURCE. > > > > https://twitter.com/ifosteve/status/1190348262500421634?lang=en > > error messages can change over time. More thoughts below. > > Sure, but I don't want the compile-time checks to silently regress, > which requires looking specifically for the error. > > > > Cc: Nathan Chancellor <nathan@kernel.org> > > > Cc: Nick Desaulniers <ndesaulniers@google.com> > > > Cc: linux-hardening@vger.kernel.org > > > Cc: llvm@lists.linux.dev > > > Signed-off-by: Kees Cook <keescook@chromium.org> > > > --- > > > I'm splitting this patch out of the main Clang FORTIFY enabling patch. > > > --- > > > scripts/test_fortify.sh | 8 ++++++-- > > > 1 file changed, 6 insertions(+), 2 deletions(-) > > > > > > diff --git a/scripts/test_fortify.sh b/scripts/test_fortify.sh > > > index a4da365508f0..c2688ab8281d 100644 > > > --- a/scripts/test_fortify.sh > > > +++ b/scripts/test_fortify.sh > > > @@ -46,8 +46,12 @@ if "$@" -Werror -c "$IN" -o "$OUT".o 2> "$TMP" ; then > > > status="warning: unsafe ${FUNC}() usage lacked '$WANT' symbol in $IN" > > > fi > > > else > > > - # If the build failed, check for the warning in the stderr (gcc). > > > - if ! grep -q -m1 "error: call to .\b${WANT}\b." "$TMP" ; then > > > + # If the build failed, check for the warning in the stderr. > > > + # GCC: > > > + # ./include/linux/fortify-string.h:316:25: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning] > > > + # Clang 14: > > > + # ./include/linux/fortify-string.h:316:4: error: call to __write_overflow_field declared with 'warning' attribute: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror,-Wattribute-warning] > > > + if ! grep -Eq -m1 "error: call to .?\b${WANT}\b.?" "$TMP" ; then > > > > Doesn't this depend on -Werror being set? I guess it did so before > > hand, too, but couldn't I unset CONFIG_WERROR then this check would > > still fail (since instead of `error:` we'd have `warning:`)? If we > > used __attribute__((error(""))) then this would always be an error. > > Right now, it is only because -Werror is set promoting the warning > > diagnostic to an error. > > Right, see earlier up in the script. "-Werror" is explicitly set: > > line 40: if "$@" -Werror -c "$IN" -o "$OUT".o 2> "$TMP" ; then Yep, I missed that. Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> > > -- > Kees Cook
diff --git a/scripts/test_fortify.sh b/scripts/test_fortify.sh index a4da365508f0..c2688ab8281d 100644 --- a/scripts/test_fortify.sh +++ b/scripts/test_fortify.sh @@ -46,8 +46,12 @@ if "$@" -Werror -c "$IN" -o "$OUT".o 2> "$TMP" ; then status="warning: unsafe ${FUNC}() usage lacked '$WANT' symbol in $IN" fi else - # If the build failed, check for the warning in the stderr (gcc). - if ! grep -q -m1 "error: call to .\b${WANT}\b." "$TMP" ; then + # If the build failed, check for the warning in the stderr. + # GCC: + # ./include/linux/fortify-string.h:316:25: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning] + # Clang 14: + # ./include/linux/fortify-string.h:316:4: error: call to __write_overflow_field declared with 'warning' attribute: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror,-Wattribute-warning] + if ! grep -Eq -m1 "error: call to .?\b${WANT}\b.?" "$TMP" ; then status="warning: unsafe ${FUNC}() usage lacked '$WANT' warning in $IN" fi fi
Clang 14 introduces support for compiletime_assert(). Update the compile-time warning regex to catch Clang's variant of the warning text in preparation for Clang supporting CONFIG_FORTIFY_SOURCE. Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: linux-hardening@vger.kernel.org Cc: llvm@lists.linux.dev Signed-off-by: Kees Cook <keescook@chromium.org> --- I'm splitting this patch out of the main Clang FORTIFY enabling patch. --- scripts/test_fortify.sh | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)