----- On Apr 29, 2019, at 1:03 PM, ndesaulniers ndesaulni...@google.com wrote:
> On Mon, Apr 29, 2019 at 8:29 AM Mathieu Desnoyers > <mathieu.desnoy...@efficios.com> wrote: >> >> Ongoing work for asm goto support from clang requires the >> -no-integrated-as compiler flag. >> >> This compiler flag is present in the toplevel kernel Makefile, >> but is not replicated for selftests. Add it specifically for >> the rseq selftest which requires asm goto. >> >> Link: https://reviews.llvm.org/D56571 >> Signed-off-by: Mathieu Desnoyers <mathieu.desnoy...@efficios.com> >> CC: Nick Desaulniers <ndesaulni...@google.com> >> CC: Thomas Gleixner <t...@linutronix.de> >> CC: Joel Fernandes <joe...@google.com> >> CC: Peter Zijlstra <pet...@infradead.org> >> CC: Catalin Marinas <catalin.mari...@arm.com> >> CC: Dave Watson <davejwat...@fb.com> >> CC: Will Deacon <will.dea...@arm.com> >> CC: Shuah Khan <sh...@kernel.org> >> CC: Andi Kleen <a...@firstfloor.org> >> CC: linux-kselft...@vger.kernel.org >> CC: "H . Peter Anvin" <h...@zytor.com> >> CC: Chris Lameter <c...@linux.com> >> CC: Russell King <li...@arm.linux.org.uk> >> CC: Michael Kerrisk <mtk.manpa...@gmail.com> >> CC: "Paul E . McKenney" <paul...@linux.vnet.ibm.com> >> CC: Paul Turner <p...@google.com> >> CC: Boqun Feng <boqun.f...@gmail.com> >> CC: Josh Triplett <j...@joshtriplett.org> >> CC: Steven Rostedt <rost...@goodmis.org> >> CC: Ben Maurer <bmau...@fb.com> >> CC: linux-...@vger.kernel.org >> CC: Andy Lutomirski <l...@amacapital.net> >> CC: Andrew Morton <a...@linux-foundation.org> >> CC: Linus Torvalds <torva...@linux-foundation.org> >> --- >> tools/testing/selftests/rseq/Makefile | 8 +++++++- >> 1 file changed, 7 insertions(+), 1 deletion(-) >> >> diff --git a/tools/testing/selftests/rseq/Makefile >> b/tools/testing/selftests/rseq/Makefile >> index c30c52e1d0d2..d6469535630a 100644 >> --- a/tools/testing/selftests/rseq/Makefile >> +++ b/tools/testing/selftests/rseq/Makefile >> @@ -1,5 +1,11 @@ >> # SPDX-License-Identifier: GPL-2.0+ OR MIT >> -CFLAGS += -O2 -Wall -g -I./ -I../../../../usr/include/ -L./ -Wl,-rpath=./ >> + >> +ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),) >> +CLANG_FLAGS += -no-integrated-as >> +endif >> + >> +CFLAGS += -O2 -Wall -g -I./ -I../../../../usr/include/ -L./ -Wl,-rpath=./ \ >> + $(CLANG_FLAGS) > > The top level Makefile exports $(CLANG_FLAGS), which should contain > `-no-integrated-as`. Is that available here? If so, then you can > just add `$(CLANG_FLAGS)`, no compiler check needed. AFAIU, the makefiles under tools/testing/selftests all end up including tools/testing/selftests/lib.mk, which states: "# This mimics the top-level Makefile. We do it explicitly here so that this # Makefile can operate with or without the kbuild infrastructure." So I don't think it's using any of the definitions from the toplevel Makefile. > If not, maybe the test for CONFIG_CC_IS_CLANG is cleaner? A quick test indicates that the toplevel CONFIG_* definitions are unavailable from the kernel selftests makefiles. > Thanks for the patch, and helping test asm goto in Clang! You're very welcome! Considering that I intend to have rseq widely adopted in user-space, it's only natural to consider that its user-space side needs to be compiled by clang as well. Thanks, Mathieu -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com
