Messages in this thread Patch in this message | | | Date | Mon, 29 Apr 2019 16:28:18 -0400 (EDT) | From | Mathieu Desnoyers <> | Subject | Re: [PATCH for 5.2 12/12] rseq/selftests: add -no-integrated-as for clang |
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----- On Apr 29, 2019, at 1:03 PM, ndesaulniers ndesaulniers@google.com wrote:
> On Mon, Apr 29, 2019 at 8:29 AM Mathieu Desnoyers > <mathieu.desnoyers@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.desnoyers@efficios.com> >> CC: Nick Desaulniers <ndesaulniers@google.com> >> CC: Thomas Gleixner <tglx@linutronix.de> >> CC: Joel Fernandes <joelaf@google.com> >> CC: Peter Zijlstra <peterz@infradead.org> >> CC: Catalin Marinas <catalin.marinas@arm.com> >> CC: Dave Watson <davejwatson@fb.com> >> CC: Will Deacon <will.deacon@arm.com> >> CC: Shuah Khan <shuah@kernel.org> >> CC: Andi Kleen <andi@firstfloor.org> >> CC: linux-kselftest@vger.kernel.org >> CC: "H . Peter Anvin" <hpa@zytor.com> >> CC: Chris Lameter <cl@linux.com> >> CC: Russell King <linux@arm.linux.org.uk> >> CC: Michael Kerrisk <mtk.manpages@gmail.com> >> CC: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> >> CC: Paul Turner <pjt@google.com> >> CC: Boqun Feng <boqun.feng@gmail.com> >> CC: Josh Triplett <josh@joshtriplett.org> >> CC: Steven Rostedt <rostedt@goodmis.org> >> CC: Ben Maurer <bmaurer@fb.com> >> CC: linux-api@vger.kernel.org >> CC: Andy Lutomirski <luto@amacapital.net> >> CC: Andrew Morton <akpm@linux-foundation.org> >> CC: Linus Torvalds <torvalds@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
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