| Message ID | 20190429152803.7719-13-mathieu.desnoyers@efficios.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [for,5.2,01/12] rseq/selftests: x86: Work-around bogus gcc-8 optimisation | expand |
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. If not, maybe the test for CONFIG_CC_IS_CLANG is cleaner? Thanks for the patch, and helping test asm goto in Clang!
----- 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
On Mon, Apr 29, 2019 at 1:28 PM Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote: > > ----- 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: > >> 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. Ok, in that case... Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Thanks again!
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) LDLIBS += -lpthread # Own dependencies because we only want to build against 1st prerequisite, but
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(-)