From: "René Scharfe" <l.s.r@web.de>
To: Jeff King <peff@peff.net>, git@vger.kernel.org
Subject: Re: [PATCH 5/5] Makefile: disable unaligned loads with UBSan
Date: Sat, 15 Jul 2017 19:18:56 +0200 [thread overview]
Message-ID: <de9c876c-f018-ad6b-3813-576ea73dd49a@web.de> (raw)
In-Reply-To: <20170710132450.yxojk5cybejy7und@sigill.intra.peff.net>
Am 10.07.2017 um 15:24 schrieb Jeff King:
> The undefined behavior sanitizer complains about unaligned
> loads, even if they're OK for a particular platform in
> practice. It's possible that they _are_ a problem, of
> course, but since it's a known tradeoff the UBSan errors are
> just noise.
>
> Let's quiet it automatically by building with
> NO_UNALIGNED_LOADS when SANITIZE=undefined is in use.
>
> Signed-off-by: Jeff King <peff@peff.net>
> ---
> Makefile | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/Makefile b/Makefile
> index cc03b3c95..3c341b2a6 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -1015,6 +1015,9 @@ endif
> ifdef SANITIZE
> BASIC_CFLAGS += -fsanitize=$(SANITIZE) -fno-sanitize-recover=$(SANITIZE)
> BASIC_CFLAGS += -fno-omit-frame-pointer
> +ifeq ($(SANITIZE),undefined)
> +BASIC_CFLAGS += -DNO_UNALIGNED_LOADS
> +endif
> endif
>
> ifndef sysconfdir
Nice, but let's be even nicer!
-- >8 --
Subject: [PATCH] Makefile: allow combining UBSan with other sanitizers
Multiple sanitizers can be specified as a comma-separated list. Set
the flag NO_UNALIGNED_LOADS even if UndefinedBehaviorSanitizer is not
the only sanitizer to build with.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
---
Makefile | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/Makefile b/Makefile
index ba4359ef8d..9b98535a04 100644
--- a/Makefile
+++ b/Makefile
@@ -1022,10 +1022,15 @@ ifdef DEVELOPER
CFLAGS += $(DEVELOPER_CFLAGS)
endif
+comma := ,
+empty :=
+space := $(empty) $(empty)
+
ifdef SANITIZE
+SANITIZERS := $(foreach flag,$(subst $(comma),$(space),$(SANITIZE)),$(flag))
BASIC_CFLAGS += -fsanitize=$(SANITIZE) -fno-sanitize-recover=$(SANITIZE)
BASIC_CFLAGS += -fno-omit-frame-pointer
-ifeq ($(SANITIZE),undefined)
+ifneq ($(filter undefined,$(SANITIZERS)),)
BASIC_CFLAGS += -DNO_UNALIGNED_LOADS
endif
endif
--
2.13.3
next prev parent reply other threads:[~2017-07-15 17:19 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-10 13:24 [PATCH 0/5] building git with clang/gcc address sanitizer Jeff King
2017-07-10 13:24 ` [PATCH 1/5] test-lib: set ASAN_OPTIONS variable before we run git Jeff King
2017-07-10 13:24 ` [PATCH 2/5] test-lib: turn on ASan abort_on_error by default Jeff King
2017-07-10 17:18 ` Junio C Hamano
2017-07-10 13:24 ` [PATCH 3/5] Makefile: add helper for compiling with -fsanitize Jeff King
2017-07-10 17:35 ` Junio C Hamano
2017-07-10 17:44 ` Jeff King
2017-07-10 18:07 ` Junio C Hamano
2017-07-10 20:02 ` Ramsay Jones
2017-07-11 4:44 ` Jeff King
2017-07-10 13:24 ` [PATCH 4/5] Makefile: turn off -fomit-frame-pointer with sanitizers Jeff King
2017-07-10 13:24 ` [PATCH 5/5] Makefile: disable unaligned loads with UBSan Jeff King
2017-07-15 17:18 ` René Scharfe [this message]
2017-07-16 10:17 ` Jeff King
2017-07-16 11:02 ` René Scharfe
2017-07-10 13:30 ` [PATCH 0/5] building git with clang/gcc address sanitizer Jeff King
2017-07-10 14:40 ` Lars Schneider
2017-07-10 15:58 ` Jeff King
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