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[PATCH 5/5] Makefile: disable unaligned loads with UBSan

From
Jeff King <peff@peff.net>
Date
Jul 10, 2017, 13:24 UTC
Message-ID
<20170710132450.yxojk5cybejy7und@sigill.intra.peff.net>
In-Reply-To
<20170710132418.d6bvzxwvbejretb4@sigill.intra.peff.net>

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

-- 
2.13.2.1071.gcd8104b61
Previous: Junio C HamanoNext: René Scharfe
Message 11 of 18 in “building git with clang/gcc address sanitizer”
  1. 0/5 building git with clang/gcc address sanitizerJeff King, Jul 10, 2017
  2. 1/5 test-lib: set ASAN_OPTIONS variable before we run gitJeff King, Jul 10, 2017
  3. 3/5 Makefile: add helper for compiling with -fsanitizeJeff King, Jul 10, 2017
  4. Junio C HamanoJul 10, 2017
  5. Jeff KingJul 10, 2017
  6. Junio C HamanoJul 10, 2017
  7. Ramsay JonesJul 10, 2017
  8. Jeff KingJul 11, 2017
  9. 2/5 test-lib: turn on ASan abort_on_error by defaultJeff King, Jul 10, 2017
  10. Junio C HamanoJul 10, 2017
  11. 5/5 Makefile: disable unaligned loads with UBSanJeff King, Jul 10, 2017
  12. René ScharfeJul 15, 2017
  13. Jeff KingJul 16, 2017
  14. René ScharfeJul 16, 2017
  15. 4/5 Makefile: turn off -fomit-frame-pointer with sanitizersJeff King, Jul 10, 2017
  16. Jeff KingJul 10, 2017
  17. Lars SchneiderJul 10, 2017
  18. Jeff KingJul 10, 2017

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