Re: [PATCH 3/5] Makefile: add helper for compiling with -fsanitize

From: Jeff King <peff@peff.net>
Date: Jul 11, 2017, 04:44 UTC
Message-ID: <20170711044401.pf7gmovxe7yss2s7@sigill.intra.peff.net>
In-Reply-To: <752db1ea-8416-3a98-babf-78b766432f0f@ramsayjones.plus.com>

On Mon, Jul 10, 2017 at 09:02:24PM +0100, Ramsay Jones wrote:

Show 17 quoted lines

> After a quick look at the ./t0000-basic.sh test, I managed to get
> the test to complete (with 15 tests failing), with the following
> patch applied:
> 
> -- >8 --
> diff --git a/Makefile b/Makefile
> index 3c341b2a6..8e6433738 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -1016,7 +1016,7 @@ ifdef SANITIZE
>  BASIC_CFLAGS += -fsanitize=$(SANITIZE) -fno-sanitize-recover=$(SANITIZE)
>  BASIC_CFLAGS += -fno-omit-frame-pointer
>  ifeq ($(SANITIZE),undefined)
> -BASIC_CFLAGS += -DNO_UNALIGNED_LOADS
> +BASIC_CFLAGS += -DNO_UNALIGNED_LOADS -DSHA1DC_FORCE_ALIGNED_ACCESS
>  endif
>  endif

Thanks, I forgot to mention SHA1DC. When I had originally tested with "undefined", it was before we had SHA1DC. I hacked around it earlier today by just using OPENSSL_SHA1. ;)

I agree if we can ask it to avoid unaligned access that is even better.

Show 11 quoted lines

> diff --git a/sha1dc/sha1.c b/sha1dc/sha1.c
> index 25eded139..3baddc636 100644
> --- a/sha1dc/sha1.c
> +++ b/sha1dc/sha1.c
> @@ -118,6 +118,10 @@
>  #define SHA1DC_ALLOW_UNALIGNED_ACCESS
>  #endif /*UNALIGNMENT DETECTION*/
>  
> +#if defined(SHA1DC_ALLOW_UNALIGNED_ACCESS) && defined(SHA1DC_FORCE_ALIGNED_ACCESS)
> +#undef SHA1DC_ALLOW_UNALIGNED_ACCESS
> +#endif

I think our current strategy is to avoid touching sha1.c as much as possible. I think we'd prefer a patch to the upstream project to support FORCE_ALIGNED_ACCESS (unfortunately I do not see a way to tweak it using only external defines.

-Peff