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From:   Alexander Potapenko <glider@google.com>
Date:   Fri, 8 Dec 2023 14:32:15 +0100
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Subject: Re: [PATCH v2 19/33] lib/zlib: Unpoison DFLTCC output buffers
To:     Ilya Leoshkevich <iii@linux.ibm.com>
Cc:     Alexander Gordeev <agordeev@linux.ibm.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Christoph Lameter <cl@linux.com>,
        David Rientjes <rientjes@google.com>,
        Heiko Carstens <hca@linux.ibm.com>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>,
        Marco Elver <elver@google.com>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Pekka Enberg <penberg@kernel.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Vasily Gorbik <gor@linux.ibm.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        Christian Borntraeger <borntraeger@linux.ibm.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Hyeonggon Yoo <42.hyeyoo@gmail.com>,
        kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, linux-s390@vger.kernel.org,
        linux-trace-kernel@vger.kernel.org,
        Mark Rutland <mark.rutland@arm.com>,
        Roman Gushchin <roman.gushchin@linux.dev>,
        Sven Schnelle <svens@linux.ibm.com>
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On Tue, Nov 21, 2023 at 11:07=E2=80=AFPM Ilya Leoshkevich <iii@linux.ibm.co=
m> wrote:
>
> The constraints of the DFLTCC inline assembly are not precise: they
> do not communicate the size of the output buffers to the compiler, so
> it cannot automatically instrument it.

KMSAN usually does a poor job instrumenting inline assembly.
Wouldn't be it better to switch to pure C ZLIB implementation, making
ZLIB_DFLTCC depend on !KMSAN?