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Date:   Wed, 13 Jul 2022 12:22:52 +0200
From:   Marco Elver <elver@google.com>
To:     Alexander Potapenko <glider@google.com>
Cc:     Alexander Viro <viro@zeniv.linux.org.uk>,
        Alexei Starovoitov <ast@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Andrey Konovalov <andreyknvl@google.com>,
        Andy Lutomirski <luto@kernel.org>,
        Arnd Bergmann <arnd@arndb.de>, Borislav Petkov <bp@alien8.de>,
        Christoph Hellwig <hch@lst.de>,
        Christoph Lameter <cl@linux.com>,
        David Rientjes <rientjes@google.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Eric Dumazet <edumazet@google.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        Ilya Leoshkevich <iii@linux.ibm.com>,
        Ingo Molnar <mingo@redhat.com>, Jens Axboe <axboe@kernel.dk>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>,
        Kees Cook <keescook@chromium.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Matthew Wilcox <willy@infradead.org>,
        "Michael S. Tsirkin" <mst@redhat.com>,
        Pekka Enberg <penberg@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Petr Mladek <pmladek@suse.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Vasily Gorbik <gor@linux.ibm.com>,
        Vegard Nossum <vegard.nossum@oracle.com>,
        Vlastimil Babka <vbabka@suse.cz>, kasan-dev@googlegroups.com,
        linux-mm@kvack.org, linux-arch@vger.kernel.org,
        linux-kernel@vger.kernel.org, Eric Biggers <ebiggers@google.com>
Subject: Re: [PATCH v4 29/45] block: kmsan: skip bio block merging logic for
 KMSAN
Message-ID: <Ys6c/JYJlQjIfZtH@elver.google.com>
References: <20220701142310.2188015-1-glider@google.com>
 <20220701142310.2188015-30-glider@google.com>
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On Fri, Jul 01, 2022 at 04:22PM +0200, 'Alexander Potapenko' via kasan-dev wrote:
[...]
> --- a/block/bio.c
> +++ b/block/bio.c
> @@ -867,6 +867,8 @@ static inline bool page_is_mergeable(const struct bio_vec *bv,
>  		return false;
>  
>  	*same_page = ((vec_end_addr & PAGE_MASK) == page_addr);
> +	if (!*same_page && IS_ENABLED(CONFIG_KMSAN))
> +		return false;
>  	if (*same_page)
>  		return true;

  	if (*same_page)
  		return true;
	else if (IS_ENABLED(CONFIG_KMSAN))
		return false;

>  	return (bv->bv_page + bv_end / PAGE_SIZE) == (page + off / PAGE_SIZE);