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From:   Thomas Gleixner <tglx@linutronix.de>
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To:     Alexander Potapenko <glider@google.com>, glider@google.com
Cc:     Alexander Viro <viro@zeniv.linux.org.uk>,
        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>,
        Marco Elver <elver@google.com>,
        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>,
        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
Subject: Re: [PATCH v3 27/46] kmsan: instrumentation.h: add
 instrumentation_begin_with_regs()
In-Reply-To: <20220426164315.625149-28-glider@google.com>
References: <20220426164315.625149-1-glider@google.com>
 <20220426164315.625149-28-glider@google.com>
Date:   Wed, 27 Apr 2022 15:28:23 +0200
Message-ID: <87bkwmy7t4.ffs@tglx>
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On Tue, Apr 26 2022 at 18:42, Alexander Potapenko wrote:
> +void kmsan_instrumentation_begin(struct pt_regs *regs)
> +{
> +	struct kmsan_context_state *state = &kmsan_get_context()->cstate;
> +
> +	if (state)
> +		__memset(state, 0, sizeof(struct kmsan_context_state));

  sizeof(*state) please

> +	if (!kmsan_enabled || !regs)
> +		return;

Why has state to be cleared when kmsan is not enabled and how do you end up
with regs == NULL here?

Thanks,

        tglx