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[2607:7c80:54:e::133]) by mx.google.com with ESMTPS id t185si12549441pgd.596.2019.07.23.18.38.44 for (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Tue, 23 Jul 2019 18:38:44 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of willy@infradead.org designates 2607:7c80:54:e::133 as permitted sender) client-ip=2607:7c80:54:e::133; Authentication-Results: mx.google.com; dkim=pass header.i=@infradead.org header.s=bombadil.20170209 header.b=RULrgcX4; spf=pass (google.com: best guess record for domain of willy@infradead.org designates 2607:7c80:54:e::133 as permitted sender) smtp.mailfrom=willy@infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=AFwPz9F7BR2KO7EHQe4D2tuUr0dHyiHUKqAqUScb/5k=; b=RULrgcX43IxPsdqZAr6lzCNtc zncXOGdm5at73wpugQrjVm/0D5jAFMwnWKMKvNEA4wlnwbE6pgoawegICLrGsEQBv3zxPp/3b/kuy irE/ozw1NZOQwzdR1gpTm0V1AtY6m0TW83pVr89t+9aWKmjX7SJCi7nfKmLroTQsKWOB+LVwEItZC qlFd1a/r5p9/fZ+bovKzNcmCrBIXwIgFiTVdaetrzDdeLU1VPV7tJXwY4XA7Gr5jj19De7QnjImV2 +emEkD2xFmY7RB4rzv8jQmLp24bAE5Y8MPNZ8EYASJsS1q40hA7KT+nJarwSVQNPfOCF6U0kNje1W SSuCf5tTg==; Received: from willy by bombadil.infradead.org with local (Exim 4.92 #3 (Red Hat Linux)) id 1hq6Eq-0008Ul-UO; Wed, 24 Jul 2019 01:38:40 +0000 Date: Tue, 23 Jul 2019 18:38:40 -0700 From: Matthew Wilcox To: Jane Chu Cc: n-horiguchi@ah.jp.nec.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org Subject: Re: [PATCH] mm/memory-failure: Poison read receives SIGKILL instead of SIGBUS if mmaped more than once Message-ID: <20190724013840.GS363@bombadil.infradead.org> References: <1563925110-19359-1-git-send-email-jane.chu@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1563925110-19359-1-git-send-email-jane.chu@oracle.com> User-Agent: Mutt/1.11.4 (2019-03-13) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Jul 23, 2019 at 05:38:30PM -0600, Jane Chu wrote: > @@ -331,16 +330,21 @@ static void add_to_kill(struct task_struct *tsk, struct page *p, > tk->size_shift = compound_order(compound_head(p)) + PAGE_SHIFT; > > /* > - * In theory we don't have to kill when the page was > - * munmaped. But it could be also a mremap. Since that's > - * likely very rare kill anyways just out of paranoia, but use > - * a SIGKILL because the error is not contained anymore. > + * Indeed a page could be mmapped N times within a process. And it's possible You should run this patch through checkpatch.pl so I don't have to tell you whats wrong with the trivial aspects of it ;-)