From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 286872910B for ; Fri, 26 May 2023 14:31:30 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 60F101B4 for ; Fri, 26 May 2023 07:31:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1685111484; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jPGukvQXP4Tai7PUqcbnIswr++Y11hB7rT1QDpn/afo=; b=aCB93gOkG18KA9gemCPpLr8VDGipmtp+uqqMrRfTUXyWCI4TdhzvyruQYSxnVcfCr41y0U 6RjfiC2RhjkyLFARVyz6fr8D44vgXMEF8pOjjVjv+AyBQPvuPa3SDfwhVYEiRnLYyACRXF uAleHjjlrLilq1kf8E0jIKoOEqmpArU= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-29-Ivy8e833NRWSYrtoVTgS-g-1; Fri, 26 May 2023 10:31:21 -0400 X-MC-Unique: Ivy8e833NRWSYrtoVTgS-g-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 8A6DD811E92; Fri, 26 May 2023 14:31:19 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.39.192.68]) by smtp.corp.redhat.com (Postfix) with ESMTP id A4D0C140E961; Fri, 26 May 2023 14:31:17 +0000 (UTC) From: David Howells To: netdev@vger.kernel.org Cc: David Howells , Herbert Xu , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Willem de Bruijn , David Ahern , Matthew Wilcox , Jens Axboe , linux-crypto@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH net-next 3/8] crypto: af_alg: Pin pages rather than ref'ing if appropriate Date: Fri, 26 May 2023 15:30:59 +0100 Message-Id: <20230526143104.882842-4-dhowells@redhat.com> In-Reply-To: <20230526143104.882842-1-dhowells@redhat.com> References: <20230526143104.882842-1-dhowells@redhat.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.7 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_NONE,T_SCC_BODY_TEXT_LINE autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Convert AF_ALG to use iov_iter_extract_pages() instead of iov_iter_get_pages(). This will pin pages or leave them unaltered rather than getting a ref on them as appropriate to the iterator. The pages need to be pinned for DIO-read rather than having refs taken on them to prevent VM copy-on-write from malfunctioning during a concurrent fork() (the result of the I/O would otherwise end up only visible to the child process and not the parent). Signed-off-by: David Howells cc: Herbert Xu cc: "David S. Miller" cc: Eric Dumazet cc: Jakub Kicinski cc: Paolo Abeni cc: Jens Axboe cc: Matthew Wilcox cc: linux-crypto@vger.kernel.org cc: netdev@vger.kernel.org --- crypto/af_alg.c | 10 +++++++--- include/crypto/if_alg.h | 1 + 2 files changed, 8 insertions(+), 3 deletions(-) diff --git a/crypto/af_alg.c b/crypto/af_alg.c index 5f7252a5b7b4..7caff10df643 100644 --- a/crypto/af_alg.c +++ b/crypto/af_alg.c @@ -533,14 +533,17 @@ static const struct net_proto_family alg_family = { int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len) { + struct page **pages = sgl->pages; size_t off; ssize_t n; int npages, i; - n = iov_iter_get_pages2(iter, sgl->pages, len, ALG_MAX_PAGES, &off); + n = iov_iter_extract_pages(iter, &pages, len, ALG_MAX_PAGES, 0, &off); if (n < 0) return n; + sgl->need_unpin = iov_iter_extract_will_pin(iter); + npages = DIV_ROUND_UP(off + n, PAGE_SIZE); if (WARN_ON(npages == 0)) return -EINVAL; @@ -573,8 +576,9 @@ void af_alg_free_sg(struct af_alg_sgl *sgl) { int i; - for (i = 0; i < sgl->npages; i++) - put_page(sgl->pages[i]); + if (sgl->need_unpin) + for (i = 0; i < sgl->npages; i++) + unpin_user_page(sgl->pages[i]); } EXPORT_SYMBOL_GPL(af_alg_free_sg); diff --git a/include/crypto/if_alg.h b/include/crypto/if_alg.h index 7e76623f9ec3..46494b33f5bc 100644 --- a/include/crypto/if_alg.h +++ b/include/crypto/if_alg.h @@ -59,6 +59,7 @@ struct af_alg_sgl { struct scatterlist sg[ALG_MAX_PAGES + 1]; struct page *pages[ALG_MAX_PAGES]; unsigned int npages; + bool need_unpin; }; /* TX SGL entry */