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 DDD58A2C for ; Tue, 4 Jul 2023 14:34:15 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DF54F10C3 for ; Tue, 4 Jul 2023 07:34:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1688481254; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=gYHch/SklDJL/CopH6fHbY5oof68s+i62UNUpHYmC24=; b=OJVmoghSPwnbmW05G9nuWZSQpv0XNdDhggPRrakKxgVCeGFea/h7Tr/ddMjRgeoB1wrayh BxsciYIUTJPYyAUJ+Dulbuuw6JANdO43dNVIJj587fUYU1NuSR21MhblofhY8T5RJsxp2E JiYFfh/sq2LBA27JGAL0vsYHoUQx6iY= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-650-TumVCkMINnWZXNJl7_pR8g-1; Tue, 04 Jul 2023 10:34:10 -0400 X-MC-Unique: TumVCkMINnWZXNJl7_pR8g-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 8077B1C04B40; Tue, 4 Jul 2023 14:34:09 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.42.28.195]) by smtp.corp.redhat.com (Postfix) with ESMTP id D0A681121314; Tue, 4 Jul 2023 14:34:08 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: References: To: =?UTF-8?B?T25kcmVqIE1vc27DocSNZWs=?= Cc: dhowells@redhat.com, Linux Crypto Mailing List , Herbert Xu , Paolo Abeni , netdev@vger.kernel.org Subject: Re: Regression bisected to "crypto: af_alg: Convert af_alg_sendpage() to use MSG_SPLICE_PAGES" Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <1506613.1688481248.1@warthog.procyon.org.uk> Date: Tue, 04 Jul 2023 15:34:08 +0100 Message-ID: <1506614.1688481248@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 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, RCVD_IN_MSPIKE_H4,RCVD_IN_MSPIKE_WL,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 The problem is caused by this bit in af_alg_sendmsg(): /* use the existing memory in an allocated page */ if (ctx->merge) { sgl = list_entry(ctx->tsgl_list.prev, struct af_alg_tsgl, list); sg = sgl->sg + sgl->cur - 1; len = min_t(size_t, len, PAGE_SIZE - sg->offset - sg->length); err = memcpy_from_msg(page_address(sg_page(sg)) + sg->offset + sg->length, msg, len); if (err) goto unlock; sg->length += len; ctx->merge = (sg->offset + sg->length) & (PAGE_SIZE - 1); ctx->used += len; copied += len; size -= len; continue; } it doesn't exist in the old af_alg_sendpage() code. It merges data supplied by sendmsg() into the last page in the list if there's space. So we need a flag to keep track of whether the last page is appendable-to or not. David