From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-23.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A85F6C433E0 for ; Tue, 2 Feb 2021 17:43:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 805A464F5F for ; Tue, 2 Feb 2021 17:43:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237805AbhBBRnQ (ORCPT ); Tue, 2 Feb 2021 12:43:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40358 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234162AbhBBRk1 (ORCPT ); Tue, 2 Feb 2021 12:40:27 -0500 Received: from mail-ot1-x32a.google.com (mail-ot1-x32a.google.com [IPv6:2607:f8b0:4864:20::32a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 904A4C061788 for ; Tue, 2 Feb 2021 09:39:47 -0800 (PST) Received: by mail-ot1-x32a.google.com with SMTP id h14so20650232otr.4 for ; Tue, 02 Feb 2021 09:39:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=BII6X9VkkCmC/J7Ey1mCa41oEbJr520MWQnzH5Xhv9Q=; b=PXjuYV0cOp+567jMKpyOOYrjzFrmMQhpSsf4yKEj5lgebN6BPUEB3mV0so6yLmEjZ/ pYQR5Gdmou19gzOoWJ02cuLckRr52qZxtZuUgRJb4FaJNr+sge515wPZqkQl0ntQoqDy 2I1jXVcIZ27bOU7BTbY6PRYYi1TfDbC0AuCrtCI9cQAk2pNS+CZhFBl5ydKPDMl1MctF DxR5LaBQwSAWdWblKfK9QJV/mQWpWk6jfKfqi+VILWUVP/kqmv33gByUpZDlWHRHmeyC CO9qGnyidze/4GQnX95hyvKsKOGzcWqlqmanJw08OXhM9+d+0EPazBulZoC2p6BQfprs rVcw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=BII6X9VkkCmC/J7Ey1mCa41oEbJr520MWQnzH5Xhv9Q=; b=rLdv4qfFmUaduH7sJUWYAxgFfLNf3/TogKIZjztJOq5lEsMO9yfoR6zmQx9NJ3IObt 14Ld8qnJXPvWwELZEkaDaH+R4Z+6txkzaUyeN0OstpMBHjipVFYIlD0K/+oiNA/MHquH DRjukVZwvCgQ5JCM6/b85158cnVllbamgV/FrQFA2DwUFxlTsyxXBGEoW3kBKHOz7PG8 Afnm6SHjJ1kL9efjyO/VlOyBFN/4cvnhXZVlqQediwRy6Uo+rutgQdBdqbyWcRckPc85 gdnChyqjSZlvjij1xUxxXvBop8CsYlY0/LS4UuH0j37vkRW1PKShsuXTgNJokl7uoP58 2tTw== X-Gm-Message-State: AOAM530CmFaSkXOY3N5njHkMq+doB3VDT4KAfR3VTJwTQTDkKE5sBjFD ZQ7nHNBgIK23E7zt6dlq+lzBXDdkW08oUarSgXV//Q== X-Google-Smtp-Source: ABdhPJyR3YEZ4MxJTnMrgfDlYCaQYg+zdfO3gVmBuM9e5QmzuE0U8HFwQZS9QkNvG8speGBODgcWI+2jh8ltkuDl1Fo= X-Received: by 2002:a9d:4687:: with SMTP id z7mr16664460ote.233.1612287586711; Tue, 02 Feb 2021 09:39:46 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Marco Elver Date: Tue, 2 Feb 2021 18:39:35 +0100 Message-ID: Subject: Re: [PATCH 02/12] kasan, mm: optimize kmalloc poisoning To: Andrey Konovalov Cc: Catalin Marinas , Vincenzo Frascino , Dmitry Vyukov , Alexander Potapenko , Andrew Morton , Will Deacon , Andrey Ryabinin , Peter Collingbourne , Evgenii Stepanov , Branislav Rankov , Kevin Brodsky , kasan-dev , Linux ARM , Linux Memory Management List , LKML Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2 Feb 2021 at 18:16, Andrey Konovalov wrote: > > On Tue, Feb 2, 2021 at 5:25 PM Marco Elver wrote: > > > > > +#ifdef CONFIG_KASAN_GENERIC > > > + > > > +/** > > > + * kasan_poison_last_granule - mark the last granule of the memory range as > > > + * unaccessible > > > + * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE > > > + * @size - range size > > > + * > > > + * This function is only available for the generic mode, as it's the only mode > > > + * that has partially poisoned memory granules. > > > + */ > > > +void kasan_poison_last_granule(const void *address, size_t size); > > > + > > > +#else /* CONFIG_KASAN_GENERIC */ > > > + > > > +static inline void kasan_poison_last_granule(const void *address, size_t size) { } > > ^ > > > > + > > > +#endif /* CONFIG_KASAN_GENERIC */ > > > + > > > /* > > > * Exported functions for interfaces called from assembly or from generated > > > * code. Declarations here to avoid warning about missing declarations. > > > > @@ -96,6 +92,16 @@ void kasan_poison(const void *address, size_t size, u8 value) > > > } > > > EXPORT_SYMBOL(kasan_poison); > > > > > > +#ifdef CONFIG_KASAN_GENERIC > > > +void kasan_poison_last_granule(const void *address, size_t size) > > > +{ > > > + if (size & KASAN_GRANULE_MASK) { > > > + u8 *shadow = (u8 *)kasan_mem_to_shadow(address + size); > > > + *shadow = size & KASAN_GRANULE_MASK; > > > + } > > > +} > > > +#endif > > > > The function declaration still needs to exist in the dead branch if > > !IS_ENABLED(CONFIG_KASAN_GENERIC). It appears in that case it's declared > > (in kasan.h), but not defined. We shouldn't get linker errors because > > the optimizer should remove the dead branch. Nevertheless, is this code > > generally acceptable? > > The function is defined as empty when !CONFIG_KASAN_GENERIC, see above. I missed that, thanks. Reviewed-by: Marco Elver From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-23.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8E1B0C433DB for ; Tue, 2 Feb 2021 17:39:49 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3F35C64F4D for ; Tue, 2 Feb 2021 17:39:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3F35C64F4D Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B18B56B0005; Tue, 2 Feb 2021 12:39:48 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id AC81B6B0006; Tue, 2 Feb 2021 12:39:48 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9B6966B0070; Tue, 2 Feb 2021 12:39:48 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0059.hostedemail.com [216.40.44.59]) by kanga.kvack.org (Postfix) with ESMTP id 825AC6B0005 for ; Tue, 2 Feb 2021 12:39:48 -0500 (EST) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 4729B1EE6 for ; Tue, 2 Feb 2021 17:39:48 +0000 (UTC) X-FDA: 77774040456.20.box82_5a0846c275cc Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin20.hostedemail.com (Postfix) with ESMTP id 14736180C07AB for ; Tue, 2 Feb 2021 17:39:48 +0000 (UTC) X-HE-Tag: box82_5a0846c275cc X-Filterd-Recvd-Size: 5385 Received: from mail-ot1-f50.google.com (mail-ot1-f50.google.com [209.85.210.50]) by imf38.hostedemail.com (Postfix) with ESMTP for ; Tue, 2 Feb 2021 17:39:47 +0000 (UTC) Received: by mail-ot1-f50.google.com with SMTP id d7so20647382otf.3 for ; Tue, 02 Feb 2021 09:39:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=BII6X9VkkCmC/J7Ey1mCa41oEbJr520MWQnzH5Xhv9Q=; b=PXjuYV0cOp+567jMKpyOOYrjzFrmMQhpSsf4yKEj5lgebN6BPUEB3mV0so6yLmEjZ/ pYQR5Gdmou19gzOoWJ02cuLckRr52qZxtZuUgRJb4FaJNr+sge515wPZqkQl0ntQoqDy 2I1jXVcIZ27bOU7BTbY6PRYYi1TfDbC0AuCrtCI9cQAk2pNS+CZhFBl5ydKPDMl1MctF DxR5LaBQwSAWdWblKfK9QJV/mQWpWk6jfKfqi+VILWUVP/kqmv33gByUpZDlWHRHmeyC CO9qGnyidze/4GQnX95hyvKsKOGzcWqlqmanJw08OXhM9+d+0EPazBulZoC2p6BQfprs rVcw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=BII6X9VkkCmC/J7Ey1mCa41oEbJr520MWQnzH5Xhv9Q=; b=JEY+B5uBw3Xq1wgg/vR1QCNqH9RlS5pAf6ocL8OaHQd2I/Shf2F45qGRnyfa2GFKNz 67wfFtATDQ2Cqy5+10bCQDWIhDbC47aqn2uNgx6drUbOZ3diD1/qalpxEWrVGjkeAl5g kaj6rhOukbtqYguFlzHRtosQcwPPE+a3fGZqUO3LRunzW+aY3h45E18OAeXrT1V0EbgJ xXXIkhiZDItH3srS+MOMaQx1c0BDudFL2sI0XggVH3ZkRLEPw3Qb6h7XahE9HwiQN8W4 4Dag1DREnsup6lMdB0ypjauBCTNhJl5og6xhj9M+FBCIgbyhhyKGrfK1Gl7Pcm9jBjWR c7GA== X-Gm-Message-State: AOAM532RWv5GeVi4nDc/aPo0xfWTUX/PJguAhmb5yCRZ2fIGQWLe00TP d/tMKjuLF+EvFa7O8rjvRr4LSM4zuZko1wIXCoOVHw== X-Google-Smtp-Source: ABdhPJyR3YEZ4MxJTnMrgfDlYCaQYg+zdfO3gVmBuM9e5QmzuE0U8HFwQZS9QkNvG8speGBODgcWI+2jh8ltkuDl1Fo= X-Received: by 2002:a9d:4687:: with SMTP id z7mr16664460ote.233.1612287586711; Tue, 02 Feb 2021 09:39:46 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Marco Elver Date: Tue, 2 Feb 2021 18:39:35 +0100 Message-ID: Subject: Re: [PATCH 02/12] kasan, mm: optimize kmalloc poisoning To: Andrey Konovalov Cc: Catalin Marinas , Vincenzo Frascino , Dmitry Vyukov , Alexander Potapenko , Andrew Morton , Will Deacon , Andrey Ryabinin , Peter Collingbourne , Evgenii Stepanov , Branislav Rankov , Kevin Brodsky , kasan-dev , Linux ARM , Linux Memory Management List , LKML Content-Type: text/plain; charset="UTF-8" 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, 2 Feb 2021 at 18:16, Andrey Konovalov wrote: > > On Tue, Feb 2, 2021 at 5:25 PM Marco Elver wrote: > > > > > +#ifdef CONFIG_KASAN_GENERIC > > > + > > > +/** > > > + * kasan_poison_last_granule - mark the last granule of the memory range as > > > + * unaccessible > > > + * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE > > > + * @size - range size > > > + * > > > + * This function is only available for the generic mode, as it's the only mode > > > + * that has partially poisoned memory granules. > > > + */ > > > +void kasan_poison_last_granule(const void *address, size_t size); > > > + > > > +#else /* CONFIG_KASAN_GENERIC */ > > > + > > > +static inline void kasan_poison_last_granule(const void *address, size_t size) { } > > ^ > > > > + > > > +#endif /* CONFIG_KASAN_GENERIC */ > > > + > > > /* > > > * Exported functions for interfaces called from assembly or from generated > > > * code. Declarations here to avoid warning about missing declarations. > > > > @@ -96,6 +92,16 @@ void kasan_poison(const void *address, size_t size, u8 value) > > > } > > > EXPORT_SYMBOL(kasan_poison); > > > > > > +#ifdef CONFIG_KASAN_GENERIC > > > +void kasan_poison_last_granule(const void *address, size_t size) > > > +{ > > > + if (size & KASAN_GRANULE_MASK) { > > > + u8 *shadow = (u8 *)kasan_mem_to_shadow(address + size); > > > + *shadow = size & KASAN_GRANULE_MASK; > > > + } > > > +} > > > +#endif > > > > The function declaration still needs to exist in the dead branch if > > !IS_ENABLED(CONFIG_KASAN_GENERIC). It appears in that case it's declared > > (in kasan.h), but not defined. We shouldn't get linker errors because > > the optimizer should remove the dead branch. Nevertheless, is this code > > generally acceptable? > > The function is defined as empty when !CONFIG_KASAN_GENERIC, see above. I missed that, thanks. Reviewed-by: Marco Elver From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-14.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_ADSP_CUSTOM_MED,DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0BBE8C433E0 for ; Tue, 2 Feb 2021 17:41:17 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C11A364F6B for ; Tue, 2 Feb 2021 17:41:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C11A364F6B Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:To:Subject:Message-ID:Date:From:In-Reply-To: References:MIME-Version:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=CTEvyXBSn8Ek07/RC5I4xtYbpARZYvO936gNvIgUKUw=; b=xJMJnYtUAp7JQ3qneOGJPscR+ PvK9w3TAmx/GJO0HPdyjJVv+0wjjz1jxIltYgcdPn59Ovm3Qm3PTRjscYp9xetcZUx07iLVjNYmR+ NpO+Mmjuv+b5vJEHkDULB/8A6dKW79/hjA5RX3ilyUxK10MBHTHKuBhNh5+y+jfcwtC4jL402vovP t7im85tdldD4TWxjwOvKk8acRQoZIaB/6kqg2ZFg6J//r4a8EonaS813HqHvyM/r0IRgp7humfin7 KfzIISWg386/bfAz1t98a4Ir5tr3WhaEfyQWQ3XgOqwdOhRftV03Fl8SmFQENT5RCKyKwQPk6AJhL AwGR0a53g==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l6zeb-00081F-7z; Tue, 02 Feb 2021 17:39:53 +0000 Received: from mail-ot1-x32f.google.com ([2607:f8b0:4864:20::32f]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l6zeX-00080I-DR for linux-arm-kernel@lists.infradead.org; Tue, 02 Feb 2021 17:39:50 +0000 Received: by mail-ot1-x32f.google.com with SMTP id t25so10519622otc.5 for ; Tue, 02 Feb 2021 09:39:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=BII6X9VkkCmC/J7Ey1mCa41oEbJr520MWQnzH5Xhv9Q=; b=PXjuYV0cOp+567jMKpyOOYrjzFrmMQhpSsf4yKEj5lgebN6BPUEB3mV0so6yLmEjZ/ pYQR5Gdmou19gzOoWJ02cuLckRr52qZxtZuUgRJb4FaJNr+sge515wPZqkQl0ntQoqDy 2I1jXVcIZ27bOU7BTbY6PRYYi1TfDbC0AuCrtCI9cQAk2pNS+CZhFBl5ydKPDMl1MctF DxR5LaBQwSAWdWblKfK9QJV/mQWpWk6jfKfqi+VILWUVP/kqmv33gByUpZDlWHRHmeyC CO9qGnyidze/4GQnX95hyvKsKOGzcWqlqmanJw08OXhM9+d+0EPazBulZoC2p6BQfprs rVcw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=BII6X9VkkCmC/J7Ey1mCa41oEbJr520MWQnzH5Xhv9Q=; b=olph/2Wth10ftBy5qyrdZnbCYtyDU+SmtaxE3JuDkbIugBPszROvgo8dS1XjlaxXF3 TGvGzK/V3oFS72CK8tD2wIY/j1ZVUPR9n02HMTC20imIy4S/oa3uM0GgWm4a/tGcTTYd +V5KD6f1arUnrzn1812lQZyzBLFsXl6uRcji2meq/SVj8uIl0bLA/nONRMHYIpA9RZLG zJ2tZdyRzX6mdBUT76KC9Or9K8vVDa8G/dOwZV2uVBpsDnWaX7pwSZEFzrsFBDbQ7PjP c64VO/JGZe2MOYoEZkHFEsaa98aU9/MzVcQvxBhGadvmawnY0N0Y27XmY6TlsiKn538L vQoA== X-Gm-Message-State: AOAM532yn8TxBGpciAkVwX0B+0XtLDuR/cwW2m1fU0qldVY8PoeKDEUQ SVOih+w6m1bYyqzO6Ps8tTGR3p+FnxxQszwv4XB9NA== X-Google-Smtp-Source: ABdhPJyR3YEZ4MxJTnMrgfDlYCaQYg+zdfO3gVmBuM9e5QmzuE0U8HFwQZS9QkNvG8speGBODgcWI+2jh8ltkuDl1Fo= X-Received: by 2002:a9d:4687:: with SMTP id z7mr16664460ote.233.1612287586711; Tue, 02 Feb 2021 09:39:46 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Marco Elver Date: Tue, 2 Feb 2021 18:39:35 +0100 Message-ID: Subject: Re: [PATCH 02/12] kasan, mm: optimize kmalloc poisoning To: Andrey Konovalov X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210202_123949_747809_BA023E8C X-CRM114-Status: GOOD ( 21.07 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Linux ARM , Branislav Rankov , Catalin Marinas , Kevin Brodsky , Will Deacon , LKML , kasan-dev , Linux Memory Management List , Alexander Potapenko , Evgenii Stepanov , Andrey Ryabinin , Andrew Morton , Vincenzo Frascino , Peter Collingbourne , Dmitry Vyukov Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, 2 Feb 2021 at 18:16, Andrey Konovalov wrote: > > On Tue, Feb 2, 2021 at 5:25 PM Marco Elver wrote: > > > > > +#ifdef CONFIG_KASAN_GENERIC > > > + > > > +/** > > > + * kasan_poison_last_granule - mark the last granule of the memory range as > > > + * unaccessible > > > + * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE > > > + * @size - range size > > > + * > > > + * This function is only available for the generic mode, as it's the only mode > > > + * that has partially poisoned memory granules. > > > + */ > > > +void kasan_poison_last_granule(const void *address, size_t size); > > > + > > > +#else /* CONFIG_KASAN_GENERIC */ > > > + > > > +static inline void kasan_poison_last_granule(const void *address, size_t size) { } > > ^ > > > > + > > > +#endif /* CONFIG_KASAN_GENERIC */ > > > + > > > /* > > > * Exported functions for interfaces called from assembly or from generated > > > * code. Declarations here to avoid warning about missing declarations. > > > > @@ -96,6 +92,16 @@ void kasan_poison(const void *address, size_t size, u8 value) > > > } > > > EXPORT_SYMBOL(kasan_poison); > > > > > > +#ifdef CONFIG_KASAN_GENERIC > > > +void kasan_poison_last_granule(const void *address, size_t size) > > > +{ > > > + if (size & KASAN_GRANULE_MASK) { > > > + u8 *shadow = (u8 *)kasan_mem_to_shadow(address + size); > > > + *shadow = size & KASAN_GRANULE_MASK; > > > + } > > > +} > > > +#endif > > > > The function declaration still needs to exist in the dead branch if > > !IS_ENABLED(CONFIG_KASAN_GENERIC). It appears in that case it's declared > > (in kasan.h), but not defined. We shouldn't get linker errors because > > the optimizer should remove the dead branch. Nevertheless, is this code > > generally acceptable? > > The function is defined as empty when !CONFIG_KASAN_GENERIC, see above. I missed that, thanks. Reviewed-by: Marco Elver _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel