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 03443C4361B for ; Wed, 9 Dec 2020 18:49:55 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 885F52228A for ; Wed, 9 Dec 2020 18:49:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 885F52228A 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 050F68D0040; Wed, 9 Dec 2020 13:49:54 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 000CD8D0031; Wed, 9 Dec 2020 13:49:53 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E31248D0040; Wed, 9 Dec 2020 13:49:53 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0179.hostedemail.com [216.40.44.179]) by kanga.kvack.org (Postfix) with ESMTP id C93258D0031 for ; Wed, 9 Dec 2020 13:49:53 -0500 (EST) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 82B1C1EE6 for ; Wed, 9 Dec 2020 18:49:53 +0000 (UTC) X-FDA: 77574633066.22.park61_2b07d8e273f1 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin22.hostedemail.com (Postfix) with ESMTP id 703D518038E7E for ; Wed, 9 Dec 2020 18:49:49 +0000 (UTC) X-HE-Tag: park61_2b07d8e273f1 X-Filterd-Recvd-Size: 4764 Received: from mail-ot1-f65.google.com (mail-ot1-f65.google.com [209.85.210.65]) by imf20.hostedemail.com (Postfix) with ESMTP for ; Wed, 9 Dec 2020 18:49:48 +0000 (UTC) Received: by mail-ot1-f65.google.com with SMTP id b62so2396152otc.5 for ; Wed, 09 Dec 2020 10:49:48 -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=nQgmlgyLspfkVp2FCuJol7fCS4Xdf4wtNQYwX+VG7Nw=; b=l9z1W9O3U56nYI143oRJfV5311iDCKWoNpQI2FpTYMgLxt+baGoxWXsWfCjBDlFppv rAUd7fVu8DpLcrjze29pY6oLvq0xYJP7cEPd6XDycAukgjlFYuQzQuX4l1Vn+rFYo+QG g0H/ZbO1qMBSjxsJ3u72sevhToBFpUIys5OjjfwTxJXvlMT9vw0djPPYnitBhWvDTwIs 7h7pBmIigp3RjL1HLHtv9syoQVrWk1z9B/usq313vp4hILK+MZVWWt4zMlvyKlRNtd8R Zvktg6+bqd4FKFyge2x3pMdFgTKxZWE7SA3IUuoI4j9T45TRCTgKygftTDOjJPQf0WU0 MI8g== 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=nQgmlgyLspfkVp2FCuJol7fCS4Xdf4wtNQYwX+VG7Nw=; b=aqrJivIrnO4oJj6lmC84tQNT3A4l8NKLNL9lzlmJWDGcYTORsXLwNk2PJv0KSFUHzw O6jOva91YhevcT9Psm+Zw/GBZByxqEfC6mf9rW6ZDddepAWiy1I9ktL21Tlw9Sz9fGRv tHVCjLGaouefYhtGja+ISEwEL61ckUylMB2yEDxAgW6EsUAEAStLoRuu+0ig0sojsXsI cdfexBUxskYWHI+/aXUVHfyoPE+41If3FDrQPG9cMIIPVmsrOCFZhI7ZSyC9nsT3Ryy3 hCHyDmtBwVU0XzDCKJc0XXXKcDBi1HXn+cRwwidypo3xZLaWteuZXLqeTao4wD3xBpPZ Nbrw== X-Gm-Message-State: AOAM533RLMgHv2g8qg4ooY7VVaoVSlZIcPUymO4UNGqV0mFPRMoc86z+ rRRN8R2W0Oe7RHbY7UFolb4ovbkaN8KGxDRSoNAWnA== X-Google-Smtp-Source: ABdhPJwWx8l8bBnMkvN9ss6l6q8oVhzQWR8f+8nZwO3h65V9XTRisIADDH5OJNTJQwhw4qc206BtFEJH6Me4d/Cdh2M= X-Received: by 2002:a9d:6317:: with SMTP id q23mr3014950otk.251.1607539788150; Wed, 09 Dec 2020 10:49:48 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Marco Elver Date: Wed, 9 Dec 2020 19:49:36 +0100 Message-ID: Subject: Re: [PATCH mm 1/2] kasan: don't use read-only static keys To: Andrey Konovalov Cc: Andrew Morton , Catalin Marinas , Will Deacon , Vincenzo Frascino , Dmitry Vyukov , Andrey Ryabinin , Alexander Potapenko , Evgenii Stepanov , Branislav Rankov , Kevin Brodsky , kasan-dev , Linux ARM , Linux Memory Management List , LKML , Kees Cook 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 Wed, 9 Dec 2020 at 19:24, Andrey Konovalov wrote: > __ro_after_init static keys are incompatible with usage in loadable kernel > modules and cause crashes. Don't use those, use normal static keys. > > Signed-off-by: Andrey Konovalov Reviewed-by: Marco Elver > --- > > This fix can be squashed into > "kasan: add and integrate kasan boot parameters". > > --- > mm/kasan/hw_tags.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c > index c91f2c06ecb5..55bd6f09c70f 100644 > --- a/mm/kasan/hw_tags.c > +++ b/mm/kasan/hw_tags.c > @@ -43,11 +43,11 @@ static enum kasan_arg_stacktrace kasan_arg_stacktrace __ro_after_init; > static enum kasan_arg_fault kasan_arg_fault __ro_after_init; > > /* Whether KASAN is enabled at all. */ > -DEFINE_STATIC_KEY_FALSE_RO(kasan_flag_enabled); > +DEFINE_STATIC_KEY_FALSE(kasan_flag_enabled); Side-node: This appears to be just a bad interface; I think the macro DEFINE_STATIC_KEY_FALSE_RO() is error-prone, if it can't be guaranteed that this is always safe, since the presence of the macro encourages its use and we'll inevitably run into this problem again. > EXPORT_SYMBOL(kasan_flag_enabled); DEFINE_STATIC_KEY_FALSE_RO() + EXPORT_SYMBOL() is an immediate bug. Given its use has not increased substantially since its introduction, it may be safer to consider its removal. Thanks, -- Marco