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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 787D8C433F5 for ; Mon, 27 Sep 2021 09:17:13 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id EC50E60E8B for ; Mon, 27 Sep 2021 09:17:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org EC50E60E8B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=shutemov.name Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 85AF56B0071; Mon, 27 Sep 2021 05:17:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 80A9D6B0072; Mon, 27 Sep 2021 05:17:12 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6FA036B0073; Mon, 27 Sep 2021 05:17:12 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0143.hostedemail.com [216.40.44.143]) by kanga.kvack.org (Postfix) with ESMTP id 5F5A56B0071 for ; Mon, 27 Sep 2021 05:17:12 -0400 (EDT) Received: from smtpin36.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 124171808A9EA for ; Mon, 27 Sep 2021 09:17:12 +0000 (UTC) X-FDA: 78632799504.36.4F661C1 Received: from mail-lf1-f51.google.com (mail-lf1-f51.google.com [209.85.167.51]) by imf19.hostedemail.com (Postfix) with ESMTP id AB25CB0000A5 for ; Mon, 27 Sep 2021 09:17:11 +0000 (UTC) Received: by mail-lf1-f51.google.com with SMTP id t10so74337191lfd.8 for ; Mon, 27 Sep 2021 02:17:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shutemov-name.20210112.gappssmtp.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=XM3IPd5Y/B3XydJlqavKkI7QaMPjEtgvkFbwbgV1/iA=; b=1Q6708tvyLCT+ef9O4jgFQMKEEc7HbJpaH/zXY3a37umoGOMBeZVmoGrsut1XykdFw Jmh0iITH0gc8KQFV8t9wWRNaNfo9z/wfSe/uMb+ch/oemogWJ9AgUkmaD2wUt/WvEqNO n31QGdgKiAsMMUE9oh/KX0l1yJzQq8Nya3do21ITVU6O2pcfYQcgswlYcwIcSJjFLiFi GGP+FDWdcu2ULdUVR1FPEBn1ZdrruYUOrEqn/pEsTCkOmpujwSvlR4gsbjIMhk11lDHL TfEswBQ27FmZMREtaCmLUYjPs3Xs2pji+Rspo5aE5LcyjUm6Sijxdl4k+3TFu1Rtpq+Z ycSQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=XM3IPd5Y/B3XydJlqavKkI7QaMPjEtgvkFbwbgV1/iA=; b=OpSTQtcoaeM7Jfu68t3P5v+W1CbkNI6EKgqMs/APZDh8NB5CWvIsrT0WN5wYutgh4o R4nkMDeLxr2vssJ8xrf0fvsh6sW94QgUUliLbYGNpYhhTpH17qXRPOcbXmgoJLYY0vfl i4IrFp5iuU+EXBkO3nPpxqm1WpSVdjHQefl/FzEWSHRwUL4iWCoj6v0wEZMQkxLsSREh 6leF/a6+cRoYpU3mFsJJB8J+v9VuL73YTCJFhBmzT0BXT7511BNSloFZ6NOjvT70rK9H yPGVUZcJ6jMzqet3yPs3YD/AKnMi3viNm3Fq9PU5BIHgG2up7Ltj3Py8c1BBPfENUPe9 I3Aw== X-Gm-Message-State: AOAM532sSejcn7cSZUpi3Ql0kND2ytpn87ulCafyUMj4mQPm8tdRqRBF e2LLDM4wvWzzeNiM4ZUu4AKaXI7U7pkwAA== X-Google-Smtp-Source: ABdhPJyz8uOfrsdc9H8zpTerjSbSsa5CUwJBTezYs+Mz79tiJ2/wjNLzHO9OqKjyaWJnt4XJcDjdFg== X-Received: by 2002:a19:5e11:: with SMTP id s17mr23486926lfb.404.1632734230305; Mon, 27 Sep 2021 02:17:10 -0700 (PDT) Received: from box.localdomain ([86.57.175.117]) by smtp.gmail.com with ESMTPSA id o1sm1684460lfc.110.2021.09.27.02.17.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Sep 2021 02:17:09 -0700 (PDT) Received: by box.localdomain (Postfix, from userid 1000) id 29B5F10306C; Mon, 27 Sep 2021 12:17:09 +0300 (+03) Date: Mon, 27 Sep 2021 12:17:09 +0300 From: "Kirill A. Shutemov" To: Nadav Amit Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Peter Xu , Nadav Amit , Andrea Arcangeli , Minchan Kim , Colin Cross , Suren Baghdasarya , Mike Rapoport Subject: Re: [RFC PATCH 3/8] mm/madvise: remove unnecessary checks on madvise_free_single_vma() Message-ID: <20210927091709.ksv2fjudjpqhnu3n@box.shutemov.name> References: <20210926161259.238054-1-namit@vmware.com> <20210926161259.238054-4-namit@vmware.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210926161259.238054-4-namit@vmware.com> X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: AB25CB0000A5 X-Stat-Signature: b3exxwmy8geyi5qkdz3ztfgsazd7odnq Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=shutemov-name.20210112.gappssmtp.com header.s=20210112 header.b=1Q6708tv; spf=none (imf19.hostedemail.com: domain of kirill@shutemov.name has no SPF policy when checking 209.85.167.51) smtp.mailfrom=kirill@shutemov.name; dmarc=none X-HE-Tag: 1632734231-932943 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000002, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Sun, Sep 26, 2021 at 09:12:54AM -0700, Nadav Amit wrote: > From: Nadav Amit > > madvise_free_single_vma() currently rechecks that the range fits within > the VMA, adapts it accordingly, and returns -EINVAL if the range is > entirely outside of the VMA. > > The error-code of -EINVAL is incorrect according to the man pages (as it > should have been -ENOMEM), but anyhow the range that is provided to > madvise_free_single_vma() should always be valid. It is set correctly in > do_madvise() and then rechecked in madvise_dontneed_free() is the > mmap-lock is dropped. > > Remove this check. > > Cc: Andrea Arcangeli > Cc: Andrew Morton > Cc: Minchan Kim > Cc: Colin Cross > Cc: Suren Baghdasarya > Cc: Mike Rapoport > Signed-off-by: Nadav Amit > --- > mm/madvise.c | 8 +------- > 1 file changed, 1 insertion(+), 7 deletions(-) > > diff --git a/mm/madvise.c b/mm/madvise.c > index fe843513a4e8..17e39c70704b 100644 > --- a/mm/madvise.c > +++ b/mm/madvise.c > @@ -716,14 +716,8 @@ static int madvise_free_single_vma(struct vm_area_struct *vma, > if (!vma_is_anonymous(vma)) > return -EINVAL; > > - range.start = max(vma->vm_start, start_addr); > - if (range.start >= vma->vm_end) > - return -EINVAL; > - range.end = min(vma->vm_end, end_addr); > - if (range.end <= vma->vm_start) > - return -EINVAL; How did you test this change? As far as I can see, you leave 'range' uninitialized, but used for walk_page_range() and mmu_notifiers. NAK. > mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, > - range.start, range.end); > + start_addr, end_addr); > > lru_add_drain(); > tlb_gather_mmu(&tlb, mm); > -- > 2.25.1 > > -- Kirill A. Shutemov