From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.218.175.39 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793094664; b=gSZYy47FstOxNcO5qk5YSLERBVN3HGxiIwPdH4LHNZ0h3ZtzhL8QWyg4n50Z8DVuGUKl 6J2hpe3QAJ0A/K/yQPxspRoLzA2Oz+leKHvEW7LQmWLj7Aicn0brefljz/54JYp4It9dm Q7J1jRsTtnqjlGSsuLXQQjAa4vxdn4yBhUEv0eFLF3EoeWKKgiVzZ8MRf9BVrxGOUDTjD 3fPoMX12YbgO72eWTFVDllxUlp3LLtOxtkXXzvfPW47yJNKTGSRP6V6FUm/J+LWiDPbZp fSJ/YcK2jAunrG8GPrtt+VJB29Zhrwxtj68mXa1+NK19ulFiGDX9WQ8Bby7Rzrt3YZA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793094664; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:Content-Type:Mime-Version:Subject:From: In-Reply-To:Date:Cc:Content-Transfer-Encoding:Message-Id:References: To:X-Mailer; bh=YikRuHrgcQQEQeNLoopicKeEponOUqqAXOCmGgP7bMc=; b=MS5nSnsbiEspBLjLq5i3y02YUnF0rD+fYFC9yHl3inviZ49xmuaP0v4C0azHRdmMWPYu G9Y9o8SAh6Wxrk6G1DS7rXaAij81aZCX7SucfeztGTlbR9zBwRwuTPVkzBrEagSQ4s90a i9LRC4ROENn4TviM2ixmJje0txJdpA7H979A+aEsDuNZ2M4439EfImX0rrXqlJgv+dPSb 0HOwuz3kIuW6GmvAQz104ISV+dOVq6/cLYG7/cejisFoG/WNWRs/QZinvQP2KD5+Zcwn2 v30OZYuiwAi0tTpELuDWwqqAsr+B3Is1n6X+Iv6INXeioAAYW23Kb+umt9YDS5x3S7Q== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=IK7uwDYg; arc=none smtp.remote-ip=91.218.175.39 Received: from mta0.migadu.com (out-39.mta0.migadu.com [91.218.175.39]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 740A3606A31B for ; Tue, 27 Oct 2026 09:51:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 740A3606A31B Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=IK7uwDYg X-Envelope-To: linux-arch@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=YikRuHrgcQQEQeNLoopicKeEponOUqqAXOCmGgP7bMc=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793094661; v=1; x=1793699461; b=IK7uwDYgWnddzMvKWJw3ya6jd1O95pxiSUka2B+d5LCvMVJF0eAMpUph7VCpo576csv7uSk+ RkWa1+WT24INtT8JnumhbrIqAEhPNriR3IJ5BOtfXhCFSYVDbHBk/S3Oe6w++M3F5lyKhOZXvxs 0YEaxOC7g+vVBRZSfwe0o1YE= X-Envelope-To: linux-arch@vger.kernel.org Received: by mta12.migadu.com with ESMTPS id 7697935976e69603; Tue, 27 Oct 2026 09:50:59 +0000 X-Mizu-Trace-ID: 7697935976e69603 X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset=us-ascii X-Mailing-List: linux-arch@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3901.100.1.1.12\)) Subject: Re: [PATCH 26/46] mm/mmu_gather: fix flushing ranges with 4 GiB or larger From: Muchun Song In-Reply-To: <20261027-fixes_core-v1-26-6f74bec9a5bb@kernel.org> Date: Tue, 27 Oct 2026 17:50:32 +0800 Cc: Andrew Morton , Johannes Weiner , Michal Hocko , Qi Zheng , Shakeel Butt , Lorenzo Stoakes , Kairui Song , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Baoquan He , Baolin Wang , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Kees Cook , Peter Zijlstra , Jann Horn , Pedro Falcato , Hugh Dickins , Pasha Tatashin , Pratyush Yadav , "Matthew Wilcox (Oracle)" , Jan Kara , Zi Yan , Lance Yang , Rik van Riel , Harry Yoo , Alistair Popple , Nico Pache , Ryan Roberts , Dev Jain , Usama Arif , Kiryl Shutsemau , Matthew Brost , John Hubbard , Peter Xu , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Oscar Salvador , Minchan Kim , Xu Xin , Chengming Zhou , Chris Li , Kemeng Shi , Nhat Pham , Youngjun Park , Gregory Price , Joshua Hahn , Rakie Kim , Ying Huang , Jason Gunthorpe , linux-mm@kvack.org, linux-kernel@vger.kernel.org, kexec@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-cxl@vger.kernel.org, Josef Bacik , stable@vger.kernel.org Content-Transfer-Encoding: quoted-printable Message-Id: <377FB184-1E61-4BF8-AC3E-33A79EC56658@linux.dev> References: <20261027-fixes_core-v1-0-6f74bec9a5bb@kernel.org> <20261027-fixes_core-v1-26-6f74bec9a5bb@kernel.org> To: "David Hildenbrand (Arm)" X-Mailer: Apple Mail (2.3901.100.1.1.12) > On Oct 27, 2026, at 07:17, David Hildenbrand (Arm) = wrote: >=20 > From: Josef Bacik >=20 > __tlb_adjust_range() takes the size of the range which has to be = flushed > as an unsigned int. Its callers, tlb_flush_{pte,pmd,pud,p4d}_range(), = get > and pass an unsigned long. Consequently, a range that is 4 GiB or = larger > gets truncated, possibly to 0. >=20 > On arm64 with hugetlb, a 64k kernel can flush 16 GiB hugetlb PMDs, and = a > 16k kernel can flush 64 GiB PUDs through tlb_unshare_pmd_ptdesc(). So > at least these two scenarios are affected. >=20 > Fix it by flushing the proper range instead of the truncated one. >=20 > Fix generated by an LLM and sent by Josef Bacik in private. >=20 > Fixes: b528e4b6405b ("mm/hugetlb: add tlb_remove_hugetlb_entry for = handling hugetlb pages") > Fixes: 8ce720d5bd91 ("mm/hugetlb: fix excessive IPI broadcasts when = unsharing PMD tables using mmu_gather") > Cc: stable@vger.kernel.org > Signed-off-by: Josef Bacik > Acked-by: Lorenzo Stoakes (ARM) > [ david: use two-tab indent, simplify description ] > Signed-off-by: David Hildenbrand (Arm) Reviewed-by: Muchun Song Thanks.