From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 0E78318E377; Mon, 27 Jan 2025 17:39:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737999565; cv=none; b=Opeqc/T4eRwvl6fqrlcq2r1RCBAfEfRcch0CouaZ8Hu2XfqPDgA8eL3uAmLNQCbQAXZcJB8i3sTg3+D5d/zHiFrO+YyryJ8pDIb3UkSkQ45efxQkJMC101EjWNq/Pf4OAyFB1aEdgZ5HBjujneJIJ2A4tD3jtD8uysxIlFokSc4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737999565; c=relaxed/simple; bh=wpuUfk3xJ+7ZFWpq2VOqbBzfkPi5/HqlF4YuWWwmh54=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=MSE+B3Sb8MvhYStddTsg5ZRAzHF/KPm5F6Tkf0ohK/NspbcaQXhnM6rEkZVWti8IN26tk2AkrxpDk9fknP2BEGay10V2cEKN+tqBjtkG8UTeEY3Xef+3BudL/wugTTIUlaTJvV6AyoXLKUYHbNLSR6gu+d+gyxdJ5MLwmCGbfdY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=dXAJ2csS; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="dXAJ2csS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 413A7C4CEE3; Mon, 27 Jan 2025 17:39:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1737999564; bh=wpuUfk3xJ+7ZFWpq2VOqbBzfkPi5/HqlF4YuWWwmh54=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=dXAJ2csS6nLZ736vpPLD7SpDUWrmtf3jUP5hxR31CarIAdXyZ1qGtVU3m+nZp3GFM nIbA1lPdklw9oC4WGVYGXHCUtJV9H1KIHuhwehGHstPi4Nic7IPIvRqEy6ffpEidH0 0Bz/XL3Xfqj1Afrn7jH6Jt1Fv8adFc9tYEOPHlnMcHqX3zf1yTpfufKpcPvbtrPrLT k+xwbUapVy28bVffprEn90InQqoR5lvWLOUtScphKMgMwCyMuv37hsbxkHGJGaQG5c mGp7v9tro4eYfNf0/r8/gtPGuCjgPYbPIuUcQ+12zd30twgyJTTVyM6q7Zf23YZXs0 8r9hEB4L+Wd5Q== Message-ID: <8392dd6b-1c20-4f7b-b879-6e940f2dcbc0@kernel.org> Date: Mon, 27 Jan 2025 18:39:11 +0100 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Beta Subject: Re: [GIT PULL] Networking for v6.13-rc7 To: Catalin Marinas Cc: torvalds@linux-foundation.org, davem@davemloft.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, pabeni@redhat.com, Guo Weikang , Andrew Morton , Jakub Kicinski , Andrea Righi , Patrick Wang References: <20250109182953.2752717-1-kuba@kernel.org> <173646486752.1541533.15419405499323104668.pr-tracker-bot@kernel.org> <20250116193821.2e12e728@kernel.org> <20250120094547.202f4718@kernel.org> <20250121074218.52ce108b@kernel.org> <426d4476-e3b4-4a95-84a1-850015651ee6@kernel.org> Content-Language: en-GB From: Matthieu Baerts Autocrypt: addr=matttbe@kernel.org; keydata= xsFNBFXj+ekBEADxVr99p2guPcqHFeI/JcFxls6KibzyZD5TQTyfuYlzEp7C7A9swoK5iCvf YBNdx5Xl74NLSgx6y/1NiMQGuKeu+2BmtnkiGxBNanfXcnl4L4Lzz+iXBvvbtCbynnnqDDqU c7SPFMpMesgpcu1xFt0F6bcxE+0ojRtSCZ5HDElKlHJNYtD1uwY4UYVGWUGCF/+cY1YLmtfb WdNb/SFo+Mp0HItfBC12qtDIXYvbfNUGVnA5jXeWMEyYhSNktLnpDL2gBUCsdbkov5VjiOX7 CRTkX0UgNWRjyFZwThaZADEvAOo12M5uSBk7h07yJ97gqvBtcx45IsJwfUJE4hy8qZqsA62A nTRflBvp647IXAiCcwWsEgE5AXKwA3aL6dcpVR17JXJ6nwHHnslVi8WesiqzUI9sbO/hXeXw TDSB+YhErbNOxvHqCzZEnGAAFf6ges26fRVyuU119AzO40sjdLV0l6LE7GshddyazWZf0iac nEhX9NKxGnuhMu5SXmo2poIQttJuYAvTVUNwQVEx/0yY5xmiuyqvXa+XT7NKJkOZSiAPlNt6 VffjgOP62S7M9wDShUghN3F7CPOrrRsOHWO/l6I/qJdUMW+MHSFYPfYiFXoLUZyPvNVCYSgs 3oQaFhHapq1f345XBtfG3fOYp1K2wTXd4ThFraTLl8PHxCn4ywARAQABzSRNYXR0aGlldSBC YWVydHMgPG1hdHR0YmVAa2VybmVsLm9yZz7CwZEEEwEIADsCGwMFCwkIBwIGFQoJCAsCBBYC AwECHgECF4AWIQToy4X3aHcFem4n93r2t4JPQmmgcwUCZUDpDAIZAQAKCRD2t4JPQmmgcz33 EACjROM3nj9FGclR5AlyPUbAq/txEX7E0EFQCDtdLPrjBcLAoaYJIQUV8IDCcPjZMJy2ADp7 /zSwYba2rE2C9vRgjXZJNt21mySvKnnkPbNQGkNRl3TZAinO1Ddq3fp2c/GmYaW1NWFSfOmw MvB5CJaN0UK5l0/drnaA6Hxsu62V5UnpvxWgexqDuo0wfpEeP1PEqMNzyiVPvJ8bJxgM8qoC cpXLp1Rq/jq7pbUycY8GeYw2j+FVZJHlhL0w0Zm9CFHThHxRAm1tsIPc+oTorx7haXP+nN0J iqBXVAxLK2KxrHtMygim50xk2QpUotWYfZpRRv8dMygEPIB3f1Vi5JMwP4M47NZNdpqVkHrm jvcNuLfDgf/vqUvuXs2eA2/BkIHcOuAAbsvreX1WX1rTHmx5ud3OhsWQQRVL2rt+0p1DpROI 3Ob8F78W5rKr4HYvjX2Inpy3WahAm7FzUY184OyfPO/2zadKCqg8n01mWA9PXxs84bFEV2mP VzC5j6K8U3RNA6cb9bpE5bzXut6T2gxj6j+7TsgMQFhbyH/tZgpDjWvAiPZHb3sV29t8XaOF BwzqiI2AEkiWMySiHwCCMsIH9WUH7r7vpwROko89Tk+InpEbiphPjd7qAkyJ+tNIEWd1+MlX ZPtOaFLVHhLQ3PLFLkrU3+Yi3tXqpvLE3gO3LM7BTQRV4/npARAA5+u/Sx1n9anIqcgHpA7l 5SUCP1e/qF7n5DK8LiM10gYglgY0XHOBi0S7vHppH8hrtpizx+7t5DBdPJgVtR6SilyK0/mp 9nWHDhc9rwU3KmHYgFFsnX58eEmZxz2qsIY8juFor5r7kpcM5dRR9aB+HjlOOJJgyDxcJTwM 1ey4L/79P72wuXRhMibN14SX6TZzf+/XIOrM6TsULVJEIv1+NdczQbs6pBTpEK/G2apME7vf mjTsZU26Ezn+LDMX16lHTmIJi7Hlh7eifCGGM+g/AlDV6aWKFS+sBbwy+YoS0Zc3Yz8zrdbi Kzn3kbKd+99//mysSVsHaekQYyVvO0KD2KPKBs1S/ImrBb6XecqxGy/y/3HWHdngGEY2v2IP Qox7mAPznyKyXEfG+0rrVseZSEssKmY01IsgwwbmN9ZcqUKYNhjv67WMX7tNwiVbSrGLZoqf Xlgw4aAdnIMQyTW8nE6hH/Iwqay4S2str4HZtWwyWLitk7N+e+vxuK5qto4AxtB7VdimvKUs x6kQO5F3YWcC3vCXCgPwyV8133+fIR2L81R1L1q3swaEuh95vWj6iskxeNWSTyFAVKYYVskG V+OTtB71P1XCnb6AJCW9cKpC25+zxQqD2Zy0dK3u2RuKErajKBa/YWzuSaKAOkneFxG3LJIv Hl7iqPF+JDCjB5sAEQEAAcLBXwQYAQIACQUCVeP56QIbDAAKCRD2t4JPQmmgc5VnD/9YgbCr HR1FbMbm7td54UrYvZV/i7m3dIQNXK2e+Cbv5PXf19ce3XluaE+wA8D+vnIW5mbAAiojt3Mb 6p0WJS3QzbObzHNgAp3zy/L4lXwc6WW5vnpWAzqXFHP8D9PTpqvBALbXqL06smP47JqbyQxj Xf7D2rrPeIqbYmVY9da1KzMOVf3gReazYa89zZSdVkMojfWsbq05zwYU+SCWS3NiyF6QghbW voxbFwX1i/0xRwJiX9NNbRj1huVKQuS4W7rbWA87TrVQPXUAdkyd7FRYICNW+0gddysIwPoa KrLfx3Ba6Rpx0JznbrVOtXlihjl4KV8mtOPjYDY9u+8x412xXnlGl6AC4HLu2F3ECkamY4G6 UxejX+E6vW6Xe4n7H+rEX5UFgPRdYkS1TA/X3nMen9bouxNsvIJv7C6adZmMHqu/2azX7S7I vrxxySzOw9GxjoVTuzWMKWpDGP8n71IFeOot8JuPZtJ8omz+DZel+WCNZMVdVNLPOd5frqOv mpz0VhFAlNTjU1Vy0CnuxX3AM51J8dpdNyG0S8rADh6C8AKCDOfUstpq28/6oTaQv7QZdge0 JY6dglzGKnCi/zsmp2+1w559frz4+IC7j/igvJGX4KDDKUs0mlld8J2u2sBXv7CGxdzQoHaz lzVbFe7fduHbABmYz9cefQpO7wDE/Q== Organization: NGI0 Core In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Catalin, On 27/01/2025 15:27, Catalin Marinas wrote: > On Thu, Jan 23, 2025 at 06:11:16PM +0100, Matthieu Baerts wrote: >> On 21/01/2025 21:46, Catalin Marinas wrote: >>> On Tue, Jan 21, 2025 at 07:42:18AM -0800, Jakub Kicinski wrote: >>>> On Tue, 21 Jan 2025 11:09:20 +0000 Catalin Marinas wrote: >>>>>>> Hmm, I don't think this would make any difference as kmemleak does scan >>>>>>> the memblock allocations as long as they have a correspondent VA in the >>>>>>> linear map. >>>>>>> >>>>>>> BTW, is NUMA enabled or disabled in your .config? >>>>>> >>>>>> It's pretty much kernel/configs/debug.config, with virtme-ng, booted >>>>>> with 4 CPUs. LMK if you can't repro with that, I can provide exact >>>>>> cmdline. >>>>> >>>>> Please do. I haven't tried to reproduce it yet on x86 as I don't have >>>>> any non-arm hardware around. It did not trigger on arm64. I think >>>>> virtme-ng may work with qemu. Anyway, I'll be off from tomorrow until >>>>> the end of the week, so more likely to try it next week. >>>> >>>> vng -b -f tools/testing/selftests/net/config -f kernel/configs/debug.config >>>> >>>> vng -r arch/x86_64/boot/bzImage --cpus 4 --user root -v --network loop >>> >>> Great, thanks. I managed to reproduce it >> >> Thank you for investigating this issue! >> >> Please note that on our side with MPTCP, I can only reproduce this issue >> locally, but not from our CI on GitHub Actions. The main difference is >> the kernel (6.8 on the CI, 6.12 here) and the fact our CI is launching >> virtme-ng from a VM. The rest should be the same. > > It won't show up in 6.8 as kmemleak did not report per-cpu allocation > leaks. But even with the latest kernel, it's probabilistic, some data > somewhere may look like a pointer and not be reported (I couldn't > reproduce it on arm64). My bad, I was talking about the host kernel. Or to be precise, I should say the kernel starting the test VM running a >=v6.13-rc7 kernel. > It turns out to be a false positive. The __percpu pointers are > referenced from node_data[]. The latter is populated in > alloc_node_data() and kmemleak registers the pg_data_t object from the > memblock allocation. However, due to an incorrect pfn range check > introduced by commit 84c326299191 ("mm: kmemleak: check physical address > when scan"), we ignore the node_data[0] allocation. Some printks in > alloc_node_data() show: > > nd_pa = 0x3ffda140 > nd_size = 0x4ec0 > min_low_pfn = 0x0 > max_low_pfn = 0x3ffdf > nd_pa + nd_size == 0x3ffdf000 > > So the "PHYS_PFN(nd_pa + nd_size) >= max_low_pfn" check in kmemleak is > true and the whole pg_data_t object ignored (not scanned). The __percpu > pointers won't be detected. The fix is simple: > > diff --git a/mm/kmemleak.c b/mm/kmemleak.c > index 820ba3b5cbfc..bb7d61fc4da3 100644 > --- a/mm/kmemleak.c > +++ b/mm/kmemleak.c > @@ -1689,7 +1689,7 @@ static void kmemleak_scan(void) > unsigned long phys = object->pointer; > > if (PHYS_PFN(phys) < min_low_pfn || > - PHYS_PFN(phys + object->size) >= max_low_pfn) > + PHYS_PFN(phys + object->size) > max_low_pfn) > __paint_it(object, KMEMLEAK_BLACK); > } Thank you for having looked at that and provided a fix quickly! I confirm that it fixes the issue on my side! Just in case you want a tested-by tag: Tested-by: Matthieu Baerts (NGI0) > I'll post this as a proper patch and I found some minor things to clean > up in kmemleak in the meantime. Great! >>> (after hacking vng to allow x86_64 as non-host architecture). >> >> Do not hesitate to report this issue + hack on vng's bug tracker :) > > Done ;) > > https://github.com/arighi/virtme-ng/issues/223 Thank you! :) Cheers, Matt -- Sponsored by the NGI0 Core fund.