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 67B9B22A4D5; Tue, 19 Aug 2025 11:03:52 +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=1755601432; cv=none; b=M09NP+xZ8x964aGb+T+ISixFltO0czoXtMqGe3pSv1tVT6kt+pvZHd7be6hZglCys9BrEPsPDHjh1AQtSqe+PskzA8P7TLINLWRIR3BrzI8UVzt10XTh/0oGo7+7ZEYAinygSoC12FJIOh10vrer72fcRDMQGJ2gA0N05jXfzEQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755601432; c=relaxed/simple; bh=UcQi5igNficMd4VE9yzQLipb16wG55Yu37q1KOU8F3I=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=OPngsJ8IMA76cYBKWNwtttHbMtwdVUcv/olZFWS+plejSJ8OWbLPPK2RUBdDUDitnaWTYpi+zHLBpgHx4KomZUOcEG/zmPFe1n+MEkEROecgQzCfW9Jv52pEcLjt01rZoa8KpWp+l1VjVFH8lqWXG7xOyWC0+2GOX7BvrtYTsuA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JxdFsQCr; 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="JxdFsQCr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7DA29C4CEF1; Tue, 19 Aug 2025 11:03:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755601432; bh=UcQi5igNficMd4VE9yzQLipb16wG55Yu37q1KOU8F3I=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=JxdFsQCr+OjBL4861fcA/j5N8Oi65KK+RZZZyZzgjdpJWamtjzsI7kPg8IClpZw80 fOWd66glzc6/gDVKCBlSWtSlEN/Wz/BqrtIKCuu0UahC8Ayy2dDToiyBer+GjsbwJ1 OiKqqguAFWrSk9KMh65PqMgMypHQEhpBOc1ZcJTnhpUPyCN60wUFDBftVgOHWuo7DS WJDHwI812W+q5eXugX7VlOo6/O07U6KmBkvF+lgB0LkH4Gax4D1Ej7x0ITsnREWlpv M4cI4GOw7v4nGQoTZDgZMVM3cgp91mgschqg3a83hpaFGYnX44tBitFQbpCRheo6hO bwDXvMFXjtyuQ== Date: Tue, 19 Aug 2025 14:03:44 +0300 From: Mike Rapoport To: Yin Tirui Cc: robh@kernel.org, saravanak@google.com, dan.j.williams@intel.com, akpm@linux-foundation.org, david@redhat.com, Jonathan.Cameron@huawei.com, devicetree@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, wangkefeng.wang@huawei.com, chenjun102@huawei.com Subject: Re: [PATCH v3] of_numa: fix uninitialized memory nodes causing kernel panic Message-ID: References: <20250819075510.2079961-1-yintirui@huawei.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250819075510.2079961-1-yintirui@huawei.com> On Tue, Aug 19, 2025 at 03:55:10PM +0800, Yin Tirui wrote: > When there are memory-only nodes (nodes without CPUs), these nodes > are not properly initialized, causing kernel panic during boot. > > of_numa_init > of_numa_parse_cpu_nodes > node_set(nid, numa_nodes_parsed); > of_numa_parse_memory_nodes > > In of_numa_parse_cpu_nodes, numa_nodes_parsed gets updated only for > nodes containing CPUs. Memory-only nodes should have been updated in > of_numa_parse_memory_nodes, but they weren't. > > Subsequently, when free_area_init() attempts to access NODE_DATA() > for these uninitialized memory nodes, the kernel panics due to NULL > pointer dereference. > > This can be reproduced on ARM64 QEMU with 1 CPU and 2 memory nodes: > > qemu-system-aarch64 \ > -cpu host -nographic \ > -m 4G -smp 1 \ > -machine virt,accel=kvm,gic-version=3,iommu=smmuv3 \ > -object memory-backend-ram,size=2G,id=mem0 \ > -object memory-backend-ram,size=2G,id=mem1 \ > -numa node,nodeid=0,memdev=mem0 \ > -numa node,nodeid=1,memdev=mem1 \ > -kernel $IMAGE \ > -hda $DISK \ > -append "console=ttyAMA0 root=/dev/vda rw earlycon" > > [ 0.000000] Booting Linux on physical CPU 0x0000000000 [0x481fd010] > [ 0.000000] Linux version 6.17.0-rc1-00001-gabb4b3daf18c-dirty (yintirui@local) (gcc (GCC) 12.3.1, GNU ld (GNU Binutils) 2.41) #52 SMP PREEMPT Mon Aug 18 09:49:40 CST 2025 > [ 0.000000] KASLR enabled > [ 0.000000] random: crng init done > [ 0.000000] Machine model: linux,dummy-virt > [ 0.000000] efi: UEFI not found. > [ 0.000000] earlycon: pl11 at MMIO 0x0000000009000000 (options '') > [ 0.000000] printk: legacy bootconsole [pl11] enabled > [ 0.000000] OF: reserved mem: Reserved memory: No reserved-memory node in the DT > [ 0.000000] NODE_DATA(0) allocated [mem 0xbfffd9c0-0xbfffffff] > [ 0.000000] node 1 must be removed before remove section 23 > [ 0.000000] Zone ranges: > [ 0.000000] DMA [mem 0x0000000040000000-0x00000000ffffffff] > [ 0.000000] DMA32 empty > [ 0.000000] Normal [mem 0x0000000100000000-0x000000013fffffff] > [ 0.000000] Movable zone start for each node > [ 0.000000] Early memory node ranges > [ 0.000000] node 0: [mem 0x0000000040000000-0x00000000bfffffff] > [ 0.000000] node 1: [mem 0x00000000c0000000-0x000000013fffffff] > [ 0.000000] Initmem setup node 0 [mem 0x0000000040000000-0x00000000bfffffff] > [ 0.000000] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000a0 > [ 0.000000] Mem abort info: > [ 0.000000] ESR = 0x0000000096000004 > [ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits > [ 0.000000] SET = 0, FnV = 0 > [ 0.000000] EA = 0, S1PTW = 0 > [ 0.000000] FSC = 0x04: level 0 translation fault > [ 0.000000] Data abort info: > [ 0.000000] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 > [ 0.000000] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 > [ 0.000000] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 > [ 0.000000] [00000000000000a0] user address but active_mm is swapper > [ 0.000000] Internal error: Oops: 0000000096000004 [#1] SMP > [ 0.000000] Modules linked in: > [ 0.000000] CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.17.0-rc1-00001-g760c6dabf762-dirty #54 PREEMPT > [ 0.000000] Hardware name: linux,dummy-virt (DT) > [ 0.000000] pstate: 800000c5 (Nzcv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--) > [ 0.000000] pc : free_area_init+0x50c/0xf9c > [ 0.000000] lr : free_area_init+0x5c0/0xf9c > [ 0.000000] sp : ffffa02ca0f33c00 > [ 0.000000] x29: ffffa02ca0f33cb0 x28: 0000000000000000 x27: 0000000000000000 > [ 0.000000] x26: 4ec4ec4ec4ec4ec5 x25: 00000000000c0000 x24: 00000000000c0000 > [ 0.000000] x23: 0000000000040000 x22: 0000000000000000 x21: ffffa02ca0f3b368 > [ 0.000000] x20: ffffa02ca14c7b98 x19: 0000000000000000 x18: 0000000000000002 > [ 0.000000] x17: 000000000000cacc x16: 0000000000000001 x15: 0000000000000001 > [ 0.000000] x14: 0000000080000000 x13: 0000000000000018 x12: 0000000000000002 > [ 0.000000] x11: ffffa02ca0fd4f00 x10: ffffa02ca14bab20 x9 : ffffa02ca14bab38 > [ 0.000000] x8 : 00000000000c0000 x7 : 0000000000000001 x6 : 0000000000000002 > [ 0.000000] x5 : 0000000140000000 x4 : ffffa02ca0f33c90 x3 : ffffa02ca0f33ca0 > [ 0.000000] x2 : ffffa02ca0f33c98 x1 : 0000000080000000 x0 : 0000000000000001 > [ 0.000000] Call trace: > [ 0.000000] free_area_init+0x50c/0xf9c (P) > [ 0.000000] bootmem_init+0x110/0x1dc > [ 0.000000] setup_arch+0x278/0x60c > [ 0.000000] start_kernel+0x70/0x748 > [ 0.000000] __primary_switched+0x88/0x90 > [ 0.000000] Code: d503201f b98093e0 52800016 f8607a93 (f9405260) > [ 0.000000] ---[ end trace 0000000000000000 ]--- > [ 0.000000] Kernel panic - not syncing: Attempted to kill the idle task! > [ 0.000000] ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]--- > > v2: Move the changes to the of_numa related. Correct the fixes tag. > v3: Only amend commit message with no code changes. > > Cc: stable@vger.kernel.org > Fixes: 767507654c22 ("arch_numa: switch over to numa_memblks") > Signed-off-by: Yin Tirui > Acked-by: David Hildenbrand Acked-by: Mike Rapoport (Microsoft) > --- > drivers/of/of_numa.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/of/of_numa.c b/drivers/of/of_numa.c > index 230d5f628c1b..cd2dc8e825c9 100644 > --- a/drivers/of/of_numa.c > +++ b/drivers/of/of_numa.c > @@ -59,8 +59,11 @@ static int __init of_numa_parse_memory_nodes(void) > r = -EINVAL; > } > > - for (i = 0; !r && !of_address_to_resource(np, i, &rsrc); i++) > + for (i = 0; !r && !of_address_to_resource(np, i, &rsrc); i++) { > r = numa_add_memblk(nid, rsrc.start, rsrc.end + 1); > + if (!r) > + node_set(nid, numa_nodes_parsed); > + } > > if (!i || r) { > of_node_put(np); > -- > 2.43.0 > -- Sincerely yours, Mike.