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 ED6127261A; Sat, 24 May 2025 13:19:59 +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=1748092800; cv=none; b=H4J+o7oWbLvZtsZ9bVXLH2R83jQPDGPA4Ql8mf2xXfggWjAG3xKFOi/3r6jcwncWzWZ35gXgEMDykIrwNt7Spq9J0YK/vDbS76T3tek3pcU6yw5F+NykPYKRZDgGpyuTgAjLLY7g63Crkw33Ux1bpji9JIWq7cD/ZmkslOiwoUc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748092800; c=relaxed/simple; bh=M0/xS0AFYmtov4bwJ8ApqaeiOVA7jV54N54Wgf8jJTw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=IoOv7RWIZn5jd+3+yJ2mRoAzoe67eVnrc3S34U2dh/yfOiQatEaVbMa6cLGYwa3Pub0klTvA+dJfkObBxcyXdS0lCH+O/jj1YQTl0qV/mBNMQPEfaKVv9di/eg6clpCifRjZEGom+oTrxfN82eIKArkDp8n+tnxQnxHoMvXV+lE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=hc7Bewia; 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="hc7Bewia" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0BCF7C4CEE4; Sat, 24 May 2025 13:19:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1748092799; bh=M0/xS0AFYmtov4bwJ8ApqaeiOVA7jV54N54Wgf8jJTw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=hc7Bewia+fk+4P20IMXK40vB2eY6bRtqz5YOsGlaNFcGQtZcED23DvvB+so5JX4xQ 6xWFojMxcbfx0Ltaf/CX0g36z1xCesLFnp4JPL8tZfLGQ8ju8pFEnZ8Ql0fgDTCXkO WWVdWfbot21w749b+qKZQBEwOv+ozX8Lagr4RwHciuYBKwN/qV/B2bCMRU0XnuwZo8 87I/3zjXUC7Iosd2/riZc0VNX2yUhiMQJzGx+RzzP0RJsxtKQfsk5UFHn1Z5mcEVCE TnaOHKMKBNOWWJi0kc7vi8huURjvMSWd0kdjyri2xpdHG5FMz3kq2sZK6Y+dgkJxax MQvyDMBGHXgBA== Date: Sat, 24 May 2025 16:19:55 +0300 From: Leon Romanovsky To: Daisuke Matsuda Cc: linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org, jgg@ziepe.ca, zyjzyj2000@gmail.com, hch@infradead.org Subject: Re: [PATCH for-next v1] RDMA/core: Avoid hmm_dma_map_alloc() for virtual DMA devices Message-ID: <20250524131955.GU7435@unreal> References: <20250523184701.11004-1-dskmtsd@gmail.com> Precedence: bulk X-Mailing-List: linux-rdma@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: <20250523184701.11004-1-dskmtsd@gmail.com> On Fri, May 23, 2025 at 06:47:01PM +0000, Daisuke Matsuda wrote: > Drivers such as rxe, which use virtual DMA, must not call into the DMA > mapping core since they lack physical DMA capabilities. Otherwise, a NULL > pointer dereference is observed as shown below. This patch ensures the RDMA > core handles virtual and physical DMA paths appropriately. > > This fixes the following kernel oops: > > BUG: kernel NULL pointer dereference, address: 00000000000002fc > #PF: supervisor read access in kernel mode > #PF: error_code(0x0000) - not-present page > PGD 1028eb067 P4D 1028eb067 PUD 105da0067 PMD 0 > Oops: Oops: 0000 [#1] SMP NOPTI > CPU: 3 UID: 1000 PID: 1854 Comm: python3 Tainted: G W 6.15.0-rc1+ #11 PREEMPT(voluntary) > Tainted: [W]=WARN > Hardware name: Trigkey Key N/Key N, BIOS KEYN101 09/02/2024 > RIP: 0010:hmm_dma_map_alloc+0x25/0x100 > Code: 90 90 90 90 90 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 49 89 d6 49 c1 e6 0c 41 55 41 54 53 49 39 ce 0f 82 c6 00 00 00 49 89 fc 87 fc 02 00 00 20 0f 84 af 00 00 00 49 89 f5 48 89 d3 49 89 cf > RSP: 0018:ffffd3d3420eb830 EFLAGS: 00010246 > RAX: 0000000000001000 RBX: ffff8b727c7f7400 RCX: 0000000000001000 > RDX: 0000000000000001 RSI: ffff8b727c7f74b0 RDI: 0000000000000000 > RBP: ffffd3d3420eb858 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 > R13: 00007262a622a000 R14: 0000000000001000 R15: ffff8b727c7f74b0 > FS: 00007262a62a1080(0000) GS:ffff8b762ac3e000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00000000000002fc CR3: 000000010a1f0004 CR4: 0000000000f72ef0 > PKRU: 55555554 > Call Trace: > > ib_init_umem_odp+0xb6/0x110 [ib_uverbs] > ib_umem_odp_get+0xf0/0x150 [ib_uverbs] > rxe_odp_mr_init_user+0x71/0x170 [rdma_rxe] > rxe_reg_user_mr+0x217/0x2e0 [rdma_rxe] > ib_uverbs_reg_mr+0x19e/0x2e0 [ib_uverbs] > ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0xd9/0x150 [ib_uverbs] > ib_uverbs_cmd_verbs+0xd19/0xee0 [ib_uverbs] > ? mmap_region+0x63/0xd0 > ? __pfx_ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0x10/0x10 [ib_uverbs] > ib_uverbs_ioctl+0xba/0x130 [ib_uverbs] > __x64_sys_ioctl+0xa4/0xe0 > x64_sys_call+0x1178/0x2660 > do_syscall_64+0x7e/0x170 > ? syscall_exit_to_user_mode+0x4e/0x250 > ? do_syscall_64+0x8a/0x170 > ? do_syscall_64+0x8a/0x170 > ? syscall_exit_to_user_mode+0x4e/0x250 > ? do_syscall_64+0x8a/0x170 > ? syscall_exit_to_user_mode+0x4e/0x250 > ? do_syscall_64+0x8a/0x170 > ? do_user_addr_fault+0x1d2/0x8d0 > ? irqentry_exit_to_user_mode+0x43/0x250 > ? irqentry_exit+0x43/0x50 > ? exc_page_fault+0x93/0x1d0 > entry_SYSCALL_64_after_hwframe+0x76/0x7e > RIP: 0033:0x7262a6124ded > Code: 04 25 28 00 00 00 48 89 45 c8 31 c0 48 8d 45 10 c7 45 b0 10 00 00 00 48 89 45 b8 48 8d 45 d0 48 89 45 c0 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1a 48 8b 45 c8 64 48 2b 04 25 28 00 00 00 > RSP: 002b:00007fffd08c3960 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 > RAX: ffffffffffffffda RBX: 00007fffd08c39f0 RCX: 00007262a6124ded > RDX: 00007fffd08c3a10 RSI: 00000000c0181b01 RDI: 0000000000000007 > RBP: 00007fffd08c39b0 R08: 0000000014107820 R09: 00007fffd08c3b44 > R10: 000000000000000c R11: 0000000000000246 R12: 00007fffd08c3b44 > R13: 000000000000000c R14: 00007fffd08c3b58 R15: 0000000014107960 > > > Fixes: 1efe8c0670d6 ("RDMA/core: Convert UMEM ODP DMA mapping to caching IOVA and page linkage") > Closes: https://lore.kernel.org/all/3e8f343f-7d66-4f7a-9f08-3910623e322f@gmail.com/ > Signed-off-by: Daisuke Matsuda > --- > drivers/infiniband/core/device.c | 24 ++++++++++++++++++++++++ > drivers/infiniband/core/umem_odp.c | 6 +++--- > include/rdma/ib_verbs.h | 12 ++++++++++++ > 3 files changed, 39 insertions(+), 3 deletions(-) > > diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c > index b4e3e4beb7f4..8be4797c66ec 100644 > --- a/drivers/infiniband/core/device.c > +++ b/drivers/infiniband/core/device.c > @@ -2864,6 +2864,30 @@ int ib_dma_virt_map_sg(struct ib_device *dev, struct scatterlist *sg, int nents) > return nents; > } > EXPORT_SYMBOL(ib_dma_virt_map_sg); > +int ib_dma_virt_map_alloc(struct device *dev, struct hmm_dma_map *map, > + size_t nr_entries, size_t dma_entry_size) > +{ > + if (!(nr_entries * PAGE_SIZE / dma_entry_size)) > + return -EINVAL; > + > + map->dma_entry_size = dma_entry_size; > + map->pfn_list = kvcalloc(nr_entries, sizeof(*map->pfn_list), > + GFP_KERNEL | __GFP_NOWARN); > + if (!map->pfn_list) > + return -ENOMEM; pfn_list is enough, virtual devices doesn't go through path which needs dma_list. They use simple CPU address to DMA address translation. > + > + map->dma_list = kvcalloc(nr_entries, sizeof(*map->dma_list), > + GFP_KERNEL | __GFP_NOWARN); > + if (!map->dma_list) > + goto err_dma; > + > + return 0; > + > +err_dma: > + kvfree(map->pfn_list); > + return -ENOMEM; > +} > +EXPORT_SYMBOL(ib_dma_virt_map_alloc); > #endif /* CONFIG_INFINIBAND_VIRT_DMA */ > > static const struct rdma_nl_cbs ibnl_ls_cb_table[RDMA_NL_LS_NUM_OPS] = { > diff --git a/drivers/infiniband/core/umem_odp.c b/drivers/infiniband/core/umem_odp.c > index 51d518989914..aa03f3fc84d0 100644 > --- a/drivers/infiniband/core/umem_odp.c > +++ b/drivers/infiniband/core/umem_odp.c > @@ -75,9 +75,9 @@ static int ib_init_umem_odp(struct ib_umem_odp *umem_odp, > if (unlikely(end < page_size)) > return -EOVERFLOW; > > - ret = hmm_dma_map_alloc(dev->dma_device, &umem_odp->map, > - (end - start) >> PAGE_SHIFT, > - 1 << umem_odp->page_shift); > + ret = ib_dma_map_alloc(dev, &umem_odp->map, > + (end - start) >> PAGE_SHIFT, > + 1 << umem_odp->page_shift); There is no need in extra function, implement if(ib_uses_virt_dma...) here. Thanks