From nobody Wed Feb 11 06:54:08 2026 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 8FAD2221577; Mon, 1 Sep 2025 21:30:45 +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=1756762245; cv=none; b=ubf7EIp8PG3KsHTr1uutRJIECE0lb116AVVpSj3DAgoCdY5YwgYQo8ZZT2CNBt3X22FTum8uWp77pTQ/EAP+zGc73pWHcVCZ/wAu1ol6REcOWUPC7VzDX2S/Ia3klVF0oGPy3G3ScbSeFGLW1nuAyhcXQrLrUG8KogbemzPctVc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756762245; c=relaxed/simple; bh=PRaBApLQy8iLSplWAmAp1oVZUt+rfypBd7IUK5L9VhM=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=C7o+NPAw2HuCXD6kXJMnCCQfiOEkGZnLY1N/vU6jHt6ZZjsCBPr7UK7g73KHRq95jyXWhjpNYpFSxZ5LaaVFlBYJSdjPEE0Bg5jwW250Yl1gDQMb5TENhRrezsVdbp2MWT5p4LhMrBDyZjfOFZB9T2gRa7G4z7XKWEvTz9L2KTk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Zvj1d+sA; 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="Zvj1d+sA" Received: by smtp.kernel.org (Postfix) with ESMTPS id 1D0C5C4CEF0; Mon, 1 Sep 2025 21:30:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756762245; bh=PRaBApLQy8iLSplWAmAp1oVZUt+rfypBd7IUK5L9VhM=; h=From:Date:Subject:To:Cc:Reply-To:From; b=Zvj1d+sAt2W4YW5Xl57DOgpg8QBsjStyQQfzpfLYcCzxD+9csXNUcimZor2V6P0KW yM7Q/6yDsMDtuJmgSTJV19AsOcujeKUWGI/it9ftfQj8vSW3TKiZb1RDoFbpwdD0ZN kp10HtU10FCbTS9unLdXvnkrwd/4nEpUrU729vmeKXKkRy7+fRcF0clKThmLAY3TrH mzqgxlSwjUMM07bnQ9w2VStWZehcdvgCP//nc+136sODLycBb2IR7hK2+LkqVJjWoV +9bITXEKehW6YCjfUbxR2ZIkBMmqwUMp3j+iZA6hp3waEqxGcCyCMhoWRLs/ffQ9vs Zqmdg+VKIThuA== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0EE3ACA1002; Mon, 1 Sep 2025 21:30:45 +0000 (UTC) From: Anthony Brandon via B4 Relay Date: Mon, 01 Sep 2025 23:30:32 +0200 Subject: [PATCH v2] dmaengine: xilinx: xdma: Fix regmap max_register 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="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250901-xdma-max-reg-v2-1-fa3723a718cd@amarulasolutions.com> X-B4-Tracking: v=1; b=H4sIAHcQtmgC/3WOQQqDMBBFryKz7pSMNaF21XsUF6NONWCMJCoW8 e5N3Xf5HvzH3yFKsBLhke0QZLXR+jFBfsmg6XnsBG2bGHKVa1Uqwq11jI43DNIhmaJsTKHLm75 DmkxB3nY7c68qcW/j7MPnrK/0s39CKyFhbVgV2pC0NT3ZcVgGjn5Y5vQpXhvvoDqO4wvf58KTs wAAAA== X-Change-ID: 20250901-xdma-max-reg-1649c6459358 To: Lizhi Hou , Brian Xu , Raj Kumar Rampelli , Vinod Koul , Michal Simek Cc: dmaengine@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Anthony Brandon X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=2662; i=anthony@amarulasolutions.com; h=from:subject:message-id; bh=EBsbI+2mqsOLjYpUAS5JaxRB+GFopFCZKJlHq1D/08o=; b=owGbwMvMwCUWIi5b4HjluATjabUkhoxtAs3zz7lceM09Jf/+SkHWJQb5fB0zROt2ty1wUwr0v 6V96varjlIWBjEuBlkxRZZyHXleD+W6cqWZT4xh5rAygQxh4OIUgInkH2X4nydzSpZLnumGyFw/ w1l2MyfMWdK0edbmfXkNUnyOpW/0eBn+x/evY7bwklfpea+6/sTppuM1CQ53NvW+7U/VfvD5H1M ZCwA= X-Developer-Key: i=anthony@amarulasolutions.com; a=openpgp; fpr=772C1F0D48237E772299E43354171D7041D4C718 X-Endpoint-Received: by B4 Relay for anthony@amarulasolutions.com/default with auth_id=505 X-Original-From: Anthony Brandon Reply-To: anthony@amarulasolutions.com From: Anthony Brandon The max_register field is assigned the size of the register memory region instead of the offset of the last register. The result is that reading from the regmap via debugfs can cause a segmentation fault: tail /sys/kernel/debug/regmap/xdma.1.auto/registers Unable to handle kernel paging request at virtual address ffff800082f70000 Mem abort info: ESR =3D 0x0000000096000007 EC =3D 0x25: DABT (current EL), IL =3D 32 bits SET =3D 0, FnV =3D 0 EA =3D 0, S1PTW =3D 0 FSC =3D 0x07: level 3 translation fault [...] Call trace: regmap_mmio_read32le+0x10/0x30 _regmap_bus_reg_read+0x74/0xc0 _regmap_read+0x68/0x198 regmap_read+0x54/0x88 regmap_read_debugfs+0x140/0x380 regmap_map_read_file+0x30/0x48 full_proxy_read+0x68/0xc8 vfs_read+0xcc/0x310 ksys_read+0x7c/0x120 __arm64_sys_read+0x24/0x40 invoke_syscall.constprop.0+0x64/0x108 do_el0_svc+0xb0/0xd8 el0_svc+0x38/0x130 el0t_64_sync_handler+0x120/0x138 el0t_64_sync+0x194/0x198 Code: aa1e03e9 d503201f f9400000 8b214000 (b9400000) Reviewed-by: Lizhi Hou ---[ end trace 0000000000000000 ]--- note: tail[1217] exited with irqs disabled note: tail[1217] exited with preempt_count 1 Segmentation fault Signed-off-by: Anthony Brandon --- Changes in v2: - Define new constant XDMA_MAX_REG_OFFSET and use that. - Link to v1: https://lore.kernel.org/r/20250901-xdma-max-reg-v1-1-b6a04561= edb1@amarulasolutions.com --- drivers/dma/xilinx/xdma-regs.h | 1 + drivers/dma/xilinx/xdma.c | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/dma/xilinx/xdma-regs.h b/drivers/dma/xilinx/xdma-regs.h index 6ad08878e93862b770febb71b8bc85e66813428e..70bca92621aa41b0367d1e236b3= e276344a26320 100644 --- a/drivers/dma/xilinx/xdma-regs.h +++ b/drivers/dma/xilinx/xdma-regs.h @@ -9,6 +9,7 @@ =20 /* The length of register space exposed to host */ #define XDMA_REG_SPACE_LEN 65536 +#define XDMA_MAX_REG_OFFSET (XDMA_REG_SPACE_LEN - 4) =20 /* * maximum number of DMA channels for each direction: diff --git a/drivers/dma/xilinx/xdma.c b/drivers/dma/xilinx/xdma.c index 0d88b1a670e142dac90d09c515809faa2476a816..5ecf8223c112e468c79ce635398= ba393a535b9e0 100644 --- a/drivers/dma/xilinx/xdma.c +++ b/drivers/dma/xilinx/xdma.c @@ -38,7 +38,7 @@ static const struct regmap_config xdma_regmap_config =3D { .reg_bits =3D 32, .val_bits =3D 32, .reg_stride =3D 4, - .max_register =3D XDMA_REG_SPACE_LEN, + .max_register =3D XDMA_MAX_REG_OFFSET, }; =20 /** --- base-commit: b320789d6883cc00ac78ce83bccbfe7ed58afcf0 change-id: 20250901-xdma-max-reg-1649c6459358 Best regards, --=20 Anthony Brandon