From: Dan Carpenter <dan.carpenter@linaro.org>
To: oe-kbuild@lists.linux.dev, Guodong Xu <guodong@riscstar.com>,
Vinod Koul <vkoul@kernel.org>, Rob Herring <robh@kernel.org>,
Krzysztof Kozlowski <krzk@kernel.org>,
Conor Dooley <conor+dt@kernel.org>, Yixun Lan <dlan@gentoo.org>,
Philipp Zabel <p.zabel@pengutronix.de>,
Paul Walmsley <paul.walmsley@sifive.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
Albert Ou <aou@eecs.berkeley.edu>,
Alexandre Ghiti <alex@ghiti.fr>,
duje@dujemihanovic.xyz
Cc: lkp@intel.com, oe-kbuild-all@lists.linux.dev,
Alex Elder <elder@riscstar.com>,
Vivian Wang <wangruikang@iscas.ac.cn>,
dmaengine@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org,
spacemit@lists.linux.dev, Guodong Xu <guodong@riscstar.com>,
Troy Mitchell <troy.mitchell@linux.spacemit.com>
Subject: Re: [PATCH v4 4/8] dmaengine: mmp_pdma: Add operations structure for controller abstraction
Date: Mon, 18 Aug 2025 10:17:31 +0300 [thread overview]
Message-ID: <202508181040.az8RxLrG-lkp@intel.com> (raw)
In-Reply-To: <20250815-working_dma_0701_v2-v4-4-62145ab6ea30@riscstar.com>
Hi Guodong,
kernel test robot noticed the following build warnings:
url: https://github.com/intel-lab-lkp/linux/commits/Guodong-Xu/dt-bindings-dma-Add-SpacemiT-K1-PDMA-controller/20250815-132049
base: 062b3e4a1f880f104a8d4b90b767788786aa7b78
patch link: https://lore.kernel.org/r/20250815-working_dma_0701_v2-v4-4-62145ab6ea30%40riscstar.com
patch subject: [PATCH v4 4/8] dmaengine: mmp_pdma: Add operations structure for controller abstraction
config: parisc-randconfig-r072-20250818 (https://download.01.org/0day-ci/archive/20250818/202508181040.az8RxLrG-lkp@intel.com/config)
compiler: hppa-linux-gcc (GCC) 8.5.0
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202508181040.az8RxLrG-lkp@intel.com/
smatch warnings:
drivers/dma/mmp_pdma.c:546 mmp_pdma_prep_memcpy() warn: variable dereferenced before check 'dchan' (see line 542)
drivers/dma/mmp_pdma.c:712 mmp_pdma_prep_dma_cyclic() warn: variable dereferenced before check 'dchan' (see line 708)
vim +/dchan +546 drivers/dma/mmp_pdma.c
c8acd6aa6bed3c Zhangfei Gao 2012-09-03 536 static struct dma_async_tx_descriptor *
c8acd6aa6bed3c Zhangfei Gao 2012-09-03 537 mmp_pdma_prep_memcpy(struct dma_chan *dchan,
c8acd6aa6bed3c Zhangfei Gao 2012-09-03 538 dma_addr_t dma_dst, dma_addr_t dma_src,
c8acd6aa6bed3c Zhangfei Gao 2012-09-03 539 size_t len, unsigned long flags)
c8acd6aa6bed3c Zhangfei Gao 2012-09-03 540 {
c8acd6aa6bed3c Zhangfei Gao 2012-09-03 541 struct mmp_pdma_chan *chan;
918da7ee50b22b Guodong Xu 2025-08-15 @542 struct mmp_pdma_device *pdev = to_mmp_pdma_dev(dchan->device);
^^^^^^^^^^^^^
The patch adds a new dereference
c8acd6aa6bed3c Zhangfei Gao 2012-09-03 543 struct mmp_pdma_desc_sw *first = NULL, *prev = NULL, *new;
c8acd6aa6bed3c Zhangfei Gao 2012-09-03 544 size_t copy = 0;
c8acd6aa6bed3c Zhangfei Gao 2012-09-03 545
c8acd6aa6bed3c Zhangfei Gao 2012-09-03 @546 if (!dchan)
^^^^^^
But the old existing code assumed dchan could be NULL
c8acd6aa6bed3c Zhangfei Gao 2012-09-03 547 return NULL;
c8acd6aa6bed3c Zhangfei Gao 2012-09-03 548
c8acd6aa6bed3c Zhangfei Gao 2012-09-03 549 if (!len)
c8acd6aa6bed3c Zhangfei Gao 2012-09-03 550 return NULL;
c8acd6aa6bed3c Zhangfei Gao 2012-09-03 551
c8acd6aa6bed3c Zhangfei Gao 2012-09-03 552 chan = to_mmp_pdma_chan(dchan);
[ snip ]
2b7f65b11d87f9 Joe Perches 2013-11-17 701 static struct dma_async_tx_descriptor *
2b7f65b11d87f9 Joe Perches 2013-11-17 702 mmp_pdma_prep_dma_cyclic(struct dma_chan *dchan,
2b7f65b11d87f9 Joe Perches 2013-11-17 703 dma_addr_t buf_addr, size_t len, size_t period_len,
2b7f65b11d87f9 Joe Perches 2013-11-17 704 enum dma_transfer_direction direction,
31c1e5a1350ae8 Laurent Pinchart 2014-08-01 705 unsigned long flags)
50440d74aae318 Daniel Mack 2013-08-21 706 {
50440d74aae318 Daniel Mack 2013-08-21 707 struct mmp_pdma_chan *chan;
918da7ee50b22b Guodong Xu 2025-08-15 @708 struct mmp_pdma_device *pdev = to_mmp_pdma_dev(dchan->device);
^^^^^^^^^^^^^
50440d74aae318 Daniel Mack 2013-08-21 709 struct mmp_pdma_desc_sw *first = NULL, *prev = NULL, *new;
50440d74aae318 Daniel Mack 2013-08-21 710 dma_addr_t dma_src, dma_dst;
50440d74aae318 Daniel Mack 2013-08-21 711
50440d74aae318 Daniel Mack 2013-08-21 @712 if (!dchan || !len || !period_len)
^^^^^^
Same.
50440d74aae318 Daniel Mack 2013-08-21 713 return NULL;
50440d74aae318 Daniel Mack 2013-08-21 714
50440d74aae318 Daniel Mack 2013-08-21 715 /* the buffer length must be a multiple of period_len */
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
next prev parent reply other threads:[~2025-08-18 7:17 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-15 5:16 [PATCH v4 0/8] dmaengine: mmp_pdma: Add SpacemiT K1 SoC support with 64-bit addressing Guodong Xu
2025-08-15 5:16 ` [PATCH v4 1/8] dt-bindings: dma: Add SpacemiT K1 PDMA controller Guodong Xu
2025-08-15 5:16 ` [PATCH v4 2/8] dmaengine: mmp_pdma: Add clock support Guodong Xu
2025-08-15 5:16 ` [PATCH v4 3/8] dmaengine: mmp_pdma: Add reset controller support Guodong Xu
2025-08-15 5:16 ` [PATCH v4 4/8] dmaengine: mmp_pdma: Add operations structure for controller abstraction Guodong Xu
2025-08-18 7:17 ` Dan Carpenter [this message]
2025-08-18 12:27 ` Guodong Xu
2025-08-15 5:16 ` [PATCH v4 5/8] dmaengine: mmp_pdma: Add SpacemiT K1 PDMA support with 64-bit addressing Guodong Xu
2025-08-15 5:16 ` [PATCH v4 6/8] riscv: dts: spacemit: Add PDMA node for K1 SoC Guodong Xu
2025-08-15 6:01 ` Troy Mitchell
2025-08-18 12:28 ` Guodong Xu
2025-08-15 5:16 ` [PATCH v4 7/8] riscv: dts: spacemit: Enable PDMA on Banana Pi F3 and Milkv Jupiter Guodong Xu
2025-08-15 5:16 ` [PATCH v4 8/8] riscv: defconfig: Enable MMP_PDMA support for SpacemiT K1 SoC Guodong Xu
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