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Message-ID: <840cdf34-f38e-ab37-623f-9744c3436350@grimberg.me>
Date:   Mon, 24 Jul 2023 10:46:34 +0300
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Subject: Re: drivers/nvme/host/tcp.c:835:12: warning: stack frame size (2256)
 exceeds limit (2048) in 'nvme_tcp_recv_skb'
Content-Language: en-US
To:     kernel test robot <lkp@intel.com>,
        Varun Prakash <varun@chelsio.com>
Cc:     llvm@lists.linux.dev, oe-kbuild-all@lists.linux.dev,
        linux-kernel@vger.kernel.org, Christoph Hellwig <hch@lst.de>
References: <202307201141.PYWS6ird-lkp@intel.com>
From:   Sagi Grimberg <sagi@grimberg.me>
In-Reply-To: <202307201141.PYWS6ird-lkp@intel.com>
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On 7/20/23 06:10, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   bfa3037d828050896ae52f6467b6ca2489ae6fb1
> commit: c2700d2886a87f83f31e0a301de1d2350b52c79b nvme-tcp: send H2CData PDUs based on MAXH2CDATA
> date:   1 year, 5 months ago
> config: riscv-randconfig-r042-20230720 (https://download.01.org/0day-ci/archive/20230720/202307201141.PYWS6ird-lkp@intel.com/config)
> compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a)
> reproduce: (https://download.01.org/0day-ci/archive/20230720/202307201141.PYWS6ird-lkp@intel.com/reproduce)
> 
> 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>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202307201141.PYWS6ird-lkp@intel.com/
> 
> All warnings (new ones prefixed by >>):
> 
>>> drivers/nvme/host/tcp.c:835:12: warning: stack frame size (2256) exceeds limit (2048) in 'nvme_tcp_recv_skb' [-Wframe-larger-than]
>       835 | static int nvme_tcp_recv_skb(read_descriptor_t *desc, struct sk_buff *skb,
>           |            ^
>     1 warning generated.
> 
> 
> vim +/nvme_tcp_recv_skb +835 drivers/nvme/host/tcp.c
> 
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  834
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03 @835  static int nvme_tcp_recv_skb(read_descriptor_t *desc, struct sk_buff *skb,
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  836  			     unsigned int offset, size_t len)
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  837  {
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  838  	struct nvme_tcp_queue *queue = desc->arg.data;
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  839  	size_t consumed = len;
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  840  	int result;
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  841
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  842  	while (len) {
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  843  		switch (nvme_tcp_recv_state(queue)) {
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  844  		case NVME_TCP_RECV_PDU:
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  845  			result = nvme_tcp_recv_pdu(queue, skb, &offset, &len);
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  846  			break;
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  847  		case NVME_TCP_RECV_DATA:
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  848  			result = nvme_tcp_recv_data(queue, skb, &offset, &len);
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  849  			break;
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  850  		case NVME_TCP_RECV_DDGST:
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  851  			result = nvme_tcp_recv_ddgst(queue, skb, &offset, &len);
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  852  			break;
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  853  		default:
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  854  			result = -EFAULT;
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  855  		}
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  856  		if (result) {
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  857  			dev_err(queue->ctrl->ctrl.device,
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  858  				"receive failed:  %d\n", result);
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  859  			queue->rd_enabled = false;
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  860  			nvme_tcp_error_recovery(&queue->ctrl->ctrl);
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  861  			return result;
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  862  		}
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  863  	}
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  864
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  865  	return consumed;
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  866  }
> 3f2304f8c6d6ed Sagi Grimberg 2018-12-03  867
> 
> :::::: The code at line 835 was first introduced by commit
> :::::: 3f2304f8c6d6ed97849057bd16fee99e434ca796 nvme-tcp: add NVMe over TCP host driver
> 
> :::::: TO: Sagi Grimberg <sagi@lightbitslabs.com>
> :::::: CC: Christoph Hellwig <hch@lst.de>
> 

I don't understand how the stack frame size is that big. Looks like a
wrong complaint?