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Date: Tue, 25 Feb 2025 10:19:10 +0000
From: Simon Horman <horms@kernel.org>
To: Breno Leitao <leitao@debian.org>
Cc: Andrew Lunn <andrew+netdev@lunn.ch>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Jonathan Corbet <corbet@lwn.net>, Shuah Khan <shuah@kernel.org>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org,
	kernel-team@meta.com
Subject: Re: [PATCH net-next 5/7] netconsole: add task name to extra data
 fields
Message-ID: <20250225101910.GM1615191@kernel.org>
References: <20250221-netcons_current-v1-0-21c86ae8fc0d@debian.org>
 <20250221-netcons_current-v1-5-21c86ae8fc0d@debian.org>
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In-Reply-To: <20250221-netcons_current-v1-5-21c86ae8fc0d@debian.org>

On Fri, Feb 21, 2025 at 05:52:10AM -0800, Breno Leitao wrote:
> This is the core patch for this whole patchset. Add support for
> including the current task's name in netconsole's extra data output.
> This adds a new append_taskname() function that writes the task name
> (from current->comm) into the target's extradata buffer, similar to how
> CPU numbers are handled.
> 
> The task name is included when the SYSDATA_TASKNAME field is set,
> appearing in the format "taskname=<name>" in the output. This additional
> context can help with debugging by showing which task generated each
> console message.
> 
> Signed-off-by: Breno Leitao <leitao@debian.org>
> ---
>  drivers/net/netconsole.c | 14 +++++++++++++-
>  1 file changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
> index 5a29144ae37ee7b487b1a252b0f2ce8574f9cefa..625f4c0be11d8deb454139b1c526abc842697219 100644
> --- a/drivers/net/netconsole.c
> +++ b/drivers/net/netconsole.c
> @@ -1179,12 +1179,22 @@ static int append_cpu_nr(struct netconsole_target *nt, int offset)
>  			 raw_smp_processor_id());
>  }
>  
> +static int append_taskname(struct netconsole_target *nt, int offset)
> +{
> +	if (WARN_ON_ONCE(!current))
> +		return 0;

Hi Breno,

I gather that theoretically this could occur, but it isn't expected
to happen in practice. Is that right?

...