linux-kernel - Re: [PATCH v3 3/3] exec: Add support for 64 byte 'tsk->real

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Message-ID: <aBtYDGOAVbLHeTHF@pathway.suse.cz>
Date: Wed, 7 May 2025 14:54:36 +0200
From: Petr Mladek <pmladek@...e.com>
To: Bhupesh <bhupesh@...lia.com>
Cc: akpm@...ux-foundation.org, kernel-dev@...lia.com,
	linux-kernel@...r.kernel.org, bpf@...r.kernel.org,
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Subject: Re: [PATCH v3 3/3] exec: Add support for 64 byte 'tsk->real_comm'

On Wed 2025-05-07 16:34:44, Bhupesh wrote:
> Historically due to the 16-byte length of TASK_COMM_LEN, the
> users of 'tsk->comm' are restricted to use a fixed-size target
> buffer also of TASK_COMM_LEN for 'memcpy()' like use-cases.
> 
> To fix the same, Linus suggested in [1] that we can add the
> following union inside 'task_struct':
>        union {
>                char    comm[TASK_COMM_LEN];
>                char    real_comm[REAL_TASK_COMM_LEN];
>        };

Nit: IMHO, the prefix "real_" is misleading. The buffer size is still
      limited and the name might be shrinked. I would suggest
      something like:

	char    comm_ext[TASK_COMM_EXT_LEN];
or
	char    comm_64[TASK_COMM_64_LEN]

> and then modify '__set_task_comm()' to pass 'tsk->real_comm'
> to the existing users.

Best Regards,
Petr