Re: [PATCH 1/9] virtio_blk: eliminate anonymous module_init & module_exit

From: "Michael S. Tsirkin" <mst@redhat.com>
To: Randy Dunlap <rdunlap@infradead.org>
Cc: linux-kernel@vger.kernel.org, "Jason Wang" <jasowang@redhat.com>,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	"Stefan Hajnoczi" <stefanha@redhat.com>,
	"Jens Axboe" <axboe@kernel.dk>, "Amit Shah" <amit@kernel.org>,
	"Arnd Bergmann" <arnd@arndb.de>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	"Eli Cohen" <eli@mellanox.com>,
	"Saeed Mahameed" <saeedm@nvidia.com>,
	"Leon Romanovsky" <leon@kernel.org>,
	"Pablo Neira Ayuso" <pablo@netfilter.org>,
	"Jozsef Kadlecsik" <kadlec@netfilter.org>,
	"Florian Westphal" <fw@strlen.de>,
	"David S. Miller" <davem@davemloft.net>,
	"Jakub Kicinski" <kuba@kernel.org>,
	"James E.J. Bottomley" <jejb@linux.ibm.com>,
	"Martin K. Petersen" <martin.petersen@oracle.com>,
	"Felipe Balbi" <felipe.balbi@linux.intel.com>,
	"Michał Mirosław" <mirq-linux@rere.qmqm.pl>,
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	"Steven Rostedt" <rostedt@goodmis.org>,
	"Ingo Molnar" <mingo@kernel.org>,
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	"Pekka Paalanen" <ppaalanen@gmail.com>,
	"Dave Hansen" <dave.hansen@linux.intel.com>,
	"Andy Lutomirski" <luto@kernel.org>,
	"Peter Zijlstra" <peterz@infradead.org>,
	"Borislav Petkov" <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	netfilter-devel@vger.kernel.org, coreteam@netfilter.org,
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	virtualization@lists.linux-foundation.org, x86@kernel.org
Subject: Re: [PATCH 1/9] virtio_blk: eliminate anonymous module_init & module_exit
Date: Sun, 20 Mar 2022 08:04:00 -0400	[thread overview]
Message-ID: <20220320080242-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <20220316192010.19001-2-rdunlap@infradead.org>

On Wed, Mar 16, 2022 at 12:20:02PM -0700, Randy Dunlap wrote:
> Eliminate anonymous module_init() and module_exit(), which can lead to
> confusion or ambiguity when reading System.map, crashes/oops/bugs,
> or an initcall_debug log.
> 
> Give each of these init and exit functions unique driver-specific
> names to eliminate the anonymous names.
> 
> Example 1: (System.map)
>  ffffffff832fc78c t init
>  ffffffff832fc79e t init
>  ffffffff832fc8f8 t init
> 
> Example 2: (initcall_debug log)
>  calling  init+0x0/0x12 @ 1
>  initcall init+0x0/0x12 returned 0 after 15 usecs
>  calling  init+0x0/0x60 @ 1
>  initcall init+0x0/0x60 returned 0 after 2 usecs
>  calling  init+0x0/0x9a @ 1
>  initcall init+0x0/0x9a returned 0 after 74 usecs
> 
> Fixes: e467cde23818 ("Block driver using virtio.")
> Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
> Cc: "Michael S. Tsirkin" <mst@redhat.com>
> Cc: Jason Wang <jasowang@redhat.com>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Stefan Hajnoczi <stefanha@redhat.com>
> Cc: virtualization@lists.linux-foundation.org
> Cc: Jens Axboe <axboe@kernel.dk>
> Cc: linux-block@vger.kernel.org

If this is done tree-wide, it's ok to do it for virtio too.

Acked-by: Michael S. Tsirkin <mst@redhat.com>

No real opinion on whether it's a good idea.

> ---
>  drivers/block/virtio_blk.c |    8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> --- lnx-517-rc8.orig/drivers/block/virtio_blk.c
> +++ lnx-517-rc8/drivers/block/virtio_blk.c
> @@ -1058,7 +1058,7 @@ static struct virtio_driver virtio_blk =
>  #endif
>  };
>  
> -static int __init init(void)
> +static int __init virtio_blk_init(void)
>  {
>  	int error;
>  
> @@ -1084,14 +1084,14 @@ out_destroy_workqueue:
>  	return error;
>  }
>  
> -static void __exit fini(void)
> +static void __exit virtio_blk_fini(void)
>  {
>  	unregister_virtio_driver(&virtio_blk);
>  	unregister_blkdev(major, "virtblk");
>  	destroy_workqueue(virtblk_wq);
>  }
> -module_init(init);
> -module_exit(fini);
> +module_init(virtio_blk_init);
> +module_exit(virtio_blk_fini);
>  
>  MODULE_DEVICE_TABLE(virtio, id_table);
>  MODULE_DESCRIPTION("Virtio block driver");