2022-03-17 03:23:05

by Randy Dunlap

[permalink] [raw]
Subject: [PATCH 1/9] virtio_blk: eliminate anonymous module_init & module_exit

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 <[email protected]>
Cc: "Michael S. Tsirkin" <[email protected]>
Cc: Jason Wang <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Stefan Hajnoczi <[email protected]>
Cc: [email protected]
Cc: Jens Axboe <[email protected]>
Cc: [email protected]
---
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");


2022-03-17 06:41:23

by Jason Wang

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

On Thu, Mar 17, 2022 at 3:25 AM Randy Dunlap <[email protected]> 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 <[email protected]>
> Cc: "Michael S. Tsirkin" <[email protected]>
> Cc: Jason Wang <[email protected]>
> Cc: Paolo Bonzini <[email protected]>
> Cc: Stefan Hajnoczi <[email protected]>
> Cc: [email protected]
> Cc: Jens Axboe <[email protected]>
> Cc: [email protected]
> ---

Acked-by: Jason Wang <[email protected]>

> 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");
>

2022-03-17 09:47:57

by Stefan Hajnoczi

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

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 <[email protected]>
> Cc: "Michael S. Tsirkin" <[email protected]>
> Cc: Jason Wang <[email protected]>
> Cc: Paolo Bonzini <[email protected]>
> Cc: Stefan Hajnoczi <[email protected]>
> Cc: [email protected]
> Cc: Jens Axboe <[email protected]>
> Cc: [email protected]
> ---
> 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");
>

Reviewed-by: Stefan Hajnoczi <[email protected]>


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2022-03-20 14:49:00

by Michael S. Tsirkin

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

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 <[email protected]>
> Cc: "Michael S. Tsirkin" <[email protected]>
> Cc: Jason Wang <[email protected]>
> Cc: Paolo Bonzini <[email protected]>
> Cc: Stefan Hajnoczi <[email protected]>
> Cc: [email protected]
> Cc: Jens Axboe <[email protected]>
> Cc: [email protected]


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

Acked-by: Michael S. Tsirkin <[email protected]>

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");