On Mon, Apr 01, 2024 at 11:34:23AM -0400, Dennis Dalessandro wrote: > On 4/1/24 10:53 AM, Jakub Kicinski wrote: > > On Mon, 1 Apr 2024 14:53:31 +0300 Leon Romanovsky wrote: > >> On Tue, Mar 19, 2024 at 02:09:43AM -0700, Breno Leitao wrote: > >>> Embedding net_device into structures prohibits the usage of flexible > >>> arrays in the net_device structure. For more details, see the discussion > >>> at [1]. > >>> > >>> Un-embed the net_device from struct hfi1_netdev_rx by converting it > >>> into a pointer. Then use the leverage alloc_netdev() to allocate the > >>> net_device object at hfi1_alloc_rx(). > >>> > >>> [1] https://lore.kernel.org/all/20240229225910.79e224cf@xxxxxxxxxx/ > >>> > >>> Signed-off-by: Breno Leitao <leitao@xxxxxxxxxx> > >>> Acked-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxxxxxxxxxxxxx> > >> > >> Jakub, > >> > >> I create shared branch for you, please pull it from: > >> https://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma.git/log/?h=remove-dummy-netdev > > > > Did you merge it in already? > > Turned out that the use of init_dummy_netdev as a setup function > > is broken, I'm not sure how Dennis tested this :( > > We should have pinged you, sorry. > > This is what I tested, Linus 6.8 tag + cherry pick + Breno patch. So if > something went in that broke it I didn't have it in my tree. > > commit 311810a6d7e37d8e7537d50e26197b7f5f02f164 (linus-master) > Author: Breno Leitao <leitao@xxxxxxxxxx> > Date: Wed Mar 13 03:33:10 2024 -0700 > > IB/hfi1: allocate dummy net_device dynamically This one has a potential bug that causes a kernel panic when the module is removed. This is because alloc_netdev() allocates some data structures that are later overwritten (memset) by init_dummy_netdev(). At the free time, free_netdev() will dereference those structures and they are zero. A new upcoming patch is creating a helper (init_dummy_netdev()) that will allocate the netdev and call a special version of init_dummy_netdev() without memsetting the structure. I would drop this patch for now, and I will submit a new version using the new helper.
