On Mon, Apr 08, 2024 at 07:43:42PM +0300, Kalle Valo wrote: > Breno Leitao <leitao@xxxxxxxxxx> writes: > > On Fri, Apr 05, 2024 at 06:15:05PM +0300, Kalle Valo wrote: > >> Breno Leitao <leitao@xxxxxxxxxx> writes: > >> > >> > struct net_device shouldn't be embedded into any structure, instead, > >> > the owner should use the private space to embed their state into > >> > net_device. > >> > > >> > This patch set fixes the problem above for ath10k and ath11k. This also > >> > fixes the conversion of qtnfmac driver to the new helper. > >> > > >> > This patch set depends on a series that is still under review: > >> > https://lore.kernel.org/all/20240404114854.2498663-1-leitao@xxxxxxxxxx/#t > >> > > >> > If it helps, I've pushed the tree to > >> > https://github.com/leitao/linux/tree/wireless-dummy > >> > > >> > PS: Due to lack of hardware, unfortunately all these patches are > >> > compiled tested only. > >> > > >> > Breno Leitao (3): > >> > wifi: qtnfmac: Use netdev dummy allocator helper > >> > wifi: ath10k: allocate dummy net_device dynamically > >> > wifi: ath11k: allocate dummy net_device dynamically > >> > >> Thanks for setting up the branch, that makes the testing very easy. I > >> now tested the branch using the commit below with ath11k WCN6855 hw2.0 > >> on an x86 box: > >> > >> 5be9a125d8e7 wifi: ath11k: allocate dummy net_device dynamically > >> > >> But unfortunately it crashes, the stack trace below. I can easily test > >> your branches, just let me know what to test. A direct 'git pull' > >> command is the best. > > > > Thanks for the test. > > > > Reading the issue, I am afraid that freeing netdev explicitly > > (free_netdev()) might not be the best approach at the exit path. > > > > I would like to try to leverage the ->needs_free_netdev netdev > > mechanism to do the clean-up, if that makes sense. I've updated the > > ath11k patch, and I am curious if that is what we want. > > > > Would you mind testing a net patch I have, please? > > > > https://github.com/leitao/linux/tree/wireless-dummy_v2 > > I tested this again with my WCN6855 hw2.0 x86 test box on this commit: > > a87674ac820e wifi: ath11k: allocate dummy net_device dynamically > > It passes my tests and doesn't crash, but I see this kmemleak warning a > lot: Thanks Kalle, that was helpful. The device is not being clean-up automatically. Chatting with Jakub, he suggested coming back to the original approach, but, adding a additional patch, at the free_netdev(). Would you mind running another test, please? https://github.com/leitao/linux/tree/wireless-dummy_v3 The branch above is basically the original branch (as in this patch series), with this additional patch: Author: Breno Leitao <leitao@xxxxxxxxxx> Date: Mon Apr 8 11:37:32 2024 -0700 net: free_netdev: exit earlier if dummy For dummy devices, exit earlier at free_netdev() instead of executing the whole function. This is necessary, because dummy devices are special, and shouldn't have the second part of the function executed. Otherwise reg_state, which is NETREG_DUMMY, will be overwritten and there will be no way to identify that this is a dummy device. Also, this device do not need the final put_device(), since dummy devices are not registered (through register_netdevice()), where the device reference is increased (at netdev_register_kobject()/device_add()). Suggested-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Breno Leitao <leitao@xxxxxxxxxx> diff --git a/net/core/dev.c b/net/core/dev.c index 2b82bd1cd2f8..5d2cb97d0ae6 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -11058,7 +11058,8 @@ void free_netdev(struct net_device *dev) dev->xdp_bulkq = NULL; /* Compatibility with error handling in drivers */ - if (dev->reg_state == NETREG_UNINITIALIZED) { + if (dev->reg_state == NETREG_UNINITIALIZED || + dev->reg_state == NETREG_DUMMY) { netdev_freemem(dev); return; }
