| Message ID | 20240718184311.3950526-2-leitao@debian.org (mailing list archive) |
|---|---|
| State | RFC |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | netconsole: Fix netconsole unsafe locking | expand |
On Thu, 2024-07-18 at 11:43 -0700, Breno Leitao wrote: > Extract the core part of netpoll_cleanup(), so, it could be called > from > a caller that has the rtnl lock already. > > Netconsole uses this in a weird way right now: > > __netpoll_cleanup(&nt->np); > spin_lock_irqsave(&target_list_lock, flags); > netdev_put(nt->np.dev, &nt->np.dev_tracker); > nt->np.dev = NULL; > nt->enabled = false; > > This will be replaced by do_netpoll_cleanup() as the locking > situation > is overhauled. > > Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Rik van Riel <riel@surriel.com>
diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h index bd19c4b91e31..cd4e28db0cbd 100644 --- a/include/linux/netpoll.h +++ b/include/linux/netpoll.h @@ -64,6 +64,7 @@ int netpoll_setup(struct netpoll *np); void __netpoll_cleanup(struct netpoll *np); void __netpoll_free(struct netpoll *np); void netpoll_cleanup(struct netpoll *np); +void do_netpoll_cleanup(struct netpoll *np); netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb); #ifdef CONFIG_NETPOLL diff --git a/net/core/netpoll.c b/net/core/netpoll.c index 55bcacf67df3..a58ea724790c 100644 --- a/net/core/netpoll.c +++ b/net/core/netpoll.c @@ -853,14 +853,20 @@ void __netpoll_free(struct netpoll *np) } EXPORT_SYMBOL_GPL(__netpoll_free); +void do_netpoll_cleanup(struct netpoll *np) +{ + __netpoll_cleanup(np); + netdev_put(np->dev, &np->dev_tracker); + np->dev = NULL; +} +EXPORT_SYMBOL(do_netpoll_cleanup); + void netpoll_cleanup(struct netpoll *np) { rtnl_lock(); if (!np->dev) goto out; - __netpoll_cleanup(np); - netdev_put(np->dev, &np->dev_tracker); - np->dev = NULL; + do_netpoll_cleanup(np); out: rtnl_unlock(); }
Extract the core part of netpoll_cleanup(), so, it could be called from a caller that has the rtnl lock already. Netconsole uses this in a weird way right now: __netpoll_cleanup(&nt->np); spin_lock_irqsave(&target_list_lock, flags); netdev_put(nt->np.dev, &nt->np.dev_tracker); nt->np.dev = NULL; nt->enabled = false; This will be replaced by do_netpoll_cleanup() as the locking situation is overhauled. Signed-off-by: Breno Leitao <leitao@debian.org> --- include/linux/netpoll.h | 1 + net/core/netpoll.c | 12 +++++++++--- 2 files changed, 10 insertions(+), 3 deletions(-)