From ae5a0456e0b4cfd7e61619e55251ffdf1bc7adfb Mon Sep 17 00:00:00 2001 From: Breno Leitao Date: Thu, 22 Aug 2024 04:10:47 -0700 Subject: netpoll: Ensure clean state on setup failures Modify netpoll_setup() and __netpoll_setup() to ensure that the netpoll structure (np) is left in a clean state if setup fails for any reason. This prevents carrying over misconfigured fields in case of partial setup success. Key changes: - np->dev is now set only after successful setup, ensuring it's always NULL if netpoll is not configured or if netpoll_setup() fails. - np->local_ip is zeroed if netpoll setup doesn't complete successfully. - Added DEBUG_NET_WARN_ON_ONCE() checks to catch unexpected states. - Reordered some operations in __netpoll_setup() for better logical flow. These changes improve the reliability of netpoll configuration, since it assures that the structure is fully initialized or totally unset. Suggested-by: Paolo Abeni Signed-off-by: Breno Leitao Link: https://patch.msgid.link/20240822111051.179850-2-leitao@debian.org Signed-off-by: Jakub Kicinski --- net/core/netpoll.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/net/core/netpoll.c b/net/core/netpoll.c index cff1f89719b6..a1aea86cf98c 100644 --- a/net/core/netpoll.c +++ b/net/core/netpoll.c @@ -624,12 +624,9 @@ int __netpoll_setup(struct netpoll *np, struct net_device *ndev) const struct net_device_ops *ops; int err; - np->dev = ndev; - strscpy(np->dev_name, ndev->name, IFNAMSIZ); - if (ndev->priv_flags & IFF_DISABLE_NETPOLL) { np_err(np, "%s doesn't support polling, aborting\n", - np->dev_name); + ndev->name); err = -ENOTSUPP; goto out; } @@ -647,7 +644,7 @@ int __netpoll_setup(struct netpoll *np, struct net_device *ndev) refcount_set(&npinfo->refcnt, 1); - ops = np->dev->netdev_ops; + ops = ndev->netdev_ops; if (ops->ndo_netpoll_setup) { err = ops->ndo_netpoll_setup(ndev, npinfo); if (err) @@ -658,6 +655,8 @@ int __netpoll_setup(struct netpoll *np, struct net_device *ndev) refcount_inc(&npinfo->refcnt); } + np->dev = ndev; + strscpy(np->dev_name, ndev->name, IFNAMSIZ); npinfo->netpoll = np; /* last thing to do is link it to the net device structure */ @@ -675,6 +674,7 @@ EXPORT_SYMBOL_GPL(__netpoll_setup); int netpoll_setup(struct netpoll *np) { struct net_device *ndev = NULL; + bool ip_overwritten = false; struct in_device *in_dev; int err; @@ -739,6 +739,7 @@ put_noaddr: } np->local_ip.ip = ifa->ifa_local; + ip_overwritten = true; np_info(np, "local IP %pI4\n", &np->local_ip.ip); } else { #if IS_ENABLED(CONFIG_IPV6) @@ -755,6 +756,7 @@ put_noaddr: !!(ipv6_addr_type(&np->remote_ip.in6) & IPV6_ADDR_LINKLOCAL)) continue; np->local_ip.in6 = ifp->addr; + ip_overwritten = true; err = 0; break; } @@ -785,6 +787,9 @@ put_noaddr: return 0; put: + DEBUG_NET_WARN_ON_ONCE(np->dev); + if (ip_overwritten) + memset(&np->local_ip, 0, sizeof(np->local_ip)); netdev_put(ndev, &np->dev_tracker); unlock: rtnl_unlock(); -- cgit From 908ee298c8fb3f9129a470735e8bb8037a95221e Mon Sep 17 00:00:00 2001 From: Breno Leitao Date: Thu, 22 Aug 2024 04:10:48 -0700 Subject: net: netconsole: Populate dynamic entry even if netpoll fails Currently, netconsole discards targets that fail during initialization, causing two issues: 1) Inconsistency between target list and configfs entries * user pass cmdline0, cmdline1. If cmdline0 fails, then cmdline1 becomes cmdline0 in configfs. 2) Inability to manage failed targets from userspace * If user pass a target that fails with netpoll (interface not loaded at netcons initialization time, such as interface is a module), then the target will not exist in the configfs, so, user cannot re-enable or modify it from userspace. Failed targets are now added to the target list and configfs, but remain disabled until manually enabled or reconfigured. This change does not change the behaviour if CONFIG_NETCONSOLE_DYNAMIC is not set. CC: Aijay Adams Signed-off-by: Breno Leitao Link: https://patch.msgid.link/20240822111051.179850-3-leitao@debian.org Signed-off-by: Jakub Kicinski --- drivers/net/netconsole.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c index 72384c1ecc5c..01cf33fa7503 100644 --- a/drivers/net/netconsole.c +++ b/drivers/net/netconsole.c @@ -1258,11 +1258,18 @@ static struct netconsole_target *alloc_param_target(char *target_config, goto fail; err = netpoll_setup(&nt->np); - if (err) - goto fail; - + if (err) { + pr_err("Not enabling netconsole for %s%d. Netpoll setup failed\n", + NETCONSOLE_PARAM_TARGET_PREFIX, cmdline_count); + if (!IS_ENABLED(CONFIG_NETCONSOLE_DYNAMIC)) + /* only fail if dynamic reconfiguration is set, + * otherwise, keep the target in the list, but disabled. + */ + goto fail; + } else { + nt->enabled = true; + } populate_configfs_item(nt, cmdline_count); - nt->enabled = true; return nt; -- cgit