kernel.git/net/core/net-sysfs.c, branch linux-5.16.y

net-sysfs: add check for netdevice being present to speed_show

2022-03-16T13:26:47Z

[ Upstream commit 4224cfd7fb6523f7a9d1c8bb91bb5df1e38eb624 ] When bringing down the netdevice or system shutdown, a panic can be triggered while accessing the sysfs path because the device is already removed. [ 755.549084] mlx5_core 0000:12:00.1: Shutdown was called [ 756.404455] mlx5_core 0000:12:00.0: Shutdown was called ... [ 757.937260] BUG: unable to handle kernel NULL pointer dereference at (null) [ 758.031397] IP: [] dma_pool_alloc+0x1ab/0x280 crash> bt ... PID: 12649 TASK: ffff8924108f2100 CPU: 1 COMMAND: "amsd" ... #9 [ffff89240e1a38b0] page_fault at ffffffff8f38c778 [exception RIP: dma_pool_alloc+0x1ab] RIP: ffffffff8ee11acb RSP: ffff89240e1a3968 RFLAGS: 00010046 RAX: 0000000000000246 RBX: ffff89243d874100 RCX: 0000000000001000 RDX: 0000000000000000 RSI: 0000000000000246 RDI: ffff89243d874090 RBP: ffff89240e1a39c0 R8: 000000000001f080 R9: ffff8905ffc03c00 R10: ffffffffc04680d4 R11: ffffffff8edde9fd R12: 00000000000080d0 R13: ffff89243d874090 R14: ffff89243d874080 R15: 0000000000000000 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #10 [ffff89240e1a39c8] mlx5_alloc_cmd_msg at ffffffffc04680f3 [mlx5_core] #11 [ffff89240e1a3a18] cmd_exec at ffffffffc046ad62 [mlx5_core] #12 [ffff89240e1a3ab8] mlx5_cmd_exec at ffffffffc046b4fb [mlx5_core] #13 [ffff89240e1a3ae8] mlx5_core_access_reg at ffffffffc0475434 [mlx5_core] #14 [ffff89240e1a3b40] mlx5e_get_fec_caps at ffffffffc04a7348 [mlx5_core] #15 [ffff89240e1a3bb0] get_fec_supported_advertised at ffffffffc04992bf [mlx5_core] #16 [ffff89240e1a3c08] mlx5e_get_link_ksettings at ffffffffc049ab36 [mlx5_core] #17 [ffff89240e1a3ce8] __ethtool_get_link_ksettings at ffffffff8f25db46 #18 [ffff89240e1a3d48] speed_show at ffffffff8f277208 #19 [ffff89240e1a3dd8] dev_attr_show at ffffffff8f0b70e3 #20 [ffff89240e1a3df8] sysfs_kf_seq_show at ffffffff8eedbedf #21 [ffff89240e1a3e18] kernfs_seq_show at ffffffff8eeda596 #22 [ffff89240e1a3e28] seq_read at ffffffff8ee76d10 #23 [ffff89240e1a3e98] kernfs_fop_read at ffffffff8eedaef5 #24 [ffff89240e1a3ed8] vfs_read at ffffffff8ee4e3ff #25 [ffff89240e1a3f08] sys_read at ffffffff8ee4f27f #26 [ffff89240e1a3f50] system_call_fastpath at ffffffff8f395f92 crash> net_device.state ffff89443b0c0000 state = 0x5 (__LINK_STATE_START| __LINK_STATE_NOCARRIER) To prevent this scenario, we also make sure that the netdevice is present. Signed-off-by: suresh kumar Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net-sysfs: update the queue counts in the unregistration path

2022-01-27T11:02:21Z

[ Upstream commit d7dac083414eb5bb99a6d2ed53dc2c1b405224e5 ] When updating Rx and Tx queue kobjects, the queue count should always be updated to match the queue kobjects count. This was not done in the net device unregistration path, fix it. Tracking all queue count updates will allow in a following up patch to detect illegal updates. Signed-off-by: Antoine Tenart Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2021-10-28T17:43:58Z

include/net/sock.h 7b50ecfcc6cd ("net: Rename ->stream_memory_read to ->sock_is_readable") 4c1e34c0dbff ("vsock: Enable y2038 safe timeval for timeout") drivers/net/ethernet/marvell/octeontx2/af/rvu_debugfs.c 0daa55d033b0 ("octeontx2-af: cn10k: debugfs for dumping LMTST map table") e77bcdd1f639 ("octeontx2-af: Display all enabled PF VF rsrc_alloc entries.") Adjacent code addition in both cases, keep both. Signed-off-by: Jakub Kicinski

net-sysfs: initialize uid and gid before calling net_ns_get_ownership

2021-10-25T15:17:32Z

Currently in net_ns_get_ownership() it may not be able to set uid or gid if make_kuid or make_kgid returns an invalid value, and an uninit-value issue can be triggered by this. This patch is to fix it by initializing the uid and gid before calling net_ns_get_ownership(), as it does in kobject_get_ownership() Fixes: e6dee9f3893c ("net-sysfs: add netdev_change_owner()") Reported-by: Paolo Abeni Signed-off-by: Xin Long Acked-by: Christian Brauner Signed-off-by: David S. Miller

net-sysfs: try not to restart the syscall if it will fail eventually

2021-10-08T14:24:02Z

Due to deadlocks in the networking subsystem spotted 12 years ago[1], a workaround was put in place[2] to avoid taking the rtnl lock when it was not available and restarting the syscall (back to VFS, letting userspace spin). The following construction is found a lot in the net sysfs and sysctl code: if (!rtnl_trylock()) return restart_syscall(); This can be problematic when multiple userspace threads use such interfaces in a short period, making them to spin a lot. This happens for example when adding and moving virtual interfaces: userspace programs listening on events, such as systemd-udevd and NetworkManager, do trigger actions reading files in sysfs. It gets worse when a lot of virtual interfaces are created concurrently, say when creating containers at boot time. Returning early without hitting the above pattern when the syscall will fail eventually does make things better. While it is not a fix for the issue, it does ease things. [1] https://lore.kernel.org/netdev/49A4D5D5.5090602@trash.net/ https://lore.kernel.org/netdev/m14oyhis31.fsf@fess.ebiederm.org/ and https://lore.kernel.org/netdev/20090226084924.16cb3e08@nehalam/ [2] Rightfully, those deadlocks are *hard* to solve. Signed-off-by: Antoine Tenart Reviewed-by: Paolo Abeni Signed-off-by: David S. Miller

of: net: move of_net under net/

2021-10-07T12:39:51Z

Rob suggests to move of_net.c from under drivers/of/ somewhere to the networking code. Suggested-by: Rob Herring Signed-off-by: Jakub Kicinski Reviewed-by: Rob Herring Signed-off-by: David S. Miller

net-sysfs: remove possible sleep from an RCU read-side critical section

2021-03-22T20:28:13Z

xps_queue_show is mostly made of an RCU read-side critical section and calls bitmap_zalloc with GFP_KERNEL in the middle of it. That is not allowed as this call may sleep and such behaviours aren't allowed in RCU read-side critical sections. Fix this by using GFP_NOWAIT instead. Fixes: 5478fcd0f483 ("net: embed nr_ids in the xps maps") Reported-by: kernel test robot Suggested-by: Matthew Wilcox Signed-off-by: Antoine Tenart Signed-off-by: David S. Miller

net-sysfs: move the xps cpus/rxqs retrieval in a common function

2021-03-18T21:56:22Z

Most of the xps_cpus_show and xps_rxqs_show functions share the same logic. Having it in two different functions does not help maintenance. This patch moves their common logic into a new function, xps_queue_show, to improve this. Signed-off-by: Antoine Tenart Signed-off-by: David S. Miller

net-sysfs: move the rtnl unlock up in the xps show helpers

2021-03-18T21:56:22Z

Now that nr_ids and num_tc are stored in the xps dev_maps, which are RCU protected, we do not have the need to protect the maps in the rtnl lock. Move the rtnl unlock up so we reduce the rtnl locking section. We also increase the reference count on the subordinate device if any, as we don't want this device to be freed while we use it (now that the rtnl lock isn't protecting it in the whole function). Signed-off-by: Antoine Tenart Signed-off-by: David S. Miller

net: move the xps maps to an array

2021-03-18T21:56:22Z

Move the xps maps (xps_cpus_map and xps_rxqs_map) to an array in net_device. That will simplify a lot the code removing the need for lots of if/else conditionals as the correct map will be available using its offset in the array. This should not modify the xps maps behaviour in any way. Suggested-by: Alexander Duyck Signed-off-by: Antoine Tenart Signed-off-by: David S. Miller