On Thu, Jan 28, 2021 at 3:43 AM Hillf Danton <hdan...@sina.com> wrote:
>
> Init the u64 stats in order to avoid the lockdep prints on the 32bit
> hardware like
FTR this is not just to avoid lockdep prints, but also to prevent very
real stalls in production.
u64_stats_init initializes seqlock, if the uninitialized
selock->sequence would be odd, the kernel will stall.
Maintainers, please send this upstream on your earliest convenience,
this breaks all 32-bit arches for testing purposes.
Thanks
> INFO: trying to register non-static key.
> the code is fine but needs lockdep annotation.
> turning off the locking correctness validator.
> CPU: 0 PID: 4695 Comm: syz-executor.0 Not tainted 5.11.0-rc5-syzkaller #0
> Hardware name: ARM-Versatile Express
> Backtrace:
> [<826fc5b8>] (dump_backtrace) from [<826fc82c>] (show_stack+0x18/0x1c
> arch/arm/kernel/traps.c:252)
> [<826fc814>] (show_stack) from [<8270d1f8>] (__dump_stack
> lib/dump_stack.c:79 [inline])
> [<826fc814>] (show_stack) from [<8270d1f8>] (dump_stack+0xa8/0xc8
> lib/dump_stack.c:120)
> [<8270d150>] (dump_stack) from [<802bf9c0>] (assign_lock_key
> kernel/locking/lockdep.c:935 [inline])
> [<8270d150>] (dump_stack) from [<802bf9c0>] (register_lock_class+0xabc/0xb68
> kernel/locking/lockdep.c:1247)
> [<802bef04>] (register_lock_class) from [<802baa2c>]
> (__lock_acquire+0x84/0x32d4 kernel/locking/lockdep.c:4711)
> [<802ba9a8>] (__lock_acquire) from [<802be840>]
> (lock_acquire.part.0+0xf0/0x554 kernel/locking/lockdep.c:5442)
> [<802be750>] (lock_acquire.part.0) from [<802bed10>] (lock_acquire+0x6c/0x74
> kernel/locking/lockdep.c:5415)
> [<802beca4>] (lock_acquire) from [<81560548>]
> (seqcount_lockdep_reader_access include/linux/seqlock.h:103 [inline])
> [<802beca4>] (lock_acquire) from [<81560548>] (__u64_stats_fetch_begin
> include/linux/u64_stats_sync.h:164 [inline])
> [<802beca4>] (lock_acquire) from [<81560548>] (u64_stats_fetch_begin
> include/linux/u64_stats_sync.h:175 [inline])
> [<802beca4>] (lock_acquire) from [<81560548>] (nsim_get_stats64+0xdc/0xf0
> drivers/net/netdevsim/netdev.c:70)
> [<8156046c>] (nsim_get_stats64) from [<81e2efa0>] (dev_get_stats+0x44/0xd0
> net/core/dev.c:10405)
> [<81e2ef5c>] (dev_get_stats) from [<81e53204>] (rtnl_fill_stats+0x38/0x120
> net/core/rtnetlink.c:1211)
> [<81e531cc>] (rtnl_fill_stats) from [<81e59d58>]
> (rtnl_fill_ifinfo+0x6d4/0x148c net/core/rtnetlink.c:1783)
> [<81e59684>] (rtnl_fill_ifinfo) from [<81e5ceb4>]
> (rtmsg_ifinfo_build_skb+0x9c/0x108 net/core/rtnetlink.c:3798)
> [<81e5ce18>] (rtmsg_ifinfo_build_skb) from [<81e5d0ac>] (rtmsg_ifinfo_event
> net/core/rtnetlink.c:3830 [inline])
> [<81e5ce18>] (rtmsg_ifinfo_build_skb) from [<81e5d0ac>] (rtmsg_ifinfo_event
> net/core/rtnetlink.c:3821 [inline])
> [<81e5ce18>] (rtmsg_ifinfo_build_skb) from [<81e5d0ac>]
> (rtmsg_ifinfo+0x44/0x70 net/core/rtnetlink.c:3839)
> [<81e5d068>] (rtmsg_ifinfo) from [<81e45c2c>]
> (register_netdevice+0x664/0x68c net/core/dev.c:10103)
> [<81e455c8>] (register_netdevice) from [<815608bc>] (nsim_create+0xf8/0x124
> drivers/net/netdevsim/netdev.c:317)
> [<815607c4>] (nsim_create) from [<81561184>]
> (__nsim_dev_port_add+0x108/0x188 drivers/net/netdevsim/dev.c:941)
> [<8156107c>] (__nsim_dev_port_add) from [<815620d8>] (nsim_dev_port_add_all
> drivers/net/netdevsim/dev.c:990 [inline])
> [<8156107c>] (__nsim_dev_port_add) from [<815620d8>]
> (nsim_dev_probe+0x5cc/0x750 drivers/net/netdevsim/dev.c:1119)
> [<81561b0c>] (nsim_dev_probe) from [<815661dc>] (nsim_bus_probe+0x10/0x14
> drivers/net/netdevsim/bus.c:287)
> [<815661cc>] (nsim_bus_probe) from [<811724c0>] (really_probe+0x100/0x50c
> drivers/base/dd.c:554)
> [<811723c0>] (really_probe) from [<811729c4>]
> (driver_probe_device+0xf8/0x1c8 drivers/base/dd.c:740)
> [<811728cc>] (driver_probe_device) from [<81172fe4>]
> (__device_attach_driver+0x8c/0xf0 drivers/base/dd.c:846)
> [<81172f58>] (__device_attach_driver) from [<8116fee0>]
> (bus_for_each_drv+0x88/0xd8 drivers/base/bus.c:431)
> [<8116fe58>] (bus_for_each_drv) from [<81172c6c>]
> (__device_attach+0xdc/0x1d0 drivers/base/dd.c:914)
> [<81172b90>] (__device_attach) from [<8117305c>]
> (device_initial_probe+0x14/0x18 drivers/base/dd.c:961)
> [<81173048>] (device_initial_probe) from [<81171358>]
> (bus_probe_device+0x90/0x98 drivers/base/bus.c:491)
> [<811712c8>] (bus_probe_device) from [<8116e77c>] (device_add+0x320/0x824
> drivers/base/core.c:3109)
> [<8116e45c>] (device_add) from [<8116ec9c>] (device_register+0x1c/0x20
> drivers/base/core.c:3182)
> [<8116ec80>] (device_register) from [<81566710>] (nsim_bus_dev_new
> drivers/net/netdevsim/bus.c:336 [inline])
> [<8116ec80>] (device_register) from [<81566710>]
> (new_device_store+0x178/0x208 drivers/net/netdevsim/bus.c:215)
> [<81566598>] (new_device_store) from [<8116fcb4>] (bus_attr_store+0x2c/0x38
> drivers/base/bus.c:122)
> [<8116fc88>] (bus_attr_store) from [<805b4b8c>] (sysfs_kf_write+0x48/0x54
> fs/sysfs/file.c:139)
> [<805b4b44>] (sysfs_kf_write) from [<805b3c90>]
> (kernfs_fop_write_iter+0x128/0x1ec fs/kernfs/file.c:296)
> [<805b3b68>] (kernfs_fop_write_iter) from [<804d22fc>] (call_write_iter
> include/linux/fs.h:1901 [inline])
> [<805b3b68>] (kernfs_fop_write_iter) from [<804d22fc>] (new_sync_write
> fs/read_write.c:518 [inline])
> [<805b3b68>] (kernfs_fop_write_iter) from [<804d22fc>]
> (vfs_write+0x3dc/0x57c fs/read_write.c:605)
> [<804d1f20>] (vfs_write) from [<804d2604>] (ksys_write+0x68/0xec
> fs/read_write.c:658)
> [<804d259c>] (ksys_write) from [<804d2698>] (__do_sys_write
> fs/read_write.c:670 [inline])
> [<804d259c>] (ksys_write) from [<804d2698>] (sys_write+0x10/0x14
> fs/read_write.c:667)
> [<804d2688>] (sys_write) from [<80200060>] (ret_fast_syscall+0x0/0x2c
> arch/arm/mm/proc-v7.S:64)
>
> Fixes: 83c9e13aa39a ("netdevsim: add software driver for testing offloads")
> Reported-by: syzbot+e74a6857f2d0efe3a...@syzkaller.appspotmail.com
> Tested-by: Dmitry Vyukov <dvyu...@google.com>
> Cc: Jakub Kicinski <jakub.kicin...@netronome.com>
> Cc: Simon Horman <simon.hor...@netronome.com>
> Cc: Quentin Monnet <quentin.mon...@netronome.com>
> Cc: Daniel Borkmann <dan...@iogearbox.net>
> Signed-off-by: Hillf Danton <hdan...@sina.com>
> ---
>
> --- a/drivers/net/netdevsim/netdev.c
> +++ b/drivers/net/netdevsim/netdev.c
> @@ -296,6 +296,7 @@ nsim_create(struct nsim_dev *nsim_dev, s
> dev_net_set(dev, nsim_dev_net(nsim_dev));
> ns = netdev_priv(dev);
> ns->netdev = dev;
> + u64_stats_init(&ns->syncp);
> ns->nsim_dev = nsim_dev;
> ns->nsim_dev_port = nsim_dev_port;
> ns->nsim_bus_dev = nsim_dev->nsim_bus_dev;
> --
>
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