On Fri, Feb 15, 2019 at 9:36 PM Kefeng Wang <wangkefeng.w...@huawei.com> wrote: > > > > On 2019/2/15 21:57, Eric Dumazet wrote: > > On Fri, Feb 15, 2019 at 5:37 AM Kefeng Wang <wangkefeng.w...@huawei.com> > > wrote: > >> > >> With CONFIG_DEBUG_SPINLOCK=y, we find following stack, > >> > >> BUG: spinlock wrong CPU on CPU#0, ip/16047 > >> lock: 0xffff803f5febc998, .magic: dead4ead, .owner: ip/16047, > >> .owner_cpu: 0 > >> CPU: 1 PID: 16047 Comm: ip Kdump: loaded Tainted: G E > >> 4.19.12.aarch64 #1 > >> Hardware name: Huawei TaiShan 2280 V2/BC82AMDA, BIOS TA BIOS TaiShan 2280 > >> V2 - B900 01/29/2019 > >> Call trace: > >> dump_backtrace+0x0/0x1c0 > >> show_stack+0x24/0x30 > >> dump_stack+0x90/0xbc > >> spin_dump+0x84/0xa8 > >> do_raw_spin_unlock+0xf8/0x100 > >> _raw_spin_unlock+0x20/0x30 > >> bond_get_stats+0x110/0x140 [bonding] > >> rtnl_fill_stats+0x50/0x150 > >> rtnl_fill_ifinfo+0x4d4/0xd18 > >> rtnl_dump_ifinfo+0x200/0x3a8 > >> netlink_dump+0x100/0x2b0 > >> netlink_recvmsg+0x310/0x3e8 > >> sock_recvmsg+0x58/0x68 > >> ___sys_recvmsg+0xd0/0x278 > >> __sys_recvmsg+0x74/0xd0 > >> __arm64_sys_recvmsg+0x2c/0x38 > >> el0_svc_common+0x7c/0x118 > >> el0_svc_handler+0x30/0x40 > >> el0_svc+0x8/0xc > >> > >> and then lead to softlockup issue, fix this by using mutex lock instead > >> of spin lock. > >> > >> Signed-off-by: Kefeng Wang <wangkefeng.w...@huawei.com> > >> --- > >> > >> Not sure if this is right fix, please correct me if I'm wrong. > >> > > > > Make sure to also try : > > > > cat /proc/net/dev > > Yes, no regression with this patch in our test or 'cat /proc/net/dev' >
You really should have a warning showing up. Make sure you have : DEBUG_ATOMIC_SLEEP=y (I thought this was automatically selected with LOCKDEP on, maybe not...) Please take a look at net/core/net-procfs.c , functions dev_seq_start(), dev_seq_printf_stats(), dev_seq_show() We can not use a mutex in a section protected by rcu_read_lock()
