• Lai Jiangshan's avatar
    KVM: use the correct RCU API for PROVE_RCU=y · 90d83dc3
    Lai Jiangshan authored
    The RCU/SRCU API have already changed for proving RCU usage.
    
    I got the following dmesg when PROVE_RCU=y because we used incorrect API.
    This patch coverts rcu_deference() to srcu_dereference() or family API.
    
    ===================================================
    [ INFO: suspicious rcu_dereference_check() usage. ]
    ---------------------------------------------------
    arch/x86/kvm/mmu.c:3020 invoked rcu_dereference_check() without protection!
    
    other info that might help us debug this:
    
    rcu_scheduler_active = 1, debug_locks = 0
    2 locks held by qemu-system-x86/8550:
     #0:  (&kvm->slots_lock){+.+.+.}, at: [<ffffffffa011a6ac>] kvm_set_memory_region+0x29/0x50 [kvm]
     #1:  (&(&kvm->mmu_lock)->rlock){+.+...}, at: [<ffffffffa012262d>] kvm_arch_commit_memory_region+0xa6/0xe2 [kvm]
    
    stack backtrace:
    Pid: 8550, comm: qemu-system-x86 Not tainted 2.6.34-rc4-tip-01028-g939eab1 #27
    Call Trace:
     [<ffffffff8106c59e>] lockdep_rcu_dereference+0xaa/0xb3
     [<ffffffffa012f6c1>] kvm_mmu_calculate_mmu_pages+0x44/0x7d [kvm]
     [<ffffffffa012263e>] kvm_arch_commit_memory_region+0xb7/0xe2 [kvm]
     [<ffffffffa011a5d7>] __kvm_set_memory_region+0x636/0x6e2 [kvm]
     [<ffffffffa011a6ba>] kvm_set_memory_region+0x37/0x50 [kvm]
     [<ffffffffa015e956>] vmx_set_tss_addr+0x46/0x5a [kvm_intel]
     [<ffffffffa0126592>] kvm_arch_vm_ioctl+0x17a/0xcf8 [kvm]
     [<ffffffff810a8692>] ? unlock_page+0x27/0x2c
     [<ffffffff810bf879>] ? __do_fault+0x3a9/0x3e1
     [<ffffffffa011b12f>] kvm_vm_ioctl+0x364/0x38d [kvm]
     [<ffffffff81060cfa>] ? up_read+0x23/0x3d
     [<ffffffff810f3587>] vfs_ioctl+0x32/0xa6
     [<ffffffff810f3b19>] do_vfs_ioctl+0x495/0x4db
     [<ffffffff810e6b2f>] ? fget_light+0xc2/0x241
     [<ffffffff810e416c>] ? do_sys_open+0x104/0x116
     [<ffffffff81382d6d>] ? retint_swapgs+0xe/0x13
     [<ffffffff810f3ba6>] sys_ioctl+0x47/0x6a
     [<ffffffff810021db>] system_call_fastpath+0x16/0x1b
    Signed-off-by: default avatarLai Jiangshan <laijs@cn.fujitsu.com>
    Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
    90d83dc3
kvm-ia64.c 44.6 KB