From mboxrd@z Thu Jan 1 00:00:00 1970 From: Borislav Petkov Subject: include/linux/kvm_host.h:488 suspicious rcu_dereference_check() usage! Date: Sun, 20 Sep 2015 18:48:51 +0200 Message-ID: <20150920164851.GB3540@pd.tnic> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: kvm ML , lkml To: Paolo Bonzini Return-path: Received: from mail.skyhub.de ([78.46.96.112]:34598 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753529AbbITQsz (ORCPT ); Sun, 20 Sep 2015 12:48:55 -0400 Content-Disposition: inline Sender: kvm-owner@vger.kernel.org List-ID: Hey Paolo, just triggered this on rc1+tip with a 32-bit guest: [26421.303750] =============================== [26421.307952] [ INFO: suspicious RCU usage. ] [26421.312161] 4.3.0-rc1+ #1 Not tainted [26421.312161] ------------------------------- [26421.312162] include/linux/kvm_host.h:488 suspicious rcu_dereference_check() usage! [26421.312163] other info that might help us debug this: [26421.312164] rcu_scheduler_active = 1, debug_locks = 0 [26421.312165] 1 lock held by qemu-system-i38/17000: [26421.312189] #0: (&(&kvm->mmu_lock)->rlock){+.+...}, at: [] kvm_zap_gfn_range+0x24/0x1a0 [kvm] [26421.312189] stack backtrace: [26421.312191] CPU: 3 PID: 17000 Comm: qemu-system-i38 Not tainted 4.3.0-rc1+ #1 [26421.312192] Hardware name: To be filled by O.E.M. To be filled by O.E.M./M5A97 EVO R2.0, BIOS 1503 01/16/2013 [26421.312195] 0000000000000001 ffff880386c0fc90 ffffffff812c8c2a ffff880423f0c740 [26421.312197] ffff880386c0fcc0 ffffffff8109e60d ffff880429ff8000 ffffffffffffffff [26421.312199] ffff880386844000 ffff880000000000 ffff880386c0fd30 ffffffffa02d6c18 [26421.312199] Call Trace: [26421.312205] [] dump_stack+0x4e/0x84 [26421.312208] [] lockdep_rcu_suspicious+0xfd/0x130 [26421.312223] [] kvm_zap_gfn_range+0x188/0x1a0 [kvm] [26421.312235] [] kvm_set_cr0+0xde/0x1e0 [kvm] [26421.312244] [] init_vmcb+0x760/0xad0 [kvm_amd] [26421.312246] [] svm_create_vcpu+0x197/0x250 [kvm_amd] [26421.312259] [] kvm_arch_vcpu_create+0x47/0x70 [kvm] [26421.312268] [] kvm_vm_ioctl+0x302/0x7e0 [kvm] [26421.312271] [] ? __lock_is_held+0x51/0x70 [26421.312273] [] ? __fget+0x101/0x210 [26421.312276] [] do_vfs_ioctl+0x2f4/0x560 [26421.312277] [] ? __fget_light+0x29/0x90 [26421.312279] [] SyS_ioctl+0x4c/0x90 [26421.312282] [] entry_SYSCALL_64_fastpath+0x16/0x73 [26421.584526] walk_shadow_page_get_mmio_spte: detect reserved bits on spte, addr 0xb8000, dump hierarchy: [26421.593927] ------ spte 0x3e5a22027 level 4. [26421.598228] ------ spte 0x38a00b027 level 3. [26421.602505] ------ spte 0x387334027 level 2. [26421.602506] ------ spte 0xffff0000000b8f67 level 1. [26421.602506] ------------[ cut here ]------------ [26421.602530] WARNING: CPU: 2 PID: 17000 at arch/x86/kvm/mmu.c:3385 handle_mmio_page_fault.part.93+0x1a/0x20 [kvm]() [26421.602550] Modules linked in: tun sha256_ssse3 sha256_generic drbg binfmt_misc ipv6 vfat fat fuse dm_crypt dm_mod kvm_amd kvm crc32_pclmul aesni_intel aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd fam15h_power amd64_edac_mod k10temp edac_core amdkfd amd_iommu_v2 radeon acpi_cpufreq [26421.602552] CPU: 2 PID: 17000 Comm: qemu-system-i38 Not tainted 4.3.0-rc1+ #1 [26421.602553] Hardware name: To be filled by O.E.M. To be filled by O.E.M./M5A97 EVO R2.0, BIOS 1503 01/16/2013 [26421.602555] ffffffffa02fc7d2 ffff880386c0fb80 ffffffff812c8c2a 0000000000000000 [26421.602556] ffff880386c0fbb8 ffffffff81053e55 ffff880429ff8000 000000000000000f [26421.602558] 00000000000b8000 0000000000000000 00000000ffffffff ffff880386c0fbc8 [26421.602558] Call Trace: [26421.602564] [] dump_stack+0x4e/0x84 [26421.602566] [] warn_slowpath_common+0x95/0xe0 [26421.602567] [] warn_slowpath_null+0x1a/0x20 [26421.602577] [] handle_mmio_page_fault.part.93+0x1a/0x20 [kvm] [26421.602587] [] tdp_page_fault+0x231/0x290 [kvm] [26421.602596] [] ? emulator_pio_in_out+0x6e/0xf0 [kvm] [26421.602606] [] kvm_mmu_page_fault+0x36/0x240 [kvm] [26421.602609] [] ? svm_set_cr0+0x95/0xc0 [kvm_amd] [26421.602610] [] pf_interception+0xde/0x1d0 [kvm_amd] [26421.602613] [] handle_exit+0x181/0xa70 [kvm_amd] [26421.602622] [] ? kvm_arch_vcpu_ioctl_run+0x68b/0x1730 [kvm] [26421.602631] [] kvm_arch_vcpu_ioctl_run+0x6f6/0x1730 [kvm] [26421.602640] [] ? kvm_arch_vcpu_ioctl_run+0x68b/0x1730 [kvm] [26421.602642] [] ? preempt_count_sub+0x9b/0xf0 [26421.602644] [] ? mutex_lock_killable_nested+0x26f/0x490 [26421.602645] [] ? preempt_count_sub+0x9b/0xf0 [26421.602651] [] kvm_vcpu_ioctl+0x358/0x710 [kvm] [26421.602654] [] ? __fget+0x5/0x210 [26421.602655] [] ? __fget+0x101/0x210 [26421.602657] [] do_vfs_ioctl+0x2f4/0x560 [26421.602658] [] ? __fget_light+0x29/0x90 [26421.602660] [] SyS_ioctl+0x4c/0x90 [26421.602661] [] entry_SYSCALL_64_fastpath+0x16/0x73 [26421.602663] ---[ end trace 37901c8686d84de6 ]--- Any ideas? Thanks. -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply.