# git rev-parse -q --verify 19d767f0429ab26cb3de6c1f7a805a973c5dbd26^{commit} 19d767f0429ab26cb3de6c1f7a805a973c5dbd26 already have revision, skipping fetch # git checkout -q -f -B kisskb 19d767f0429ab26cb3de6c1f7a805a973c5dbd26 # git clean -qxdf # < git log -1 # commit 19d767f0429ab26cb3de6c1f7a805a973c5dbd26 # Author: Michael Ellerman # Date: Mon Mar 1 14:32:14 2021 +1100 # # KVM: PPC: Book3S HV: Convert tbacct/stoltb_lock to raw spinlocks # # With CONFIG_PROVE_RAW_LOCK_NESTING=y we see lockdep splats when # running KVM: # # ============================= # [ BUG: Invalid wait context ] # 5.11.0-11811-gb49a419bbf28 #1 Not tainted # ----------------------------- # qemu-system-ppc/14068 is trying to lock: # c000000134282100 (&vcpu->arch.tbacct_lock){....}-{3:3}, at: kvmppc_core_vcpu_put_hv+0x44/0xd0 [kvm_hv] # other info that might help us debug this: # context-{5:5} # 2 locks held by qemu-system-ppc/14068: # #0: c0000001342800c8 (&vcpu->mutex){+.+.}-{4:4}, at: kvm_vcpu_ioctl+0xdc/0x8c0 [kvm] # #1: c000001e612cfa98 (&rq->lock){-.-.}-{2:2}, at: __schedule+0x1a4/0xdd0 # stack backtrace: # CPU: 10 PID: 14068 Comm: qemu-system-ppc Not tainted 5.11.0-11811-gb49a419bbf28 #1 # Call Trace: # dump_stack+0xec/0x144 (unreliable) # __lock_acquire+0xab0/0x2e70 # lock_acquire+0x128/0x600 # _raw_spin_lock_irqsave+0x6c/0xc0 # kvmppc_core_vcpu_put_hv+0x44/0xd0 [kvm_hv] # kvmppc_core_vcpu_put+0x34/0x50 [kvm] # kvm_arch_vcpu_put+0x20/0x40 [kvm] # kvm_sched_out+0x44/0x80 [kvm] # __schedule+0x684/0xdd0 # preempt_schedule_common+0x30/0x60 # __cond_resched+0x60/0x80 # kvmhv_run_single_vcpu+0xe2c/0x1220 [kvm_hv] # kvmppc_vcpu_run_hv+0x984/0xcd0 [kvm_hv] # kvmppc_vcpu_run+0x34/0x48 [kvm] # kvm_arch_vcpu_ioctl_run+0x340/0x450 [kvm] # kvm_vcpu_ioctl+0x2ac/0x8c0 [kvm] # sys_ioctl+0x300/0x1050 # system_call_exception+0x160/0x230 # system_call_common+0xec/0x278 # # Which is complaining that we're taking a regular # spinlock (tbacct_lock) while holding a raw spinlock (rq->lock). # # To fix it, convert tbacct_lock to a raw spinlock. # # We see a similar splat for stoltb_lock, the analysis & fix is the # same. # # Signed-off-by: Michael Ellerman # < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version # < git log --format=%s --max-count=1 19d767f0429ab26cb3de6c1f7a805a973c5dbd26 # < make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-next_85xx_ksi8560_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- 85xx/ksi8560_defconfig # < make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-next_85xx_ksi8560_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- help # make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-next_85xx_ksi8560_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- olddefconfig # make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-next_85xx_ksi8560_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- INFO: Uncompressed kernel (size 0x53d8c0) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x52d308) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) Image Name: Linux-5.12.0-rc1-94789-g19d767f0 Created: Tue Mar 2 03:29:45 2021 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2682464 Bytes = 2619.59 KiB = 2.56 MiB Load Address: 00000000 Entry Point: 00000000 Image Name: Linux-5.12.0-rc1-94789-g19d767f0 Created: Tue Mar 2 03:29:46 2021 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2711885 Bytes = 2648.33 KiB = 2.59 MiB Load Address: 00600000 Entry Point: 00600314 Completed OK # rm -rf /kisskb/build/powerpc-next_85xx_ksi8560_defconfig_powerpc-gcc5 # Build took: 0:00:44.655118