linux/arch/powerpc/kvm
Alexey Kardashevskiy 345077c8e1 KVM: PPC: Book3S: Protect memslots while validating user address
Guest physical to user address translation uses KVM memslots and reading
these requires holding the kvm->srcu lock. However recently introduced
kvmppc_tce_validate() broke the rule (see the lockdep warning below).

This moves srcu_read_lock(&vcpu->kvm->srcu) earlier to protect
kvmppc_tce_validate() as well.

=============================
WARNING: suspicious RCU usage
5.1.0-rc2-le_nv2_aikATfstn1-p1 #380 Not tainted
-----------------------------
include/linux/kvm_host.h:605 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
1 lock held by qemu-system-ppc/8020:
 #0: 0000000094972fe9 (&vcpu->mutex){+.+.}, at: kvm_vcpu_ioctl+0xdc/0x850 [kvm]

stack backtrace:
CPU: 44 PID: 8020 Comm: qemu-system-ppc Not tainted 5.1.0-rc2-le_nv2_aikATfstn1-p1 #380
Call Trace:
[c000003fece8f740] [c000000000bcc134] dump_stack+0xe8/0x164 (unreliable)
[c000003fece8f790] [c000000000181be0] lockdep_rcu_suspicious+0x130/0x170
[c000003fece8f810] [c0000000000d5f50] kvmppc_tce_to_ua+0x280/0x290
[c000003fece8f870] [c00800001a7e2c78] kvmppc_tce_validate+0x80/0x1b0 [kvm]
[c000003fece8f8e0] [c00800001a7e3fac] kvmppc_h_put_tce+0x94/0x3e4 [kvm]
[c000003fece8f9a0] [c00800001a8baac4] kvmppc_pseries_do_hcall+0x30c/0xce0 [kvm_hv]
[c000003fece8fa10] [c00800001a8bd89c] kvmppc_vcpu_run_hv+0x694/0xec0 [kvm_hv]
[c000003fece8fae0] [c00800001a7d95dc] kvmppc_vcpu_run+0x34/0x48 [kvm]
[c000003fece8fb00] [c00800001a7d56bc] kvm_arch_vcpu_ioctl_run+0x2f4/0x400 [kvm]
[c000003fece8fb90] [c00800001a7c3618] kvm_vcpu_ioctl+0x460/0x850 [kvm]
[c000003fece8fd00] [c00000000041c4f4] do_vfs_ioctl+0xe4/0x930
[c000003fece8fdb0] [c00000000041ce04] ksys_ioctl+0xc4/0x110
[c000003fece8fe00] [c00000000041ce78] sys_ioctl+0x28/0x80
[c000003fece8fe20] [c00000000000b5a4] system_call+0x5c/0x70

Fixes: 42de7b9e21 ("KVM: PPC: Validate TCEs against preregistered memory page sizes", 2018-09-10)
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-04-05 14:37:24 +11:00
..
book3s_32_mmu_host.c
book3s_32_mmu.c KVM: PPC: Book3S PR: Add emulation for slbfee. instruction 2019-02-19 14:25:52 +11:00
book3s_32_sr.S
book3s_64_mmu_host.c * ARM: HYP mode stub supports kexec/kdump on 32-bit; improved PMU 2017-05-08 12:37:56 -07:00
book3s_64_mmu_hv.c KVM: PPC: Book3S HV: Optimise mmio emulation for devices on FAST_MMIO_BUS 2019-02-19 16:00:15 +11:00
book3s_64_mmu_radix.c KVM: PPC: Book3S HV: Add KVM stat largepages_[2M/1G] 2019-02-19 16:00:15 +11:00
book3s_64_mmu.c KVM: PPC: Book3S PR: Add emulation for slbfee. instruction 2019-02-19 14:25:52 +11:00
book3s_64_slb.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
book3s_64_vio_hv.c KVM: PPC: Optimize clearing TCEs for sparse tables 2018-10-20 20:47:02 +11:00
book3s_64_vio.c KVM: PPC: Book3S: Protect memslots while validating user address 2019-04-05 14:37:24 +11:00
book3s_emulate.c KVM: PPC: Book3S PR: Add emulation for slbfee. instruction 2019-02-19 14:25:52 +11:00
book3s_exports.c
book3s_hv_builtin.c KVM: PPC: Book3S: Allow XICS emulation to work in nested hosts using XIVE 2019-02-19 16:00:15 +11:00
book3s_hv_hmi.c powerpc: Avoid circular header inclusion in mmu-hash.h 2019-02-23 22:31:39 +11:00
book3s_hv_interrupts.S KVM: PPC: Book3S HV: Extract PMU save/restore operations as C-callable functions 2018-10-09 16:04:27 +11:00
book3s_hv_nested.c KVM: PPC: Book3S HV: Introduce kvmhv_update_nest_rmap_rc_list() 2018-12-21 14:39:35 +11:00
book3s_hv_ras.c KVM: PPC: Book3S HV: Simplify machine check handling 2019-02-21 23:16:44 +11:00
book3s_hv_rm_mmu.c KVM: PPC: Book3S HV: Cleanups - constify memslots, fix comments 2018-12-17 10:58:43 +11:00
book3s_hv_rm_xics.c KVM: PPC: Book3S: Allow XICS emulation to work in nested hosts using XIVE 2019-02-19 16:00:15 +11:00
book3s_hv_rm_xive.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
book3s_hv_rmhandlers.S Merge remote-tracking branch 'remotes/powerpc/topic/ppc-kvm' into kvm-ppc-next 2019-02-22 13:52:30 +11:00
book3s_hv_tm_builtin.c KVM: PPC: Use ccr field in pt_regs struct embedded in vcpu struct 2018-10-09 16:04:27 +11:00
book3s_hv_tm.c KVM: PPC: Use ccr field in pt_regs struct embedded in vcpu struct 2018-10-09 16:04:27 +11:00
book3s_hv.c KVM: PPC: Book3S HV: Perserve PSSCR FAKE_SUSPEND bit on guest exit 2019-04-05 14:37:24 +11:00
book3s_interrupts.S powerpc: move ASM_CONST and stringify_in_c() into asm-const.h 2018-07-30 22:48:16 +10:00
book3s_mmu_hpte.c sched/headers: Prepare to use <linux/rcuupdate.h> instead of <linux/rculist.h> in <linux/sched.h> 2017-03-02 08:42:38 +01:00
book3s_paired_singles.c
book3s_pr_papr.c KVM: PPC: Book3S PR: Enable in-kernel TCE handlers for PR KVM 2017-10-14 16:38:19 +11:00
book3s_pr.c KVM: PPC: Pass change type down to memslot commit function 2018-12-17 10:57:27 +11:00
book3s_rmhandlers.S powerpc: move ASM_CONST and stringify_in_c() into asm-const.h 2018-07-30 22:48:16 +10:00
book3s_rtas.c KVM: PPC: Book3S: Allow XICS emulation to work in nested hosts using XIVE 2019-02-19 16:00:15 +11:00
book3s_segment.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
book3s_xics.c KVM: PPC: Book3S HV: Change to use DEFINE_SHOW_ATTRIBUTE macro 2018-12-14 15:39:47 +11:00
book3s_xics.h KVM: PPC: Book3S HV: Native usage of the XIVE interrupt controller 2017-04-27 21:37:29 +10:00
book3s_xive_template.c KVM: PPC: Book3S HV: Remove left-over code in XICS-on-XIVE emulation 2018-10-09 16:04:27 +11:00
book3s_xive.c KVM: PPC: Book3S HV: Change to use DEFINE_SHOW_ATTRIBUTE macro 2018-12-14 15:39:47 +11:00
book3s_xive.h KVM: PPC: Book3S HV: Enable use of the new XIVE "single escalation" feature 2018-01-19 12:10:21 +11:00
book3s.c Merge remote-tracking branch 'remotes/powerpc/topic/ppc-kvm' into kvm-ppc-next 2019-02-22 13:52:30 +11:00
book3s.h KVM: PPC: Book3S PR: Add guard code to prevent returning to guest with PR=0 and Transactional state 2018-06-01 10:30:39 +10:00
booke_emulate.c KVM: PPC: Move nip/ctr/lr/xer registers to pt_regs in kvm_vcpu_arch 2018-05-18 15:38:23 +10:00
booke_interrupts.S
booke.c KVM: PPC: Pass change type down to memslot commit function 2018-12-17 10:57:27 +11:00
booke.h
bookehv_interrupts.S powerpc/fsl: Flush branch predictor when entering KVM 2018-12-20 22:59:03 +11:00
e500_emulate.c powerpc/fsl: Emulate SPRN_BUCSR register 2018-12-20 22:59:03 +11:00
e500_mmu_host.c KVM: Make kvm_set_spte_hva() return int 2018-12-21 11:28:41 +01:00
e500_mmu_host.h
e500_mmu.c KVM: PPC: Move nip/ctr/lr/xer registers to pt_regs in kvm_vcpu_arch 2018-05-18 15:38:23 +10:00
e500.c powerpc: remove unnecessary inclusion of asm/tlbflush.h 2018-07-30 22:48:20 +10:00
e500.h powerpc/mm: move platform specific mmu-xxx.h in platform directories 2018-12-04 19:45:01 +11:00
e500mc.c powerpc: remove unnecessary inclusion of asm/tlbflush.h 2018-07-30 22:48:20 +10:00
emulate_loadstore.c KVM: PPC: Use ccr field in pt_regs struct embedded in vcpu struct 2018-10-09 16:04:27 +11:00
emulate.c KVM: PPC: Use exported tb_to_ns() function in decrementer emulation 2018-10-26 21:58:58 +11:00
fpu.S
irq.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kconfig treewide: surround Kconfig file paths with double quotes 2018-12-22 00:25:54 +09:00
Makefile KVM: PPC: Remove -I. header search paths 2019-02-19 16:00:15 +11:00
mpic.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
powerpc.c KVM: PPC: Book3S: Add count cache flush parameters to kvmppc_get_cpu_char() 2019-03-01 15:11:14 +11:00
timing.c KVM: PPC: Use seq_puts() in kvmppc_exit_timing_show() 2018-01-11 20:36:06 +11:00
timing.h
tm.S KVM: PPC: Book3S: Rework TM save/restore code and make it C-callable 2018-10-09 16:04:27 +11:00
trace_book3s.h KVM: PPC: Book3S: Simplify external interrupt handling 2018-10-09 16:04:27 +11:00
trace_booke.h KVM: PPC: Move and undef TRACE_INCLUDE_PATH/FILE 2018-11-07 23:04:38 +11:00
trace_hv.h KVM: PPC: Move and undef TRACE_INCLUDE_PATH/FILE 2018-11-07 23:04:38 +11:00
trace_pr.h KVM: PPC: Move and undef TRACE_INCLUDE_PATH/FILE 2018-11-07 23:04:38 +11:00
trace.h KVM: PPC: Move and undef TRACE_INCLUDE_PATH/FILE 2018-11-07 23:04:38 +11:00