From: Sasha Levin <sashal@kernel•org>
To: linux-kernel@vger•kernel.org, stable@vger•kernel.org
Cc: Alexey Kardashevskiy <aik@ozlabs•ru>,
linuxppc-dev@lists•ozlabs.org, kvm-ppc@vger•kernel.org,
Sasha Levin <sashal@kernel•org>
Subject: [PATCH AUTOSEL 4.19 319/671] KVM: PPC: Book3S HV: Fix lockdep warning when entering the guest
Date: Thu, 16 Jan 2020 11:59:17 -0500 [thread overview]
Message-ID: <20200116170509.12787-56-sashal@kernel.org> (raw)
In-Reply-To: <20200116170509.12787-1-sashal@kernel.org>
From: Alexey Kardashevskiy <aik@ozlabs•ru>
[ Upstream commit 3309bec85e60d60d6394802cb8e183a4f4a72def ]
The trace_hardirqs_on() sets current->hardirqs_enabled and from here
the lockdep assumes interrupts are enabled although they are remain
disabled until the context switches to the guest. Consequent
srcu_read_lock() checks the flags in rcu_lock_acquire(), observes
disabled interrupts and prints a warning (see below).
This moves trace_hardirqs_on/off closer to __kvmppc_vcore_entry to
prevent lockdep from being confused.
DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled)
WARNING: CPU: 16 PID: 8038 at kernel/locking/lockdep.c:4128 check_flags.part.25+0x224/0x280
[...]
NIP [c000000000185b84] check_flags.part.25+0x224/0x280
LR [c000000000185b80] check_flags.part.25+0x220/0x280
Call Trace:
[c000003fec253710] [c000000000185b80] check_flags.part.25+0x220/0x280 (unreliable)
[c000003fec253780] [c000000000187ea4] lock_acquire+0x94/0x260
[c000003fec253840] [c00800001a1e9768] kvmppc_run_core+0xa60/0x1ab0 [kvm_hv]
[c000003fec253a10] [c00800001a1ed944] kvmppc_vcpu_run_hv+0x73c/0xec0 [kvm_hv]
[c000003fec253ae0] [c00800001a1095dc] kvmppc_vcpu_run+0x34/0x48 [kvm]
[c000003fec253b00] [c00800001a1056bc] kvm_arch_vcpu_ioctl_run+0x2f4/0x400 [kvm]
[c000003fec253b90] [c00800001a0f3618] kvm_vcpu_ioctl+0x460/0x850 [kvm]
[c000003fec253d00] [c00000000041c4f4] do_vfs_ioctl+0xe4/0x930
[c000003fec253db0] [c00000000041ce04] ksys_ioctl+0xc4/0x110
[c000003fec253e00] [c00000000041ce78] sys_ioctl+0x28/0x80
[c000003fec253e20] [c00000000000b5a4] system_call+0x5c/0x70
Instruction dump:
419e0034 3d220004 39291730 81290000 2f890000 409e0020 3c82ffc6 3c62ffc5
3884be70 386329c0 4bf6ea71 60000000 <0fe00000> 3c62ffc6 3863be90 4801273d
irq event stamp: 1025
hardirqs last enabled at (1025): [<c00800001a1e9728>] kvmppc_run_core+0xa20/0x1ab0 [kvm_hv]
hardirqs last disabled at (1024): [<c00800001a1e9358>] kvmppc_run_core+0x650/0x1ab0 [kvm_hv]
softirqs last enabled at (0): [<c0000000000f1210>] copy_process.isra.4.part.5+0x5f0/0x1d00
softirqs last disabled at (0): [<0000000000000000>] (null)
---[ end trace 31180adcc848993e ]---
possible reason: unannotated irqs-off.
irq event stamp: 1025
hardirqs last enabled at (1025): [<c00800001a1e9728>] kvmppc_run_core+0xa20/0x1ab0 [kvm_hv]
hardirqs last disabled at (1024): [<c00800001a1e9358>] kvmppc_run_core+0x650/0x1ab0 [kvm_hv]
softirqs last enabled at (0): [<c0000000000f1210>] copy_process.isra.4.part.5+0x5f0/0x1d00
softirqs last disabled at (0): [<0000000000000000>] (null)
Fixes: 8b24e69fc47e ("KVM: PPC: Book3S HV: Close race with testing for signals on guest entry", 2017-06-26)
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs•ru>
Signed-off-by: Paul Mackerras <paulus@ozlabs•org>
Signed-off-by: Sasha Levin <sashal@kernel•org>
---
arch/powerpc/kvm/book3s_hv.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 3ae3e8d141e3..dbfe32327212 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -2993,25 +2993,26 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
}
}
- /*
- * Interrupts will be enabled once we get into the guest,
- * so tell lockdep that we're about to enable interrupts.
- */
- trace_hardirqs_on();
-
guest_enter_irqoff();
srcu_idx = srcu_read_lock(&vc->kvm->srcu);
this_cpu_disable_ftrace();
+ /*
+ * Interrupts will be enabled once we get into the guest,
+ * so tell lockdep that we're about to enable interrupts.
+ */
+ trace_hardirqs_on();
+
trap = __kvmppc_vcore_entry();
+ trace_hardirqs_off();
+
this_cpu_enable_ftrace();
srcu_read_unlock(&vc->kvm->srcu, srcu_idx);
- trace_hardirqs_off();
set_irq_happened(trap);
spin_lock(&vc->lock);
--
2.20.1
next prev parent reply other threads:[~2020-01-16 17:50 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20200116170509.12787-1-sashal@kernel.org>
2020-01-16 16:58 ` [PATCH AUTOSEL 4.19 273/671] soc/fsl/qe: Fix an error code in qe_pin_request() Sasha Levin
2020-01-16 16:59 ` [PATCH AUTOSEL 4.19 304/671] powerpc: vdso: Make vdso32 installation conditional in vdso_install Sasha Levin
2020-01-16 16:59 ` Sasha Levin [this message]
2020-01-16 17:00 ` [PATCH AUTOSEL 4.19 415/671] powerpc/cacheinfo: add cacheinfo_teardown, cacheinfo_rebuild Sasha Levin
2020-01-16 17:00 ` [PATCH AUTOSEL 4.19 416/671] powerpc/pseries/mobility: rebuild cacheinfo hierarchy post-migration Sasha Levin
2020-01-16 17:01 ` [PATCH AUTOSEL 4.19 432/671] perf/ioctl: Add check for the sample_period value Sasha Levin
2020-01-16 17:01 ` [PATCH AUTOSEL 4.19 475/671] ALSA: aoa: onyx: always initialize register read value Sasha Levin
2020-01-16 17:02 ` [PATCH AUTOSEL 4.19 499/671] powerpc/64s/radix: Fix memory hot-unplug page table split Sasha Levin
2020-01-16 17:03 ` [PATCH AUTOSEL 4.19 557/671] powerpc/mm/mce: Keep irqs disabled during lockless page table walk Sasha Levin
2020-01-16 17:04 ` [PATCH AUTOSEL 4.19 655/671] powerpc/powernv: Disable native PCIe port management Sasha Levin
2020-01-16 17:05 ` [PATCH AUTOSEL 4.19 665/671] powerpc/archrandom: fix arch_get_random_seed_int() Sasha Levin
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