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authorJames Hogan <james.hogan@imgtec.com>2015-02-24 11:46:20 +0000
committerMarcelo Tosatti <mtosatti@redhat.com>2015-03-02 19:17:52 -0300
commitb3cffac04eca9af46e1e23560a8ee22b1bd36d43 (patch)
treee505d77449190e1c8141e8a2165d7caaf7044d17
parentf563db4bdb8ef5ea73d0f5ea2b20384c10fbd617 (diff)
KVM: MIPS: Fix trace event to save PC directly
Currently the guest exit trace event saves the VCPU pointer to the structure, and the guest PC is retrieved by dereferencing it when the event is printed rather than directly from the trace record. This isn't safe as the printing may occur long afterwards, after the PC has changed and potentially after the VCPU has been freed. Usually this results in the same (wrong) PC being printed for multiple trace events. It also isn't portable as userland has no way to access the VCPU data structure when interpreting the trace record itself. Lets save the actual PC in the structure so that the correct value is accessible later. Fixes: 669e846e6c4e ("KVM/MIPS32: MIPS arch specific APIs for KVM") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Cc: <stable@vger.kernel.org> # v3.10+ Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
-rw-r--r--arch/mips/kvm/trace.h6
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/mips/kvm/trace.h b/arch/mips/kvm/trace.h
index c1388d40663b..bd6437f67dc0 100644
--- a/arch/mips/kvm/trace.h
+++ b/arch/mips/kvm/trace.h
@@ -24,18 +24,18 @@ TRACE_EVENT(kvm_exit,
TP_PROTO(struct kvm_vcpu *vcpu, unsigned int reason),
TP_ARGS(vcpu, reason),
TP_STRUCT__entry(
- __field(struct kvm_vcpu *, vcpu)
+ __field(unsigned long, pc)
__field(unsigned int, reason)
),
TP_fast_assign(
- __entry->vcpu = vcpu;
+ __entry->pc = vcpu->arch.pc;
__entry->reason = reason;
),
TP_printk("[%s]PC: 0x%08lx",
kvm_mips_exit_types_str[__entry->reason],
- __entry->vcpu->arch.pc)
+ __entry->pc)
);
#endif /* _TRACE_KVM_H */