From 18e3cd7c4675d18e08352d3e69af1c5d6f05d7f6 Mon Sep 17 00:00:00 2001 From: James Hogan Date: Tue, 24 Feb 2015 11:46:20 +0000 Subject: KVM: MIPS: Fix trace event to save PC directly commit b3cffac04eca9af46e1e23560a8ee22b1bd36d43 upstream. 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 Cc: Paolo Bonzini Cc: Ralf Baechle Cc: Marcelo Tosatti Cc: Gleb Natapov Cc: Steven Rostedt Cc: Ingo Molnar Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Acked-by: Steven Rostedt Signed-off-by: Marcelo Tosatti Signed-off-by: Greg Kroah-Hartman --- arch/mips/kvm/trace.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'arch/mips/kvm') diff --git a/arch/mips/kvm/trace.h b/arch/mips/kvm/trace.h index bc9e0f406c08..e51621e36152 100644 --- a/arch/mips/kvm/trace.h +++ b/arch/mips/kvm/trace.h @@ -26,18 +26,18 @@ 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 */ -- cgit v1.2.3