projects / thirdparty / kernel / stable-queue.git / blame
| Commit | Line | Data |
|---|---|---|
| 26b5eebe GKH |
1 | From b3cffac04eca9af46e1e23560a8ee22b1bd36d43 Mon Sep 17 00:00:00 2001 |
| 2 | From: James Hogan <james.hogan@imgtec.com> | |
| 3 | Date: Tue, 24 Feb 2015 11:46:20 +0000 | |
| 4 | Subject: KVM: MIPS: Fix trace event to save PC directly | |
| 5 | ||
| 6 | From: James Hogan <james.hogan@imgtec.com> | |
| 7 | ||
| 8 | commit b3cffac04eca9af46e1e23560a8ee22b1bd36d43 upstream. | |
| 9 | ||
| 10 | Currently the guest exit trace event saves the VCPU pointer to the | |
| 11 | structure, and the guest PC is retrieved by dereferencing it when the | |
| 12 | event is printed rather than directly from the trace record. This isn't | |
| 13 | safe as the printing may occur long afterwards, after the PC has changed | |
| 14 | and potentially after the VCPU has been freed. Usually this results in | |
| 15 | the same (wrong) PC being printed for multiple trace events. It also | |
| 16 | isn't portable as userland has no way to access the VCPU data structure | |
| 17 | when interpreting the trace record itself. | |
| 18 | ||
| 19 | Lets save the actual PC in the structure so that the correct value is | |
| 20 | accessible later. | |
| 21 | ||
| 22 | Fixes: 669e846e6c4e ("KVM/MIPS32: MIPS arch specific APIs for KVM") | |
| 23 | Signed-off-by: James Hogan <james.hogan@imgtec.com> | |
| 24 | Cc: Paolo Bonzini <pbonzini@redhat.com> | |
| 25 | Cc: Ralf Baechle <ralf@linux-mips.org> | |
| 26 | Cc: Marcelo Tosatti <mtosatti@redhat.com> | |
| 27 | Cc: Gleb Natapov <gleb@kernel.org> | |
| 28 | Cc: Steven Rostedt <rostedt@goodmis.org> | |
| 29 | Cc: Ingo Molnar <mingo@redhat.com> | |
| 30 | Cc: linux-mips@linux-mips.org | |
| 31 | Cc: kvm@vger.kernel.org | |
| 32 | Acked-by: Steven Rostedt <rostedt@goodmis.org> | |
| 33 | Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> | |
| 34 | Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
| 35 | ||
| 36 | --- | |
| 37 | arch/mips/kvm/trace.h | 6 +++--- | |
| 38 | 1 file changed, 3 insertions(+), 3 deletions(-) | |
| 39 | ||
| 40 | --- a/arch/mips/kvm/trace.h | |
| 41 | +++ b/arch/mips/kvm/trace.h | |
| 42 | @@ -26,18 +26,18 @@ TRACE_EVENT(kvm_exit, | |
| 43 | TP_PROTO(struct kvm_vcpu *vcpu, unsigned int reason), | |
| 44 | TP_ARGS(vcpu, reason), | |
| 45 | TP_STRUCT__entry( | |
| 46 | - __field(struct kvm_vcpu *, vcpu) | |
| 47 | + __field(unsigned long, pc) | |
| 48 | __field(unsigned int, reason) | |
| 49 | ), | |
| 50 | ||
| 51 | TP_fast_assign( | |
| 52 | - __entry->vcpu = vcpu; | |
| 53 | + __entry->pc = vcpu->arch.pc; | |
| 54 | __entry->reason = reason; | |
| 55 | ), | |
| 56 | ||
| 57 | TP_printk("[%s]PC: 0x%08lx", | |
| 58 | kvm_mips_exit_types_str[__entry->reason], | |
| 59 | - __entry->vcpu->arch.pc) | |
| 60 | + __entry->pc) | |
| 61 | ); | |
| 62 | ||
| 63 | #endif /* _TRACE_KVM_H */ |