From: Paul Mackerras <[email protected]> Commit 595e4f7e697e ("KVM: PPC: Book3S HV: Use load/store_fp_state functions in HV guest entry/exit") changed the register usage in kvmppc_save_fp() and kvmppc_load_fp() but omitted changing the instructions that load and save VRSAVE. The result is that the VRSAVE value was loaded from a constant address, and saved to a location past the end of the vcpu struct, causing host kernel memory corruption and various kinds of host kernel crashes.
This fixes the problem by using register r31, which contains the vcpu pointer, instead of r3 and r4. Signed-off-by: Paul Mackerras <[email protected]> Signed-off-by: Aneesh Kumar K.V <[email protected]> --- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index 557a47800ca1..6962d38c76f5 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -2132,7 +2132,7 @@ BEGIN_FTR_SECTION END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) #endif mfspr r6,SPRN_VRSAVE - stw r6,VCPU_VRSAVE(r3) + stw r6,VCPU_VRSAVE(r31) mtlr r30 mtmsrd r5 isync @@ -2169,7 +2169,7 @@ BEGIN_FTR_SECTION bl .load_vr_state END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) #endif - lwz r7,VCPU_VRSAVE(r4) + lwz r7,VCPU_VRSAVE(r31) mtspr SPRN_VRSAVE,r7 mtlr r30 mr r4,r31 -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
