From 8eeab81c3d55ba41ae68888b13a1a34893104e12 Mon Sep 17 00:00:00 2001 From: James Hogan Date: Mon, 4 Jul 2016 19:35:14 +0100 Subject: [PATCH] MIPS: KVM: Decode RDHWR more strictly MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit When KVM emulates the RDHWR instruction, decode the instruction more strictly. The rs field (bits 25:21) should be zero, as should bits 10:9. Bits 8:6 is the register select field in MIPSr6, so we aren't strict about those bits (no other operations should use that encoding space). Signed-off-by: James Hogan Cc: Paolo Bonzini Cc: Radim KrÄmář Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini --- arch/mips/kvm/emulate.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/mips/kvm/emulate.c b/arch/mips/kvm/emulate.c index 62e6a7b313ae..be18dfe9ecaa 100644 --- a/arch/mips/kvm/emulate.c +++ b/arch/mips/kvm/emulate.c @@ -2357,7 +2357,9 @@ enum emulation_result kvm_mips_handle_ri(u32 cause, u32 *opc, } if (inst.r_format.opcode == spec3_op && - inst.r_format.func == rdhwr_op) { + inst.r_format.func == rdhwr_op && + inst.r_format.rs == 0 && + (inst.r_format.re >> 3) == 0) { int usermode = !KVM_GUEST_KERNEL_MODE(vcpu); int rd = inst.r_format.rd; int rt = inst.r_format.rt; -- 2.20.1