4.2-stable review patch. If anyone has any objections, please let me know.
------------------
From: James Hogan <james.hogan@xxxxxxxxxx>
commit c5c2a3b998f1ff5a586f9d37e154070b8d550d17 upstream.
The immediate field of the CACHE instruction is signed, so ensure that
it gets sign extended by casting it to an int16_t rather than just
masking the low 16 bits.
Fixes: e685c689f3a8 ("KVM/MIPS32: Privileged instruction/target branch emulation.")
Signed-off-by: James Hogan <james.hogan@xxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Gleb Natapov <gleb@xxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: kvm@xxxxxxxxxxxxxxx
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/mips/kvm/emulate.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/mips/kvm/emulate.c
+++ b/arch/mips/kvm/emulate.c
@@ -1581,7 +1581,7 @@ enum emulation_result kvm_mips_emulate_c
base = (inst >> 21) & 0x1f;
op_inst = (inst >> 16) & 0x1f;
- offset = inst & 0xffff;
+ offset = (int16_t)inst;
cache = (inst >> 16) & 0x3;
op = (inst >> 18) & 0x7;
