From: James Hogan <james.hogan@xxxxxxxxxx>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
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: James Hogan <james.hogan@xxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
arch/mips/kvm/kvm_mips_emul.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/mips/kvm/kvm_mips_emul.c b/arch/mips/kvm/kvm_mips_emul.c
index c76f297b7149..33085819cd89 100644
--- a/arch/mips/kvm/kvm_mips_emul.c
+++ b/arch/mips/kvm/kvm_mips_emul.c
@@ -935,7 +935,7 @@ kvm_mips_emulate_cache(uint32_t inst, uint32_t *opc, uint32_t cause,
base = (inst >> 21) & 0x1f;
op_inst = (inst >> 16) & 0x1f;
- offset = inst & 0xffff;
+ offset = (int16_t)inst;
cache = (inst >> 16) & 0x3;
op = (inst >> 18) & 0x7;
--
2.6.4
