From: Cameron Kaiser spectre@floodgap.com
[ Upstream commit 1006284c5e411872333967b1970c2ca46a9e225f ]
When an OS (currently only classic Mac OS) is running in KVM-PR and makes a linked jump from code with split hack addressing enabled into code that does not, LR is not correctly updated and reflects the previously munged PC.
To fix this, this patch undoes the address munge when exiting split hack mode so that code relying on LR being a proper address will now execute. This does not affect OS X or other operating systems running on KVM-PR.
Signed-off-by: Cameron Kaiser spectre@floodgap.com Signed-off-by: Paul Mackerras paulus@ozlabs.org Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/kvm/book3s.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c index d38280b01ef08..1eda812499376 100644 --- a/arch/powerpc/kvm/book3s.c +++ b/arch/powerpc/kvm/book3s.c @@ -79,8 +79,11 @@ void kvmppc_unfixup_split_real(struct kvm_vcpu *vcpu) { if (vcpu->arch.hflags & BOOK3S_HFLAG_SPLIT_HACK) { ulong pc = kvmppc_get_pc(vcpu); + ulong lr = kvmppc_get_lr(vcpu); if ((pc & SPLIT_HACK_MASK) == SPLIT_HACK_OFFS) kvmppc_set_pc(vcpu, pc & ~SPLIT_HACK_MASK); + if ((lr & SPLIT_HACK_MASK) == SPLIT_HACK_OFFS) + kvmppc_set_lr(vcpu, lr & ~SPLIT_HACK_MASK); vcpu->arch.hflags &= ~BOOK3S_HFLAG_SPLIT_HACK; } }