From 758380b8155f69b4e2f77f27562f8a7a466749d6 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Tue, 12 Jun 2018 19:38:08 +1000 Subject: powerpc/64s/radix: Fix radix_kvm_prefetch_workaround paca access of not possible CPU If possible CPUs are limited (e.g., by kexec), then the kvm prefetch workaround function can access the paca pointer for a !possible CPU. Fixes: d2e60075a3d44 ("powerpc/64: Use array of paca pointers and allocate pacas individually") Cc: stable@kernel.org Reported-by: Pridhiviraj Paidipeddi Tested-by: Pridhiviraj Paidipeddi Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman --- arch/powerpc/mm/tlb-radix.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/powerpc/mm/tlb-radix.c') diff --git a/arch/powerpc/mm/tlb-radix.c b/arch/powerpc/mm/tlb-radix.c index a734e486664d..1135b43a597c 100644 --- a/arch/powerpc/mm/tlb-radix.c +++ b/arch/powerpc/mm/tlb-radix.c @@ -1097,6 +1097,8 @@ extern void radix_kvm_prefetch_workaround(struct mm_struct *mm) for (; sib <= cpu_last_thread_sibling(cpu) && !flush; sib++) { if (sib == cpu) continue; + if (!cpu_possible(sib)) + continue; if (paca_ptrs[sib]->kvm_hstate.kvm_vcpu) flush = true; } -- cgit v1.2.3