* [PATCH] powerpc/64s/radix: Fix radix_kvm_prefetch_workaround paca access of not possible CPU
@ 2018-06-12 9:38 Nicholas Piggin
2018-06-23 12:56 ` Michael Ellerman
0 siblings, 1 reply; 2+ messages in thread
From: Nicholas Piggin @ 2018-06-12 9:38 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Nicholas Piggin, Pridhiviraj Paidipeddi, stable
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 <ppaidipe@linux.vnet.ibm.com>
Tested-by: Pridhiviraj Paidipeddi <ppaidipe@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
[kdump still seems to have a problem upstream, but this solves one crash]
arch/powerpc/mm/tlb-radix.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/powerpc/mm/tlb-radix.c b/arch/powerpc/mm/tlb-radix.c
index 67a6e86d3e7e..06ea845d8033 100644
--- a/arch/powerpc/mm/tlb-radix.c
+++ b/arch/powerpc/mm/tlb-radix.c
@@ -1043,6 +1043,8 @@ 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;
}
--
2.17.0
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2018-06-23 12:56 ` Michael Ellerman
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