From 6466119452a83ed77d7e4638833b3594b785bbf5 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Sat, 28 Nov 2020 17:07:21 +1000 Subject: [PATCH] powerpc/64s/powernv: Fix memory corruption when saving SLB entries on MCE commit a1ee28117077c3bf24e5ab6324c835eaab629c45 upstream. This can be hit by an HPT guest running on an HPT host and bring down the host, so it's quite important to fix. Fixes: 7290f3b3d3e6 ("powerpc/64s/powernv: machine check dump SLB contents") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Nicholas Piggin Acked-by: Mahesh Salgaonkar Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201128070728.825934-2-npiggin@gmail.com Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/platforms/powernv/setup.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c index 3a9f79d18f6b..1b7b0d0c3ebd 100644 --- a/arch/powerpc/platforms/powernv/setup.c +++ b/arch/powerpc/platforms/powernv/setup.c @@ -186,11 +186,16 @@ static void __init pnv_init(void) add_preferred_console("hvc", 0, NULL); if (!radix_enabled()) { + size_t size = sizeof(struct slb_entry) * mmu_slb_size; int i; /* Allocate per cpu area to save old slb contents during MCE */ - for_each_possible_cpu(i) - paca_ptrs[i]->mce_faulty_slbs = memblock_alloc_node(mmu_slb_size, __alignof__(*paca_ptrs[i]->mce_faulty_slbs), cpu_to_node(i)); + for_each_possible_cpu(i) { + paca_ptrs[i]->mce_faulty_slbs = + memblock_alloc_node(size, + __alignof__(struct slb_entry), + cpu_to_node(i)); + } } }