From 6b3fad2ad0ae988ed7b46acc7a1217c8e5b53065 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 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: 4c412e498999 ("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 --- 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 46115231a3b2b..4426a109ec2f4 100644 --- a/arch/powerpc/platforms/powernv/setup.c +++ b/arch/powerpc/platforms/powernv/setup.c @@ -211,11 +211,16 @@ 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)); + } } } -- 2.39.5