From a1ee28117077c3bf24e5ab6324c835eaab629c45 Mon Sep 17 00:00:00 2001
From: Nicholas Piggin <npiggin@gmail.com>
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: 7290f3b3d3e6 ("powerpc/64s/powernv: machine check dump SLB contents")
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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));
+ }
}
}
--
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