Commit aa18e0e6 authored Jul 22, 2020 by David Hildenbrand Committed by Heiko Carstens Jul 27, 2020

s390/vmemmap: take the vmem_mutex when populating/freeing

Let's synchronize all accesses to the 1:1 and vmemmap mappings. This will
be especially relevant when wanting to cleanup empty page tables that could
be shared by both. Avoid races when removing tables that might be just
about to get reused.

Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20200722094558.9828-6-david@redhat.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

parent c00f05a9

arch/s390/mm/vmem.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -334,17 +334,21 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
		{
		int ret;

		mutex_lock(&vmem_mutex);
		/* We don't care about the node, just use NUMA_NO_NODE on allocations */
		ret = add_pagetable(start, end, false);
		if (ret)
		remove_pagetable(start, end, false);
		mutex_unlock(&vmem_mutex);
		return ret;
		}

		void vmemmap_free(unsigned long start, unsigned long end,
		struct vmem_altmap *altmap)
		{
		mutex_lock(&vmem_mutex);
		remove_pagetable(start, end, false);
		mutex_unlock(&vmem_mutex);
		}

		void vmem_remove_mapping(unsigned long start, unsigned long size)

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