6.5-stable review patch. If anyone has any objections, please let me know.
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From: Heiko Carstens hca@linux.ibm.com
commit 09cda0a400519b1541591c506e54c9c48e3101bf upstream.
If the cmma no-dat feature is available all pages that are not used for dynamic address translation are marked as "no-dat" with the ESSA instruction. This information is visible to the hypervisor, so that the hypervisor can optimize purging of guest TLB entries. This also means that pages which are used for dynamic address translation must not be marked as "no-dat", since the hypervisor may then incorrectly not purge guest TLB entries.
Region and segment tables allocated via vmem_crst_alloc() are incorrectly marked as "no-dat", as soon as slab_is_available() returns true.
Such tables are allocated e.g. when kernel page tables are split, memory is hotplugged, or a DCSS segment is loaded.
Fix this by adding the missing arch_set_page_dat() call.
Cc: stable@vger.kernel.org Reviewed-by: Claudio Imbrenda imbrenda@linux.ibm.com Signed-off-by: Heiko Carstens hca@linux.ibm.com Signed-off-by: Vasily Gorbik gor@linux.ibm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/s390/mm/vmem.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
--- a/arch/s390/mm/vmem.c +++ b/arch/s390/mm/vmem.c @@ -13,6 +13,7 @@ #include <linux/hugetlb.h> #include <linux/slab.h> #include <linux/sort.h> +#include <asm/page-states.h> #include <asm/cacheflush.h> #include <asm/nospec-branch.h> #include <asm/pgalloc.h> @@ -46,8 +47,11 @@ void *vmem_crst_alloc(unsigned long val) unsigned long *table;
table = vmem_alloc_pages(CRST_ALLOC_ORDER); - if (table) - crst_table_init(table, val); + if (!table) + return NULL; + crst_table_init(table, val); + if (slab_is_available()) + arch_set_page_dat(virt_to_page(table), CRST_ALLOC_ORDER); return table; }