From: Ira Weiny ira.weiny@intel.com Subject: mm/highmem: fix CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP

The kernel test robot found that __kmap_local_sched_out() was not correctly skipping the guard pages when CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP was set.[1] This was due to CONFIG_DEBUG_HIGHMEM check being used.

Change the configuration check to be correct.

[1] https://lore.kernel.org/lkml/20210304083825.GB17830@xsang-OptiPlex-9020/

Link: https://lkml.kernel.org/r/20210318230657.1497881-1-ira.weiny@intel.com Fixes: 0e91a0c6984c ("mm/highmem: Provide CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP") Signed-off-by: Ira Weiny ira.weiny@intel.com Reported-by: kernel test robot oliver.sang@intel.com Reviewed-by: Thomas Gleixner tglx@linutronix.de Cc: Thomas Gleixner tglx@linutronix.de Cc: Oliver Sang oliver.sang@intel.com Cc: Chaitanya Kulkarni Chaitanya.Kulkarni@wdc.com Cc: David Sterba dsterba@suse.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

mm/highmem.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/mm/highmem.c~mm-highmem-fix-config_debug_kmap_local_force_map +++ a/mm/highmem.c @@ -618,7 +618,7 @@ void __kmap_local_sched_out(void) int idx;

/* With debug all even slots are unmapped and act as guard */ - if (IS_ENABLED(CONFIG_DEBUG_HIGHMEM) && !(i & 0x01)) { + if (IS_ENABLED(CONFIG_DEBUG_KMAP_LOCAL) && !(i & 0x01)) { WARN_ON_ONCE(!pte_none(pteval)); continue; } @@ -654,7 +654,7 @@ void __kmap_local_sched_in(void) int idx;

/* With debug all even slots are unmapped and act as guard */ - if (IS_ENABLED(CONFIG_DEBUG_HIGHMEM) && !(i & 0x01)) { + if (IS_ENABLED(CONFIG_DEBUG_KMAP_LOCAL) && !(i & 0x01)) { WARN_ON_ONCE(!pte_none(pteval)); continue; } _