From: Rick Edgecombe rick.p.edgecombe@intel.com
commit ab5130186d7476dcee0d4e787d19a521ca552ce9 upstream.
As an optimization, cpa_flush() was changed to optionally only flush the range in @cpa if it was small enough. However, this range does not include any direct map aliases changed in cpa_process_alias(). So small set_memory_() calls that touch that alias don't get the direct map changes flushed. This situation can happen when the virtual address taking variants are passed an address in vmalloc or modules space.
In these cases, force a full TLB flush.
Note this issue does not extend to cases where the set_memory_() calls are passed a direct map address, or page array, etc, as the primary target. In those cases the direct map would be flushed.
Fixes: 935f5839827e ("x86/mm/cpa: Optimize cpa_flush_array() TLB invalidation") Signed-off-by: Rick Edgecombe rick.p.edgecombe@intel.com Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Link: https://lkml.kernel.org/r/20200424105343.GA20730@hirez.programming.kicks-ass... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/mm/pat/set_memory.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
--- a/arch/x86/mm/pat/set_memory.c +++ b/arch/x86/mm/pat/set_memory.c @@ -42,7 +42,8 @@ struct cpa_data { unsigned long pfn; unsigned int flags; unsigned int force_split : 1, - force_static_prot : 1; + force_static_prot : 1, + force_flush_all : 1; struct page **pages; };
@@ -352,10 +353,10 @@ static void cpa_flush(struct cpa_data *d return; }
- if (cpa->numpages <= tlb_single_page_flush_ceiling) - on_each_cpu(__cpa_flush_tlb, cpa, 1); - else + if (cpa->force_flush_all || cpa->numpages > tlb_single_page_flush_ceiling) flush_tlb_all(); + else + on_each_cpu(__cpa_flush_tlb, cpa, 1);
if (!cache) return; @@ -1595,6 +1596,8 @@ static int cpa_process_alias(struct cpa_ alias_cpa.flags &= ~(CPA_PAGES_ARRAY | CPA_ARRAY); alias_cpa.curpage = 0;
+ cpa->force_flush_all = 1; + ret = __change_page_attr_set_clr(&alias_cpa, 0); if (ret) return ret; @@ -1615,6 +1618,7 @@ static int cpa_process_alias(struct cpa_ alias_cpa.flags &= ~(CPA_PAGES_ARRAY | CPA_ARRAY); alias_cpa.curpage = 0;
+ cpa->force_flush_all = 1; /* * The high mapping range is imprecise, so ignore the * return value.