From: Rick Edgecombe rick.p.edgecombe@intel.com
[ Upstream commit ab5130186d7476dcee0d4e787d19a521ca552ce9 ]
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: Sasha Levin sashal@kernel.org --- arch/x86/mm/pageattr.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index a19a71b4d185..281e584cfe39 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.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 *data, int cache) 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; @@ -1584,6 +1585,8 @@ static int cpa_process_alias(struct cpa_data *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; @@ -1604,6 +1607,7 @@ static int cpa_process_alias(struct cpa_data *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.