From 560b423dd9af4272a1f3685c2d6b073fdc4af7c7 Mon Sep 17 00:00:00 2001 From: Stafford Horne Date: Mon, 18 Jun 2018 06:52:58 +0900 Subject: [PATCH] openrisc: Call destructor during __pte_free_tlb This fixes an issue uncovered when a recent change to add the "page table" flag was merged. During bootup we see many errors like the following: BUG: Bad page state in process mkdir pfn:00bae page:c1ff15c0 count:0 mapcount:-1024 mapping:00000000 index:0x0 flags: 0x0() raw: 00000000 00000000 00000000 fffffbff 00000000 00000100 00000200 00000000 page dumped because: nonzero mapcount Modules linked in: CPU: 0 PID: 46 Comm: mkdir Tainted: G B 4.17.0-simple-smp-07461-g1d40a5ea01d5-dirty #993 Call trace: [<(ptrval)>] show_stack+0x44/0x54 [<(ptrval)>] dump_stack+0xb0/0xe8 [<(ptrval)>] bad_page+0x138/0x174 [<(ptrval)>] ? cpumask_next+0x24/0x34 [<(ptrval)>] free_pages_check_bad+0x6c/0xd0 [<(ptrval)>] free_pcppages_bulk+0x174/0x42c [<(ptrval)>] free_unref_page_commit.isra.17+0xb8/0xc8 [<(ptrval)>] free_unref_page_list+0x10c/0x190 [<(ptrval)>] ? set_reset_devices+0x0/0x2c [<(ptrval)>] release_pages+0x3a0/0x414 [<(ptrval)>] tlb_flush_mmu_free+0x5c/0x90 [<(ptrval)>] tlb_flush_mmu+0x90/0xa4 [<(ptrval)>] arch_tlb_finish_mmu+0x50/0x94 [<(ptrval)>] tlb_finish_mmu+0x30/0x64 [<(ptrval)>] exit_mmap+0x110/0x1e0 [<(ptrval)>] mmput+0x50/0xf0 [<(ptrval)>] do_exit+0x274/0xa94 [<(ptrval)>] do_group_exit+0x50/0x110 [<(ptrval)>] __wake_up_parent+0x0/0x38 [<(ptrval)>] _syscall_return+0x0/0x4 During the __pte_free_tlb path openrisc fails to call the page destructor which would clear the new bits that were introduced. To fix this we are calling the destructor. It seem openrisc was the only architecture missing this, all other architectures either call the destructor like we are doing here or use pte_free. Note: failing to call the destructor was also messing up the zone stats (and will be cause other problems if you were using SPLIT_PTE_PTLOCKS, which we are not yet). Fixes: 1d40a5ea01d53 ("mm: mark pages in use for page tables") Acked-by: Matthew Wilcox Signed-off-by: Stafford Horne --- arch/openrisc/include/asm/pgalloc.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/openrisc/include/asm/pgalloc.h b/arch/openrisc/include/asm/pgalloc.h index 3e1a466..8999b92 100644 --- a/arch/openrisc/include/asm/pgalloc.h +++ b/arch/openrisc/include/asm/pgalloc.h @@ -98,8 +98,12 @@ static inline void pte_free(struct mm_struct *mm, struct page *pte) __free_page(pte); } +#define __pte_free_tlb(tlb, pte, addr) \ +do { \ + pgtable_page_dtor(pte); \ + tlb_remove_page((tlb), (pte)); \ +} while (0) -#define __pte_free_tlb(tlb, pte, addr) tlb_remove_page((tlb), (pte)) #define pmd_pgtable(pmd) pmd_page(pmd) #define check_pgt_cache() do { } while (0) -- 2.7.4