diff options
Diffstat (limited to 'arch/arm/mm/fault-armv.c')
| -rw-r--r-- | arch/arm/mm/fault-armv.c | 37 |
1 files changed, 25 insertions, 12 deletions
diff --git a/arch/arm/mm/fault-armv.c b/arch/arm/mm/fault-armv.c index 2bec87c3327d..39fd5df73317 100644 --- a/arch/arm/mm/fault-armv.c +++ b/arch/arm/mm/fault-armv.c @@ -62,7 +62,7 @@ static int do_adjust_pte(struct vm_area_struct *vma, unsigned long address, } static int adjust_pte(struct vm_area_struct *vma, unsigned long address, - unsigned long pfn, struct vm_fault *vmf) + unsigned long pfn, bool need_lock) { spinlock_t *ptl; pgd_t *pgd; @@ -99,12 +99,11 @@ again: if (!pte) return 0; - /* - * If we are using split PTE locks, then we need to take the page - * lock here. Otherwise we are using shared mm->page_table_lock - * which is already locked, thus cannot take it. - */ - if (ptl != vmf->ptl) { + if (need_lock) { + /* + * Use nested version here to indicate that we are already + * holding one similar spinlock. + */ spin_lock_nested(ptl, SINGLE_DEPTH_NESTING); if (unlikely(!pmd_same(pmdval, pmdp_get_lockless(pmd)))) { pte_unmap_unlock(pte, ptl); @@ -114,7 +113,7 @@ again: ret = do_adjust_pte(vma, address, pfn, pte); - if (ptl != vmf->ptl) + if (need_lock) spin_unlock(ptl); pte_unmap(pte); @@ -123,9 +122,10 @@ again: static void make_coherent(struct address_space *mapping, struct vm_area_struct *vma, - unsigned long addr, pte_t *ptep, unsigned long pfn, - struct vm_fault *vmf) + unsigned long addr, pte_t *ptep, unsigned long pfn) { + const unsigned long pmd_start_addr = ALIGN_DOWN(addr, PMD_SIZE); + const unsigned long pmd_end_addr = pmd_start_addr + PMD_SIZE; struct mm_struct *mm = vma->vm_mm; struct vm_area_struct *mpnt; unsigned long offset; @@ -142,6 +142,14 @@ make_coherent(struct address_space *mapping, struct vm_area_struct *vma, flush_dcache_mmap_lock(mapping); vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) { /* + * If we are using split PTE locks, then we need to take the pte + * lock. Otherwise we are using shared mm->page_table_lock which + * is already locked, thus cannot take it. + */ + bool need_lock = IS_ENABLED(CONFIG_SPLIT_PTE_PTLOCKS); + unsigned long mpnt_addr; + + /* * If this VMA is not in our MM, we can ignore it. * Note that we intentionally mask out the VMA * that we are fixing up. @@ -151,7 +159,12 @@ make_coherent(struct address_space *mapping, struct vm_area_struct *vma, if (!(mpnt->vm_flags & VM_MAYSHARE)) continue; offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT; - aliases += adjust_pte(mpnt, mpnt->vm_start + offset, pfn, vmf); + mpnt_addr = mpnt->vm_start + offset; + + /* Avoid deadlocks by not grabbing the same PTE lock again. */ + if (mpnt_addr >= pmd_start_addr && mpnt_addr < pmd_end_addr) + need_lock = false; + aliases += adjust_pte(mpnt, mpnt_addr, pfn, need_lock); } flush_dcache_mmap_unlock(mapping); if (aliases) @@ -194,7 +207,7 @@ void update_mmu_cache_range(struct vm_fault *vmf, struct vm_area_struct *vma, __flush_dcache_folio(mapping, folio); if (mapping) { if (cache_is_vivt()) - make_coherent(mapping, vma, addr, ptep, pfn, vmf); + make_coherent(mapping, vma, addr, ptep, pfn); else if (vma->vm_flags & VM_EXEC) __flush_icache_all(); } |