From 60ec5585496871345c1a8113d7b60ed9d9474866 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Sat, 29 Oct 2005 18:16:34 -0700 Subject: [PATCH] mm: i386 sh sh64 ready for split ptlock Use pte_offset_map_lock, instead of pte_offset_map (or inappropriate pte_offset_kernel) and mm-wide page_table_lock, in sundry arch places. The i386 vm86 mark_screen_rdonly: yes, there was and is an assumption that the screen fits inside the one page table, as indeed it does. The sh __do_page_fault: which handles both kernel faults (without lock) and user mm faults (locked - though it set_pte without locking before). The sh64 flush_cache_range and helpers: which wrongly thought callers held page_table_lock before (only its tlb_start_vma did, and no longer does so); moved the flush loop down, and adjusted the large versus small range decision to consider a range which spans page tables as large. Signed-off-by: Hugh Dickins Acked-by: Paul Mundt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/sh/mm/fault.c | 40 +++++++++++++++++++++++----------------- 1 file changed, 23 insertions(+), 17 deletions(-) (limited to 'arch/sh/mm/fault.c') diff --git a/arch/sh/mm/fault.c b/arch/sh/mm/fault.c index 7abba2161da..775f86cd3fe 100644 --- a/arch/sh/mm/fault.c +++ b/arch/sh/mm/fault.c @@ -194,10 +194,13 @@ asmlinkage int __do_page_fault(struct pt_regs *regs, unsigned long writeaccess, unsigned long address) { unsigned long addrmax = P4SEG; - pgd_t *dir; + pgd_t *pgd; pmd_t *pmd; pte_t *pte; pte_t entry; + struct mm_struct *mm; + spinlock_t *ptl; + int ret = 1; #ifdef CONFIG_SH_KGDB if (kgdb_nofault && kgdb_bus_err_hook) @@ -208,28 +211,28 @@ asmlinkage int __do_page_fault(struct pt_regs *regs, unsigned long writeaccess, addrmax = P4SEG_STORE_QUE + 0x04000000; #endif - if (address >= P3SEG && address < addrmax) - dir = pgd_offset_k(address); - else if (address >= TASK_SIZE) + if (address >= P3SEG && address < addrmax) { + pgd = pgd_offset_k(address); + mm = NULL; + } else if (address >= TASK_SIZE) return 1; - else if (!current->mm) + else if (!(mm = current->mm)) return 1; else - dir = pgd_offset(current->mm, address); + pgd = pgd_offset(mm, address); - pmd = pmd_offset(dir, address); - if (pmd_none(*pmd)) - return 1; - if (pmd_bad(*pmd)) { - pmd_ERROR(*pmd); - pmd_clear(pmd); + pmd = pmd_offset(pgd, address); + if (pmd_none_or_clear_bad(pmd)) return 1; - } - pte = pte_offset_kernel(pmd, address); + if (mm) + pte = pte_offset_map_lock(mm, pmd, address, &ptl); + else + pte = pte_offset_kernel(pmd, address); + entry = *pte; if (pte_none(entry) || pte_not_present(entry) || (writeaccess && !pte_write(entry))) - return 1; + goto unlock; if (writeaccess) entry = pte_mkdirty(entry); @@ -251,8 +254,11 @@ asmlinkage int __do_page_fault(struct pt_regs *regs, unsigned long writeaccess, set_pte(pte, entry); update_mmu_cache(NULL, address, entry); - - return 0; + ret = 0; +unlock: + if (mm) + pte_unmap_unlock(pte, ptl); + return ret; } void flush_tlb_page(struct vm_area_struct *vma, unsigned long page) -- cgit v1.2.3