[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 <hugh@veritas.com> Acked-by: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Hugh Dickins
Linus Torvalds
Родитель
deceb6cd17
Коммит
60ec558549
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@ -134,17 +134,16 @@ struct pt_regs * fastcall save_v86_state(struct kernel_vm86_regs * regs)
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return ret;
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}
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static void mark_screen_rdonly(struct task_struct * tsk)
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static void mark_screen_rdonly(struct mm_struct *mm)
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{
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pgd_t *pgd;
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pud_t *pud;
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pmd_t *pmd;
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pte_t *pte, *mapped;
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pte_t *pte;
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spinlock_t *ptl;
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int i;
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preempt_disable();
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spin_lock(&tsk->mm->page_table_lock);
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pgd = pgd_offset(tsk->mm, 0xA0000);
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pgd = pgd_offset(mm, 0xA0000);
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if (pgd_none_or_clear_bad(pgd))
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goto out;
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pud = pud_offset(pgd, 0xA0000);
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@ -153,16 +152,14 @@ static void mark_screen_rdonly(struct task_struct * tsk)
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pmd = pmd_offset(pud, 0xA0000);
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if (pmd_none_or_clear_bad(pmd))
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goto out;
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pte = mapped = pte_offset_map(pmd, 0xA0000);
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pte = pte_offset_map_lock(mm, pmd, 0xA0000, &ptl);
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for (i = 0; i < 32; i++) {
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if (pte_present(*pte))
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set_pte(pte, pte_wrprotect(*pte));
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pte++;
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}
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pte_unmap(mapped);
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pte_unmap_unlock(pte, ptl);
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out:
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spin_unlock(&tsk->mm->page_table_lock);
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preempt_enable();
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flush_tlb();
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}
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@ -306,7 +303,7 @@ static void do_sys_vm86(struct kernel_vm86_struct *info, struct task_struct *tsk
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tsk->thread.screen_bitmap = info->screen_bitmap;
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if (info->flags & VM86_SCREEN_BITMAP)
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mark_screen_rdonly(tsk);
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mark_screen_rdonly(tsk->mm);
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__asm__ __volatile__(
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"xorl %%eax,%%eax; movl %%eax,%%fs; movl %%eax,%%gs\n\t"
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"movl %0,%%esp\n\t"
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@ -194,10 +194,13 @@ asmlinkage int __do_page_fault(struct pt_regs *regs, unsigned long writeaccess,
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unsigned long address)
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{
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unsigned long addrmax = P4SEG;
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pgd_t *dir;
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pgd_t *pgd;
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pmd_t *pmd;
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pte_t *pte;
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pte_t entry;
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struct mm_struct *mm;
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spinlock_t *ptl;
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int ret = 1;
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#ifdef CONFIG_SH_KGDB
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if (kgdb_nofault && kgdb_bus_err_hook)
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@ -208,28 +211,28 @@ asmlinkage int __do_page_fault(struct pt_regs *regs, unsigned long writeaccess,
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addrmax = P4SEG_STORE_QUE + 0x04000000;
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#endif
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if (address >= P3SEG && address < addrmax)
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dir = pgd_offset_k(address);
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else if (address >= TASK_SIZE)
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if (address >= P3SEG && address < addrmax) {
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pgd = pgd_offset_k(address);
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mm = NULL;
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} else if (address >= TASK_SIZE)
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return 1;
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else if (!current->mm)
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else if (!(mm = current->mm))
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return 1;
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else
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dir = pgd_offset(current->mm, address);
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pgd = pgd_offset(mm, address);
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pmd = pmd_offset(dir, address);
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if (pmd_none(*pmd))
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pmd = pmd_offset(pgd, address);
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if (pmd_none_or_clear_bad(pmd))
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return 1;
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if (pmd_bad(*pmd)) {
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pmd_ERROR(*pmd);
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pmd_clear(pmd);
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return 1;
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}
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pte = pte_offset_kernel(pmd, address);
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if (mm)
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pte = pte_offset_map_lock(mm, pmd, address, &ptl);
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else
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pte = pte_offset_kernel(pmd, address);
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entry = *pte;
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if (pte_none(entry) || pte_not_present(entry)
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|| (writeaccess && !pte_write(entry)))
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return 1;
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goto unlock;
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if (writeaccess)
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entry = pte_mkdirty(entry);
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@ -251,8 +254,11 @@ asmlinkage int __do_page_fault(struct pt_regs *regs, unsigned long writeaccess,
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set_pte(pte, entry);
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update_mmu_cache(NULL, address, entry);
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return 0;
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ret = 0;
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unlock:
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if (mm)
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pte_unmap_unlock(pte, ptl);
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return ret;
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}
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void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
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@ -584,32 +584,36 @@ static void sh64_dcache_purge_phy_page(unsigned long paddr)
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}
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}
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static void sh64_dcache_purge_user_page(struct mm_struct *mm, unsigned long eaddr)
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static void sh64_dcache_purge_user_pages(struct mm_struct *mm,
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unsigned long addr, unsigned long end)
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{
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pgd_t *pgd;
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pmd_t *pmd;
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pte_t *pte;
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pte_t entry;
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spinlock_t *ptl;
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unsigned long paddr;
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/* NOTE : all the callers of this have mm->page_table_lock held, so the
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following page table traversal is safe even on SMP/pre-emptible. */
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if (!mm)
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return; /* No way to find physical address of page */
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if (!mm) return; /* No way to find physical address of page */
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pgd = pgd_offset(mm, eaddr);
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if (pgd_bad(*pgd)) return;
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pgd = pgd_offset(mm, addr);
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if (pgd_bad(*pgd))
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return;
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pmd = pmd_offset(pgd, eaddr);
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if (pmd_none(*pmd) || pmd_bad(*pmd)) return;
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pte = pte_offset_kernel(pmd, eaddr);
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entry = *pte;
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if (pte_none(entry) || !pte_present(entry)) return;
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paddr = pte_val(entry) & PAGE_MASK;
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sh64_dcache_purge_coloured_phy_page(paddr, eaddr);
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pmd = pmd_offset(pgd, addr);
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if (pmd_none(*pmd) || pmd_bad(*pmd))
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return;
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pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
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do {
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entry = *pte;
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if (pte_none(entry) || !pte_present(entry))
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continue;
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paddr = pte_val(entry) & PAGE_MASK;
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sh64_dcache_purge_coloured_phy_page(paddr, addr);
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} while (pte++, addr += PAGE_SIZE, addr != end);
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pte_unmap_unlock(pte - 1, ptl);
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}
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/****************************************************************************/
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@ -668,7 +672,7 @@ static void sh64_dcache_purge_user_range(struct mm_struct *mm,
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int n_pages;
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n_pages = ((end - start) >> PAGE_SHIFT);
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if (n_pages >= 64) {
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if (n_pages >= 64 || ((start ^ (end - 1)) & PMD_MASK)) {
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#if 1
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sh64_dcache_purge_all();
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#else
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@ -707,20 +711,10 @@ static void sh64_dcache_purge_user_range(struct mm_struct *mm,
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}
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#endif
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} else {
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/* 'Small' range */
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unsigned long aligned_start;
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unsigned long eaddr;
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unsigned long last_page_start;
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aligned_start = start & PAGE_MASK;
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/* 'end' is 1 byte beyond the end of the range */
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last_page_start = (end - 1) & PAGE_MASK;
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eaddr = aligned_start;
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while (eaddr <= last_page_start) {
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sh64_dcache_purge_user_page(mm, eaddr);
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eaddr += PAGE_SIZE;
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}
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/* Small range, covered by a single page table page */
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start &= PAGE_MASK; /* should already be so */
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end = PAGE_ALIGN(end); /* should already be so */
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sh64_dcache_purge_user_pages(mm, start, end);
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}
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return;
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}
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@ -880,9 +874,7 @@ void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
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addresses from the user address space specified by mm, after writing
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back any dirty data.
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Note(1), 'end' is 1 byte beyond the end of the range to flush.
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Note(2), this is called with mm->page_table_lock held.*/
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Note, 'end' is 1 byte beyond the end of the range to flush. */
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sh64_dcache_purge_user_range(mm, start, end);
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sh64_icache_inv_user_page_range(mm, start, end);
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@ -898,7 +890,7 @@ void flush_cache_page(struct vm_area_struct *vma, unsigned long eaddr, unsigned
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the I-cache must be searched too in case the page in question is
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both writable and being executed from (e.g. stack trampolines.)
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Note(1), this is called with mm->page_table_lock held.
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Note, this is called with pte lock held.
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*/
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sh64_dcache_purge_phy_page(pfn << PAGE_SHIFT);
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