[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>
diff --git a/arch/i386/kernel/vm86.c b/arch/i386/kernel/vm86.c
index 16b4850..fc19935 100644
--- a/arch/i386/kernel/vm86.c
+++ b/arch/i386/kernel/vm86.c
@@ -134,17 +134,16 @@
return ret;
}
-static void mark_screen_rdonly(struct task_struct * tsk)
+static void mark_screen_rdonly(struct mm_struct *mm)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
- pte_t *pte, *mapped;
+ pte_t *pte;
+ spinlock_t *ptl;
int i;
- preempt_disable();
- spin_lock(&tsk->mm->page_table_lock);
- pgd = pgd_offset(tsk->mm, 0xA0000);
+ pgd = pgd_offset(mm, 0xA0000);
if (pgd_none_or_clear_bad(pgd))
goto out;
pud = pud_offset(pgd, 0xA0000);
@@ -153,16 +152,14 @@
pmd = pmd_offset(pud, 0xA0000);
if (pmd_none_or_clear_bad(pmd))
goto out;
- pte = mapped = pte_offset_map(pmd, 0xA0000);
+ pte = pte_offset_map_lock(mm, pmd, 0xA0000, &ptl);
for (i = 0; i < 32; i++) {
if (pte_present(*pte))
set_pte(pte, pte_wrprotect(*pte));
pte++;
}
- pte_unmap(mapped);
+ pte_unmap_unlock(pte, ptl);
out:
- spin_unlock(&tsk->mm->page_table_lock);
- preempt_enable();
flush_tlb();
}
@@ -306,7 +303,7 @@
tsk->thread.screen_bitmap = info->screen_bitmap;
if (info->flags & VM86_SCREEN_BITMAP)
- mark_screen_rdonly(tsk);
+ mark_screen_rdonly(tsk->mm);
__asm__ __volatile__(
"xorl %%eax,%%eax; movl %%eax,%%fs; movl %%eax,%%gs\n\t"
"movl %0,%%esp\n\t"
