The 32-bit x86 PAT code uses __set_pmd_pte() to update pmds. This uses pgd_list currently, but we don't need the global list as we can walk the task list under RCU.
(This code already holds the pgd_lock.) Cc: Andrew Morton <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Waiman Long <[email protected]> Cc: [email protected] Signed-off-by: Ingo Molnar <[email protected]> --- arch/x86/mm/pageattr.c | 26 ++++++++++++++++++++------ 1 file changed, 20 insertions(+), 6 deletions(-) diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 997fc97e9072..4ff6a1808f1d 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -438,17 +438,31 @@ static void __set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte) set_pte_atomic(kpte, pte); #ifdef CONFIG_X86_32 if (!SHARED_KERNEL_PMD) { - struct page *page; + struct task_struct *g, *p; - list_for_each_entry(page, &pgd_list, lru) { + /* We are holding pgd_lock, which implies rcu_read_lock(): */ + + for_each_process_thread(g, p) { + struct mm_struct *mm; + spinlock_t *pgt_lock; pgd_t *pgd; pud_t *pud; pmd_t *pmd; - pgd = (pgd_t *)page_address(page) + pgd_index(address); - pud = pud_offset(pgd, address); - pmd = pmd_offset(pud, address); - set_pte_atomic((pte_t *)pmd, pte); + task_lock(p); + mm = p->mm; + if (mm) { + pgt_lock = &mm->page_table_lock; + spin_lock(pgt_lock); + + pgd = mm->pgd + pgd_index(address); + pud = pud_offset(pgd, address); + pmd = pmd_offset(pud, address); + set_pte_atomic((pte_t *)pmd, pte); + + spin_unlock(pgt_lock); + } + task_unlock(p); } } #endif -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
