Merge branch 'proc-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan...

[~andy/linux] / mm / memory.c

diff --git a/mm/memory.c b/mm/memory.c
index 0f9abbaf618cb8b21ceb7145b53d955a64f462db..3f8fa06b963b281191ac2c1350af0b21b2dad7c5 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -383,30 +383,54 @@ static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr,
        pmd_t *pmd = pmd_offset(pud, addr);
        struct address_space *mapping;
        pgoff_t index;
+       static unsigned long resume;
+       static unsigned long nr_shown;
+       static unsigned long nr_unshown;
+
+       /*
+        * Allow a burst of 60 reports, then keep quiet for that minute;
+        * or allow a steady drip of one report per second.
+        */
+       if (nr_shown == 60) {
+               if (time_before(jiffies, resume)) {
+                       nr_unshown++;
+                       return;
+               }
+               if (nr_unshown) {
+                       printk(KERN_ALERT
+                               "BUG: Bad page map: %lu messages suppressed\n",
+                               nr_unshown);
+                       nr_unshown = 0;
+               }
+               nr_shown = 0;
+       }
+       if (nr_shown++ == 0)
+               resume = jiffies + 60 * HZ;
 
        mapping = vma->vm_file ? vma->vm_file->f_mapping : NULL;
        index = linear_page_index(vma, addr);
 
-       printk(KERN_EMERG "Bad page map in process %s  pte:%08llx pmd:%08llx\n",
+       printk(KERN_ALERT
+               "BUG: Bad page map in process %s  pte:%08llx pmd:%08llx\n",
                current->comm,
                (long long)pte_val(pte), (long long)pmd_val(*pmd));
        if (page) {
-               printk(KERN_EMERG
+               printk(KERN_ALERT
                "page:%p flags:%p count:%d mapcount:%d mapping:%p index:%lx\n",
                page, (void *)page->flags, page_count(page),
                page_mapcount(page), page->mapping, page->index);
        }
-       printk(KERN_EMERG
+       printk(KERN_ALERT
                "addr:%p vm_flags:%08lx anon_vma:%p mapping:%p index:%lx\n",
                (void *)addr, vma->vm_flags, vma->anon_vma, mapping, index);
        /*
         * Choose text because data symbols depend on CONFIG_KALLSYMS_ALL=y
         */
        if (vma->vm_ops)
-               print_symbol(KERN_EMERG "vma->vm_ops->fault: %s\n",
+               print_symbol(KERN_ALERT "vma->vm_ops->fault: %s\n",
                                (unsigned long)vma->vm_ops->fault);
        if (vma->vm_file && vma->vm_file->f_op)
-               print_symbol(KERN_EMERG "vma->vm_file->f_op->mmap: %s\n",
+               print_symbol(KERN_ALERT "vma->vm_file->f_op->mmap: %s\n",
                                (unsigned long)vma->vm_file->f_op->mmap);
        dump_stack();
        add_taint(TAINT_BAD_PAGE);
@@ -1186,6 +1210,7 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
        int write = !!(flags & GUP_FLAGS_WRITE);
        int force = !!(flags & GUP_FLAGS_FORCE);
        int ignore = !!(flags & GUP_FLAGS_IGNORE_VMA_PERMISSIONS);
+       int ignore_sigkill = !!(flags & GUP_FLAGS_IGNORE_SIGKILL);
 
        if (len <= 0)
                return 0;
@@ -1264,12 +1289,15 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
                        struct page *page;
 
                        /*
-                        * If tsk is ooming, cut off its access to large memory
-                        * allocations. It has a pending SIGKILL, but it can't
-                        * be processed until returning to user space.
+                        * If we have a pending SIGKILL, don't keep faulting
+                        * pages and potentially allocating memory, unless
+                        * current is handling munlock--e.g., on exit. In
+                        * that case, we are not allocating memory.  Rather,
+                        * we're only unlocking already resident/mapped pages.
                         */
-                       if (unlikely(test_tsk_thread_flag(tsk, TIF_MEMDIE)))
-                               return i ? i : -ENOMEM;
+                       if (unlikely(!ignore_sigkill &&
+                                       fatal_signal_pending(current)))
+                               return i ? i : -ERESTARTSYS;
 
                        if (write)
                                foll_flags |= FOLL_WRITE;