Re: [PATCH 01/33] mm: introduce get_user_pages_remote()

diff -puN kernel/events/uprobes.c~introduce-get_user_pages_remote kernel/events/uprobes.c

--- a/kernel/events/uprobes.c~introduce-get_user_pages_remote	2016-02-12 10:44:13.178107026 -0800
+++ b/kernel/events/uprobes.c	2016-02-12 10:44:13.193107711 -0800

@@ -299,7 +299,7 @@ int uprobe_write_opcode(struct mm_struct

 retry:
 	/* Read the page with vaddr into memory */
-	ret = get_user_pages(NULL, mm, vaddr, 1, 0, 1, &old_page, &vma);
+	ret = get_user_pages_remote(NULL, mm, vaddr, 1, 0, 1, &old_page, &vma);
 	if (ret <= 0)
 		return ret;

@@ -1700,7 +1700,13 @@ static int is_trap_at_addr(struct mm_str
 	if (likely(result == 0))
 		goto out;

-	result = get_user_pages(NULL, mm, vaddr, 1, 0, 1, &page, NULL);
+	/*
+	 * The NULL 'tsk' here ensures that any faults that occur here
+	 * will not be accounted to the task.  'mm' *is* current->mm,
+	 * but we treat this as a 'remote' access since it is
+	 * essentially a kernel access to the memory.
+	 */
+	result = get_user_pages_remote(NULL, mm, vaddr, 1, 0, 1, &page, NULL);
 	if (result < 0)
 		return result;