Merge ssh://master.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6…

…-x86 * ssh://master.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-x86: x86: fix global_flush_tlb() bug
git-mirror · Oct 19, 2007 · 2679065 · 2679065
2 parents f768f9d + 9a24d04
commit 2679065
Showing 1 changed file with 7 additions and 2 deletions.
diff --git a/arch/x86/mm/pageattr_64.c b/arch/x86/mm/pageattr_64.c
@@ -230,9 +230,14 @@ void global_flush_tlb(void)
 	struct page *pg, *next;
 	struct list_head l;
 
-	down_read(&init_mm.mmap_sem);
+	/*
+	 * Write-protect the semaphore, to exclude two contexts
+	 * doing a list_replace_init() call in parallel and to
+	 * exclude new additions to the deferred_pages list:
+	 */
+	down_write(&init_mm.mmap_sem);
 	list_replace_init(&deferred_pages, &l);
-	up_read(&init_mm.mmap_sem);
+	up_write(&init_mm.mmap_sem);
 
 	flush_map(&l);