---

yaml --- r: 334766 b: refs/heads/master c: 142b18d h: refs/heads/master v: v3
git-mirror · Oct 7, 2012 · fe7b564 · fe7b564
1 parent cce6ca9
commit fe7b564
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Showing 2 changed files with 10 additions and 1 deletion.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 076a365b3da99b68c5d58e394714d0611f1fa002
+refs/heads/master: 142b18ddc81439acda4bc4231b291e99fe67d507
diff --git a/trunk/kernel/events/uprobes.c b/trunk/kernel/events/uprobes.c
@@ -596,6 +596,7 @@ install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm,
 		BUG_ON((uprobe->offset & ~PAGE_MASK) +
 				UPROBE_SWBP_INSN_SIZE > PAGE_SIZE);
 
+		smp_wmb(); /* pairs with rmb() in find_active_uprobe() */
 		uprobe->flags |= UPROBE_COPY_INSN;
 	}
 
@@ -1436,6 +1437,14 @@ static void handle_swbp(struct pt_regs *regs)
 		}
 		return;
 	}
+	/*
+	 * TODO: move copy_insn/etc into _register and remove this hack.
+	 * After we hit the bp, _unregister + _register can install the
+	 * new and not-yet-analyzed uprobe at the same address, restart.
+	 */
+	smp_rmb(); /* pairs with wmb() in install_breakpoint() */
+	if (unlikely(!(uprobe->flags & UPROBE_COPY_INSN)))
+		goto restart;
 
 	utask = current->utask;
 	if (!utask) {