linux-kernel - [PATCH 1/5] uprobes: Do not leak UTASK_BP_HIT if find_active

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Message-ID: <20120914171551.GA29632@redhat.com>
Date:	Fri, 14 Sep 2012 19:15:51 +0200
From:	Oleg Nesterov <oleg@...hat.com>
To:	Ingo Molnar <mingo@...e.hu>, Peter Zijlstra <peterz@...radead.org>,
	Srikar Dronamraju <srikar@...ux.vnet.ibm.com>
Cc:	Ananth N Mavinakayanahalli <ananth@...ibm.com>,
	Anton Arapov <anton@...hat.com>,
	Sebastian Andrzej Siewior <bigeasy@...utronix.de>,
	linux-kernel@...r.kernel.org
Subject: [PATCH 1/5] uprobes: Do not leak UTASK_BP_HIT if
	find_active_uprobe() fails

If handle_swbp()->find_active_uprobe() fails we return with
utask->state = UTASK_BP_HIT.

Change handle_swbp() to reset utask->state at the start. Note
that we do this unconditionally, see the next patch(es).

Signed-off-by: Oleg Nesterov <oleg@...hat.com>
---
 kernel/events/uprobes.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 26f06a6..760acc1 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1468,6 +1468,10 @@ static void handle_swbp(struct pt_regs *regs)
 	bp_vaddr = uprobe_get_swbp_addr(regs);
 	uprobe = find_active_uprobe(bp_vaddr, &is_swbp);
 
+	utask = current->utask;
+	if (utask)
+		utask->state = UTASK_RUNNING;
+
 	if (!uprobe) {
 		if (is_swbp > 0) {
 			/* No matching uprobe; signal SIGTRAP. */
@@ -1486,7 +1490,6 @@ static void handle_swbp(struct pt_regs *regs)
 		return;
 	}
 
-	utask = current->utask;
 	if (!utask) {
 		utask = add_utask();
 		/* Cannot allocate; re-execute the instruction. */
-- 
1.5.5.1

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