This is a note to let you know that I've just added the patch titled
clocksource: mtk: Fix race conditions in probe code
to the 3.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
clocksource-mtk-fix-race-conditions-in-probe-code.patch
and it can be found in the queue-3.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From d4a19eb3b15a4ba98f627182f48d5bc0cffae670 Mon Sep 17 00:00:00 2001
From: Matthias Brugger <[email protected]>
Date: Thu, 19 Feb 2015 11:41:33 +0100
Subject: clocksource: mtk: Fix race conditions in probe code
From: Matthias Brugger <[email protected]>
commit d4a19eb3b15a4ba98f627182f48d5bc0cffae670 upstream.
We have two race conditions in the probe code which could lead to a null
pointer dereference in the interrupt handler.
The interrupt handler accesses the clockevent device, which may not yet be
registered.
First race condition happens when the interrupt handler gets registered before
the interrupts get disabled. The second race condition happens when the
interrupts get enabled, but the clockevent device is not yet registered.
Fix that by disabling the interrupts before we register the interrupt and enable
the interrupts after the clockevent device got registered.
Reported-by: Gongbae Park <[email protected]>
Signed-off-by: Matthias Brugger <[email protected]>
Signed-off-by: Daniel Lezcano <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/clocksource/mtk_timer.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
--- a/drivers/clocksource/mtk_timer.c
+++ b/drivers/clocksource/mtk_timer.c
@@ -224,6 +224,8 @@ static void __init mtk_timer_init(struct
}
rate = clk_get_rate(clk);
+ mtk_timer_global_reset(evt);
+
if (request_irq(evt->dev.irq, mtk_timer_interrupt,
IRQF_TIMER | IRQF_IRQPOLL, "mtk_timer", evt)) {
pr_warn("failed to setup irq %d\n", evt->dev.irq);
@@ -232,8 +234,6 @@ static void __init mtk_timer_init(struct
evt->ticks_per_jiffy = DIV_ROUND_UP(rate, HZ);
- mtk_timer_global_reset(evt);
-
/* Configure clock source */
mtk_timer_setup(evt, GPT_CLK_SRC, TIMER_CTRL_OP_FREERUN);
clocksource_mmio_init(evt->gpt_base + TIMER_CNT_REG(GPT_CLK_SRC),
@@ -241,10 +241,11 @@ static void __init mtk_timer_init(struct
/* Configure clock event */
mtk_timer_setup(evt, GPT_CLK_EVT, TIMER_CTRL_OP_REPEAT);
- mtk_timer_enable_irq(evt, GPT_CLK_EVT);
-
clockevents_config_and_register(&evt->dev, rate, 0x3,
0xffffffff);
+
+ mtk_timer_enable_irq(evt, GPT_CLK_EVT);
+
return;
err_clk_disable:
Patches currently in stable-queue which might be from [email protected] are
queue-3.19/clocksource-mtk-fix-race-conditions-in-probe-code.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
