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 3.18-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-3.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From d4a19eb3b15a4ba98f627182f48d5bc0cffae670 Mon Sep 17 00:00:00 2001 From: Matthias Brugger <matthias.bgg@xxxxxxxxx> Date: Thu, 19 Feb 2015 11:41:33 +0100 Subject: clocksource: mtk: Fix race conditions in probe code From: Matthias Brugger <matthias.bgg@xxxxxxxxx> 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 <yongbae2@xxxxxxxxx> Signed-off-by: Matthias Brugger <matthias.bgg@xxxxxxxxx> Signed-off-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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 matthias.bgg@xxxxxxxxx are queue-3.18/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 majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html