This is a note to let you know that I've just added the patch titled

ARM: cpuidle: Correct driver unregistration if init fails

to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: arm-cpuidle-correct-driver-unregistration-if-init-fails.patch and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Wed Dec 6 18:04:41 CET 2017

From: Leo Yan leo.yan@linaro.org Date: Tue, 10 Oct 2017 13:47:55 +0800 Subject: ARM: cpuidle: Correct driver unregistration if init fails

From: Leo Yan leo.yan@linaro.org

[ Upstream commit 0f87855d969a87f02048ff5ced7503465d5ab2f1 ]

If cpuidle init fails, the code misses to unregister the driver for current CPU. Furthermore, we also need to rollback to cancel all previous CPUs registration; but the code retrieves driver handler by using function cpuidle_get_driver(), this function returns back current CPU driver handler but not previous CPU's handler, which leads to the failure handling code cannot unregister previous CPUs driver.

This commit fixes two mentioned issues, it adds error handling path 'goto out_unregister_drv' for current CPU driver unregistration; and it is to replace cpuidle_get_driver() with cpuidle_get_cpu_driver(), the later function can retrieve driver handler for previous CPUs according to the CPU device handler so can unregister the driver properly.

This patch also adds extra error handling paths 'goto out_kfree_dev' and 'goto out_kfree_drv' and adjusts the freeing sentences for previous CPUs; so make the code more readable for freeing 'dev' and 'drv' structures.

Suggested-by: Daniel Lezcano daniel.lezcano@linaro.org Signed-off-by: Leo Yan leo.yan@linaro.org Fixes: d50a7d8acd78 (ARM: cpuidle: Support asymmetric idle definition) Acked-by: Daniel Lezcano daniel.lezcano@linaro.org Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/cpuidle/cpuidle-arm.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-)

--- a/drivers/cpuidle/cpuidle-arm.c +++ b/drivers/cpuidle/cpuidle-arm.c @@ -104,13 +104,13 @@ static int __init arm_idle_init(void) ret = dt_init_idle_driver(drv, arm_idle_state_match, 1); if (ret <= 0) { ret = ret ? : -ENODEV; - goto init_fail; + goto out_kfree_drv; }

ret = cpuidle_register_driver(drv); if (ret) { pr_err("Failed to register cpuidle driver\n"); - goto init_fail; + goto out_kfree_drv; }

/* @@ -128,14 +128,14 @@ static int __init arm_idle_init(void)

if (ret) { pr_err("CPU %d failed to init idle CPU ops\n", cpu); - goto out_fail; + goto out_unregister_drv; }

dev = kzalloc(sizeof(*dev), GFP_KERNEL); if (!dev) { pr_err("Failed to allocate cpuidle device\n"); ret = -ENOMEM; - goto out_fail; + goto out_unregister_drv; } dev->cpu = cpu;

@@ -143,21 +143,25 @@ static int __init arm_idle_init(void) if (ret) { pr_err("Failed to register cpuidle device for CPU %d\n", cpu); - kfree(dev); - goto out_fail; + goto out_kfree_dev; } }

return 0; -init_fail: + +out_kfree_dev: + kfree(dev); +out_unregister_drv: + cpuidle_unregister_driver(drv); +out_kfree_drv: kfree(drv); out_fail: while (--cpu >= 0) { dev = per_cpu(cpuidle_devices, cpu); + drv = cpuidle_get_cpu_driver(dev); cpuidle_unregister_device(dev); - kfree(dev); - drv = cpuidle_get_driver(); cpuidle_unregister_driver(drv); + kfree(dev); kfree(drv); }

Patches currently in stable-queue which might be from leo.yan@linaro.org are

queue-4.14/arm-cpuidle-correct-driver-unregistration-if-init-fails.patch