* [PATCH] clocksource: exynos_mct: clear irq at stop local mct to fix suspend
[not found] <CGME20170117045403epcas1p1c64f1563c31947059430e0fbf370ee75@epcas1p1.samsung.com>
@ 2017-01-17 4:54 ` Joonyoung Shim
2017-01-17 9:03 ` Thomas Gleixner
2017-01-17 9:13 ` [tip:timers/urgent] clocksource/exynos_mct: Clear interrupt when cpu is shut down tip-bot for Joonyoung Shim
0 siblings, 2 replies; 3+ messages in thread
From: Joonyoung Shim @ 2017-01-17 4:54 UTC (permalink / raw)
To: linux-kernel
Cc: linux-arm-kernel, linux-samsung-soc, stable, daniel.lezcano,
tglx, kgene, krzk, javier, sw0312.kim, cw00.choi, jy0922.shim
This patch adds clear interrupt to exynos4_mct_dying_cpu(). Without
clearing, after turning on non boot cpu at wakeup from suspend to
ram, not cleared tick interrupt occurs and it causes following null
deference for MCT_INT_SPI type mct.
[ 51.251378] Unable to handle kernel NULL pointer dereference at virtual address 00000040
[ 51.257980] pgd = c0004000
[ 51.260666] [00000040] *pgd=00000000
[ 51.264222] Internal error: Oops: 5 [#1] PREEMPT SMP ARM
[ 51.269503] Modules linked in:
[ 51.272541] CPU: 7 PID: 53 Comm: ksoftirqd/7 Tainted: G W 4.9.0-rc7-next-20161201-00007-g74076859ec44 #140
[ 51.283282] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[ 51.289348] task: ee942d00 task.stack: ee960000
[ 51.293861] PC is at tick_periodic+0x38/0xb0
[ 51.298102] LR is at tick_handle_periodic+0x1c/0x90
[ 51.302956] pc : [<c0183358>] lr : [<c01833ec>] psr: 20000093
[ 51.302956] sp : ee961e18 ip : f0806000 fp : 00000100
[ 51.314391] r10: c0c0ef6a r9 : 0000000b r8 : eebcf080
[ 51.319591] r7 : ee961e7c r6 : 00000000 r5 : 00000007 r4 : ef013ec0
[ 51.326090] r3 : 00000000 r2 : 2e4ac000 r1 : c09ae9a8 r0 : 00000007
[ 51.332591] Flags: nzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment none
[ 51.339781] Control: 10c5387d Table: 4000406a DAC: 00000051
[ 51.345501] Process ksoftirqd/7 (pid: 53, stack limit = 0xee960210)
[ 51.351740] Stack: (0xee961e18 to 0xee962000)
[ 51.356073] 1e00: ef014db0 c0c03dac
[ 51.364222] 1e20: 00000000 ef013ec0 ee854100 00000000 ee961e7c 00000039 ee854100 c0c0ef6a
[ 51.372367] 1e40: 00000100 c055bd44 ee852840 c0164a18 00000000 00000001 ee854100 ee854100
[ 51.380512] 1e60: c0c03f24 c0b6324c c0c02080 c0c02080 40000006 c0164ac4 00000000 00000000
[ 51.388658] 1e80: 00000100 ee854100 ee854160 c0164b38 ee854100 ee854160 c0c03f24 c0167e9c
[ 51.396804] 1ea0: 00000039 c0c0cbac c0c0cbac c0b6324c c0c02080 c01675e0 c0c0cc5c c0c0cc60
[ 51.404949] 1ec0: 00000000 c011fd3c 00000000 00000006 c0c02098 ee960000 c0c02080 c011ff6c
[ 51.413095] 1ee0: ee961f0c c06fb4a4 ee961ee0 c0c47f80 0000000a ffff9ed5 c0c03900 04208040
[ 51.421240] 1f00: c0c0a174 ee960000 ee867b00 00000007 00000001 c0c0a174 00000002 00000000
[ 51.429385] 1f20: 00000000 c01200b8 ee960000 c013a50c 00000000 ee867b80 ee867b00 c013a3b0
[ 51.437530] 1f40: 00000000 00000000 00000000 c0136cbc ffffffff 00000001 00000007 ee867b00
[ 51.445676] 1f60: 00000000 00270027 dead4ead ffffffff ffffffff ee961f74 ee961f74 00000000
[ 51.453822] 1f80: 00000000 dead4ead ffffffff ffffffff ee961f90 ee961f90 ee961fac ee867b80
[ 51.461967] 1fa0: c0136be0 00000000 00000000 c0107a78 00000000 00000000 00000000 00000000
[ 51.470112] 1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 51.478258] 1fe0: 00000000 00000000 00000000 00000000 00000013 00000000 ffffffff ffffffff
[ 51.486409] [<c0183358>] (tick_periodic) from [<ef013ec0>] (0xef013ec0)
[ 51.492990] Code: ee1d2f90 e34c30b6 e8bd4070 e7923003 (e5933040)
[ 51.499057] ---[ end trace 995703fe1bede0b4 ]---
Fixes: 56a94f13919c ("clocksource: exynos_mct: Avoid blocking calls in the cpu hotplug notifier")
Cc: stable@vger.kernel.org #v4.2+ #v4.1.4+ #3.18.18+ #v3.16.18+ #v3.12.46+
Reported-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
---
drivers/clocksource/exynos_mct.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c
index 4da1dc2..670ff0f 100644
--- a/drivers/clocksource/exynos_mct.c
+++ b/drivers/clocksource/exynos_mct.c
@@ -495,6 +495,7 @@ static int exynos4_mct_dying_cpu(unsigned int cpu)
if (mct_int_type == MCT_INT_SPI) {
if (evt->irq != -1)
disable_irq_nosync(evt->irq);
+ exynos4_mct_write(0x1, mevt->base + MCT_L_INT_CSTAT_OFFSET);
} else {
disable_percpu_irq(mct_irqs[MCT_L0_IRQ]);
}
--
1.9.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] clocksource: exynos_mct: clear irq at stop local mct to fix suspend
2017-01-17 4:54 ` [PATCH] clocksource: exynos_mct: clear irq at stop local mct to fix suspend Joonyoung Shim
@ 2017-01-17 9:03 ` Thomas Gleixner
2017-01-17 9:13 ` [tip:timers/urgent] clocksource/exynos_mct: Clear interrupt when cpu is shut down tip-bot for Joonyoung Shim
1 sibling, 0 replies; 3+ messages in thread
From: Thomas Gleixner @ 2017-01-17 9:03 UTC (permalink / raw)
To: Joonyoung Shim
Cc: linux-kernel, linux-arm-kernel, linux-samsung-soc, stable,
daniel.lezcano, kgene, krzk, javier, sw0312.kim, cw00.choi
On Tue, 17 Jan 2017, Joonyoung Shim wrote:
> This patch adds clear interrupt to exynos4_mct_dying_cpu(). Without
Please read Documentation/process/SubmittingPatches. Search for 'This
patch' ....
A changelog should explain the problem first and then explain the concept
of the fix. You start explaining WHAT the patch does and not what the
problem is.
> clearing, after turning on non boot cpu at wakeup from suspend to
> ram, not cleared tick interrupt occurs and it causes following null
> deference for MCT_INT_SPI type mct.
This has nothing to do with suspend. That can happen with a normal cpu
offline/online sequence as well, which happens to be utilized by
suspend/resume.
Please trim back traces so they contain only useful information. There is
no point in having all these useless stack entries and whatever, which do
not at all help to diagnose the problem.
I'll fix that up when applying the patch. Checkout the resulting changelog
and please be more careful next time.
> [ 51.251378] Unable to handle kernel NULL pointer dereference at virtual address 00000040
> [ 51.257980] pgd = c0004000
> [ 51.260666] [00000040] *pgd=00000000
> [ 51.264222] Internal error: Oops: 5 [#1] PREEMPT SMP ARM
> [ 51.269503] Modules linked in:
> [ 51.272541] CPU: 7 PID: 53 Comm: ksoftirqd/7 Tainted: G W 4.9.0-rc7-next-20161201-00007-g74076859ec44 #140
> [ 51.283282] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
> [ 51.289348] task: ee942d00 task.stack: ee960000
> [ 51.293861] PC is at tick_periodic+0x38/0xb0
> [ 51.298102] LR is at tick_handle_periodic+0x1c/0x90
> [ 51.486409] [<c0183358>] (tick_periodic) from [<ef013ec0>] (0xef013ec0)
> [ 51.492990] Code: ee1d2f90 e34c30b6 e8bd4070 e7923003 (e5933040)
> [ 51.499057] ---[ end trace 995703fe1bede0b4 ]---
> Fixes: 56a94f13919c ("clocksource: exynos_mct: Avoid blocking calls in the cpu hotplug notifier")
> Cc: stable@vger.kernel.org #v4.2+ #v4.1.4+ #3.18.18+ #v3.16.18+ #v3.12.46+
Adding the version tags is pointless when you have a Fixes tag, which
allows the stable maintainers to find the affected kernels automatically.
> Reported-by: Seung-Woo Kim <sw0312.kim@samsung.com>
> Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
> Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
This Signed-off-by sequence is wrong.
Seung-Woo reported the problem. You wrote the patch and sent it to the
mailing list. The above sequence suggests that you wrote the patch and
Seung-Woo sent it to the mailing list, which is obviously not the case.
Thanks,
tglx
^ permalink raw reply [flat|nested] 3+ messages in thread
* [tip:timers/urgent] clocksource/exynos_mct: Clear interrupt when cpu is shut down
2017-01-17 4:54 ` [PATCH] clocksource: exynos_mct: clear irq at stop local mct to fix suspend Joonyoung Shim
2017-01-17 9:03 ` Thomas Gleixner
@ 2017-01-17 9:13 ` tip-bot for Joonyoung Shim
1 sibling, 0 replies; 3+ messages in thread
From: tip-bot for Joonyoung Shim @ 2017-01-17 9:13 UTC (permalink / raw)
To: linux-tip-commits; +Cc: linux-kernel, hpa, jy0922.shim, tglx, mingo, sw0312.kim
Commit-ID: bc7c36eedb0c7004aa06c2afc3c5385adada8fa3
Gitweb: http://git.kernel.org/tip/bc7c36eedb0c7004aa06c2afc3c5385adada8fa3
Author: Joonyoung Shim <jy0922.shim@samsung.com>
AuthorDate: Tue, 17 Jan 2017 13:54:36 +0900
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Tue, 17 Jan 2017 10:08:38 +0100
clocksource/exynos_mct: Clear interrupt when cpu is shut down
When a CPU goes offline a potentially pending timer interrupt is not
cleared. When the CPU comes online again then the pending interrupt is
delivered before the per cpu clockevent device is initialized. As a
consequence the tick interrupt handler dereferences a NULL pointer.
[ 51.251378] Unable to handle kernel NULL pointer dereference at virtual address 00000040
[ 51.289348] task: ee942d00 task.stack: ee960000
[ 51.293861] PC is at tick_periodic+0x38/0xb0
[ 51.298102] LR is at tick_handle_periodic+0x1c/0x90
Clear the pending interrupt in the cpu dying path.
Fixes: 56a94f13919c ("clocksource: exynos_mct: Avoid blocking calls in the cpu hotplug notifier")
Reported-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Cc: linux-samsung-soc@vger.kernel.org
Cc: cw00.choi@samsung.com
Cc: daniel.lezcano@linaro.org
Cc: stable@vger.kernel.org
Cc: javier@osg.samsung.com
Cc: kgene@kernel.org
Cc: krzk@kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1484628876-22065-1-git-send-email-jy0922.shim@samsung.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
drivers/clocksource/exynos_mct.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c
index 4da1dc2..670ff0f 100644
--- a/drivers/clocksource/exynos_mct.c
+++ b/drivers/clocksource/exynos_mct.c
@@ -495,6 +495,7 @@ static int exynos4_mct_dying_cpu(unsigned int cpu)
if (mct_int_type == MCT_INT_SPI) {
if (evt->irq != -1)
disable_irq_nosync(evt->irq);
+ exynos4_mct_write(0x1, mevt->base + MCT_L_INT_CSTAT_OFFSET);
} else {
disable_percpu_irq(mct_irqs[MCT_L0_IRQ]);
}
^ permalink raw reply related [flat|nested] 3+ messages in thread
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2017-01-17 4:54 ` [PATCH] clocksource: exynos_mct: clear irq at stop local mct to fix suspend Joonyoung Shim
2017-01-17 9:03 ` Thomas Gleixner
2017-01-17 9:13 ` [tip:timers/urgent] clocksource/exynos_mct: Clear interrupt when cpu is shut down tip-bot for Joonyoung Shim
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