2016-11-14 01:11:29

by Christian Lamparter

Subject: [PATCH] watchdog: qcom: fix kernel panic due to external abort on non-linefetch

This patch fixes a off-by-one in the "watchdog: qcom: add option for
standalone watchdog not in timer block" patch that causes the
following panic on boot:

> Unhandled fault: external abort on non-linefetch (0x1008) at 0xc8874002
> pgd = c0204000
> [c8874002] *pgd=87806811, *pte=0b017653, *ppte=0b017453
> Internal error: : 1008 [#1] SMP ARM
> CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.8.6 #0
> Hardware name: Generic DT based system
> PC is at 0xc02222f4
> LR is at 0x1
> pc : [<c02222f4>] lr : [<00000001>] psr: 00000113
> sp : c782fc98 ip : 00000003 fp : 00000000
> r10: 00000004 r9 : c782e000 r8 : c04ab98c
> r7 : 00000001 r6 : c8874002 r5 : c782fe00 r4 : 00000002
> r3 : 00000000 r2 : c782fe00 r1 : 00100000 r0 : c8874002
> Flags: nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none
> Control: 10c5387d Table: 8020406a DAC: 00000051
> Process swapper/0 (pid: 1, stack limit = 0xc782e210)
> Stack: (0xc782fc98 to 0xc7830000)
> [...]

The WDT_STS (status) needs to be translated via wdt_addr as well.

fixes: f0d9d0f4b44a ("watchdog: qcom: add option for standalone watchdog not in timer block")
Cc: [email protected] # 4.8
Signed-off-by: Christian Lamparter <[email protected]>
---
drivers/watchdog/qcom-wdt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/watchdog/qcom-wdt.c b/drivers/watchdog/qcom-wdt.c
index 5796b5d..4f47b5e 100644
--- a/drivers/watchdog/qcom-wdt.c
+++ b/drivers/watchdog/qcom-wdt.c
@@ -209,7 +209,7 @@ static int qcom_wdt_probe(struct platform_device *pdev)
wdt->wdd.parent = &pdev->dev;
wdt->layout = regs;

- if (readl(wdt->base + WDT_STS) & 1)
+ if (readl(wdt_addr(wdt, WDT_STS)) & 1)
wdt->wdd.bootstatus = WDIOF_CARDRESET;

/*
--
2.10.2

2016-11-14 01:42:24

by Guenter Roeck

Subject: Re: [PATCH] watchdog: qcom: fix kernel panic due to external abort on non-linefetch

On 11/13/2016 05:11 PM, Christian Lamparter wrote:
> This patch fixes a off-by-one in the "watchdog: qcom: add option for
> standalone watchdog not in timer block" patch that causes the
> following panic on boot:
>
>> Unhandled fault: external abort on non-linefetch (0x1008) at 0xc8874002
>> pgd = c0204000
>> [c8874002] *pgd=87806811, *pte=0b017653, *ppte=0b017453
>> Internal error: : 1008 [#1] SMP ARM
>> CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.8.6 #0
>> Hardware name: Generic DT based system
>> PC is at 0xc02222f4
>> LR is at 0x1
>> pc : [<c02222f4>] lr : [<00000001>] psr: 00000113
>> sp : c782fc98 ip : 00000003 fp : 00000000
>> r10: 00000004 r9 : c782e000 r8 : c04ab98c
>> r7 : 00000001 r6 : c8874002 r5 : c782fe00 r4 : 00000002
>> r3 : 00000000 r2 : c782fe00 r1 : 00100000 r0 : c8874002
>> Flags: nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none
>> Control: 10c5387d Table: 8020406a DAC: 00000051
>> Process swapper/0 (pid: 1, stack limit = 0xc782e210)
>> Stack: (0xc782fc98 to 0xc7830000)
>> [...]
>
> The WDT_STS (status) needs to be translated via wdt_addr as well.
>
> fixes: f0d9d0f4b44a ("watchdog: qcom: add option for standalone watchdog not in timer block")
> Cc: [email protected] # 4.8
> Signed-off-by: Christian Lamparter <[email protected]>

Reviewed-by: Guenter Roeck <[email protected]>

> ---
> drivers/watchdog/qcom-wdt.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/watchdog/qcom-wdt.c b/drivers/watchdog/qcom-wdt.c
> index 5796b5d..4f47b5e 100644
> --- a/drivers/watchdog/qcom-wdt.c
> +++ b/drivers/watchdog/qcom-wdt.c
> @@ -209,7 +209,7 @@ static int qcom_wdt_probe(struct platform_device *pdev)
> wdt->wdd.parent = &pdev->dev;
> wdt->layout = regs;
>
> - if (readl(wdt->base + WDT_STS) & 1)
> + if (readl(wdt_addr(wdt, WDT_STS)) & 1)
> wdt->wdd.bootstatus = WDIOF_CARDRESET;
>
> /*
>