Re: [PATCH v2 4/4] ARM: OMAP2+: omap_device: fix crash on omap_device removal

2016-07-29 Thread Grygorii Strashko 

On 07/29/2016 08:15 AM, Peter Ujfalusi wrote:

On 07/28/16 20:50, Grygorii Strashko wrote:

Below call chain causes system crash when OMAP device is
removed by calling of_platform_depopulate()/device_del():


Should you swap 3 <-> 4 in the series?
Currently patch 3 will introduce the crash you are fixing in patch 4...


No. The key function here is device_del() - of_device_unregister(), 
which was used previously has the same issue:

  of_device_unregister() -> device_unregister() ->device_del()

In general all these patches are independent and they were created just 
in bugs detection order.






device_del()
- blocking_notifier_call_chain(>bus->p->bus_notifier,
 BUS_NOTIFY_DEL_DEVICE, dev);
  - _omap_device_notifier_call()
- omap_device_delete()
  - od->pdev->archdata.od = NULL;
kfree(od->hwmods);
kfree(od);
  - bus_remove_device()
- device_release_driver()
  - __device_release_driver()
- pm_runtime_get_sync()
   - _od_runtime_resume()
 - omap_hwmod_enable() <- OOPS od's delted already

Backtrace:
Unable to handle kernel NULL pointer dereference at virtual address 000d
pgd = eb10
[000d] *pgd=ad6e1831, *pte=, *ppte=
Internal error: Oops: 17 [#1] PREEMPT SMP ARM
CPU: 1 PID: 1273 Comm: modprobe Not tainted 4.4.15-rt19-00115-ge4d3cd3-dirty #68
Hardware name: Generic DRA74X (Flattened Device Tree)
task: eb1ee800 ti: ec962000 task.ti: ec962000
PC is at omap_device_enable+0x10/0x90
LR is at _od_runtime_resume+0x10/0x24
[...]
[] (omap_device_enable) from [] 
(_od_runtime_resume+0x10/0x24)
[] (_od_runtime_resume) from [] (__rpm_callback+0x20/0x34)
[] (__rpm_callback) from [] (rpm_callback+0x20/0x80)
[] (rpm_callback) from [] (rpm_resume+0x48c/0x964)
[] (rpm_resume) from [] (__pm_runtime_resume+0x60/0x88)
[] (__pm_runtime_resume) from [] 
(__device_release_driver+0x30/0x100)
[] (__device_release_driver) from [] 
(device_release_driver+0x1c/0x28)
[] (device_release_driver) from [] 
(bus_remove_device+0xec/0x144)
[] (bus_remove_device) from [] (device_del+0x10c/0x210)
[] (device_del) from [] (platform_device_del+0x18/0x84)
[] (platform_device_del) from [] 
(platform_device_unregister+0xc/0x20)
[] (platform_device_unregister) from [] 
(of_platform_device_destroy+0x8c/0x90)
[] (of_platform_device_destroy) from [] 
(device_for_each_child+0x4c/0x78)
[] (device_for_each_child) from [] 
(of_platform_depopulate+0x30/0x44)
[] (of_platform_depopulate) from [] (cpsw_remove+0x68/0xf4 
[ti_cpsw])
[] (cpsw_remove [ti_cpsw]) from [] 
(platform_drv_remove+0x24/0x3c)
[] (platform_drv_remove) from [] 
(__device_release_driver+0x84/0x100)
[] (__device_release_driver) from [] 
(driver_detach+0xac/0xb0)
[] (driver_detach) from [] (bus_remove_driver+0x60/0xd4)
[] (bus_remove_driver) from [] 
(SyS_delete_module+0x184/0x20c)
[] (SyS_delete_module) from [] (ret_fast_syscall+0x0/0x1c)
Code: e350 e92d4070 1590630c 01a06000 (e5d6300d)

Hence, fix it by using BUS_NOTIFY_REMOVED_DEVICE event for OMAP device
deletion which is sent when DD has finished processing of device
deletion.

Cc: Tony Lindgren 
Cc: Tero Kristo 
Signed-off-by: Grygorii Strashko 
---
 arch/arm/mach-omap2/omap_device.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/mach-omap2/omap_device.c 
b/arch/arm/mach-omap2/omap_device.c
index f7ff3b9..208f115 100644
--- a/arch/arm/mach-omap2/omap_device.c
+++ b/arch/arm/mach-omap2/omap_device.c
@@ -194,7 +194,7 @@ static int _omap_device_notifier_call(struct notifier_block 
*nb,
int err;

switch (event) {
-   case BUS_NOTIFY_DEL_DEVICE:
+   case BUS_NOTIFY_REMOVED_DEVICE:
if (pdev->archdata.od)
omap_device_delete(pdev->archdata.od);
break;







--
regards,
-grygorii

Re: [PATCH v2 4/4] ARM: OMAP2+: omap_device: fix crash on omap_device removal

2016-07-28 Thread Peter Ujfalusi 
On 07/28/16 20:50, Grygorii Strashko wrote:
> Below call chain causes system crash when OMAP device is
> removed by calling of_platform_depopulate()/device_del():

Should you swap 3 <-> 4 in the series?
Currently patch 3 will introduce the crash you are fixing in patch 4...

> 
> device_del()
> - blocking_notifier_call_chain(>bus->p->bus_notifier,
>BUS_NOTIFY_DEL_DEVICE, dev);
>   - _omap_device_notifier_call()
> - omap_device_delete()
>   - od->pdev->archdata.od = NULL;
>   kfree(od->hwmods);
>   kfree(od);
>   - bus_remove_device()
> - device_release_driver()
>   - __device_release_driver()
>   - pm_runtime_get_sync()
>  - _od_runtime_resume()
>- omap_hwmod_enable() <- OOPS od's delted already
> 
> Backtrace:
> Unable to handle kernel NULL pointer dereference at virtual address 000d
> pgd = eb10
> [000d] *pgd=ad6e1831, *pte=, *ppte=
> Internal error: Oops: 17 [#1] PREEMPT SMP ARM
> CPU: 1 PID: 1273 Comm: modprobe Not tainted 4.4.15-rt19-00115-ge4d3cd3-dirty 
> #68
> Hardware name: Generic DRA74X (Flattened Device Tree)
> task: eb1ee800 ti: ec962000 task.ti: ec962000
> PC is at omap_device_enable+0x10/0x90
> LR is at _od_runtime_resume+0x10/0x24
> [...]
> [] (omap_device_enable) from [] 
> (_od_runtime_resume+0x10/0x24)
> [] (_od_runtime_resume) from [] (__rpm_callback+0x20/0x34)
> [] (__rpm_callback) from [] (rpm_callback+0x20/0x80)
> [] (rpm_callback) from [] (rpm_resume+0x48c/0x964)
> [] (rpm_resume) from [] (__pm_runtime_resume+0x60/0x88)
> [] (__pm_runtime_resume) from [] 
> (__device_release_driver+0x30/0x100)
> [] (__device_release_driver) from [] 
> (device_release_driver+0x1c/0x28)
> [] (device_release_driver) from [] 
> (bus_remove_device+0xec/0x144)
> [] (bus_remove_device) from [] (device_del+0x10c/0x210)
> [] (device_del) from [] (platform_device_del+0x18/0x84)
> [] (platform_device_del) from [] 
> (platform_device_unregister+0xc/0x20)
> [] (platform_device_unregister) from [] 
> (of_platform_device_destroy+0x8c/0x90)
> [] (of_platform_device_destroy) from [] 
> (device_for_each_child+0x4c/0x78)
> [] (device_for_each_child) from [] 
> (of_platform_depopulate+0x30/0x44)
> [] (of_platform_depopulate) from [] 
> (cpsw_remove+0x68/0xf4 [ti_cpsw])
> [] (cpsw_remove [ti_cpsw]) from [] 
> (platform_drv_remove+0x24/0x3c)
> [] (platform_drv_remove) from [] 
> (__device_release_driver+0x84/0x100)
> [] (__device_release_driver) from [] 
> (driver_detach+0xac/0xb0)
> [] (driver_detach) from [] (bus_remove_driver+0x60/0xd4)
> [] (bus_remove_driver) from [] 
> (SyS_delete_module+0x184/0x20c)
> [] (SyS_delete_module) from [] (ret_fast_syscall+0x0/0x1c)
> Code: e350 e92d4070 1590630c 01a06000 (e5d6300d)
> 
> Hence, fix it by using BUS_NOTIFY_REMOVED_DEVICE event for OMAP device
> deletion which is sent when DD has finished processing of device
> deletion.
> 
> Cc: Tony Lindgren 
> Cc: Tero Kristo 
> Signed-off-by: Grygorii Strashko 
> ---
>  arch/arm/mach-omap2/omap_device.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm/mach-omap2/omap_device.c 
> b/arch/arm/mach-omap2/omap_device.c
> index f7ff3b9..208f115 100644
> --- a/arch/arm/mach-omap2/omap_device.c
> +++ b/arch/arm/mach-omap2/omap_device.c
> @@ -194,7 +194,7 @@ static int _omap_device_notifier_call(struct 
> notifier_block *nb,
>   int err;
>  
>   switch (event) {
> - case BUS_NOTIFY_DEL_DEVICE:
> + case BUS_NOTIFY_REMOVED_DEVICE:
>   if (pdev->archdata.od)
>   omap_device_delete(pdev->archdata.od);
>   break;
> 


-- 
Péter

[PATCH v2 4/4] ARM: OMAP2+: omap_device: fix crash on omap_device removal

2016-07-28 Thread Grygorii Strashko 
Below call chain causes system crash when OMAP device is
removed by calling of_platform_depopulate()/device_del():

device_del()
- blocking_notifier_call_chain(>bus->p->bus_notifier,
 BUS_NOTIFY_DEL_DEVICE, dev);
  - _omap_device_notifier_call()
- omap_device_delete()
  - od->pdev->archdata.od = NULL;
kfree(od->hwmods);
kfree(od);
  - bus_remove_device()
- device_release_driver()
  - __device_release_driver()
- pm_runtime_get_sync()
   - _od_runtime_resume()
 - omap_hwmod_enable() <- OOPS od's delted already

Backtrace:
Unable to handle kernel NULL pointer dereference at virtual address 000d
pgd = eb10
[000d] *pgd=ad6e1831, *pte=, *ppte=
Internal error: Oops: 17 [#1] PREEMPT SMP ARM
CPU: 1 PID: 1273 Comm: modprobe Not tainted 4.4.15-rt19-00115-ge4d3cd3-dirty #68
Hardware name: Generic DRA74X (Flattened Device Tree)
task: eb1ee800 ti: ec962000 task.ti: ec962000
PC is at omap_device_enable+0x10/0x90
LR is at _od_runtime_resume+0x10/0x24
[...]
[] (omap_device_enable) from [] 
(_od_runtime_resume+0x10/0x24)
[] (_od_runtime_resume) from [] (__rpm_callback+0x20/0x34)
[] (__rpm_callback) from [] (rpm_callback+0x20/0x80)
[] (rpm_callback) from [] (rpm_resume+0x48c/0x964)
[] (rpm_resume) from [] (__pm_runtime_resume+0x60/0x88)
[] (__pm_runtime_resume) from [] 
(__device_release_driver+0x30/0x100)
[] (__device_release_driver) from [] 
(device_release_driver+0x1c/0x28)
[] (device_release_driver) from [] 
(bus_remove_device+0xec/0x144)
[] (bus_remove_device) from [] (device_del+0x10c/0x210)
[] (device_del) from [] (platform_device_del+0x18/0x84)
[] (platform_device_del) from [] 
(platform_device_unregister+0xc/0x20)
[] (platform_device_unregister) from [] 
(of_platform_device_destroy+0x8c/0x90)
[] (of_platform_device_destroy) from [] 
(device_for_each_child+0x4c/0x78)
[] (device_for_each_child) from [] 
(of_platform_depopulate+0x30/0x44)
[] (of_platform_depopulate) from [] (cpsw_remove+0x68/0xf4 
[ti_cpsw])
[] (cpsw_remove [ti_cpsw]) from [] 
(platform_drv_remove+0x24/0x3c)
[] (platform_drv_remove) from [] 
(__device_release_driver+0x84/0x100)
[] (__device_release_driver) from [] 
(driver_detach+0xac/0xb0)
[] (driver_detach) from [] (bus_remove_driver+0x60/0xd4)
[] (bus_remove_driver) from [] 
(SyS_delete_module+0x184/0x20c)
[] (SyS_delete_module) from [] (ret_fast_syscall+0x0/0x1c)
Code: e350 e92d4070 1590630c 01a06000 (e5d6300d)

Hence, fix it by using BUS_NOTIFY_REMOVED_DEVICE event for OMAP device
deletion which is sent when DD has finished processing of device
deletion.

Cc: Tony Lindgren 
Cc: Tero Kristo 
Signed-off-by: Grygorii Strashko 
---
 arch/arm/mach-omap2/omap_device.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/mach-omap2/omap_device.c 
b/arch/arm/mach-omap2/omap_device.c
index f7ff3b9..208f115 100644
--- a/arch/arm/mach-omap2/omap_device.c
+++ b/arch/arm/mach-omap2/omap_device.c
@@ -194,7 +194,7 @@ static int _omap_device_notifier_call(struct notifier_block 
*nb,
int err;
 
switch (event) {
-   case BUS_NOTIFY_DEL_DEVICE:
+   case BUS_NOTIFY_REMOVED_DEVICE:
if (pdev->archdata.od)
omap_device_delete(pdev->archdata.od);
break;
-- 
2.9.2