* [PATCH v3 1/3] acpi : cpu hot-remove returns error when cpu_down() fails
@ 2012-07-12 11:22 ` Yasuaki Ishimatsu
0 siblings, 0 replies; 26+ messages in thread
From: Yasuaki Ishimatsu @ 2012-07-12 11:22 UTC (permalink / raw)
To: linux-acpi, linux-kernel, lenb, srivatsa.bhat, toshi.kani
Even if cpu_down() fails, acpi_processor_remove() continues to remove the cpu.
But in this case, it should return error number since some process may run on
the cpu. If the cpu has a running process and the cpu is turned the power off,
the system may not work well.
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
---
drivers/acpi/processor_driver.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
Index: linux-3.5-rc4/drivers/acpi/processor_driver.c
===================================================================
--- linux-3.5-rc4.orig/drivers/acpi/processor_driver.c 2012-06-25 04:53:04.000000000 +0900
+++ linux-3.5-rc4/drivers/acpi/processor_driver.c 2012-07-05 21:02:58.711285382 +0900
@@ -610,7 +610,7 @@ err_free_pr:
static int acpi_processor_remove(struct acpi_device *device, int type)
{
struct acpi_processor *pr = NULL;
-
+ int ret;
if (!device || !acpi_driver_data(device))
return -EINVAL;
@@ -621,8 +621,9 @@ static int acpi_processor_remove(struct
goto free;
if (type == ACPI_BUS_REMOVAL_EJECT) {
- if (acpi_processor_handle_eject(pr))
- return -EINVAL;
+ ret = acpi_processor_handle_eject(pr);
+ if (ret)
+ return ret;
}
acpi_processor_power_exit(pr, device);
@@ -841,12 +842,17 @@ static acpi_status acpi_processor_hotadd
static int acpi_processor_handle_eject(struct acpi_processor *pr)
{
- if (cpu_online(pr->id))
- cpu_down(pr->id);
+ int ret;
+
+ if (cpu_online(pr->id)) {
+ ret = cpu_down(pr->id);
+ if (ret)
+ return ret;
+ }
arch_unregister_cpu(pr->id);
acpi_unmap_lsapic(pr->id);
- return (0);
+ return ret;
}
#else
static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr)
^ permalink raw reply [flat|nested] 26+ messages in thread* [PATCH v3 2/3] acpi : prevent cpu from becoming online
2012-07-12 11:22 ` Yasuaki Ishimatsu
@ 2012-07-12 11:27 ` Yasuaki Ishimatsu
-1 siblings, 0 replies; 26+ messages in thread
From: Yasuaki Ishimatsu @ 2012-07-12 11:27 UTC (permalink / raw)
To: linux-acpi, linux-kernel, lenb, srivatsa.bhat, toshi.kani
Even if acpi_processor_handle_eject() offlines cpu, there is a chance
to online the cpu after that. So the patch closes the window by using
get/put_online_cpus().
Why does the patch change _cpu_up() logic?
The patch cares the race of hot-remove cpu and _cpu_up(). If the patch
does not change it, there is the following race.
hot-remove cpu | _cpu_up()
------------------------------------- ------------------------------------
call acpi_processor_handle_eject() |
call cpu_down() |
call get_online_cpus() |
| call cpu_hotplug_begin() and stop here
call arch_unregister_cpu() |
call acpi_unmap_lsapic() |
call put_online_cpus() |
| start and continue _cpu_up()
return acpi_processor_remove() |
continue hot-remove the cpu |
So _cpu_up() can continue to itself. And hot-remove cpu can also continue
itself. If the patch changes _cpu_up() logic, the race disappears as below:
hot-remove cpu | _cpu_up()
-----------------------------------------------------------------------
call acpi_processor_handle_eject() |
call cpu_down() |
call get_online_cpus() |
| call cpu_hotplug_begin() and stop here
call arch_unregister_cpu() |
call acpi_unmap_lsapic() |
cpu's cpu_present is set |
to false by set_cpu_present()|
call put_online_cpus() |
| start _cpu_up()
| check cpu_present() and return -EINVAL
return acpi_processor_remove() |
continue hot-remove the cpu |
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
---
drivers/acpi/processor_driver.c | 14 ++++++++++++++
kernel/cpu.c | 8 +++++---
2 files changed, 19 insertions(+), 3 deletions(-)
Index: linux-3.5-rc6/drivers/acpi/processor_driver.c
===================================================================
--- linux-3.5-rc6.orig/drivers/acpi/processor_driver.c 2012-07-12 20:16:17.985934856 +0900
+++ linux-3.5-rc6/drivers/acpi/processor_driver.c 2012-07-12 20:16:20.122908531 +0900
@@ -850,8 +850,22 @@ static int acpi_processor_handle_eject(s
return ret;
}
+ get_online_cpus();
+ /*
+ * The cpu might become online again at this point. So we check whether
+ * the cpu has been onlined or not. If the cpu became online, it means
+ * that someone wants to use the cpu. So acpi_processor_handle_eject()
+ * returns -EAGAIN.
+ */
+ if (unlikely(cpu_online(pr->id))) {
+ put_online_cpus();
+ printk("Failed to remove CPU %d, since someone onlines it\n"
+ , pr->id);
+ return -EAGAIN;
+ }
arch_unregister_cpu(pr->id);
acpi_unmap_lsapic(pr->id);
+ put_online_cpus();
return ret;
}
#else
Index: linux-3.5-rc6/kernel/cpu.c
===================================================================
--- linux-3.5-rc6.orig/kernel/cpu.c 2012-07-12 20:16:17.985934856 +0900
+++ linux-3.5-rc6/kernel/cpu.c 2012-07-12 20:25:07.940309872 +0900
@@ -343,11 +343,13 @@ static int __cpuinit _cpu_up(unsigned in
unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
struct task_struct *idle;
- if (cpu_online(cpu) || !cpu_present(cpu))
- return -EINVAL;
-
cpu_hotplug_begin();
+ if (cpu_online(cpu) || !cpu_present(cpu)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
idle = idle_thread_get(cpu);
if (IS_ERR(idle)) {
ret = PTR_ERR(idle);
^ permalink raw reply [flat|nested] 26+ messages in thread* [PATCH v3 2/3] acpi : prevent cpu from becoming online
@ 2012-07-12 11:27 ` Yasuaki Ishimatsu
0 siblings, 0 replies; 26+ messages in thread
From: Yasuaki Ishimatsu @ 2012-07-12 11:27 UTC (permalink / raw)
To: linux-acpi, linux-kernel, lenb, srivatsa.bhat, toshi.kani
Even if acpi_processor_handle_eject() offlines cpu, there is a chance
to online the cpu after that. So the patch closes the window by using
get/put_online_cpus().
Why does the patch change _cpu_up() logic?
The patch cares the race of hot-remove cpu and _cpu_up(). If the patch
does not change it, there is the following race.
hot-remove cpu | _cpu_up()
------------------------------------- ------------------------------------
call acpi_processor_handle_eject() |
call cpu_down() |
call get_online_cpus() |
| call cpu_hotplug_begin() and stop here
call arch_unregister_cpu() |
call acpi_unmap_lsapic() |
call put_online_cpus() |
| start and continue _cpu_up()
return acpi_processor_remove() |
continue hot-remove the cpu |
So _cpu_up() can continue to itself. And hot-remove cpu can also continue
itself. If the patch changes _cpu_up() logic, the race disappears as below:
hot-remove cpu | _cpu_up()
-----------------------------------------------------------------------
call acpi_processor_handle_eject() |
call cpu_down() |
call get_online_cpus() |
| call cpu_hotplug_begin() and stop here
call arch_unregister_cpu() |
call acpi_unmap_lsapic() |
cpu's cpu_present is set |
to false by set_cpu_present()|
call put_online_cpus() |
| start _cpu_up()
| check cpu_present() and return -EINVAL
return acpi_processor_remove() |
continue hot-remove the cpu |
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
---
drivers/acpi/processor_driver.c | 14 ++++++++++++++
kernel/cpu.c | 8 +++++---
2 files changed, 19 insertions(+), 3 deletions(-)
Index: linux-3.5-rc6/drivers/acpi/processor_driver.c
===================================================================
--- linux-3.5-rc6.orig/drivers/acpi/processor_driver.c 2012-07-12 20:16:17.985934856 +0900
+++ linux-3.5-rc6/drivers/acpi/processor_driver.c 2012-07-12 20:16:20.122908531 +0900
@@ -850,8 +850,22 @@ static int acpi_processor_handle_eject(s
return ret;
}
+ get_online_cpus();
+ /*
+ * The cpu might become online again at this point. So we check whether
+ * the cpu has been onlined or not. If the cpu became online, it means
+ * that someone wants to use the cpu. So acpi_processor_handle_eject()
+ * returns -EAGAIN.
+ */
+ if (unlikely(cpu_online(pr->id))) {
+ put_online_cpus();
+ printk("Failed to remove CPU %d, since someone onlines it\n"
+ , pr->id);
+ return -EAGAIN;
+ }
arch_unregister_cpu(pr->id);
acpi_unmap_lsapic(pr->id);
+ put_online_cpus();
return ret;
}
#else
Index: linux-3.5-rc6/kernel/cpu.c
===================================================================
--- linux-3.5-rc6.orig/kernel/cpu.c 2012-07-12 20:16:17.985934856 +0900
+++ linux-3.5-rc6/kernel/cpu.c 2012-07-12 20:25:07.940309872 +0900
@@ -343,11 +343,13 @@ static int __cpuinit _cpu_up(unsigned in
unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
struct task_struct *idle;
- if (cpu_online(cpu) || !cpu_present(cpu))
- return -EINVAL;
-
cpu_hotplug_begin();
+ if (cpu_online(cpu) || !cpu_present(cpu)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
idle = idle_thread_get(cpu);
if (IS_ERR(idle)) {
ret = PTR_ERR(idle);
^ permalink raw reply [flat|nested] 26+ messages in thread* [PATCH v3 2/3 RESEND] acpi : prevent cpu from becoming online
2012-07-12 11:27 ` Yasuaki Ishimatsu
@ 2012-07-12 11:40 ` Yasuaki Ishimatsu
-1 siblings, 0 replies; 26+ messages in thread
From: Yasuaki Ishimatsu @ 2012-07-12 11:40 UTC (permalink / raw)
To: linux-acpi, linux-kernel, lenb, srivatsa.bhat, toshi.kani
Even if acpi_processor_handle_eject() offlines cpu, there is a chance
to online the cpu after that. So the patch closes the window by using
get/put_online_cpus().
Why does the patch change _cpu_up() logic?
The patch cares the race of hot-remove cpu and _cpu_up(). If the patch
does not change it, there is the following race.
hot-remove cpu | _cpu_up()
------------------------------------- ------------------------------------
call acpi_processor_handle_eject() |
call cpu_down() |
call get_online_cpus() |
| call cpu_hotplug_begin() and stop here
call arch_unregister_cpu() |
call acpi_unmap_lsapic() |
call put_online_cpus() |
| start and continue _cpu_up()
return acpi_processor_remove() |
continue hot-remove the cpu |
So _cpu_up() can continue to itself. And hot-remove cpu can also continue
itself. If the patch changes _cpu_up() logic, the race disappears as below:
hot-remove cpu | _cpu_up()
-----------------------------------------------------------------------
call acpi_processor_handle_eject() |
call cpu_down() |
call get_online_cpus() |
| call cpu_hotplug_begin() and stop here
call arch_unregister_cpu() |
call acpi_unmap_lsapic() |
cpu's cpu_present is set |
to false by set_cpu_present()|
call put_online_cpus() |
| start _cpu_up()
| check cpu_present() and return -EINVAL
return acpi_processor_remove() |
continue hot-remove the cpu |
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
---
drivers/acpi/processor_driver.c | 14 ++++++++++++++
kernel/cpu.c | 8 +++++---
2 files changed, 19 insertions(+), 3 deletions(-)
Index: linux-3.5-rc6/drivers/acpi/processor_driver.c
===================================================================
--- linux-3.5-rc6.orig/drivers/acpi/processor_driver.c 2012-07-12 20:34:29.438289841 +0900
+++ linux-3.5-rc6/drivers/acpi/processor_driver.c 2012-07-12 20:39:29.190542257 +0900
@@ -850,8 +850,22 @@ static int acpi_processor_handle_eject(s
return ret;
}
+ get_online_cpus();
+ /*
+ * The cpu might become online again at this point. So we check whether
+ * the cpu has been onlined or not. If the cpu became online, it means
+ * that someone wants to use the cpu. So acpi_processor_handle_eject()
+ * returns -EAGAIN.
+ */
+ if (unlikely(cpu_online(pr->id))) {
+ put_online_cpus();
+ printk(KERN_WARNING "Failed to remove CPU %d, "
+ "since someone onlines the cpu\n" , pr->id);
+ return -EAGAIN;
+ }
arch_unregister_cpu(pr->id);
acpi_unmap_lsapic(pr->id);
+ put_online_cpus();
return ret;
}
#else
Index: linux-3.5-rc6/kernel/cpu.c
===================================================================
--- linux-3.5-rc6.orig/kernel/cpu.c 2012-07-12 20:34:29.438289841 +0900
+++ linux-3.5-rc6/kernel/cpu.c 2012-07-12 20:34:35.040219535 +0900
@@ -343,11 +343,13 @@ static int __cpuinit _cpu_up(unsigned in
unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
struct task_struct *idle;
- if (cpu_online(cpu) || !cpu_present(cpu))
- return -EINVAL;
-
cpu_hotplug_begin();
+ if (cpu_online(cpu) || !cpu_present(cpu)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
idle = idle_thread_get(cpu);
if (IS_ERR(idle)) {
ret = PTR_ERR(idle);
^ permalink raw reply [flat|nested] 26+ messages in thread* [PATCH v3 2/3 RESEND] acpi : prevent cpu from becoming online
@ 2012-07-12 11:40 ` Yasuaki Ishimatsu
0 siblings, 0 replies; 26+ messages in thread
From: Yasuaki Ishimatsu @ 2012-07-12 11:40 UTC (permalink / raw)
To: linux-acpi, linux-kernel, lenb, srivatsa.bhat, toshi.kani
Even if acpi_processor_handle_eject() offlines cpu, there is a chance
to online the cpu after that. So the patch closes the window by using
get/put_online_cpus().
Why does the patch change _cpu_up() logic?
The patch cares the race of hot-remove cpu and _cpu_up(). If the patch
does not change it, there is the following race.
hot-remove cpu | _cpu_up()
------------------------------------- ------------------------------------
call acpi_processor_handle_eject() |
call cpu_down() |
call get_online_cpus() |
| call cpu_hotplug_begin() and stop here
call arch_unregister_cpu() |
call acpi_unmap_lsapic() |
call put_online_cpus() |
| start and continue _cpu_up()
return acpi_processor_remove() |
continue hot-remove the cpu |
So _cpu_up() can continue to itself. And hot-remove cpu can also continue
itself. If the patch changes _cpu_up() logic, the race disappears as below:
hot-remove cpu | _cpu_up()
-----------------------------------------------------------------------
call acpi_processor_handle_eject() |
call cpu_down() |
call get_online_cpus() |
| call cpu_hotplug_begin() and stop here
call arch_unregister_cpu() |
call acpi_unmap_lsapic() |
cpu's cpu_present is set |
to false by set_cpu_present()|
call put_online_cpus() |
| start _cpu_up()
| check cpu_present() and return -EINVAL
return acpi_processor_remove() |
continue hot-remove the cpu |
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
---
drivers/acpi/processor_driver.c | 14 ++++++++++++++
kernel/cpu.c | 8 +++++---
2 files changed, 19 insertions(+), 3 deletions(-)
Index: linux-3.5-rc6/drivers/acpi/processor_driver.c
===================================================================
--- linux-3.5-rc6.orig/drivers/acpi/processor_driver.c 2012-07-12 20:34:29.438289841 +0900
+++ linux-3.5-rc6/drivers/acpi/processor_driver.c 2012-07-12 20:39:29.190542257 +0900
@@ -850,8 +850,22 @@ static int acpi_processor_handle_eject(s
return ret;
}
+ get_online_cpus();
+ /*
+ * The cpu might become online again at this point. So we check whether
+ * the cpu has been onlined or not. If the cpu became online, it means
+ * that someone wants to use the cpu. So acpi_processor_handle_eject()
+ * returns -EAGAIN.
+ */
+ if (unlikely(cpu_online(pr->id))) {
+ put_online_cpus();
+ printk(KERN_WARNING "Failed to remove CPU %d, "
+ "since someone onlines the cpu\n" , pr->id);
+ return -EAGAIN;
+ }
arch_unregister_cpu(pr->id);
acpi_unmap_lsapic(pr->id);
+ put_online_cpus();
return ret;
}
#else
Index: linux-3.5-rc6/kernel/cpu.c
===================================================================
--- linux-3.5-rc6.orig/kernel/cpu.c 2012-07-12 20:34:29.438289841 +0900
+++ linux-3.5-rc6/kernel/cpu.c 2012-07-12 20:34:35.040219535 +0900
@@ -343,11 +343,13 @@ static int __cpuinit _cpu_up(unsigned in
unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
struct task_struct *idle;
- if (cpu_online(cpu) || !cpu_present(cpu))
- return -EINVAL;
-
cpu_hotplug_begin();
+ if (cpu_online(cpu) || !cpu_present(cpu)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
idle = idle_thread_get(cpu);
if (IS_ERR(idle)) {
ret = PTR_ERR(idle);
^ permalink raw reply [flat|nested] 26+ messages in thread* Re: [PATCH v3 2/3 RESEND] acpi : prevent cpu from becoming online
2012-07-12 11:40 ` Yasuaki Ishimatsu
(?)
@ 2012-07-12 12:41 ` Srivatsa S. Bhat
2012-07-13 6:24 ` Yasuaki Ishimatsu
-1 siblings, 1 reply; 26+ messages in thread
From: Srivatsa S. Bhat @ 2012-07-12 12:41 UTC (permalink / raw)
To: Yasuaki Ishimatsu; +Cc: linux-acpi, linux-kernel, lenb, toshi.kani
On 07/12/2012 05:10 PM, Yasuaki Ishimatsu wrote:
> Even if acpi_processor_handle_eject() offlines cpu, there is a chance
> to online the cpu after that. So the patch closes the window by using
> get/put_online_cpus().
>
> Why does the patch change _cpu_up() logic?
>
> The patch cares the race of hot-remove cpu and _cpu_up(). If the patch
> does not change it, there is the following race.
>
> hot-remove cpu | _cpu_up()
> ------------------------------------- ------------------------------------
> call acpi_processor_handle_eject() |
> call cpu_down() |
> call get_online_cpus() |
> | call cpu_hotplug_begin() and stop here
> call arch_unregister_cpu() |
> call acpi_unmap_lsapic() |
> call put_online_cpus() |
> | start and continue _cpu_up()
> return acpi_processor_remove() |
> continue hot-remove the cpu |
>
> So _cpu_up() can continue to itself. And hot-remove cpu can also continue
> itself. If the patch changes _cpu_up() logic, the race disappears as below:
>
> hot-remove cpu | _cpu_up()
> -----------------------------------------------------------------------
> call acpi_processor_handle_eject() |
> call cpu_down() |
> call get_online_cpus() |
> | call cpu_hotplug_begin() and stop here
> call arch_unregister_cpu() |
> call acpi_unmap_lsapic() |
> cpu's cpu_present is set |
> to false by set_cpu_present()|
> call put_online_cpus() |
> | start _cpu_up()
> | check cpu_present() and return -EINVAL
> return acpi_processor_remove() |
> continue hot-remove the cpu |
>
> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
>
Please consider fixing the grammar issue below (since it is a user-visible
print statement). Other than that, everything looks fine.
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
> ---
> drivers/acpi/processor_driver.c | 14 ++++++++++++++
> kernel/cpu.c | 8 +++++---
> 2 files changed, 19 insertions(+), 3 deletions(-)
>
> Index: linux-3.5-rc6/drivers/acpi/processor_driver.c
> ===================================================================
> --- linux-3.5-rc6.orig/drivers/acpi/processor_driver.c 2012-07-12 20:34:29.438289841 +0900
> +++ linux-3.5-rc6/drivers/acpi/processor_driver.c 2012-07-12 20:39:29.190542257 +0900
> @@ -850,8 +850,22 @@ static int acpi_processor_handle_eject(s
> return ret;
> }
>
> + get_online_cpus();
> + /*
> + * The cpu might become online again at this point. So we check whether
> + * the cpu has been onlined or not. If the cpu became online, it means
> + * that someone wants to use the cpu. So acpi_processor_handle_eject()
> + * returns -EAGAIN.
> + */
> + if (unlikely(cpu_online(pr->id))) {
> + put_online_cpus();
> + printk(KERN_WARNING "Failed to remove CPU %d, "
> + "since someone onlines the cpu\n" , pr->id);
How about:
"Failed to remove CPU %d, because some other task brought the CPU back online\n"
Regards,
Srivatsa S. Bhat
> + return -EAGAIN;
> + }
> arch_unregister_cpu(pr->id);
> acpi_unmap_lsapic(pr->id);
> + put_online_cpus();
> return ret;
> }
> #else
> Index: linux-3.5-rc6/kernel/cpu.c
> ===================================================================
> --- linux-3.5-rc6.orig/kernel/cpu.c 2012-07-12 20:34:29.438289841 +0900
> +++ linux-3.5-rc6/kernel/cpu.c 2012-07-12 20:34:35.040219535 +0900
> @@ -343,11 +343,13 @@ static int __cpuinit _cpu_up(unsigned in
> unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
> struct task_struct *idle;
>
> - if (cpu_online(cpu) || !cpu_present(cpu))
> - return -EINVAL;
> -
> cpu_hotplug_begin();
>
> + if (cpu_online(cpu) || !cpu_present(cpu)) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> idle = idle_thread_get(cpu);
> if (IS_ERR(idle)) {
> ret = PTR_ERR(idle);
>
^ permalink raw reply [flat|nested] 26+ messages in thread* Re: [PATCH v3 2/3 RESEND] acpi : prevent cpu from becoming online
2012-07-12 12:41 ` Srivatsa S. Bhat
@ 2012-07-13 6:24 ` Yasuaki Ishimatsu
0 siblings, 0 replies; 26+ messages in thread
From: Yasuaki Ishimatsu @ 2012-07-13 6:24 UTC (permalink / raw)
To: Srivatsa S. Bhat; +Cc: linux-acpi, linux-kernel, lenb, toshi.kani
2012/07/12 21:41, Srivatsa S. Bhat wrote:
> On 07/12/2012 05:10 PM, Yasuaki Ishimatsu wrote:
>> Even if acpi_processor_handle_eject() offlines cpu, there is a chance
>> to online the cpu after that. So the patch closes the window by using
>> get/put_online_cpus().
>>
>> Why does the patch change _cpu_up() logic?
>>
>> The patch cares the race of hot-remove cpu and _cpu_up(). If the patch
>> does not change it, there is the following race.
>>
>> hot-remove cpu | _cpu_up()
>> ------------------------------------- ------------------------------------
>> call acpi_processor_handle_eject() |
>> call cpu_down() |
>> call get_online_cpus() |
>> | call cpu_hotplug_begin() and stop here
>> call arch_unregister_cpu() |
>> call acpi_unmap_lsapic() |
>> call put_online_cpus() |
>> | start and continue _cpu_up()
>> return acpi_processor_remove() |
>> continue hot-remove the cpu |
>>
>> So _cpu_up() can continue to itself. And hot-remove cpu can also continue
>> itself. If the patch changes _cpu_up() logic, the race disappears as below:
>>
>> hot-remove cpu | _cpu_up()
>> -----------------------------------------------------------------------
>> call acpi_processor_handle_eject() |
>> call cpu_down() |
>> call get_online_cpus() |
>> | call cpu_hotplug_begin() and stop here
>> call arch_unregister_cpu() |
>> call acpi_unmap_lsapic() |
>> cpu's cpu_present is set |
>> to false by set_cpu_present()|
>> call put_online_cpus() |
>> | start _cpu_up()
>> | check cpu_present() and return -EINVAL
>> return acpi_processor_remove() |
>> continue hot-remove the cpu |
>>
>> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
>>
>
> Please consider fixing the grammar issue below (since it is a user-visible
> print statement). Other than that, everything looks fine.
>
> Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
>
>> ---
>> drivers/acpi/processor_driver.c | 14 ++++++++++++++
>> kernel/cpu.c | 8 +++++---
>> 2 files changed, 19 insertions(+), 3 deletions(-)
>>
>> Index: linux-3.5-rc6/drivers/acpi/processor_driver.c
>> ===================================================================
>> --- linux-3.5-rc6.orig/drivers/acpi/processor_driver.c 2012-07-12 20:34:29.438289841 +0900
>> +++ linux-3.5-rc6/drivers/acpi/processor_driver.c 2012-07-12 20:39:29.190542257 +0900
>> @@ -850,8 +850,22 @@ static int acpi_processor_handle_eject(s
>> return ret;
>> }
>>
>> + get_online_cpus();
>> + /*
>> + * The cpu might become online again at this point. So we check whether
>> + * the cpu has been onlined or not. If the cpu became online, it means
>> + * that someone wants to use the cpu. So acpi_processor_handle_eject()
>> + * returns -EAGAIN.
>> + */
>> + if (unlikely(cpu_online(pr->id))) {
>> + put_online_cpus();
>> + printk(KERN_WARNING "Failed to remove CPU %d, "
>> + "since someone onlines the cpu\n" , pr->id);
>
> How about:
> "Failed to remove CPU %d, because some other task brought the CPU back online\n"
Looks good to me. I'll update it.
Thanks,
Yasuaki Ishimatsu
>
> Regards,
> Srivatsa S. Bhat
>
>> + return -EAGAIN;
>> + }
>> arch_unregister_cpu(pr->id);
>> acpi_unmap_lsapic(pr->id);
>> + put_online_cpus();
>> return ret;
>> }
>> #else
>> Index: linux-3.5-rc6/kernel/cpu.c
>> ===================================================================
>> --- linux-3.5-rc6.orig/kernel/cpu.c 2012-07-12 20:34:29.438289841 +0900
>> +++ linux-3.5-rc6/kernel/cpu.c 2012-07-12 20:34:35.040219535 +0900
>> @@ -343,11 +343,13 @@ static int __cpuinit _cpu_up(unsigned in
>> unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
>> struct task_struct *idle;
>>
>> - if (cpu_online(cpu) || !cpu_present(cpu))
>> - return -EINVAL;
>> -
>> cpu_hotplug_begin();
>>
>> + if (cpu_online(cpu) || !cpu_present(cpu)) {
>> + ret = -EINVAL;
>> + goto out;
>> + }
>> +
>> idle = idle_thread_get(cpu);
>> if (IS_ERR(idle)) {
>> ret = PTR_ERR(idle);
>>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 26+ messages in thread* Re: [PATCH v3 2/3 RESEND] acpi : prevent cpu from becoming online
@ 2012-07-13 6:24 ` Yasuaki Ishimatsu
0 siblings, 0 replies; 26+ messages in thread
From: Yasuaki Ishimatsu @ 2012-07-13 6:24 UTC (permalink / raw)
To: Srivatsa S. Bhat; +Cc: linux-acpi, linux-kernel, lenb, toshi.kani
2012/07/12 21:41, Srivatsa S. Bhat wrote:
> On 07/12/2012 05:10 PM, Yasuaki Ishimatsu wrote:
>> Even if acpi_processor_handle_eject() offlines cpu, there is a chance
>> to online the cpu after that. So the patch closes the window by using
>> get/put_online_cpus().
>>
>> Why does the patch change _cpu_up() logic?
>>
>> The patch cares the race of hot-remove cpu and _cpu_up(). If the patch
>> does not change it, there is the following race.
>>
>> hot-remove cpu | _cpu_up()
>> ------------------------------------- ------------------------------------
>> call acpi_processor_handle_eject() |
>> call cpu_down() |
>> call get_online_cpus() |
>> | call cpu_hotplug_begin() and stop here
>> call arch_unregister_cpu() |
>> call acpi_unmap_lsapic() |
>> call put_online_cpus() |
>> | start and continue _cpu_up()
>> return acpi_processor_remove() |
>> continue hot-remove the cpu |
>>
>> So _cpu_up() can continue to itself. And hot-remove cpu can also continue
>> itself. If the patch changes _cpu_up() logic, the race disappears as below:
>>
>> hot-remove cpu | _cpu_up()
>> -----------------------------------------------------------------------
>> call acpi_processor_handle_eject() |
>> call cpu_down() |
>> call get_online_cpus() |
>> | call cpu_hotplug_begin() and stop here
>> call arch_unregister_cpu() |
>> call acpi_unmap_lsapic() |
>> cpu's cpu_present is set |
>> to false by set_cpu_present()|
>> call put_online_cpus() |
>> | start _cpu_up()
>> | check cpu_present() and return -EINVAL
>> return acpi_processor_remove() |
>> continue hot-remove the cpu |
>>
>> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
>>
>
> Please consider fixing the grammar issue below (since it is a user-visible
> print statement). Other than that, everything looks fine.
>
> Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
>
>> ---
>> drivers/acpi/processor_driver.c | 14 ++++++++++++++
>> kernel/cpu.c | 8 +++++---
>> 2 files changed, 19 insertions(+), 3 deletions(-)
>>
>> Index: linux-3.5-rc6/drivers/acpi/processor_driver.c
>> ===================================================================
>> --- linux-3.5-rc6.orig/drivers/acpi/processor_driver.c 2012-07-12 20:34:29.438289841 +0900
>> +++ linux-3.5-rc6/drivers/acpi/processor_driver.c 2012-07-12 20:39:29.190542257 +0900
>> @@ -850,8 +850,22 @@ static int acpi_processor_handle_eject(s
>> return ret;
>> }
>>
>> + get_online_cpus();
>> + /*
>> + * The cpu might become online again at this point. So we check whether
>> + * the cpu has been onlined or not. If the cpu became online, it means
>> + * that someone wants to use the cpu. So acpi_processor_handle_eject()
>> + * returns -EAGAIN.
>> + */
>> + if (unlikely(cpu_online(pr->id))) {
>> + put_online_cpus();
>> + printk(KERN_WARNING "Failed to remove CPU %d, "
>> + "since someone onlines the cpu\n" , pr->id);
>
> How about:
> "Failed to remove CPU %d, because some other task brought the CPU back online\n"
Looks good to me. I'll update it.
Thanks,
Yasuaki Ishimatsu
>
> Regards,
> Srivatsa S. Bhat
>
>> + return -EAGAIN;
>> + }
>> arch_unregister_cpu(pr->id);
>> acpi_unmap_lsapic(pr->id);
>> + put_online_cpus();
>> return ret;
>> }
>> #else
>> Index: linux-3.5-rc6/kernel/cpu.c
>> ===================================================================
>> --- linux-3.5-rc6.orig/kernel/cpu.c 2012-07-12 20:34:29.438289841 +0900
>> +++ linux-3.5-rc6/kernel/cpu.c 2012-07-12 20:34:35.040219535 +0900
>> @@ -343,11 +343,13 @@ static int __cpuinit _cpu_up(unsigned in
>> unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
>> struct task_struct *idle;
>>
>> - if (cpu_online(cpu) || !cpu_present(cpu))
>> - return -EINVAL;
>> -
>> cpu_hotplug_begin();
>>
>> + if (cpu_online(cpu) || !cpu_present(cpu)) {
>> + ret = -EINVAL;
>> + goto out;
>> + }
>> +
>> idle = idle_thread_get(cpu);
>> if (IS_ERR(idle)) {
>> ret = PTR_ERR(idle);
>>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 26+ messages in thread
* Re: [PATCH v3 2/3 RESEND] acpi : prevent cpu from becoming online
2012-07-12 11:40 ` Yasuaki Ishimatsu
(?)
(?)
@ 2012-07-12 16:49 ` Toshi Kani
2012-07-13 6:27 ` Yasuaki Ishimatsu
-1 siblings, 1 reply; 26+ messages in thread
From: Toshi Kani @ 2012-07-12 16:49 UTC (permalink / raw)
To: Yasuaki Ishimatsu; +Cc: linux-acpi, linux-kernel, lenb, srivatsa.bhat
On Thu, 2012-07-12 at 20:40 +0900, Yasuaki Ishimatsu wrote:
> Even if acpi_processor_handle_eject() offlines cpu, there is a chance
> to online the cpu after that. So the patch closes the window by using
> get/put_online_cpus().
>
> Why does the patch change _cpu_up() logic?
>
> The patch cares the race of hot-remove cpu and _cpu_up(). If the patch
> does not change it, there is the following race.
>
> hot-remove cpu | _cpu_up()
> ------------------------------------- ------------------------------------
> call acpi_processor_handle_eject() |
> call cpu_down() |
> call get_online_cpus() |
> | call cpu_hotplug_begin() and stop here
> call arch_unregister_cpu() |
> call acpi_unmap_lsapic() |
> call put_online_cpus() |
> | start and continue _cpu_up()
> return acpi_processor_remove() |
> continue hot-remove the cpu |
>
> So _cpu_up() can continue to itself. And hot-remove cpu can also continue
> itself. If the patch changes _cpu_up() logic, the race disappears as below:
>
> hot-remove cpu | _cpu_up()
> -----------------------------------------------------------------------
> call acpi_processor_handle_eject() |
> call cpu_down() |
> call get_online_cpus() |
> | call cpu_hotplug_begin() and stop here
> call arch_unregister_cpu() |
> call acpi_unmap_lsapic() |
> cpu's cpu_present is set |
> to false by set_cpu_present()|
> call put_online_cpus() |
> | start _cpu_up()
> | check cpu_present() and return -EINVAL
> return acpi_processor_remove() |
> continue hot-remove the cpu |
>
> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
>
> ---
> drivers/acpi/processor_driver.c | 14 ++++++++++++++
> kernel/cpu.c | 8 +++++---
> 2 files changed, 19 insertions(+), 3 deletions(-)
>
> Index: linux-3.5-rc6/drivers/acpi/processor_driver.c
> ===================================================================
> --- linux-3.5-rc6.orig/drivers/acpi/processor_driver.c 2012-07-12 20:34:29.438289841 +0900
> +++ linux-3.5-rc6/drivers/acpi/processor_driver.c 2012-07-12 20:39:29.190542257 +0900
> @@ -850,8 +850,22 @@ static int acpi_processor_handle_eject(s
> return ret;
> }
>
> + get_online_cpus();
> + /*
> + * The cpu might become online again at this point. So we check whether
> + * the cpu has been onlined or not. If the cpu became online, it means
> + * that someone wants to use the cpu. So acpi_processor_handle_eject()
> + * returns -EAGAIN.
> + */
> + if (unlikely(cpu_online(pr->id))) {
> + put_online_cpus();
> + printk(KERN_WARNING "Failed to remove CPU %d, "
> + "since someone onlines the cpu\n" , pr->id);
pr_warn() should be used per the recent checkpatch change.
Thanks,
-Toshi
> + return -EAGAIN;
> + }
> arch_unregister_cpu(pr->id);
> acpi_unmap_lsapic(pr->id);
> + put_online_cpus();
> return ret;
> }
> #else
> Index: linux-3.5-rc6/kernel/cpu.c
> ===================================================================
> --- linux-3.5-rc6.orig/kernel/cpu.c 2012-07-12 20:34:29.438289841 +0900
> +++ linux-3.5-rc6/kernel/cpu.c 2012-07-12 20:34:35.040219535 +0900
> @@ -343,11 +343,13 @@ static int __cpuinit _cpu_up(unsigned in
> unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
> struct task_struct *idle;
>
> - if (cpu_online(cpu) || !cpu_present(cpu))
> - return -EINVAL;
> -
> cpu_hotplug_begin();
>
> + if (cpu_online(cpu) || !cpu_present(cpu)) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> idle = idle_thread_get(cpu);
> if (IS_ERR(idle)) {
> ret = PTR_ERR(idle);
>
^ permalink raw reply [flat|nested] 26+ messages in thread* Re: [PATCH v3 2/3 RESEND] acpi : prevent cpu from becoming online
2012-07-12 16:49 ` Toshi Kani
@ 2012-07-13 6:27 ` Yasuaki Ishimatsu
0 siblings, 0 replies; 26+ messages in thread
From: Yasuaki Ishimatsu @ 2012-07-13 6:27 UTC (permalink / raw)
To: Toshi Kani; +Cc: linux-acpi, linux-kernel, lenb, srivatsa.bhat
Hi Toshi,
2012/07/13 1:49, Toshi Kani wrote:
> On Thu, 2012-07-12 at 20:40 +0900, Yasuaki Ishimatsu wrote:
>> Even if acpi_processor_handle_eject() offlines cpu, there is a chance
>> to online the cpu after that. So the patch closes the window by using
>> get/put_online_cpus().
>>
>> Why does the patch change _cpu_up() logic?
>>
>> The patch cares the race of hot-remove cpu and _cpu_up(). If the patch
>> does not change it, there is the following race.
>>
>> hot-remove cpu | _cpu_up()
>> ------------------------------------- ------------------------------------
>> call acpi_processor_handle_eject() |
>> call cpu_down() |
>> call get_online_cpus() |
>> | call cpu_hotplug_begin() and stop here
>> call arch_unregister_cpu() |
>> call acpi_unmap_lsapic() |
>> call put_online_cpus() |
>> | start and continue _cpu_up()
>> return acpi_processor_remove() |
>> continue hot-remove the cpu |
>>
>> So _cpu_up() can continue to itself. And hot-remove cpu can also continue
>> itself. If the patch changes _cpu_up() logic, the race disappears as below:
>>
>> hot-remove cpu | _cpu_up()
>> -----------------------------------------------------------------------
>> call acpi_processor_handle_eject() |
>> call cpu_down() |
>> call get_online_cpus() |
>> | call cpu_hotplug_begin() and stop here
>> call arch_unregister_cpu() |
>> call acpi_unmap_lsapic() |
>> cpu's cpu_present is set |
>> to false by set_cpu_present()|
>> call put_online_cpus() |
>> | start _cpu_up()
>> | check cpu_present() and return -EINVAL
>> return acpi_processor_remove() |
>> continue hot-remove the cpu |
>>
>> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
>>
>> ---
>> drivers/acpi/processor_driver.c | 14 ++++++++++++++
>> kernel/cpu.c | 8 +++++---
>> 2 files changed, 19 insertions(+), 3 deletions(-)
>>
>> Index: linux-3.5-rc6/drivers/acpi/processor_driver.c
>> ===================================================================
>> --- linux-3.5-rc6.orig/drivers/acpi/processor_driver.c 2012-07-12 20:34:29.438289841 +0900
>> +++ linux-3.5-rc6/drivers/acpi/processor_driver.c 2012-07-12 20:39:29.190542257 +0900
>> @@ -850,8 +850,22 @@ static int acpi_processor_handle_eject(s
>> return ret;
>> }
>>
>> + get_online_cpus();
>> + /*
>> + * The cpu might become online again at this point. So we check whether
>> + * the cpu has been onlined or not. If the cpu became online, it means
>> + * that someone wants to use the cpu. So acpi_processor_handle_eject()
>> + * returns -EAGAIN.
>> + */
>> + if (unlikely(cpu_online(pr->id))) {
>> + put_online_cpus();
>> + printk(KERN_WARNING "Failed to remove CPU %d, "
>> + "since someone onlines the cpu\n" , pr->id);
>
> pr_warn() should be used per the recent checkpatch change.
O.K. I'll update it.
Thanks,
Yasuaki Ishimatsu
> Thanks,
> -Toshi
>
>> + return -EAGAIN;
>> + }
>> arch_unregister_cpu(pr->id);
>> acpi_unmap_lsapic(pr->id);
>> + put_online_cpus();
>> return ret;
>> }
>> #else
>> Index: linux-3.5-rc6/kernel/cpu.c
>> ===================================================================
>> --- linux-3.5-rc6.orig/kernel/cpu.c 2012-07-12 20:34:29.438289841 +0900
>> +++ linux-3.5-rc6/kernel/cpu.c 2012-07-12 20:34:35.040219535 +0900
>> @@ -343,11 +343,13 @@ static int __cpuinit _cpu_up(unsigned in
>> unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
>> struct task_struct *idle;
>>
>> - if (cpu_online(cpu) || !cpu_present(cpu))
>> - return -EINVAL;
>> -
>> cpu_hotplug_begin();
>>
>> + if (cpu_online(cpu) || !cpu_present(cpu)) {
>> + ret = -EINVAL;
>> + goto out;
>> + }
>> +
>> idle = idle_thread_get(cpu);
>> if (IS_ERR(idle)) {
>> ret = PTR_ERR(idle);
>>
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 26+ messages in thread* Re: [PATCH v3 2/3 RESEND] acpi : prevent cpu from becoming online
@ 2012-07-13 6:27 ` Yasuaki Ishimatsu
0 siblings, 0 replies; 26+ messages in thread
From: Yasuaki Ishimatsu @ 2012-07-13 6:27 UTC (permalink / raw)
To: Toshi Kani; +Cc: linux-acpi, linux-kernel, lenb, srivatsa.bhat
Hi Toshi,
2012/07/13 1:49, Toshi Kani wrote:
> On Thu, 2012-07-12 at 20:40 +0900, Yasuaki Ishimatsu wrote:
>> Even if acpi_processor_handle_eject() offlines cpu, there is a chance
>> to online the cpu after that. So the patch closes the window by using
>> get/put_online_cpus().
>>
>> Why does the patch change _cpu_up() logic?
>>
>> The patch cares the race of hot-remove cpu and _cpu_up(). If the patch
>> does not change it, there is the following race.
>>
>> hot-remove cpu | _cpu_up()
>> ------------------------------------- ------------------------------------
>> call acpi_processor_handle_eject() |
>> call cpu_down() |
>> call get_online_cpus() |
>> | call cpu_hotplug_begin() and stop here
>> call arch_unregister_cpu() |
>> call acpi_unmap_lsapic() |
>> call put_online_cpus() |
>> | start and continue _cpu_up()
>> return acpi_processor_remove() |
>> continue hot-remove the cpu |
>>
>> So _cpu_up() can continue to itself. And hot-remove cpu can also continue
>> itself. If the patch changes _cpu_up() logic, the race disappears as below:
>>
>> hot-remove cpu | _cpu_up()
>> -----------------------------------------------------------------------
>> call acpi_processor_handle_eject() |
>> call cpu_down() |
>> call get_online_cpus() |
>> | call cpu_hotplug_begin() and stop here
>> call arch_unregister_cpu() |
>> call acpi_unmap_lsapic() |
>> cpu's cpu_present is set |
>> to false by set_cpu_present()|
>> call put_online_cpus() |
>> | start _cpu_up()
>> | check cpu_present() and return -EINVAL
>> return acpi_processor_remove() |
>> continue hot-remove the cpu |
>>
>> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
>>
>> ---
>> drivers/acpi/processor_driver.c | 14 ++++++++++++++
>> kernel/cpu.c | 8 +++++---
>> 2 files changed, 19 insertions(+), 3 deletions(-)
>>
>> Index: linux-3.5-rc6/drivers/acpi/processor_driver.c
>> ===================================================================
>> --- linux-3.5-rc6.orig/drivers/acpi/processor_driver.c 2012-07-12 20:34:29.438289841 +0900
>> +++ linux-3.5-rc6/drivers/acpi/processor_driver.c 2012-07-12 20:39:29.190542257 +0900
>> @@ -850,8 +850,22 @@ static int acpi_processor_handle_eject(s
>> return ret;
>> }
>>
>> + get_online_cpus();
>> + /*
>> + * The cpu might become online again at this point. So we check whether
>> + * the cpu has been onlined or not. If the cpu became online, it means
>> + * that someone wants to use the cpu. So acpi_processor_handle_eject()
>> + * returns -EAGAIN.
>> + */
>> + if (unlikely(cpu_online(pr->id))) {
>> + put_online_cpus();
>> + printk(KERN_WARNING "Failed to remove CPU %d, "
>> + "since someone onlines the cpu\n" , pr->id);
>
> pr_warn() should be used per the recent checkpatch change.
O.K. I'll update it.
Thanks,
Yasuaki Ishimatsu
> Thanks,
> -Toshi
>
>> + return -EAGAIN;
>> + }
>> arch_unregister_cpu(pr->id);
>> acpi_unmap_lsapic(pr->id);
>> + put_online_cpus();
>> return ret;
>> }
>> #else
>> Index: linux-3.5-rc6/kernel/cpu.c
>> ===================================================================
>> --- linux-3.5-rc6.orig/kernel/cpu.c 2012-07-12 20:34:29.438289841 +0900
>> +++ linux-3.5-rc6/kernel/cpu.c 2012-07-12 20:34:35.040219535 +0900
>> @@ -343,11 +343,13 @@ static int __cpuinit _cpu_up(unsigned in
>> unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
>> struct task_struct *idle;
>>
>> - if (cpu_online(cpu) || !cpu_present(cpu))
>> - return -EINVAL;
>> -
>> cpu_hotplug_begin();
>>
>> + if (cpu_online(cpu) || !cpu_present(cpu)) {
>> + ret = -EINVAL;
>> + goto out;
>> + }
>> +
>> idle = idle_thread_get(cpu);
>> if (IS_ERR(idle)) {
>> ret = PTR_ERR(idle);
>>
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 26+ messages in thread
* [PATCH v3 3/3] acpi : acpi_bus_trim() stops removing devices when failing to remove the device
2012-07-12 11:22 ` Yasuaki Ishimatsu
@ 2012-07-12 11:28 ` Yasuaki Ishimatsu
-1 siblings, 0 replies; 26+ messages in thread
From: Yasuaki Ishimatsu @ 2012-07-12 11:28 UTC (permalink / raw)
To: linux-acpi, linux-kernel, lenb, srivatsa.bhat, toshi.kani
acpi_bus_trim() stops removing devices, when acpi_bus_remove() return error
number. But acpi_bus_remove() cannot return error number correctly.
acpi_bus_remove() only return -EINVAL, when dev argument is NULL. Thus even if
device cannot be removed correctly, acpi_bus_trim() ignores and continues to
remove devices. acpi_bus_hot_remove_device() uses acpi_bus_trim() for removing
devices. Therefore acpi_bus_hot_remove_device() can send "_EJ0" to firmware,
even if the device is running on the system. In this case, the system cannot
work well. So acpi_bus_trim() should check whether device was removed or not
correctly. The patch adds error check into some functions to remove the device.
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
---
drivers/acpi/scan.c | 15 ++++++++++++---
drivers/base/dd.c | 22 +++++++++++++++++-----
include/linux/device.h | 2 +-
3 files changed, 30 insertions(+), 9 deletions(-)
Index: linux-3.5-rc6/drivers/acpi/scan.c
===================================================================
--- linux-3.5-rc6.orig/drivers/acpi/scan.c 2012-07-12 20:11:37.316443808 +0900
+++ linux-3.5-rc6/drivers/acpi/scan.c 2012-07-12 20:17:17.927185231 +0900
@@ -425,12 +425,17 @@ static int acpi_device_remove(struct dev
{
struct acpi_device *acpi_dev = to_acpi_device(dev);
struct acpi_driver *acpi_drv = acpi_dev->driver;
+ int ret;
if (acpi_drv) {
if (acpi_drv->ops.notify)
acpi_device_remove_notify_handler(acpi_dev);
- if (acpi_drv->ops.remove)
- acpi_drv->ops.remove(acpi_dev, acpi_dev->removal_type);
+ if (acpi_drv->ops.remove) {
+ ret = acpi_drv->ops.remove(acpi_dev,
+ acpi_dev->removal_type);
+ if (ret)
+ return ret;
+ }
}
acpi_dev->driver = NULL;
acpi_dev->driver_data = NULL;
@@ -1208,11 +1213,15 @@ static int acpi_device_set_context(struc
static int acpi_bus_remove(struct acpi_device *dev, int rmdevice)
{
+ int ret;
+
if (!dev)
return -EINVAL;
dev->removal_type = ACPI_BUS_REMOVAL_EJECT;
- device_release_driver(&dev->dev);
+ ret = device_release_driver(&dev->dev);
+ if (ret)
+ return ret;
if (!rmdevice)
return 0;
Index: linux-3.5-rc6/drivers/base/dd.c
===================================================================
--- linux-3.5-rc6.orig/drivers/base/dd.c 2012-07-12 20:11:37.316443808 +0900
+++ linux-3.5-rc6/drivers/base/dd.c 2012-07-12 20:17:17.928185218 +0900
@@ -464,9 +464,10 @@ EXPORT_SYMBOL_GPL(driver_attach);
* __device_release_driver() must be called with @dev lock held.
* When called for a USB interface, @dev->parent lock must be held as well.
*/
-static void __device_release_driver(struct device *dev)
+static int __device_release_driver(struct device *dev)
{
struct device_driver *drv;
+ int ret;
drv = dev->driver;
if (drv) {
@@ -482,9 +483,11 @@ static void __device_release_driver(stru
pm_runtime_put_sync(dev);
if (dev->bus && dev->bus->remove)
- dev->bus->remove(dev);
+ ret = dev->bus->remove(dev);
else if (drv->remove)
- drv->remove(dev);
+ ret = drv->remove(dev);
+ if (ret)
+ goto rollback;
devres_release_all(dev);
dev->driver = NULL;
klist_remove(&dev->p->knode_driver);
@@ -494,6 +497,12 @@ static void __device_release_driver(stru
dev);
}
+
+ return ret;
+
+rollback:
+ driver_sysfs_add(dev);
+ return ret;
}
/**
@@ -503,16 +512,19 @@ static void __device_release_driver(stru
* Manually detach device from driver.
* When called for a USB interface, @dev->parent lock must be held.
*/
-void device_release_driver(struct device *dev)
+int device_release_driver(struct device *dev)
{
+ int ret;
/*
* If anyone calls device_release_driver() recursively from
* within their ->remove callback for the same device, they
* will deadlock right here.
*/
device_lock(dev);
- __device_release_driver(dev);
+ ret = __device_release_driver(dev);
device_unlock(dev);
+
+ return ret;
}
EXPORT_SYMBOL_GPL(device_release_driver);
Index: linux-3.5-rc6/include/linux/device.h
===================================================================
--- linux-3.5-rc6.orig/include/linux/device.h 2012-07-12 20:11:37.317443779 +0900
+++ linux-3.5-rc6/include/linux/device.h 2012-07-12 20:17:17.936185118 +0900
@@ -827,7 +827,7 @@ static inline void *dev_get_platdata(con
* for information on use.
*/
extern int __must_check device_bind_driver(struct device *dev);
-extern void device_release_driver(struct device *dev);
+extern int device_release_driver(struct device *dev);
extern int __must_check device_attach(struct device *dev);
extern int __must_check driver_attach(struct device_driver *drv);
extern int __must_check device_reprobe(struct device *dev);
^ permalink raw reply [flat|nested] 26+ messages in thread* [PATCH v3 3/3] acpi : acpi_bus_trim() stops removing devices when failing to remove the device
@ 2012-07-12 11:28 ` Yasuaki Ishimatsu
0 siblings, 0 replies; 26+ messages in thread
From: Yasuaki Ishimatsu @ 2012-07-12 11:28 UTC (permalink / raw)
To: linux-acpi, linux-kernel, lenb, srivatsa.bhat, toshi.kani
acpi_bus_trim() stops removing devices, when acpi_bus_remove() return error
number. But acpi_bus_remove() cannot return error number correctly.
acpi_bus_remove() only return -EINVAL, when dev argument is NULL. Thus even if
device cannot be removed correctly, acpi_bus_trim() ignores and continues to
remove devices. acpi_bus_hot_remove_device() uses acpi_bus_trim() for removing
devices. Therefore acpi_bus_hot_remove_device() can send "_EJ0" to firmware,
even if the device is running on the system. In this case, the system cannot
work well. So acpi_bus_trim() should check whether device was removed or not
correctly. The patch adds error check into some functions to remove the device.
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
---
drivers/acpi/scan.c | 15 ++++++++++++---
drivers/base/dd.c | 22 +++++++++++++++++-----
include/linux/device.h | 2 +-
3 files changed, 30 insertions(+), 9 deletions(-)
Index: linux-3.5-rc6/drivers/acpi/scan.c
===================================================================
--- linux-3.5-rc6.orig/drivers/acpi/scan.c 2012-07-12 20:11:37.316443808 +0900
+++ linux-3.5-rc6/drivers/acpi/scan.c 2012-07-12 20:17:17.927185231 +0900
@@ -425,12 +425,17 @@ static int acpi_device_remove(struct dev
{
struct acpi_device *acpi_dev = to_acpi_device(dev);
struct acpi_driver *acpi_drv = acpi_dev->driver;
+ int ret;
if (acpi_drv) {
if (acpi_drv->ops.notify)
acpi_device_remove_notify_handler(acpi_dev);
- if (acpi_drv->ops.remove)
- acpi_drv->ops.remove(acpi_dev, acpi_dev->removal_type);
+ if (acpi_drv->ops.remove) {
+ ret = acpi_drv->ops.remove(acpi_dev,
+ acpi_dev->removal_type);
+ if (ret)
+ return ret;
+ }
}
acpi_dev->driver = NULL;
acpi_dev->driver_data = NULL;
@@ -1208,11 +1213,15 @@ static int acpi_device_set_context(struc
static int acpi_bus_remove(struct acpi_device *dev, int rmdevice)
{
+ int ret;
+
if (!dev)
return -EINVAL;
dev->removal_type = ACPI_BUS_REMOVAL_EJECT;
- device_release_driver(&dev->dev);
+ ret = device_release_driver(&dev->dev);
+ if (ret)
+ return ret;
if (!rmdevice)
return 0;
Index: linux-3.5-rc6/drivers/base/dd.c
===================================================================
--- linux-3.5-rc6.orig/drivers/base/dd.c 2012-07-12 20:11:37.316443808 +0900
+++ linux-3.5-rc6/drivers/base/dd.c 2012-07-12 20:17:17.928185218 +0900
@@ -464,9 +464,10 @@ EXPORT_SYMBOL_GPL(driver_attach);
* __device_release_driver() must be called with @dev lock held.
* When called for a USB interface, @dev->parent lock must be held as well.
*/
-static void __device_release_driver(struct device *dev)
+static int __device_release_driver(struct device *dev)
{
struct device_driver *drv;
+ int ret;
drv = dev->driver;
if (drv) {
@@ -482,9 +483,11 @@ static void __device_release_driver(stru
pm_runtime_put_sync(dev);
if (dev->bus && dev->bus->remove)
- dev->bus->remove(dev);
+ ret = dev->bus->remove(dev);
else if (drv->remove)
- drv->remove(dev);
+ ret = drv->remove(dev);
+ if (ret)
+ goto rollback;
devres_release_all(dev);
dev->driver = NULL;
klist_remove(&dev->p->knode_driver);
@@ -494,6 +497,12 @@ static void __device_release_driver(stru
dev);
}
+
+ return ret;
+
+rollback:
+ driver_sysfs_add(dev);
+ return ret;
}
/**
@@ -503,16 +512,19 @@ static void __device_release_driver(stru
* Manually detach device from driver.
* When called for a USB interface, @dev->parent lock must be held.
*/
-void device_release_driver(struct device *dev)
+int device_release_driver(struct device *dev)
{
+ int ret;
/*
* If anyone calls device_release_driver() recursively from
* within their ->remove callback for the same device, they
* will deadlock right here.
*/
device_lock(dev);
- __device_release_driver(dev);
+ ret = __device_release_driver(dev);
device_unlock(dev);
+
+ return ret;
}
EXPORT_SYMBOL_GPL(device_release_driver);
Index: linux-3.5-rc6/include/linux/device.h
===================================================================
--- linux-3.5-rc6.orig/include/linux/device.h 2012-07-12 20:11:37.317443779 +0900
+++ linux-3.5-rc6/include/linux/device.h 2012-07-12 20:17:17.936185118 +0900
@@ -827,7 +827,7 @@ static inline void *dev_get_platdata(con
* for information on use.
*/
extern int __must_check device_bind_driver(struct device *dev);
-extern void device_release_driver(struct device *dev);
+extern int device_release_driver(struct device *dev);
extern int __must_check device_attach(struct device *dev);
extern int __must_check driver_attach(struct device_driver *drv);
extern int __must_check device_reprobe(struct device *dev);
^ permalink raw reply [flat|nested] 26+ messages in thread* Re: [PATCH v3 3/3] acpi : acpi_bus_trim() stops removing devices when failing to remove the device
2012-07-12 11:28 ` Yasuaki Ishimatsu
(?)
@ 2012-07-12 16:50 ` Toshi Kani
2012-07-13 7:16 ` Yasuaki Ishimatsu
-1 siblings, 1 reply; 26+ messages in thread
From: Toshi Kani @ 2012-07-12 16:50 UTC (permalink / raw)
To: Yasuaki Ishimatsu; +Cc: linux-acpi, linux-kernel, lenb, srivatsa.bhat
On Thu, 2012-07-12 at 20:28 +0900, Yasuaki Ishimatsu wrote:
> acpi_bus_trim() stops removing devices, when acpi_bus_remove() return error
> number. But acpi_bus_remove() cannot return error number correctly.
> acpi_bus_remove() only return -EINVAL, when dev argument is NULL. Thus even if
> device cannot be removed correctly, acpi_bus_trim() ignores and continues to
> remove devices. acpi_bus_hot_remove_device() uses acpi_bus_trim() for removing
> devices. Therefore acpi_bus_hot_remove_device() can send "_EJ0" to firmware,
> even if the device is running on the system. In this case, the system cannot
> work well. So acpi_bus_trim() should check whether device was removed or not
> correctly. The patch adds error check into some functions to remove the device.
>
> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
>
> ---
> drivers/acpi/scan.c | 15 ++++++++++++---
> drivers/base/dd.c | 22 +++++++++++++++++-----
> include/linux/device.h | 2 +-
> 3 files changed, 30 insertions(+), 9 deletions(-)
>
> Index: linux-3.5-rc6/drivers/acpi/scan.c
> ===================================================================
> --- linux-3.5-rc6.orig/drivers/acpi/scan.c 2012-07-12 20:11:37.316443808 +0900
> +++ linux-3.5-rc6/drivers/acpi/scan.c 2012-07-12 20:17:17.927185231 +0900
> @@ -425,12 +425,17 @@ static int acpi_device_remove(struct dev
> {
> struct acpi_device *acpi_dev = to_acpi_device(dev);
> struct acpi_driver *acpi_drv = acpi_dev->driver;
> + int ret;
>
> if (acpi_drv) {
> if (acpi_drv->ops.notify)
> acpi_device_remove_notify_handler(acpi_dev);
> - if (acpi_drv->ops.remove)
> - acpi_drv->ops.remove(acpi_dev, acpi_dev->removal_type);
> + if (acpi_drv->ops.remove) {
> + ret = acpi_drv->ops.remove(acpi_dev,
> + acpi_dev->removal_type);
> + if (ret)
> + return ret;
> + }
> }
> acpi_dev->driver = NULL;
> acpi_dev->driver_data = NULL;
> @@ -1208,11 +1213,15 @@ static int acpi_device_set_context(struc
>
> static int acpi_bus_remove(struct acpi_device *dev, int rmdevice)
> {
> + int ret;
> +
> if (!dev)
> return -EINVAL;
>
> dev->removal_type = ACPI_BUS_REMOVAL_EJECT;
> - device_release_driver(&dev->dev);
> + ret = device_release_driver(&dev->dev);
> + if (ret)
> + return ret;
>
> if (!rmdevice)
> return 0;
> Index: linux-3.5-rc6/drivers/base/dd.c
> ===================================================================
> --- linux-3.5-rc6.orig/drivers/base/dd.c 2012-07-12 20:11:37.316443808 +0900
> +++ linux-3.5-rc6/drivers/base/dd.c 2012-07-12 20:17:17.928185218 +0900
> @@ -464,9 +464,10 @@ EXPORT_SYMBOL_GPL(driver_attach);
> * __device_release_driver() must be called with @dev lock held.
> * When called for a USB interface, @dev->parent lock must be held as well.
> */
> -static void __device_release_driver(struct device *dev)
> +static int __device_release_driver(struct device *dev)
> {
> struct device_driver *drv;
> + int ret;
>
> drv = dev->driver;
> if (drv) {
> @@ -482,9 +483,11 @@ static void __device_release_driver(stru
> pm_runtime_put_sync(dev);
>
> if (dev->bus && dev->bus->remove)
> - dev->bus->remove(dev);
> + ret = dev->bus->remove(dev);
> else if (drv->remove)
> - drv->remove(dev);
> + ret = drv->remove(dev);
> + if (ret)
> + goto rollback;
> devres_release_all(dev);
> dev->driver = NULL;
> klist_remove(&dev->p->knode_driver);
> @@ -494,6 +497,12 @@ static void __device_release_driver(stru
> dev);
>
> }
> +
> + return ret;
ret is uninitialized when !drv.
> +
> +rollback:
> + driver_sysfs_add(dev);
> + return ret;
> }
>
> /**
> @@ -503,16 +512,19 @@ static void __device_release_driver(stru
> * Manually detach device from driver.
> * When called for a USB interface, @dev->parent lock must be held.
> */
> -void device_release_driver(struct device *dev)
> +int device_release_driver(struct device *dev)
I agree with this change as driver's remove interface can fail.
However, there are other callers to this function, which do not check
the return value. I suppose there is no impact to the other paths since
you only changed the CPU hotplug path to fail properly, but please
confirm this is the case. I recommend documenting this change to the
change log.
Thanks,
-Toshi
> {
> + int ret;
> /*
> * If anyone calls device_release_driver() recursively from
> * within their ->remove callback for the same device, they
> * will deadlock right here.
> */
> device_lock(dev);
> - __device_release_driver(dev);
> + ret = __device_release_driver(dev);
> device_unlock(dev);
> +
> + return ret;
> }
> EXPORT_SYMBOL_GPL(device_release_driver);
>
> Index: linux-3.5-rc6/include/linux/device.h
> ===================================================================
> --- linux-3.5-rc6.orig/include/linux/device.h 2012-07-12 20:11:37.317443779 +0900
> +++ linux-3.5-rc6/include/linux/device.h 2012-07-12 20:17:17.936185118 +0900
> @@ -827,7 +827,7 @@ static inline void *dev_get_platdata(con
> * for information on use.
> */
> extern int __must_check device_bind_driver(struct device *dev);
> -extern void device_release_driver(struct device *dev);
> +extern int device_release_driver(struct device *dev);
> extern int __must_check device_attach(struct device *dev);
> extern int __must_check driver_attach(struct device_driver *drv);
> extern int __must_check device_reprobe(struct device *dev);
>
^ permalink raw reply [flat|nested] 26+ messages in thread* Re: [PATCH v3 3/3] acpi : acpi_bus_trim() stops removing devices when failing to remove the device
2012-07-12 16:50 ` Toshi Kani
@ 2012-07-13 7:16 ` Yasuaki Ishimatsu
0 siblings, 0 replies; 26+ messages in thread
From: Yasuaki Ishimatsu @ 2012-07-13 7:16 UTC (permalink / raw)
To: Toshi Kani; +Cc: linux-acpi, linux-kernel, lenb, srivatsa.bhat
2012/07/13 1:50, Toshi Kani wrote:
> On Thu, 2012-07-12 at 20:28 +0900, Yasuaki Ishimatsu wrote:
>> acpi_bus_trim() stops removing devices, when acpi_bus_remove() return error
>> number. But acpi_bus_remove() cannot return error number correctly.
>> acpi_bus_remove() only return -EINVAL, when dev argument is NULL. Thus even if
>> device cannot be removed correctly, acpi_bus_trim() ignores and continues to
>> remove devices. acpi_bus_hot_remove_device() uses acpi_bus_trim() for removing
>> devices. Therefore acpi_bus_hot_remove_device() can send "_EJ0" to firmware,
>> even if the device is running on the system. In this case, the system cannot
>> work well. So acpi_bus_trim() should check whether device was removed or not
>> correctly. The patch adds error check into some functions to remove the device.
>>
>> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
>>
>> ---
>> drivers/acpi/scan.c | 15 ++++++++++++---
>> drivers/base/dd.c | 22 +++++++++++++++++-----
>> include/linux/device.h | 2 +-
>> 3 files changed, 30 insertions(+), 9 deletions(-)
>>
>> Index: linux-3.5-rc6/drivers/acpi/scan.c
>> ===================================================================
>> --- linux-3.5-rc6.orig/drivers/acpi/scan.c 2012-07-12 20:11:37.316443808 +0900
>> +++ linux-3.5-rc6/drivers/acpi/scan.c 2012-07-12 20:17:17.927185231 +0900
>> @@ -425,12 +425,17 @@ static int acpi_device_remove(struct dev
>> {
>> struct acpi_device *acpi_dev = to_acpi_device(dev);
>> struct acpi_driver *acpi_drv = acpi_dev->driver;
>> + int ret;
>>
>> if (acpi_drv) {
>> if (acpi_drv->ops.notify)
>> acpi_device_remove_notify_handler(acpi_dev);
>> - if (acpi_drv->ops.remove)
>> - acpi_drv->ops.remove(acpi_dev, acpi_dev->removal_type);
>> + if (acpi_drv->ops.remove) {
>> + ret = acpi_drv->ops.remove(acpi_dev,
>> + acpi_dev->removal_type);
>> + if (ret)
>> + return ret;
>> + }
>> }
>> acpi_dev->driver = NULL;
>> acpi_dev->driver_data = NULL;
>> @@ -1208,11 +1213,15 @@ static int acpi_device_set_context(struc
>>
>> static int acpi_bus_remove(struct acpi_device *dev, int rmdevice)
>> {
>> + int ret;
>> +
>> if (!dev)
>> return -EINVAL;
>>
>> dev->removal_type = ACPI_BUS_REMOVAL_EJECT;
>> - device_release_driver(&dev->dev);
>> + ret = device_release_driver(&dev->dev);
>> + if (ret)
>> + return ret;
>>
>> if (!rmdevice)
>> return 0;
>> Index: linux-3.5-rc6/drivers/base/dd.c
>> ===================================================================
>> --- linux-3.5-rc6.orig/drivers/base/dd.c 2012-07-12 20:11:37.316443808 +0900
>> +++ linux-3.5-rc6/drivers/base/dd.c 2012-07-12 20:17:17.928185218 +0900
>> @@ -464,9 +464,10 @@ EXPORT_SYMBOL_GPL(driver_attach);
>> * __device_release_driver() must be called with @dev lock held.
>> * When called for a USB interface, @dev->parent lock must be held as well.
>> */
>> -static void __device_release_driver(struct device *dev)
>> +static int __device_release_driver(struct device *dev)
>> {
>> struct device_driver *drv;
>> + int ret;
>>
>> drv = dev->driver;
>> if (drv) {
>> @@ -482,9 +483,11 @@ static void __device_release_driver(stru
>> pm_runtime_put_sync(dev);
>>
>> if (dev->bus && dev->bus->remove)
>> - dev->bus->remove(dev);
>> + ret = dev->bus->remove(dev);
>> else if (drv->remove)
>> - drv->remove(dev);
>> + ret = drv->remove(dev);
>> + if (ret)
>> + goto rollback;
>> devres_release_all(dev);
>> dev->driver = NULL;
>> klist_remove(&dev->p->knode_driver);
>> @@ -494,6 +497,12 @@ static void __device_release_driver(stru
>> dev);
>>
>> }
>> +
>> + return ret;
>
> ret is uninitialized when !drv.
Thanks! I'll update it.
>
>> +
>> +rollback:
>> + driver_sysfs_add(dev);
>> + return ret;
>> }
>>
>> /**
>> @@ -503,16 +512,19 @@ static void __device_release_driver(stru
>> * Manually detach device from driver.
>> * When called for a USB interface, @dev->parent lock must be held.
>> */
>> -void device_release_driver(struct device *dev)
>> +int device_release_driver(struct device *dev)
>
> I agree with this change as driver's remove interface can fail.
> However, there are other callers to this function, which do not check
> the return value. I suppose there is no impact to the other paths since
> you only changed the CPU hotplug path to fail properly, but please
> confirm this is the case. I recommend documenting this change to the
> change log.
Thank you for your agreement. As you know, there are other callers. I
believe the patch does not impact to them, since all of them does not
check return value of device_release_driver().
I will write it to the patch.
Thanks,
Yasuaki Ishimatsu
> Thanks,
> -Toshi
>
>
>> {
>> + int ret;
>> /*
>> * If anyone calls device_release_driver() recursively from
>> * within their ->remove callback for the same device, they
>> * will deadlock right here.
>> */
>> device_lock(dev);
>> - __device_release_driver(dev);
>> + ret = __device_release_driver(dev);
>> device_unlock(dev);
>> +
>> + return ret;
>> }
>> EXPORT_SYMBOL_GPL(device_release_driver);
>>
>> Index: linux-3.5-rc6/include/linux/device.h
>> ===================================================================
>> --- linux-3.5-rc6.orig/include/linux/device.h 2012-07-12 20:11:37.317443779 +0900
>> +++ linux-3.5-rc6/include/linux/device.h 2012-07-12 20:17:17.936185118 +0900
>> @@ -827,7 +827,7 @@ static inline void *dev_get_platdata(con
>> * for information on use.
>> */
>> extern int __must_check device_bind_driver(struct device *dev);
>> -extern void device_release_driver(struct device *dev);
>> +extern int device_release_driver(struct device *dev);
>> extern int __must_check device_attach(struct device *dev);
>> extern int __must_check driver_attach(struct device_driver *drv);
>> extern int __must_check device_reprobe(struct device *dev);
>>
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 26+ messages in thread* Re: [PATCH v3 3/3] acpi : acpi_bus_trim() stops removing devices when failing to remove the device
@ 2012-07-13 7:16 ` Yasuaki Ishimatsu
0 siblings, 0 replies; 26+ messages in thread
From: Yasuaki Ishimatsu @ 2012-07-13 7:16 UTC (permalink / raw)
To: Toshi Kani; +Cc: linux-acpi, linux-kernel, lenb, srivatsa.bhat
2012/07/13 1:50, Toshi Kani wrote:
> On Thu, 2012-07-12 at 20:28 +0900, Yasuaki Ishimatsu wrote:
>> acpi_bus_trim() stops removing devices, when acpi_bus_remove() return error
>> number. But acpi_bus_remove() cannot return error number correctly.
>> acpi_bus_remove() only return -EINVAL, when dev argument is NULL. Thus even if
>> device cannot be removed correctly, acpi_bus_trim() ignores and continues to
>> remove devices. acpi_bus_hot_remove_device() uses acpi_bus_trim() for removing
>> devices. Therefore acpi_bus_hot_remove_device() can send "_EJ0" to firmware,
>> even if the device is running on the system. In this case, the system cannot
>> work well. So acpi_bus_trim() should check whether device was removed or not
>> correctly. The patch adds error check into some functions to remove the device.
>>
>> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
>>
>> ---
>> drivers/acpi/scan.c | 15 ++++++++++++---
>> drivers/base/dd.c | 22 +++++++++++++++++-----
>> include/linux/device.h | 2 +-
>> 3 files changed, 30 insertions(+), 9 deletions(-)
>>
>> Index: linux-3.5-rc6/drivers/acpi/scan.c
>> ===================================================================
>> --- linux-3.5-rc6.orig/drivers/acpi/scan.c 2012-07-12 20:11:37.316443808 +0900
>> +++ linux-3.5-rc6/drivers/acpi/scan.c 2012-07-12 20:17:17.927185231 +0900
>> @@ -425,12 +425,17 @@ static int acpi_device_remove(struct dev
>> {
>> struct acpi_device *acpi_dev = to_acpi_device(dev);
>> struct acpi_driver *acpi_drv = acpi_dev->driver;
>> + int ret;
>>
>> if (acpi_drv) {
>> if (acpi_drv->ops.notify)
>> acpi_device_remove_notify_handler(acpi_dev);
>> - if (acpi_drv->ops.remove)
>> - acpi_drv->ops.remove(acpi_dev, acpi_dev->removal_type);
>> + if (acpi_drv->ops.remove) {
>> + ret = acpi_drv->ops.remove(acpi_dev,
>> + acpi_dev->removal_type);
>> + if (ret)
>> + return ret;
>> + }
>> }
>> acpi_dev->driver = NULL;
>> acpi_dev->driver_data = NULL;
>> @@ -1208,11 +1213,15 @@ static int acpi_device_set_context(struc
>>
>> static int acpi_bus_remove(struct acpi_device *dev, int rmdevice)
>> {
>> + int ret;
>> +
>> if (!dev)
>> return -EINVAL;
>>
>> dev->removal_type = ACPI_BUS_REMOVAL_EJECT;
>> - device_release_driver(&dev->dev);
>> + ret = device_release_driver(&dev->dev);
>> + if (ret)
>> + return ret;
>>
>> if (!rmdevice)
>> return 0;
>> Index: linux-3.5-rc6/drivers/base/dd.c
>> ===================================================================
>> --- linux-3.5-rc6.orig/drivers/base/dd.c 2012-07-12 20:11:37.316443808 +0900
>> +++ linux-3.5-rc6/drivers/base/dd.c 2012-07-12 20:17:17.928185218 +0900
>> @@ -464,9 +464,10 @@ EXPORT_SYMBOL_GPL(driver_attach);
>> * __device_release_driver() must be called with @dev lock held.
>> * When called for a USB interface, @dev->parent lock must be held as well.
>> */
>> -static void __device_release_driver(struct device *dev)
>> +static int __device_release_driver(struct device *dev)
>> {
>> struct device_driver *drv;
>> + int ret;
>>
>> drv = dev->driver;
>> if (drv) {
>> @@ -482,9 +483,11 @@ static void __device_release_driver(stru
>> pm_runtime_put_sync(dev);
>>
>> if (dev->bus && dev->bus->remove)
>> - dev->bus->remove(dev);
>> + ret = dev->bus->remove(dev);
>> else if (drv->remove)
>> - drv->remove(dev);
>> + ret = drv->remove(dev);
>> + if (ret)
>> + goto rollback;
>> devres_release_all(dev);
>> dev->driver = NULL;
>> klist_remove(&dev->p->knode_driver);
>> @@ -494,6 +497,12 @@ static void __device_release_driver(stru
>> dev);
>>
>> }
>> +
>> + return ret;
>
> ret is uninitialized when !drv.
Thanks! I'll update it.
>
>> +
>> +rollback:
>> + driver_sysfs_add(dev);
>> + return ret;
>> }
>>
>> /**
>> @@ -503,16 +512,19 @@ static void __device_release_driver(stru
>> * Manually detach device from driver.
>> * When called for a USB interface, @dev->parent lock must be held.
>> */
>> -void device_release_driver(struct device *dev)
>> +int device_release_driver(struct device *dev)
>
> I agree with this change as driver's remove interface can fail.
> However, there are other callers to this function, which do not check
> the return value. I suppose there is no impact to the other paths since
> you only changed the CPU hotplug path to fail properly, but please
> confirm this is the case. I recommend documenting this change to the
> change log.
Thank you for your agreement. As you know, there are other callers. I
believe the patch does not impact to them, since all of them does not
check return value of device_release_driver().
I will write it to the patch.
Thanks,
Yasuaki Ishimatsu
> Thanks,
> -Toshi
>
>
>> {
>> + int ret;
>> /*
>> * If anyone calls device_release_driver() recursively from
>> * within their ->remove callback for the same device, they
>> * will deadlock right here.
>> */
>> device_lock(dev);
>> - __device_release_driver(dev);
>> + ret = __device_release_driver(dev);
>> device_unlock(dev);
>> +
>> + return ret;
>> }
>> EXPORT_SYMBOL_GPL(device_release_driver);
>>
>> Index: linux-3.5-rc6/include/linux/device.h
>> ===================================================================
>> --- linux-3.5-rc6.orig/include/linux/device.h 2012-07-12 20:11:37.317443779 +0900
>> +++ linux-3.5-rc6/include/linux/device.h 2012-07-12 20:17:17.936185118 +0900
>> @@ -827,7 +827,7 @@ static inline void *dev_get_platdata(con
>> * for information on use.
>> */
>> extern int __must_check device_bind_driver(struct device *dev);
>> -extern void device_release_driver(struct device *dev);
>> +extern int device_release_driver(struct device *dev);
>> extern int __must_check device_attach(struct device *dev);
>> extern int __must_check driver_attach(struct device_driver *drv);
>> extern int __must_check device_reprobe(struct device *dev);
>>
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 26+ messages in thread
* Re: [PATCH v3 3/3] acpi : acpi_bus_trim() stops removing devices when failing to remove the device
2012-07-12 11:28 ` Yasuaki Ishimatsu
(?)
(?)
@ 2012-10-09 8:02 ` Wen Congyang
2012-10-09 8:24 ` Yasuaki Ishimatsu
-1 siblings, 1 reply; 26+ messages in thread
From: Wen Congyang @ 2012-10-09 8:02 UTC (permalink / raw)
To: Yasuaki Ishimatsu
Cc: linux-acpi, linux-kernel, lenb, srivatsa.bhat, toshi.kani
Hi, ishimatsu:
At 07/12/2012 07:28 PM, Yasuaki Ishimatsu Wrote:
> acpi_bus_trim() stops removing devices, when acpi_bus_remove() return error
> number. But acpi_bus_remove() cannot return error number correctly.
> acpi_bus_remove() only return -EINVAL, when dev argument is NULL. Thus even if
> device cannot be removed correctly, acpi_bus_trim() ignores and continues to
> remove devices. acpi_bus_hot_remove_device() uses acpi_bus_trim() for removing
> devices. Therefore acpi_bus_hot_remove_device() can send "_EJ0" to firmware,
> even if the device is running on the system. In this case, the system cannot
> work well. So acpi_bus_trim() should check whether device was removed or not
> correctly. The patch adds error check into some functions to remove the device.
What is the status about this patch?
Vasilis Liaskovitis found a similar bug about the memory hotplug, and this patch
can fix this problem:
https://lkml.org/lkml/2012/9/26/318
Thanks
Wen Congyang
>
> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
>
> ---
> drivers/acpi/scan.c | 15 ++++++++++++---
> drivers/base/dd.c | 22 +++++++++++++++++-----
> include/linux/device.h | 2 +-
> 3 files changed, 30 insertions(+), 9 deletions(-)
>
> Index: linux-3.5-rc6/drivers/acpi/scan.c
> ===================================================================
> --- linux-3.5-rc6.orig/drivers/acpi/scan.c 2012-07-12 20:11:37.316443808 +0900
> +++ linux-3.5-rc6/drivers/acpi/scan.c 2012-07-12 20:17:17.927185231 +0900
> @@ -425,12 +425,17 @@ static int acpi_device_remove(struct dev
> {
> struct acpi_device *acpi_dev = to_acpi_device(dev);
> struct acpi_driver *acpi_drv = acpi_dev->driver;
> + int ret;
>
> if (acpi_drv) {
> if (acpi_drv->ops.notify)
> acpi_device_remove_notify_handler(acpi_dev);
> - if (acpi_drv->ops.remove)
> - acpi_drv->ops.remove(acpi_dev, acpi_dev->removal_type);
> + if (acpi_drv->ops.remove) {
> + ret = acpi_drv->ops.remove(acpi_dev,
> + acpi_dev->removal_type);
> + if (ret)
> + return ret;
> + }
> }
> acpi_dev->driver = NULL;
> acpi_dev->driver_data = NULL;
> @@ -1208,11 +1213,15 @@ static int acpi_device_set_context(struc
>
> static int acpi_bus_remove(struct acpi_device *dev, int rmdevice)
> {
> + int ret;
> +
> if (!dev)
> return -EINVAL;
>
> dev->removal_type = ACPI_BUS_REMOVAL_EJECT;
> - device_release_driver(&dev->dev);
> + ret = device_release_driver(&dev->dev);
> + if (ret)
> + return ret;
>
> if (!rmdevice)
> return 0;
> Index: linux-3.5-rc6/drivers/base/dd.c
> ===================================================================
> --- linux-3.5-rc6.orig/drivers/base/dd.c 2012-07-12 20:11:37.316443808 +0900
> +++ linux-3.5-rc6/drivers/base/dd.c 2012-07-12 20:17:17.928185218 +0900
> @@ -464,9 +464,10 @@ EXPORT_SYMBOL_GPL(driver_attach);
> * __device_release_driver() must be called with @dev lock held.
> * When called for a USB interface, @dev->parent lock must be held as well.
> */
> -static void __device_release_driver(struct device *dev)
> +static int __device_release_driver(struct device *dev)
> {
> struct device_driver *drv;
> + int ret;
>
> drv = dev->driver;
> if (drv) {
> @@ -482,9 +483,11 @@ static void __device_release_driver(stru
> pm_runtime_put_sync(dev);
>
> if (dev->bus && dev->bus->remove)
> - dev->bus->remove(dev);
> + ret = dev->bus->remove(dev);
> else if (drv->remove)
> - drv->remove(dev);
> + ret = drv->remove(dev);
> + if (ret)
> + goto rollback;
> devres_release_all(dev);
> dev->driver = NULL;
> klist_remove(&dev->p->knode_driver);
> @@ -494,6 +497,12 @@ static void __device_release_driver(stru
> dev);
>
> }
> +
> + return ret;
> +
> +rollback:
> + driver_sysfs_add(dev);
> + return ret;
> }
>
> /**
> @@ -503,16 +512,19 @@ static void __device_release_driver(stru
> * Manually detach device from driver.
> * When called for a USB interface, @dev->parent lock must be held.
> */
> -void device_release_driver(struct device *dev)
> +int device_release_driver(struct device *dev)
> {
> + int ret;
> /*
> * If anyone calls device_release_driver() recursively from
> * within their ->remove callback for the same device, they
> * will deadlock right here.
> */
> device_lock(dev);
> - __device_release_driver(dev);
> + ret = __device_release_driver(dev);
> device_unlock(dev);
> +
> + return ret;
> }
> EXPORT_SYMBOL_GPL(device_release_driver);
>
> Index: linux-3.5-rc6/include/linux/device.h
> ===================================================================
> --- linux-3.5-rc6.orig/include/linux/device.h 2012-07-12 20:11:37.317443779 +0900
> +++ linux-3.5-rc6/include/linux/device.h 2012-07-12 20:17:17.936185118 +0900
> @@ -827,7 +827,7 @@ static inline void *dev_get_platdata(con
> * for information on use.
> */
> extern int __must_check device_bind_driver(struct device *dev);
> -extern void device_release_driver(struct device *dev);
> +extern int device_release_driver(struct device *dev);
> extern int __must_check device_attach(struct device *dev);
> extern int __must_check driver_attach(struct device_driver *drv);
> extern int __must_check device_reprobe(struct device *dev);
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
>
^ permalink raw reply [flat|nested] 26+ messages in thread* Re: [PATCH v3 3/3] acpi : acpi_bus_trim() stops removing devices when failing to remove the device
2012-10-09 8:02 ` Wen Congyang
@ 2012-10-09 8:24 ` Yasuaki Ishimatsu
0 siblings, 0 replies; 26+ messages in thread
From: Yasuaki Ishimatsu @ 2012-10-09 8:24 UTC (permalink / raw)
To: Wen Congyang; +Cc: linux-acpi, linux-kernel, lenb, srivatsa.bhat, toshi.kani
Hi Wen,
2012/10/09 17:02, Wen Congyang wrote:
> Hi, ishimatsu:
>
> At 07/12/2012 07:28 PM, Yasuaki Ishimatsu Wrote:
>> acpi_bus_trim() stops removing devices, when acpi_bus_remove() return error
>> number. But acpi_bus_remove() cannot return error number correctly.
>> acpi_bus_remove() only return -EINVAL, when dev argument is NULL. Thus even if
>> device cannot be removed correctly, acpi_bus_trim() ignores and continues to
>> remove devices. acpi_bus_hot_remove_device() uses acpi_bus_trim() for removing
>> devices. Therefore acpi_bus_hot_remove_device() can send "_EJ0" to firmware,
>> even if the device is running on the system. In this case, the system cannot
>> work well. So acpi_bus_trim() should check whether device was removed or not
>> correctly. The patch adds error check into some functions to remove the device.
>
> What is the status about this patch?
I need to update the description against Toshi's comment as follows:
"I agree with this change as driver's remove interface can fail.
However, there are other callers to this function, which do not check
the return value. I suppose there is no impact to the other paths since
you only changed the CPU hotplug path to fail properly, but please
confirm this is the case. I recommend documenting this change to the
change log."
I have already checked that the patch does not impact the other path
with the exception of CPU and Memory hotplug path. So I will adds the
result of investigation and following Vasislis's problem into the patch
and resend to lklml.
> Vasilis Liaskovitis found a similar bug about the memory hotplug, and this patch
> can fix this problem:
> https://lkml.org/lkml/2012/9/26/318
Thanks,
Yasuaki Ishimatsu
>
> Thanks
> Wen Congyang
>>
>> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
>>
>> ---
>> drivers/acpi/scan.c | 15 ++++++++++++---
>> drivers/base/dd.c | 22 +++++++++++++++++-----
>> include/linux/device.h | 2 +-
>> 3 files changed, 30 insertions(+), 9 deletions(-)
>>
>> Index: linux-3.5-rc6/drivers/acpi/scan.c
>> ===================================================================
>> --- linux-3.5-rc6.orig/drivers/acpi/scan.c 2012-07-12 20:11:37.316443808 +0900
>> +++ linux-3.5-rc6/drivers/acpi/scan.c 2012-07-12 20:17:17.927185231 +0900
>> @@ -425,12 +425,17 @@ static int acpi_device_remove(struct dev
>> {
>> struct acpi_device *acpi_dev = to_acpi_device(dev);
>> struct acpi_driver *acpi_drv = acpi_dev->driver;
>> + int ret;
>>
>> if (acpi_drv) {
>> if (acpi_drv->ops.notify)
>> acpi_device_remove_notify_handler(acpi_dev);
>> - if (acpi_drv->ops.remove)
>> - acpi_drv->ops.remove(acpi_dev, acpi_dev->removal_type);
>> + if (acpi_drv->ops.remove) {
>> + ret = acpi_drv->ops.remove(acpi_dev,
>> + acpi_dev->removal_type);
>> + if (ret)
>> + return ret;
>> + }
>> }
>> acpi_dev->driver = NULL;
>> acpi_dev->driver_data = NULL;
>> @@ -1208,11 +1213,15 @@ static int acpi_device_set_context(struc
>>
>> static int acpi_bus_remove(struct acpi_device *dev, int rmdevice)
>> {
>> + int ret;
>> +
>> if (!dev)
>> return -EINVAL;
>>
>> dev->removal_type = ACPI_BUS_REMOVAL_EJECT;
>> - device_release_driver(&dev->dev);
>> + ret = device_release_driver(&dev->dev);
>> + if (ret)
>> + return ret;
>>
>> if (!rmdevice)
>> return 0;
>> Index: linux-3.5-rc6/drivers/base/dd.c
>> ===================================================================
>> --- linux-3.5-rc6.orig/drivers/base/dd.c 2012-07-12 20:11:37.316443808 +0900
>> +++ linux-3.5-rc6/drivers/base/dd.c 2012-07-12 20:17:17.928185218 +0900
>> @@ -464,9 +464,10 @@ EXPORT_SYMBOL_GPL(driver_attach);
>> * __device_release_driver() must be called with @dev lock held.
>> * When called for a USB interface, @dev->parent lock must be held as well.
>> */
>> -static void __device_release_driver(struct device *dev)
>> +static int __device_release_driver(struct device *dev)
>> {
>> struct device_driver *drv;
>> + int ret;
>>
>> drv = dev->driver;
>> if (drv) {
>> @@ -482,9 +483,11 @@ static void __device_release_driver(stru
>> pm_runtime_put_sync(dev);
>>
>> if (dev->bus && dev->bus->remove)
>> - dev->bus->remove(dev);
>> + ret = dev->bus->remove(dev);
>> else if (drv->remove)
>> - drv->remove(dev);
>> + ret = drv->remove(dev);
>> + if (ret)
>> + goto rollback;
>> devres_release_all(dev);
>> dev->driver = NULL;
>> klist_remove(&dev->p->knode_driver);
>> @@ -494,6 +497,12 @@ static void __device_release_driver(stru
>> dev);
>>
>> }
>> +
>> + return ret;
>> +
>> +rollback:
>> + driver_sysfs_add(dev);
>> + return ret;
>> }
>>
>> /**
>> @@ -503,16 +512,19 @@ static void __device_release_driver(stru
>> * Manually detach device from driver.
>> * When called for a USB interface, @dev->parent lock must be held.
>> */
>> -void device_release_driver(struct device *dev)
>> +int device_release_driver(struct device *dev)
>> {
>> + int ret;
>> /*
>> * If anyone calls device_release_driver() recursively from
>> * within their ->remove callback for the same device, they
>> * will deadlock right here.
>> */
>> device_lock(dev);
>> - __device_release_driver(dev);
>> + ret = __device_release_driver(dev);
>> device_unlock(dev);
>> +
>> + return ret;
>> }
>> EXPORT_SYMBOL_GPL(device_release_driver);
>>
>> Index: linux-3.5-rc6/include/linux/device.h
>> ===================================================================
>> --- linux-3.5-rc6.orig/include/linux/device.h 2012-07-12 20:11:37.317443779 +0900
>> +++ linux-3.5-rc6/include/linux/device.h 2012-07-12 20:17:17.936185118 +0900
>> @@ -827,7 +827,7 @@ static inline void *dev_get_platdata(con
>> * for information on use.
>> */
>> extern int __must_check device_bind_driver(struct device *dev);
>> -extern void device_release_driver(struct device *dev);
>> +extern int device_release_driver(struct device *dev);
>> extern int __must_check device_attach(struct device *dev);
>> extern int __must_check driver_attach(struct device_driver *drv);
>> extern int __must_check device_reprobe(struct device *dev);
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>> Please read the FAQ at http://www.tux.org/lkml/
>>
>
^ permalink raw reply [flat|nested] 26+ messages in thread* Re: [PATCH v3 3/3] acpi : acpi_bus_trim() stops removing devices when failing to remove the device
@ 2012-10-09 8:24 ` Yasuaki Ishimatsu
0 siblings, 0 replies; 26+ messages in thread
From: Yasuaki Ishimatsu @ 2012-10-09 8:24 UTC (permalink / raw)
To: Wen Congyang; +Cc: linux-acpi, linux-kernel, lenb, srivatsa.bhat, toshi.kani
Hi Wen,
2012/10/09 17:02, Wen Congyang wrote:
> Hi, ishimatsu:
>
> At 07/12/2012 07:28 PM, Yasuaki Ishimatsu Wrote:
>> acpi_bus_trim() stops removing devices, when acpi_bus_remove() return error
>> number. But acpi_bus_remove() cannot return error number correctly.
>> acpi_bus_remove() only return -EINVAL, when dev argument is NULL. Thus even if
>> device cannot be removed correctly, acpi_bus_trim() ignores and continues to
>> remove devices. acpi_bus_hot_remove_device() uses acpi_bus_trim() for removing
>> devices. Therefore acpi_bus_hot_remove_device() can send "_EJ0" to firmware,
>> even if the device is running on the system. In this case, the system cannot
>> work well. So acpi_bus_trim() should check whether device was removed or not
>> correctly. The patch adds error check into some functions to remove the device.
>
> What is the status about this patch?
I need to update the description against Toshi's comment as follows:
"I agree with this change as driver's remove interface can fail.
However, there are other callers to this function, which do not check
the return value. I suppose there is no impact to the other paths since
you only changed the CPU hotplug path to fail properly, but please
confirm this is the case. I recommend documenting this change to the
change log."
I have already checked that the patch does not impact the other path
with the exception of CPU and Memory hotplug path. So I will adds the
result of investigation and following Vasislis's problem into the patch
and resend to lklml.
> Vasilis Liaskovitis found a similar bug about the memory hotplug, and this patch
> can fix this problem:
> https://lkml.org/lkml/2012/9/26/318
Thanks,
Yasuaki Ishimatsu
>
> Thanks
> Wen Congyang
>>
>> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
>>
>> ---
>> drivers/acpi/scan.c | 15 ++++++++++++---
>> drivers/base/dd.c | 22 +++++++++++++++++-----
>> include/linux/device.h | 2 +-
>> 3 files changed, 30 insertions(+), 9 deletions(-)
>>
>> Index: linux-3.5-rc6/drivers/acpi/scan.c
>> ===================================================================
>> --- linux-3.5-rc6.orig/drivers/acpi/scan.c 2012-07-12 20:11:37.316443808 +0900
>> +++ linux-3.5-rc6/drivers/acpi/scan.c 2012-07-12 20:17:17.927185231 +0900
>> @@ -425,12 +425,17 @@ static int acpi_device_remove(struct dev
>> {
>> struct acpi_device *acpi_dev = to_acpi_device(dev);
>> struct acpi_driver *acpi_drv = acpi_dev->driver;
>> + int ret;
>>
>> if (acpi_drv) {
>> if (acpi_drv->ops.notify)
>> acpi_device_remove_notify_handler(acpi_dev);
>> - if (acpi_drv->ops.remove)
>> - acpi_drv->ops.remove(acpi_dev, acpi_dev->removal_type);
>> + if (acpi_drv->ops.remove) {
>> + ret = acpi_drv->ops.remove(acpi_dev,
>> + acpi_dev->removal_type);
>> + if (ret)
>> + return ret;
>> + }
>> }
>> acpi_dev->driver = NULL;
>> acpi_dev->driver_data = NULL;
>> @@ -1208,11 +1213,15 @@ static int acpi_device_set_context(struc
>>
>> static int acpi_bus_remove(struct acpi_device *dev, int rmdevice)
>> {
>> + int ret;
>> +
>> if (!dev)
>> return -EINVAL;
>>
>> dev->removal_type = ACPI_BUS_REMOVAL_EJECT;
>> - device_release_driver(&dev->dev);
>> + ret = device_release_driver(&dev->dev);
>> + if (ret)
>> + return ret;
>>
>> if (!rmdevice)
>> return 0;
>> Index: linux-3.5-rc6/drivers/base/dd.c
>> ===================================================================
>> --- linux-3.5-rc6.orig/drivers/base/dd.c 2012-07-12 20:11:37.316443808 +0900
>> +++ linux-3.5-rc6/drivers/base/dd.c 2012-07-12 20:17:17.928185218 +0900
>> @@ -464,9 +464,10 @@ EXPORT_SYMBOL_GPL(driver_attach);
>> * __device_release_driver() must be called with @dev lock held.
>> * When called for a USB interface, @dev->parent lock must be held as well.
>> */
>> -static void __device_release_driver(struct device *dev)
>> +static int __device_release_driver(struct device *dev)
>> {
>> struct device_driver *drv;
>> + int ret;
>>
>> drv = dev->driver;
>> if (drv) {
>> @@ -482,9 +483,11 @@ static void __device_release_driver(stru
>> pm_runtime_put_sync(dev);
>>
>> if (dev->bus && dev->bus->remove)
>> - dev->bus->remove(dev);
>> + ret = dev->bus->remove(dev);
>> else if (drv->remove)
>> - drv->remove(dev);
>> + ret = drv->remove(dev);
>> + if (ret)
>> + goto rollback;
>> devres_release_all(dev);
>> dev->driver = NULL;
>> klist_remove(&dev->p->knode_driver);
>> @@ -494,6 +497,12 @@ static void __device_release_driver(stru
>> dev);
>>
>> }
>> +
>> + return ret;
>> +
>> +rollback:
>> + driver_sysfs_add(dev);
>> + return ret;
>> }
>>
>> /**
>> @@ -503,16 +512,19 @@ static void __device_release_driver(stru
>> * Manually detach device from driver.
>> * When called for a USB interface, @dev->parent lock must be held.
>> */
>> -void device_release_driver(struct device *dev)
>> +int device_release_driver(struct device *dev)
>> {
>> + int ret;
>> /*
>> * If anyone calls device_release_driver() recursively from
>> * within their ->remove callback for the same device, they
>> * will deadlock right here.
>> */
>> device_lock(dev);
>> - __device_release_driver(dev);
>> + ret = __device_release_driver(dev);
>> device_unlock(dev);
>> +
>> + return ret;
>> }
>> EXPORT_SYMBOL_GPL(device_release_driver);
>>
>> Index: linux-3.5-rc6/include/linux/device.h
>> ===================================================================
>> --- linux-3.5-rc6.orig/include/linux/device.h 2012-07-12 20:11:37.317443779 +0900
>> +++ linux-3.5-rc6/include/linux/device.h 2012-07-12 20:17:17.936185118 +0900
>> @@ -827,7 +827,7 @@ static inline void *dev_get_platdata(con
>> * for information on use.
>> */
>> extern int __must_check device_bind_driver(struct device *dev);
>> -extern void device_release_driver(struct device *dev);
>> +extern int device_release_driver(struct device *dev);
>> extern int __must_check device_attach(struct device *dev);
>> extern int __must_check driver_attach(struct device_driver *drv);
>> extern int __must_check device_reprobe(struct device *dev);
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>> Please read the FAQ at http://www.tux.org/lkml/
>>
>
^ permalink raw reply [flat|nested] 26+ messages in thread
* Re: [PATCH v3 1/3] acpi : cpu hot-remove returns error when cpu_down() fails
2012-07-12 11:22 ` Yasuaki Ishimatsu
` (2 preceding siblings ...)
(?)
@ 2012-07-12 12:32 ` Srivatsa S. Bhat
2012-07-13 6:29 ` Yasuaki Ishimatsu
-1 siblings, 1 reply; 26+ messages in thread
From: Srivatsa S. Bhat @ 2012-07-12 12:32 UTC (permalink / raw)
To: Yasuaki Ishimatsu; +Cc: linux-acpi, linux-kernel, lenb, toshi.kani
On 07/12/2012 04:52 PM, Yasuaki Ishimatsu wrote:
> Even if cpu_down() fails, acpi_processor_remove() continues to remove the cpu.
> But in this case, it should return error number since some process may run on
> the cpu. If the cpu has a running process and the cpu is turned the power off,
> the system may not work well.
>
> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Regards,
Srivatsa S. Bhat
> ---
> drivers/acpi/processor_driver.c | 18 ++++++++++++------
> 1 file changed, 12 insertions(+), 6 deletions(-)
>
> Index: linux-3.5-rc4/drivers/acpi/processor_driver.c
> ===================================================================
> --- linux-3.5-rc4.orig/drivers/acpi/processor_driver.c 2012-06-25 04:53:04.000000000 +0900
> +++ linux-3.5-rc4/drivers/acpi/processor_driver.c 2012-07-05 21:02:58.711285382 +0900
> @@ -610,7 +610,7 @@ err_free_pr:
> static int acpi_processor_remove(struct acpi_device *device, int type)
> {
> struct acpi_processor *pr = NULL;
> -
> + int ret;
>
> if (!device || !acpi_driver_data(device))
> return -EINVAL;
> @@ -621,8 +621,9 @@ static int acpi_processor_remove(struct
> goto free;
>
> if (type == ACPI_BUS_REMOVAL_EJECT) {
> - if (acpi_processor_handle_eject(pr))
> - return -EINVAL;
> + ret = acpi_processor_handle_eject(pr);
> + if (ret)
> + return ret;
> }
>
> acpi_processor_power_exit(pr, device);
> @@ -841,12 +842,17 @@ static acpi_status acpi_processor_hotadd
>
> static int acpi_processor_handle_eject(struct acpi_processor *pr)
> {
> - if (cpu_online(pr->id))
> - cpu_down(pr->id);
> + int ret;
> +
> + if (cpu_online(pr->id)) {
> + ret = cpu_down(pr->id);
> + if (ret)
> + return ret;
> + }
>
> arch_unregister_cpu(pr->id);
> acpi_unmap_lsapic(pr->id);
> - return (0);
> + return ret;
> }
> #else
> static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr)
>
^ permalink raw reply [flat|nested] 26+ messages in thread* Re: [PATCH v3 1/3] acpi : cpu hot-remove returns error when cpu_down() fails
2012-07-12 12:32 ` [PATCH v3 1/3] acpi : cpu hot-remove returns error when cpu_down() fails Srivatsa S. Bhat
@ 2012-07-13 6:29 ` Yasuaki Ishimatsu
0 siblings, 0 replies; 26+ messages in thread
From: Yasuaki Ishimatsu @ 2012-07-13 6:29 UTC (permalink / raw)
To: Srivatsa S. Bhat; +Cc: linux-acpi, linux-kernel, lenb, toshi.kani
Hi Srivatsa,
2012/07/12 21:32, Srivatsa S. Bhat wrote:
> On 07/12/2012 04:52 PM, Yasuaki Ishimatsu wrote:
>> Even if cpu_down() fails, acpi_processor_remove() continues to remove the cpu.
>> But in this case, it should return error number since some process may run on
>> the cpu. If the cpu has a running process and the cpu is turned the power off,
>> the system may not work well.
>>
>> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
>>
>
> Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Thank you for reviewing.
Thanks,
Yasuaki Ishimatsu
> Regards,
> Srivatsa S. Bhat
>
>> ---
>> drivers/acpi/processor_driver.c | 18 ++++++++++++------
>> 1 file changed, 12 insertions(+), 6 deletions(-)
>>
>> Index: linux-3.5-rc4/drivers/acpi/processor_driver.c
>> ===================================================================
>> --- linux-3.5-rc4.orig/drivers/acpi/processor_driver.c 2012-06-25 04:53:04.000000000 +0900
>> +++ linux-3.5-rc4/drivers/acpi/processor_driver.c 2012-07-05 21:02:58.711285382 +0900
>> @@ -610,7 +610,7 @@ err_free_pr:
>> static int acpi_processor_remove(struct acpi_device *device, int type)
>> {
>> struct acpi_processor *pr = NULL;
>> -
>> + int ret;
>>
>> if (!device || !acpi_driver_data(device))
>> return -EINVAL;
>> @@ -621,8 +621,9 @@ static int acpi_processor_remove(struct
>> goto free;
>>
>> if (type == ACPI_BUS_REMOVAL_EJECT) {
>> - if (acpi_processor_handle_eject(pr))
>> - return -EINVAL;
>> + ret = acpi_processor_handle_eject(pr);
>> + if (ret)
>> + return ret;
>> }
>>
>> acpi_processor_power_exit(pr, device);
>> @@ -841,12 +842,17 @@ static acpi_status acpi_processor_hotadd
>>
>> static int acpi_processor_handle_eject(struct acpi_processor *pr)
>> {
>> - if (cpu_online(pr->id))
>> - cpu_down(pr->id);
>> + int ret;
>> +
>> + if (cpu_online(pr->id)) {
>> + ret = cpu_down(pr->id);
>> + if (ret)
>> + return ret;
>> + }
>>
>> arch_unregister_cpu(pr->id);
>> acpi_unmap_lsapic(pr->id);
>> - return (0);
>> + return ret;
>> }
>> #else
>> static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr)
>>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 26+ messages in thread* Re: [PATCH v3 1/3] acpi : cpu hot-remove returns error when cpu_down() fails
@ 2012-07-13 6:29 ` Yasuaki Ishimatsu
0 siblings, 0 replies; 26+ messages in thread
From: Yasuaki Ishimatsu @ 2012-07-13 6:29 UTC (permalink / raw)
To: Srivatsa S. Bhat; +Cc: linux-acpi, linux-kernel, lenb, toshi.kani
Hi Srivatsa,
2012/07/12 21:32, Srivatsa S. Bhat wrote:
> On 07/12/2012 04:52 PM, Yasuaki Ishimatsu wrote:
>> Even if cpu_down() fails, acpi_processor_remove() continues to remove the cpu.
>> But in this case, it should return error number since some process may run on
>> the cpu. If the cpu has a running process and the cpu is turned the power off,
>> the system may not work well.
>>
>> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
>>
>
> Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Thank you for reviewing.
Thanks,
Yasuaki Ishimatsu
> Regards,
> Srivatsa S. Bhat
>
>> ---
>> drivers/acpi/processor_driver.c | 18 ++++++++++++------
>> 1 file changed, 12 insertions(+), 6 deletions(-)
>>
>> Index: linux-3.5-rc4/drivers/acpi/processor_driver.c
>> ===================================================================
>> --- linux-3.5-rc4.orig/drivers/acpi/processor_driver.c 2012-06-25 04:53:04.000000000 +0900
>> +++ linux-3.5-rc4/drivers/acpi/processor_driver.c 2012-07-05 21:02:58.711285382 +0900
>> @@ -610,7 +610,7 @@ err_free_pr:
>> static int acpi_processor_remove(struct acpi_device *device, int type)
>> {
>> struct acpi_processor *pr = NULL;
>> -
>> + int ret;
>>
>> if (!device || !acpi_driver_data(device))
>> return -EINVAL;
>> @@ -621,8 +621,9 @@ static int acpi_processor_remove(struct
>> goto free;
>>
>> if (type == ACPI_BUS_REMOVAL_EJECT) {
>> - if (acpi_processor_handle_eject(pr))
>> - return -EINVAL;
>> + ret = acpi_processor_handle_eject(pr);
>> + if (ret)
>> + return ret;
>> }
>>
>> acpi_processor_power_exit(pr, device);
>> @@ -841,12 +842,17 @@ static acpi_status acpi_processor_hotadd
>>
>> static int acpi_processor_handle_eject(struct acpi_processor *pr)
>> {
>> - if (cpu_online(pr->id))
>> - cpu_down(pr->id);
>> + int ret;
>> +
>> + if (cpu_online(pr->id)) {
>> + ret = cpu_down(pr->id);
>> + if (ret)
>> + return ret;
>> + }
>>
>> arch_unregister_cpu(pr->id);
>> acpi_unmap_lsapic(pr->id);
>> - return (0);
>> + return ret;
>> }
>> #else
>> static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr)
>>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 26+ messages in thread
* Re: [PATCH v3 1/3] acpi : cpu hot-remove returns error when cpu_down() fails
2012-07-12 11:22 ` Yasuaki Ishimatsu
` (3 preceding siblings ...)
(?)
@ 2012-07-12 16:48 ` Toshi Kani
2012-07-13 6:26 ` Yasuaki Ishimatsu
-1 siblings, 1 reply; 26+ messages in thread
From: Toshi Kani @ 2012-07-12 16:48 UTC (permalink / raw)
To: Yasuaki Ishimatsu; +Cc: linux-acpi, linux-kernel, lenb, srivatsa.bhat
On Thu, 2012-07-12 at 20:22 +0900, Yasuaki Ishimatsu wrote:
> Even if cpu_down() fails, acpi_processor_remove() continues to remove the cpu.
> But in this case, it should return error number since some process may run on
> the cpu. If the cpu has a running process and the cpu is turned the power off,
> the system may not work well.
>
> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
>
> ---
> drivers/acpi/processor_driver.c | 18 ++++++++++++------
> 1 file changed, 12 insertions(+), 6 deletions(-)
>
> Index: linux-3.5-rc4/drivers/acpi/processor_driver.c
> ===================================================================
> --- linux-3.5-rc4.orig/drivers/acpi/processor_driver.c 2012-06-25 04:53:04.000000000 +0900
> +++ linux-3.5-rc4/drivers/acpi/processor_driver.c 2012-07-05 21:02:58.711285382 +0900
> @@ -610,7 +610,7 @@ err_free_pr:
> static int acpi_processor_remove(struct acpi_device *device, int type)
> {
> struct acpi_processor *pr = NULL;
> -
> + int ret;
>
> if (!device || !acpi_driver_data(device))
> return -EINVAL;
> @@ -621,8 +621,9 @@ static int acpi_processor_remove(struct
> goto free;
>
> if (type == ACPI_BUS_REMOVAL_EJECT) {
> - if (acpi_processor_handle_eject(pr))
> - return -EINVAL;
> + ret = acpi_processor_handle_eject(pr);
> + if (ret)
> + return ret;
> }
>
> acpi_processor_power_exit(pr, device);
> @@ -841,12 +842,17 @@ static acpi_status acpi_processor_hotadd
>
> static int acpi_processor_handle_eject(struct acpi_processor *pr)
> {
> - if (cpu_online(pr->id))
> - cpu_down(pr->id);
> + int ret;
> +
> + if (cpu_online(pr->id)) {
> + ret = cpu_down(pr->id);
> + if (ret)
> + return ret;
> + }
>
> arch_unregister_cpu(pr->id);
> acpi_unmap_lsapic(pr->id);
> - return (0);
> + return ret;
ret is uninitialized when !cpu_online().
Thanks,
-Toshi
> }
> #else
> static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr)
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 26+ messages in thread* Re: [PATCH v3 1/3] acpi : cpu hot-remove returns error when cpu_down() fails
2012-07-12 16:48 ` Toshi Kani
@ 2012-07-13 6:26 ` Yasuaki Ishimatsu
0 siblings, 0 replies; 26+ messages in thread
From: Yasuaki Ishimatsu @ 2012-07-13 6:26 UTC (permalink / raw)
To: Toshi Kani; +Cc: linux-acpi, linux-kernel, lenb, srivatsa.bhat
Hi Toshi,
2012/07/13 1:48, Toshi Kani wrote:
> On Thu, 2012-07-12 at 20:22 +0900, Yasuaki Ishimatsu wrote:
>> Even if cpu_down() fails, acpi_processor_remove() continues to remove the cpu.
>> But in this case, it should return error number since some process may run on
>> the cpu. If the cpu has a running process and the cpu is turned the power off,
>> the system may not work well.
>>
>> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
>>
>> ---
>> drivers/acpi/processor_driver.c | 18 ++++++++++++------
>> 1 file changed, 12 insertions(+), 6 deletions(-)
>>
>> Index: linux-3.5-rc4/drivers/acpi/processor_driver.c
>> ===================================================================
>> --- linux-3.5-rc4.orig/drivers/acpi/processor_driver.c 2012-06-25 04:53:04.000000000 +0900
>> +++ linux-3.5-rc4/drivers/acpi/processor_driver.c 2012-07-05 21:02:58.711285382 +0900
>> @@ -610,7 +610,7 @@ err_free_pr:
>> static int acpi_processor_remove(struct acpi_device *device, int type)
>> {
>> struct acpi_processor *pr = NULL;
>> -
>> + int ret;
>>
>> if (!device || !acpi_driver_data(device))
>> return -EINVAL;
>> @@ -621,8 +621,9 @@ static int acpi_processor_remove(struct
>> goto free;
>>
>> if (type == ACPI_BUS_REMOVAL_EJECT) {
>> - if (acpi_processor_handle_eject(pr))
>> - return -EINVAL;
>> + ret = acpi_processor_handle_eject(pr);
>> + if (ret)
>> + return ret;
>> }
>>
>> acpi_processor_power_exit(pr, device);
>> @@ -841,12 +842,17 @@ static acpi_status acpi_processor_hotadd
>>
>> static int acpi_processor_handle_eject(struct acpi_processor *pr)
>> {
>> - if (cpu_online(pr->id))
>> - cpu_down(pr->id);
>> + int ret;
>> +
>> + if (cpu_online(pr->id)) {
>> + ret = cpu_down(pr->id);
>> + if (ret)
>> + return ret;
>> + }
>>
>> arch_unregister_cpu(pr->id);
>> acpi_unmap_lsapic(pr->id);
>> - return (0);
>> + return ret;
>
> ret is uninitialized when !cpu_online().
Oops! I'll update it.
Thanks,
Yasuaki Ishimatsu
> Thanks,
> -Toshi
>
>> }
>> #else
>> static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr)
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 26+ messages in thread* Re: [PATCH v3 1/3] acpi : cpu hot-remove returns error when cpu_down() fails
@ 2012-07-13 6:26 ` Yasuaki Ishimatsu
0 siblings, 0 replies; 26+ messages in thread
From: Yasuaki Ishimatsu @ 2012-07-13 6:26 UTC (permalink / raw)
To: Toshi Kani; +Cc: linux-acpi, linux-kernel, lenb, srivatsa.bhat
Hi Toshi,
2012/07/13 1:48, Toshi Kani wrote:
> On Thu, 2012-07-12 at 20:22 +0900, Yasuaki Ishimatsu wrote:
>> Even if cpu_down() fails, acpi_processor_remove() continues to remove the cpu.
>> But in this case, it should return error number since some process may run on
>> the cpu. If the cpu has a running process and the cpu is turned the power off,
>> the system may not work well.
>>
>> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
>>
>> ---
>> drivers/acpi/processor_driver.c | 18 ++++++++++++------
>> 1 file changed, 12 insertions(+), 6 deletions(-)
>>
>> Index: linux-3.5-rc4/drivers/acpi/processor_driver.c
>> ===================================================================
>> --- linux-3.5-rc4.orig/drivers/acpi/processor_driver.c 2012-06-25 04:53:04.000000000 +0900
>> +++ linux-3.5-rc4/drivers/acpi/processor_driver.c 2012-07-05 21:02:58.711285382 +0900
>> @@ -610,7 +610,7 @@ err_free_pr:
>> static int acpi_processor_remove(struct acpi_device *device, int type)
>> {
>> struct acpi_processor *pr = NULL;
>> -
>> + int ret;
>>
>> if (!device || !acpi_driver_data(device))
>> return -EINVAL;
>> @@ -621,8 +621,9 @@ static int acpi_processor_remove(struct
>> goto free;
>>
>> if (type == ACPI_BUS_REMOVAL_EJECT) {
>> - if (acpi_processor_handle_eject(pr))
>> - return -EINVAL;
>> + ret = acpi_processor_handle_eject(pr);
>> + if (ret)
>> + return ret;
>> }
>>
>> acpi_processor_power_exit(pr, device);
>> @@ -841,12 +842,17 @@ static acpi_status acpi_processor_hotadd
>>
>> static int acpi_processor_handle_eject(struct acpi_processor *pr)
>> {
>> - if (cpu_online(pr->id))
>> - cpu_down(pr->id);
>> + int ret;
>> +
>> + if (cpu_online(pr->id)) {
>> + ret = cpu_down(pr->id);
>> + if (ret)
>> + return ret;
>> + }
>>
>> arch_unregister_cpu(pr->id);
>> acpi_unmap_lsapic(pr->id);
>> - return (0);
>> + return ret;
>
> ret is uninitialized when !cpu_online().
Oops! I'll update it.
Thanks,
Yasuaki Ishimatsu
> Thanks,
> -Toshi
>
>> }
>> #else
>> static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr)
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 26+ messages in thread