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[PATCH] ACPI: CPPC: Make rmw_lock a raw_spin_lock

Pierre Gondois posted 1 patch 3 weeks, 6 days ago
There is a newer version of this series
drivers/acpi/cppc_acpi.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
[PATCH] ACPI: CPPC: Make rmw_lock a raw_spin_lock
Posted by Pierre Gondois 3 weeks, 6 days ago 
The following BUG was triggered. sugov_update_shared() locks a
raw_spinlock while cpc_write() locks a spinlock. To have a correct
wait-type order, update rmw_lock to a raw_spinlock.

Also save irq state.

=============================
[ BUG: Invalid wait context ]
6.12.0-rc2-XXX #406 Not tainted
-----------------------------
kworker/1:1/62 is trying to lock:
ffffff8801593030 (&cpc_ptr->rmw_lock){+.+.}-{3:3}, at: cpc_write+0xcc/0x370
other info that might help us debug this:
context-{5:5}
2 locks held by kworker/1:1/62:
  #0: ffffff897ef5ec98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2c/0x50
  #1: ffffff880154e238 (&sg_policy->update_lock){....}-{2:2}, at: sugov_update_shared+0x3c/0x280
stack backtrace:
CPU: 1 UID: 0 PID: 62 Comm: kworker/1:1 Not tainted 6.12.0-rc2-g9654bd3e8806 #406
Workqueue:  0x0 (events)
Call trace:
  dump_backtrace+0xa4/0x130
  show_stack+0x20/0x38
  dump_stack_lvl+0x90/0xd0
  dump_stack+0x18/0x28
  __lock_acquire+0x480/0x1ad8
  lock_acquire+0x114/0x310
  _raw_spin_lock+0x50/0x70
  cpc_write+0xcc/0x370
  cppc_set_perf+0xa0/0x3a8
  cppc_cpufreq_fast_switch+0x40/0xc0
  cpufreq_driver_fast_switch+0x4c/0x218
  sugov_update_shared+0x234/0x280
  update_load_avg+0x6ec/0x7b8
  dequeue_entities+0x108/0x830
  dequeue_task_fair+0x58/0x408
  __schedule+0x4f0/0x1070
  schedule+0x54/0x130
  worker_thread+0xc0/0x2e8
  kthread+0x130/0x148
  ret_from_fork+0x10/0x20

Fixes: 60949b7b8054 ("ACPI: CPPC: Fix MASK_VAL() usage")
Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
---
 drivers/acpi/cppc_acpi.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index 1a40f0514eaa..e7e4bf932e28 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -1127,7 +1127,7 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
 			return -ENODEV;
 		}
 
-		raw_spin_lock_irqsave(&cpc_desc->rmw_lock, flags);
+		raw_spin_lock(&cpc_desc->rmw_lock);
 		switch (size) {
 		case 8:
 			prev_val = readb_relaxed(vaddr);
@@ -1142,7 +1142,7 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
 			prev_val = readq_relaxed(vaddr);
 			break;
 		default:
-			raw_spin_unlock_irqrestore(&cpc_desc->rmw_lock, flags);
+			raw_spin_unlock(&cpc_desc->rmw_lock);
 			return -EFAULT;
 		}
 		val = MASK_VAL_WRITE(reg, prev_val, val);
@@ -1175,7 +1175,7 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
 	}
 
 	if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
-		raw_spin_unlock_irqrestore(&cpc_desc->rmw_lock, flags);
+		raw_spin_unlock(&cpc_desc->rmw_lock);
 
 	return ret_val;
 }
-- 
2.25.1
Re: [PATCH] ACPI: CPPC: Make rmw_lock a raw_spin_lock
Posted by Greg Kroah-Hartman 3 weeks, 6 days ago 
On Mon, Oct 28, 2024 at 11:51:49AM +0100, Pierre Gondois wrote:
> The following BUG was triggered. sugov_update_shared() locks a
> raw_spinlock while cpc_write() locks a spinlock. To have a correct
> wait-type order, update rmw_lock to a raw_spinlock.
> 
> Also save irq state.
> 
> =============================
> [ BUG: Invalid wait context ]
> 6.12.0-rc2-XXX #406 Not tainted
> -----------------------------
> kworker/1:1/62 is trying to lock:
> ffffff8801593030 (&cpc_ptr->rmw_lock){+.+.}-{3:3}, at: cpc_write+0xcc/0x370
> other info that might help us debug this:
> context-{5:5}
> 2 locks held by kworker/1:1/62:
>   #0: ffffff897ef5ec98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2c/0x50
>   #1: ffffff880154e238 (&sg_policy->update_lock){....}-{2:2}, at: sugov_update_shared+0x3c/0x280
> stack backtrace:
> CPU: 1 UID: 0 PID: 62 Comm: kworker/1:1 Not tainted 6.12.0-rc2-g9654bd3e8806 #406
> Workqueue:  0x0 (events)
> Call trace:
>   dump_backtrace+0xa4/0x130
>   show_stack+0x20/0x38
>   dump_stack_lvl+0x90/0xd0
>   dump_stack+0x18/0x28
>   __lock_acquire+0x480/0x1ad8
>   lock_acquire+0x114/0x310
>   _raw_spin_lock+0x50/0x70
>   cpc_write+0xcc/0x370
>   cppc_set_perf+0xa0/0x3a8
>   cppc_cpufreq_fast_switch+0x40/0xc0
>   cpufreq_driver_fast_switch+0x4c/0x218
>   sugov_update_shared+0x234/0x280
>   update_load_avg+0x6ec/0x7b8
>   dequeue_entities+0x108/0x830
>   dequeue_task_fair+0x58/0x408
>   __schedule+0x4f0/0x1070
>   schedule+0x54/0x130
>   worker_thread+0xc0/0x2e8
>   kthread+0x130/0x148
>   ret_from_fork+0x10/0x20
> 
> Fixes: 60949b7b8054 ("ACPI: CPPC: Fix MASK_VAL() usage")
> Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
> ---
>  drivers/acpi/cppc_acpi.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created.  Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.

You are receiving this message because of the following common error(s)
as indicated below:

- You have marked a patch with a "Fixes:" tag for a commit that is in an
  older released kernel, yet you do not have a cc: stable line in the
  signed-off-by area at all, which means that the patch will not be
  applied to any older kernel releases.  To properly fix this, please
  follow the documented rules in the
  Documentation/process/stable-kernel-rules.rst file for how to resolve
  this.

If you wish to discuss this problem further, or you have questions about
how to resolve this issue, please feel free to respond to this email and
Greg will reply once he has dug out from the pending patches received
from other developers.

thanks,

greg k-h's patch email bot
Re: [PATCH] ACPI: CPPC: Make rmw_lock a raw_spin_lock
Posted by Rafael J. Wysocki 3 weeks, 6 days ago 
On Mon, Oct 28, 2024 at 11:52 AM Pierre Gondois <pierre.gondois@arm.com> wrote:
>
> The following BUG was triggered. sugov_update_shared() locks a
> raw_spinlock while cpc_write() locks a spinlock. To have a correct
> wait-type order, update rmw_lock to a raw_spinlock.
>
> Also save irq state.
>
> =============================
> [ BUG: Invalid wait context ]
> 6.12.0-rc2-XXX #406 Not tainted
> -----------------------------
> kworker/1:1/62 is trying to lock:
> ffffff8801593030 (&cpc_ptr->rmw_lock){+.+.}-{3:3}, at: cpc_write+0xcc/0x370
> other info that might help us debug this:
> context-{5:5}
> 2 locks held by kworker/1:1/62:
>   #0: ffffff897ef5ec98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2c/0x50
>   #1: ffffff880154e238 (&sg_policy->update_lock){....}-{2:2}, at: sugov_update_shared+0x3c/0x280
> stack backtrace:
> CPU: 1 UID: 0 PID: 62 Comm: kworker/1:1 Not tainted 6.12.0-rc2-g9654bd3e8806 #406
> Workqueue:  0x0 (events)
> Call trace:
>   dump_backtrace+0xa4/0x130
>   show_stack+0x20/0x38
>   dump_stack_lvl+0x90/0xd0
>   dump_stack+0x18/0x28
>   __lock_acquire+0x480/0x1ad8
>   lock_acquire+0x114/0x310
>   _raw_spin_lock+0x50/0x70
>   cpc_write+0xcc/0x370
>   cppc_set_perf+0xa0/0x3a8
>   cppc_cpufreq_fast_switch+0x40/0xc0
>   cpufreq_driver_fast_switch+0x4c/0x218
>   sugov_update_shared+0x234/0x280
>   update_load_avg+0x6ec/0x7b8
>   dequeue_entities+0x108/0x830
>   dequeue_task_fair+0x58/0x408
>   __schedule+0x4f0/0x1070
>   schedule+0x54/0x130
>   worker_thread+0xc0/0x2e8
>   kthread+0x130/0x148
>   ret_from_fork+0x10/0x20
>
> Fixes: 60949b7b8054 ("ACPI: CPPC: Fix MASK_VAL() usage")
> Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
> ---
>  drivers/acpi/cppc_acpi.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
> index 1a40f0514eaa..e7e4bf932e28 100644
> --- a/drivers/acpi/cppc_acpi.c
> +++ b/drivers/acpi/cppc_acpi.c
> @@ -1127,7 +1127,7 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
>                         return -ENODEV;
>                 }
>
> -               raw_spin_lock_irqsave(&cpc_desc->rmw_lock, flags);
> +               raw_spin_lock(&cpc_desc->rmw_lock);

This won't apply because the current code is

spin_lock(&cpc_desc->rmw_lock);

and analogously below.  I think that it needs to be
raw_spin_lock_irqsave(), though.

Besides, a raw spin lock needs to be declared as such.

>                 switch (size) {
>                 case 8:
>                         prev_val = readb_relaxed(vaddr);
> @@ -1142,7 +1142,7 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
>                         prev_val = readq_relaxed(vaddr);
>                         break;
>                 default:
> -                       raw_spin_unlock_irqrestore(&cpc_desc->rmw_lock, flags);
> +                       raw_spin_unlock(&cpc_desc->rmw_lock);
>                         return -EFAULT;
>                 }
>                 val = MASK_VAL_WRITE(reg, prev_val, val);
> @@ -1175,7 +1175,7 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
>         }
>
>         if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
> -               raw_spin_unlock_irqrestore(&cpc_desc->rmw_lock, flags);
> +               raw_spin_unlock(&cpc_desc->rmw_lock);
>
>         return ret_val;
>  }
> --
> 2.25.1
>

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