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From: Dmitry Safonov <0x7f454c46@gmail.com>
To: Francesco Ruggeri <fruggeri@arista.com>
Cc: lenb@kernel.org, "Rafael J. Wysocki" <rjw@rjwysocki.net>,
	open list <linux-kernel@vger.kernel.org>,
	linux-acpi@vger.kernel.org
Subject: Re: [PATCH] ACPI: only free map once in osl.c
Date: Thu, 21 Nov 2019 21:19:43 +0000	[thread overview]
Message-ID: <CAJwJo6ZTSw93zKdN3i-YqVtEEwh4qWc22Hk-emHvJth+HsaQbQ@mail.gmail.com> (raw)
In-Reply-To: <20191120054728.0979695C0FE4@us180.sjc.aristanetworks.com>

Hi Francesco,

I believe, there's still an issue with your patch.

On Wed, 20 Nov 2019 at 05:50, Francesco Ruggeri <fruggeri@arista.com> wrote:
> @@ -472,10 +477,11 @@ void acpi_os_unmap_generic_address(struct acpi_generic_address *gas)
>                 mutex_unlock(&acpi_ioremap_lock);
>                 return;
>         }
> -       acpi_os_drop_map_ref(map);
> +       refcount = acpi_os_drop_map_ref(map);
>         mutex_unlock(&acpi_ioremap_lock);

Here comes acpi_os_get_iomem() increasing the refcount again.

>
> -       acpi_os_map_cleanup(map);
> +       if (!refcount)
> +               acpi_os_map_cleanup(map);
>  }
>  EXPORT_SYMBOL(acpi_os_unmap_generic_address);

And you free the acpi_ioremap that's being used:

>  static void acpi_os_map_cleanup(struct acpi_ioremap *map)
>  {
> -       if (!map->refcount) {
> -               synchronize_rcu_expedited();
> -               acpi_unmap(map->phys, map->virt);
> -               kfree(map);
> -       }
> +       synchronize_rcu_expedited();
> +       acpi_unmap(map->phys, map->virt);
> +       kfree(map);
>  }

Thanks,
             Dmitry

  reply	other threads:[~2019-11-21 21:19 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-20  5:47 [PATCH] ACPI: only free map once in osl.c Francesco Ruggeri
2019-11-21 21:19 ` Dmitry Safonov [this message]
2019-11-21 22:49   ` Francesco Ruggeri
2019-11-21 22:57     ` Dmitry Safonov
2019-11-21 22:58 ` Dmitry Safonov
2019-11-26 22:42   ` Francesco Ruggeri
2019-11-29 11:22 ` Rafael J. Wysocki

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