Re: [PATCH] ACPI: Fix lockdep false positives in acpi_power_off()

Borislav Petkov
2011-07-05T07:40:29Z

On Tue, Jul 05, 2011 at 01:32:11AM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rjw@sisk.pl>
> Subject: ACPI: Fix lockdep false positives in acpi_power_off()
>
> All ACPICA locks are allocated and initialized by the same function,
> acpi_os_create_lock(), with the help of a local variable called
> "lock". Thus, when lockdep is enabled, it uses "lock" as the
> name of all those locks and regards them as instances of the same
> lock, which causes it to report possible locking problems with them
> when there aren't any.
>
> To work around this problem, define acpi_os_create_lock() as a macro
> and make it pass its argument to spin_lock_init(), so that lockdep
> uses it as the name of the new lock. Define this macron in a
> Linux-specific file to minimize the resulting modifications of
> the OS-independent ACPICA parts.
>
> This change is based on an earlier patch from Andrea Righi and it
> addresses a regression from 2.6.39 tracked as
> https://bugzilla.kernel.org/show_bug.cgi?id=38152
>
> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
> Reported-by: Borislav Petkov <bp@alien8.de>
> Tested-by: Andrea Righi <andrea@betterlinux.com>

Tested-by: Borislav Petkov <bp@alien8.de>

--
Regards/Gruss,
Boris.