lkml.org 
[lkml]   [2011]   [Jul]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    SubjectRe: [PATCH v2] ACPI: fix acpi_power_off lockdep splat
    Date
    On Sunday, July 03, 2011, Andrea Righi wrote:
    > Implement acpi_os_create_lock() as a C-preprocessor macro to suppress
    > lockdep false positive.
    >
    > When lockdep is enabled the spin_lock_init macro stringifies it's
    > argument and uses that as a name for the lock in the debugging.
    >
    > By executing spin_lock_init in a macro the key changes from "lock" for
    > all locks to the actual argument of acpi_os_create_lock()
    > ("&acpi_gbl_global_lock_pending_lock", "&acpi_gbl_gpe_lock" or
    > "&acpi_gbl_hardware_lock" for now).
    >
    > This fixes:
    > https://bugzilla.kernel.org/show_bug.cgi?id=38152
    >
    > ChangeLog (v1 -> v2):
    > - avoid to call spin_lock_init multiple times on the same lock
    > - rewrite patch description (thanks to Florian for providing a better
    > description of the patch)
    >
    > Reported-by: Borislav Petkov <bp@alien8.de>
    > CC: Florian Mickler <florian@mickler.org>
    > Signed-off-by: Andrea Righi <andrea@betterlinux.com>
    > ---
    > drivers/acpi/osl.c | 3 +--
    > include/acpi/acpiosxf.h | 12 +++++++++++-
    > 2 files changed, 12 insertions(+), 3 deletions(-)
    >
    > diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
    > index 52ca964..4c985d3 100644
    > --- a/drivers/acpi/osl.c
    > +++ b/drivers/acpi/osl.c
    > @@ -1336,14 +1336,13 @@ EXPORT_SYMBOL(acpi_resources_are_enforced);
    > * Create and initialize a spinlock.
    > */
    > acpi_status
    > -acpi_os_create_lock(acpi_spinlock *out_handle)
    > +__acpi_os_create_lock(acpi_spinlock *out_handle)
    > {

    I would rename this to acpi_os_allocate_lock() or acpi_os_alloc_lock(),
    so that it doesn't suggest the lock is initialized by this function.

    Hmm. There's one more thing we need to take into account here. Namely,
    include/acpi/acpiosxf.h is used by other OSes, so we shouldn't put
    Linux-specific stuff into it.

    I'm not sure how to work around that at the moment.

    Thanks,
    Rafael


    > spinlock_t *lock;
    >
    > lock = ACPI_ALLOCATE(sizeof(spinlock_t));
    > if (!lock)
    > return AE_NO_MEMORY;
    > - spin_lock_init(lock);
    > *out_handle = lock;
    >
    > return AE_OK;
    > diff --git a/include/acpi/acpiosxf.h b/include/acpi/acpiosxf.h
    > index a756bc8..4a0385d 100644
    > --- a/include/acpi/acpiosxf.h
    > +++ b/include/acpi/acpiosxf.h
    > @@ -99,7 +99,17 @@ acpi_os_table_override(struct acpi_table_header *existing_table,
    > * Spinlock primitives
    > */
    > acpi_status
    > -acpi_os_create_lock(acpi_spinlock *out_handle);
    > +__acpi_os_create_lock(acpi_spinlock *out_handle);
    > +
    > +#define acpi_os_create_lock(__handle) \
    > +({ \
    > + acpi_status ret; \
    > + \
    > + ret = __acpi_os_create_lock(__handle); \
    > + if (ret == AE_OK) \
    > + spin_lock_init(*(__handle)); \
    > + ret; \
    > +})
    >
    > void acpi_os_delete_lock(acpi_spinlock handle);
    >
    >



    \
     
     \ /
      Last update: 2011-07-03 23:01    [W:0.024 / U:0.252 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site