lkml.org 
[lkml]   [2011]   [Nov]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Subject[PATCH -v1] acpi: Fix possible recursive locking in hwregs.c
    From
    Date
    Calling pm-suspend might trigger a recursive lock in it's code path. In function acpi_hw_clear_acpi_status, 
    acpi_os_acquire_lock holds the lock acpi_gbl_hardware_lock before calling acpi_hw_register_write(), then
    without releasing acpi_gbl_hardware_lock, this function calls acpi_ev_walk_gpe_list, which tries to hold
    acpi_gbl_gpe_lock and thus might causes possible recursive lock.

    Following patch fixes this scenario by just releasing acpi_gbl_hardware_lock before calling acpi_ev_walk_gpe_list.

    Changes since v0(https://lkml.org/lkml/2011/9/21/355):
    - Fix changelog, thanks to Lin Ming.

    Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
    Cc: Lin Ming <ming.m.lin@intel.com>
    Cc: Andrew Morton <akpm@linux-foundation.org>
    Cc: Len Brown <len.brown@intel.com>
    ---

    diff --git a/drivers/acpi/acpica/hwregs.c b/drivers/acpi/acpica/hwregs.c
    index 55accb7..e3110ac 100644
    --- a/drivers/acpi/acpica/hwregs.c
    +++ b/drivers/acpi/acpica/hwregs.c
    @@ -269,6 +269,9 @@ acpi_status acpi_hw_clear_acpi_status(void)

    status = acpi_hw_register_write(ACPI_REGISTER_PM1_STATUS,
    ACPI_BITMASK_ALL_FIXED_STATUS);
    +
    + acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags);
    +
    if (ACPI_FAILURE(status)) {
    goto unlock_and_exit;
    }
    @@ -278,7 +281,6 @@ acpi_status acpi_hw_clear_acpi_status(void)
    status = acpi_ev_walk_gpe_list(acpi_hw_clear_gpe_block, NULL);

    unlock_and_exit:
    - acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags);
    return_ACPI_STATUS(status);
    }




    \
     
     \ /
      Last update: 2011-11-03 11:51    [W:0.022 / U:0.072 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site