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| author | Rakib Mullick <rakib.mullick@gmail.com> | 2011-11-06 21:18:17 +0600 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2011-11-06 20:09:23 -0500 |
| commit | f7f71cfbf0c276ee3d8d856d0f35a41aed997fa4 (patch) | |
| tree | 946537396845cdda9f4b9803d27c577d3566901e /drivers/acpi | |
| parent | c3b92c8787367a8bb53d57d9789b558f1295cc96 (diff) | |
| download | linux-f7f71cfbf0c276ee3d8d856d0f35a41aed997fa4.tar.gz linux-f7f71cfbf0c276ee3d8d856d0f35a41aed997fa4.tar.bz2 linux-f7f71cfbf0c276ee3d8d856d0f35a41aed997fa4.zip | |
ACPI: Fix possible recursive locking in hwregs.c
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.
Both acpi_gbl_hardware_lock and acpi_gbl_gpe_lock are at same
lock-class and which might cause lock recursion deadlock.
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.
Changes since v1 (https://lkml.org/lkml/2011/11/3/89):
- Update changelog and rename goto label, courtesy Srivatsa S. Bhat.
Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/acpica/hwregs.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/drivers/acpi/acpica/hwregs.c b/drivers/acpi/acpica/hwregs.c index 55accb7018bb..cc70f3fdcdd1 100644 --- a/drivers/acpi/acpica/hwregs.c +++ b/drivers/acpi/acpica/hwregs.c @@ -269,16 +269,17 @@ acpi_status acpi_hw_clear_acpi_status(void) status = acpi_hw_register_write(ACPI_REGISTER_PM1_STATUS, ACPI_BITMASK_ALL_FIXED_STATUS); - if (ACPI_FAILURE(status)) { - goto unlock_and_exit; - } + + acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags); + + if (ACPI_FAILURE(status)) + goto exit; /* Clear the GPE Bits in all GPE registers in all GPE blocks */ 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); +exit: return_ACPI_STATUS(status); } |