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author | Lv Zheng <lv.zheng@intel.com> | 2016-07-05 08:53:12 +0300 |
---|---|---|
committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2016-07-05 23:48:44 +0300 |
commit | 45209046c47b93fadf26dc59a9da724f387b9cf2 (patch) | |
tree | 0eaaaeee0a25b9bb2c86260f6a7ab0fb3fab9099 | |
parent | 2f38b1b16d9280689e5cfa47a4c50956bf437f0d (diff) | |
download | linux-45209046c47b93fadf26dc59a9da724f387b9cf2.tar.xz |
ACPICA: Namespace: Fix namespace/interpreter lock ordering
There is a lock order issue in acpi_load_tables(). The namespace lock
is held before holding the interpreter lock.
With ACPI_MUTEX_DEBUG enabled in the kernel, this is printed to the
log during boot:
[ 0.885699] ACPI Error: Invalid acquire order: Thread 405884224 owns [ACPI_MTX_Namespace], wants [ACPI_MTX_Interpreter] (20160422/utmutex-263)
[ 0.885881] ACPI Error: Could not acquire AML Interpreter mutex (20160422/exutils-95)
[ 0.893846] ACPI Error: Mutex [0x0] is not acquired, cannot release (20160422/utmutex-326)
[ 0.894019] ACPI Error: Could not release AML Interpreter mutex (20160422/exutils-133)
The issue has been introduced by the following commit:
Commit: 2f38b1b16d9280689e5cfa47a4c50956bf437f0d
ACPICA Commit: bfe03ffcde8ed56a7eae38ea0b188aeb12f9c52e
Subject: ACPICA: Namespace: Fix a regression that MLC support triggers
dead lock in dynamic table loading
Which fixed a deadlock issue for acpi_ns_load_table() in
acpi_ex_add_table() but didn't take care of the lock order in
acpi_ns_load_table() correctly.
Originally (before the above commit), ACPICA used the
namespace/interpreter locks in the following 2 key code
paths:
1. Table loading:
acpi_ns_load_table
L(Namespace)
acpi_ns_parse_table
acpi_ns_one_complete_parse
U(Namespace)
2. Object evaluation:
acpi_ns_evaluate
L(Interpreter)
acpi_ps_execute_method
U(Interpreter)
acpi_ns_load_table
L(Namespace)
U(Namespace)
acpi_ev_initialize_region
L(Namespace)
U(Namespace)
address_space.setup
L(Namespace)
U(Namespace)
address_space.handler
L(Namespace)
U(Namespace)
acpi_os_wait_semaphore
acpi_os_acquire_mutex
acpi_os_sleep
L(Interpreter)
U(Interpreter)
During runtime, while acpi_ns_evaluate is called, the lock order is
always Interpreter -> Namespace.
In turn, the problematic commit acquires the locks in the following
order:
3. Table loading:
acpi_ns_load_table
L(Namespace)
acpi_ns_parse_table
L(Interpreter)
acpi_ns_one_complete_parse
U(Interpreter)
U(Namespace)
To fix the lock order issue, move the interpreter lock to
acpi_ns_load_table() to ensure the lock order correctness:
4. Table loading:
acpi_ns_load_table
L(Interpreter)
L(Namespace)
acpi_ns_parse_table
acpi_ns_one_complete_parse
U(Namespace)
U(Interpreter)
However, this doesn't fix the current design issues related to the
namespace lock. For example, we can notice that in acpi_ns_evaluate(),
outside of acpi_ns_load_table(), the namespace objects may be created
by the named object creation control methods. And the creation of
the method-owned namespace objects are not locked by the namespace
lock. This patch doesn't try to fix such kind of existing issues.
Fixes: 2f38b1b16d92 (ACPICA: Namespace: Fix a regression that MLC support triggers dead lock in dynamic table loading)
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
-rw-r--r-- | drivers/acpi/acpica/nsload.c | 7 | ||||
-rw-r--r-- | drivers/acpi/acpica/nsparse.c | 9 |
2 files changed, 8 insertions, 8 deletions
diff --git a/drivers/acpi/acpica/nsload.c b/drivers/acpi/acpica/nsload.c index b5e2b0ada0ab..297f6aacd7d4 100644 --- a/drivers/acpi/acpica/nsload.c +++ b/drivers/acpi/acpica/nsload.c @@ -46,6 +46,7 @@ #include "acnamesp.h" #include "acdispat.h" #include "actables.h" +#include "acinterp.h" #define _COMPONENT ACPI_NAMESPACE ACPI_MODULE_NAME("nsload") @@ -78,6 +79,8 @@ acpi_ns_load_table(u32 table_index, struct acpi_namespace_node *node) ACPI_FUNCTION_TRACE(ns_load_table); + acpi_ex_enter_interpreter(); + /* * Parse the table and load the namespace with all named * objects found within. Control methods are NOT parsed @@ -89,7 +92,7 @@ acpi_ns_load_table(u32 table_index, struct acpi_namespace_node *node) */ status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE); if (ACPI_FAILURE(status)) { - return_ACPI_STATUS(status); + goto unlock_interp; } /* If table already loaded into namespace, just return */ @@ -130,6 +133,8 @@ acpi_ns_load_table(u32 table_index, struct acpi_namespace_node *node) unlock: (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE); +unlock_interp: + (void)acpi_ex_exit_interpreter(); if (ACPI_FAILURE(status)) { return_ACPI_STATUS(status); diff --git a/drivers/acpi/acpica/nsparse.c b/drivers/acpi/acpica/nsparse.c index 1783cd7e1446..f631a47724f0 100644 --- a/drivers/acpi/acpica/nsparse.c +++ b/drivers/acpi/acpica/nsparse.c @@ -47,7 +47,6 @@ #include "acparser.h" #include "acdispat.h" #include "actables.h" -#include "acinterp.h" #define _COMPONENT ACPI_NAMESPACE ACPI_MODULE_NAME("nsparse") @@ -171,8 +170,6 @@ acpi_ns_parse_table(u32 table_index, struct acpi_namespace_node *start_node) ACPI_FUNCTION_TRACE(ns_parse_table); - acpi_ex_enter_interpreter(); - /* * AML Parse, pass 1 * @@ -188,7 +185,7 @@ acpi_ns_parse_table(u32 table_index, struct acpi_namespace_node *start_node) status = acpi_ns_one_complete_parse(ACPI_IMODE_LOAD_PASS1, table_index, start_node); if (ACPI_FAILURE(status)) { - goto error_exit; + return_ACPI_STATUS(status); } /* @@ -204,10 +201,8 @@ acpi_ns_parse_table(u32 table_index, struct acpi_namespace_node *start_node) status = acpi_ns_one_complete_parse(ACPI_IMODE_LOAD_PASS2, table_index, start_node); if (ACPI_FAILURE(status)) { - goto error_exit; + return_ACPI_STATUS(status); } -error_exit: - acpi_ex_exit_interpreter(); return_ACPI_STATUS(status); } |