Re: [PATCH v3 1/5] ACPICA: Namespace: Fix a regression that MLC support triggers dead lock in dynamic table loading

From: Mika Westerberg
Date: Mon Jun 20 2016 - 06:58:30 EST


On Mon, Jun 20, 2016 at 05:07:22PM +0800, Lv Zheng wrote:
> The new MLC approach invokes MLC per-table basis. But the dynamic loading
> support of this is incorrect because of the lock order:
> acpi_ns_evaluate
> acpi_ex_enter_intperter
> acpi_ns_load_table (triggered by Load opcode)
> acpi_ns_exec_module_code_list
> acpi_ex_enter_intperter
> The regression is introduced by the following commit:
> Commit: 2785ce8d0da1cac9d8f78615e116cf929e9a9123
> ACPICA Commit: 071eff738c59eda1792ac24b3b688b61691d7e7c
> Subject: ACPICA: Add per-table execution of module-level code
> This patch fixes this regression by unlocking the interpreter lock before
> invoking MLC. However the unlocking is done to the acpi_ns_load_table(), in
> which, the interpreter lock should be locked by acpi_ns_parse_table() but
> wasn't. Reported by Mika Westerberg. Fixed by Lv Zheng.
>
> Fixes: 2785ce8d0da1 ("ACPICA: Add per-table execution of module-level code")
> Reported-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx>
> ---
> drivers/acpi/acpica/exconfig.c | 2 ++
> drivers/acpi/acpica/nsparse.c | 8 ++++++--
> 2 files changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/acpi/acpica/exconfig.c b/drivers/acpi/acpica/exconfig.c
> index a1d177d..21932d6 100644
> --- a/drivers/acpi/acpica/exconfig.c
> +++ b/drivers/acpi/acpica/exconfig.c
> @@ -108,7 +108,9 @@ acpi_ex_add_table(u32 table_index,
>
> /* Add the table to the namespace */
>
> + acpi_ex_exit_interpreter();
> status = acpi_ns_load_table(table_index, parent_node);
> + acpi_ex_enter_interpreter();
> if (ACPI_FAILURE(status)) {
> acpi_ut_remove_reference(obj_desc);
> *ddb_handle = NULL;
> diff --git a/drivers/acpi/acpica/nsparse.c b/drivers/acpi/acpica/nsparse.c
> index f631a47..0d29383 100644
> --- a/drivers/acpi/acpica/nsparse.c
> +++ b/drivers/acpi/acpica/nsparse.c
> @@ -170,6 +170,8 @@ acpi_ns_parse_table(u32 table_index, struct acpi_namespace_node *start_node)
>
> ACPI_FUNCTION_TRACE(ns_parse_table);
>
> + acpi_ex_enter_interpreter();

I'm getting these:

drivers/acpi/acpica/nsparse.c: In function âacpi_ns_parse_tableâ:
drivers/acpi/acpica/nsparse.c:173:2: error: implicit declaration of function âacpi_ex_enter_interpreterâ [-Werror=implicit-function-declaration]
acpi_ex_enter_interpreter();
^
drivers/acpi/acpica/nsparse.c:210:2: error: implicit declaration of function âacpi_ex_exit_interpreterâ [-Werror=implicit-function-declaration]
acpi_ex_exit_interpreter();
^
cc1: some warnings being treated as errors

Do I need to have some other patch applied before this?