Hi, Vegard > From: linux-acpi-ow...@vger.kernel.org [mailto:linux-acpi- > ow...@vger.kernel.org] On Behalf Of Vegard Nossum > Subject: [PATCH] ACPICA: cleanup method properly on error > > If the call to acpi_ds_init_aml_walk() fails, then we have to undo the > walk state push done by acpi_ds_create_walk_state(). Otherwise, the new > walk state (which has just been freed) will remain on the thread's > walk_state_list and be dereferenced in acpi_ps_parse_aml() when we try > to get the new state. [Lv Zheng] I haven't looked into the detail. Let me first ask simple questions and present simple concerns in order to move this discussion on.
> > You can observe this when reading e.g. > > /sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0F:01/status [Lv Zheng] Do you mean you have real issues related to this? If so, could provide the .config and dmesg for us? > > Cc: sta...@vger.kernel.org > Signed-off-by: Vegard Nossum <vegard.nos...@oracle.com> > --- > drivers/acpi/acpica/dsmethod.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/acpi/acpica/dsmethod.c > b/drivers/acpi/acpica/dsmethod.c > index 47c7b52..44b50a6 100644 > --- a/drivers/acpi/acpica/dsmethod.c > +++ b/drivers/acpi/acpica/dsmethod.c > @@ -596,6 +596,8 @@ cleanup: > /* On error, we must terminate the method properly */ > > acpi_ds_terminate_control_method(obj_desc, next_walk_state); > + if (thread) > + acpi_ds_pop_walk_state(thread); > acpi_ds_delete_walk_state(next_walk_state); [Lv Zheng] It seems, if acpi_ds_create_walk_state() fails, acpi_ds_delete_walk_state() will be invoked. So they are paired. Fixing this in acpi_ds_delete_walk_state() could help to fix all of them. Given the fix is useful, why don't you do this in acpi_ds_delete_walk_state()? Thanks and best regards -Lv
