On Tuesday, July 10, 2018 5:44:05 AM CEST Jeremy Linton wrote: > Hi, > > On 07/09/2018 04:28 PM, Rafael J. Wysocki wrote: > > On Mon, Jul 9, 2018 at 10:45 PM, Jeremy Linton <jeremy.linton@xxxxxxx> wrote: > >> Hi, > >> > >> First thanks for the patch.. > >> > >> On 07/08/2018 04:14 AM, Rafael J. Wysocki wrote: > >>> > >>> On Monday, July 2, 2018 11:41:42 PM CEST Jeremy Linton wrote: > >>>> > >>>> Hi, > >>>> > >>>> I'm experiencing two problems with commit 5088814a6e931 which is > >>>> "ACPICA: AML parser: attempt to continue loading table after error" > >>>> > >>>> The first is this boot failure on a thunderX2: > >>>> > >>>> [ 10.770098] ACPI Error: Ignore error and continue table load > >> > >> > >> [trimming] > >> > >>>> ]--- > >>>> > >>>> Which does appear to be the result of some bad data in the table, but it > >>>> was working with 4.17, and reverting this commit solves the problem. > >>> > >>> > >>> Does the patch below make any difference? > >>> > >>> --- > >>> drivers/acpi/acpica/psobject.c | 3 +++ > >>> 1 file changed, 3 insertions(+) > >>> > >>> Index: linux-pm/drivers/acpi/acpica/psobject.c > >>> =================================================================== > >>> --- linux-pm.orig/drivers/acpi/acpica/psobject.c > >>> +++ linux-pm/drivers/acpi/acpica/psobject.c > >>> @@ -39,6 +39,9 @@ static acpi_status acpi_ps_get_aml_opcod > >>> ACPI_FUNCTION_TRACE_PTR(ps_get_aml_opcode, walk_state); > >>> walk_state->aml = walk_state->parser_state.aml; > >>> + if (!walk_state->aml) > >>> + return AE_CTRL_PARSE_CONTINUE; > >>> + > >> > >> > >> Well this seems to avoid the crash, but now it hangs right after on the > >> "Ignore error and continue table load" message. > > > > Well, maybe we should just abort in that case. > > > > I'm wondering what happens if you replace the return statement in the > > patch above with > > > > return_ACPI_STATUS(AE_AML_BAD_OPCODE) > > Yes, that is where I went when I applied the patch but I used > AE_CTRL_TERMINATE, which terminates the loop in acpi_ps_parse_loop() and > that appears to successfully finish/terminate the initial parsing pass. > But, it then crashes in acpi_ns_lookup called via the > acpi_walk_resources sequences that goes through ut_evalute_object() due > to the path/scope_info->scope.node being ACPI_ROOT_OBJECT (-1) and > bypassing the null check. Adding a ACPI_ROOT_OBJECT check as well as the > null checks in acpi_ns_lookup results in a successful boot. Tracking > down how the terminate (or whatever) is leaving the info->prefix_node > (in acpi_ns_evaluate) set to ROOT_OBJECT instead of null, is something I > don't yet understand. > > Anyway, I tried Using BAD_OPCODE rather than TERMINATE and it seems to > have the same basic result as PARSE_CONTINUE. OK, thanks! I evidently didn't look deep enough. Can you please check the patch below? I'm not sure if we can pass this broken state to acpi_ps_complete_final_op(), so it may be necessary to return an error directly when aml_op_start is NULL. --- drivers/acpi/acpica/psloop.c | 3 +++ 1 file changed, 3 insertions(+) Index: linux-pm/drivers/acpi/acpica/psloop.c =================================================================== --- linux-pm.orig/drivers/acpi/acpica/psloop.c +++ linux-pm/drivers/acpi/acpica/psloop.c @@ -493,6 +493,9 @@ acpi_status acpi_ps_parse_loop(struct ac ASL_CV_CAPTURE_COMMENTS(walk_state); aml_op_start = parser_state->aml; + if (!aml_op_start) + break; + if (!op) { status = acpi_ps_create_op(walk_state, aml_op_start, &op); -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html