[PATCH 3.16 060/133] ACPI, APEI, EINJ: Subtract any matching Register Region from Trigger resources

From: Ben Hutchings
Date: Tue Nov 21 2017 - 21:27:30 EST


3.16.51-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Yazen Ghannam <yazen.ghannam@xxxxxxx>

commit 1d5d820b8fe83b5f859d1ebb028a09ada426447e upstream.

ACPI defines a number of instructions to use for triggering errors. However
we are currently removing the address resources from the trigger resources
for only the WRITE_REGISTER_VALUE instruction. This leads to a resource
conflict for any other valid instruction.

Check that the instruction is less than or equal to the
WRITE_REGISTER_VALUE instruction. This allows all valid memory access
instructions and protects against invalid instructions.

Fixes: b4e008dc53a3 (ACPI, APEI, EINJ, Refine the fix of resource conflict)
Signed-off-by: Yazen Ghannam <yazen.ghannam@xxxxxxx>
Acked-by: Tony Luck <tony.luck@xxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/acpi/apei/einj.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/acpi/apei/einj.c
+++ b/drivers/acpi/apei/einj.c
@@ -285,7 +285,7 @@ static struct acpi_generic_address *einj
((char *)trigger_tab + sizeof(struct acpi_einj_trigger));
for (i = 0; i < trigger_tab->entry_count; i++) {
if (entry->action == ACPI_EINJ_TRIGGER_ERROR &&
- entry->instruction == ACPI_EINJ_WRITE_REGISTER_VALUE &&
+ entry->instruction <= ACPI_EINJ_WRITE_REGISTER_VALUE &&
entry->register_region.space_id ==
ACPI_ADR_SPACE_SYSTEM_MEMORY &&
(entry->register_region.address & param2) == (param1 & param2))