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authorLinus Torvalds <torvalds@linux-foundation.org>2017-06-15 17:51:19 +0900
committerLinus Torvalds <torvalds@linux-foundation.org>2017-06-15 17:51:19 +0900
commit35e60a6b7577218ac7eb7777c8849822a080e127 (patch)
treea1578093e1e88e17a53ac7b99b0638bd110e04ee /drivers
parent92091c438bad93ba2591e8c4ba86126227327be2 (diff)
parent9522933454f4c4bd5bedf3d71c538708b7c5de5b (diff)
Merge tag 'acpi-4.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI fixes from Rafael Wysocki: "These revert an ACPICA commit from the 4.11 cycle that causes problems to happen on some systems and add a protection against possible kernel crashes due to table reference counter imbalance. Specifics: - Revert a 4.11 ACPICA change that made assumptions which are not satisfied on some systems and caused the enumeration of resources to fail on them (Rafael Wysocki). - Add a mechanism to prevent tables from being unmapped prematurely due to reference counter overflows (Lv Zheng)" * tag 'acpi-4.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: ACPICA: Tables: Mechanism to handle late stage acpi_get_table() imbalance Revert "ACPICA: Disassembler: Enhance resource descriptor detection"
Diffstat (limited to 'drivers')
-rw-r--r--drivers/acpi/acpica/tbutils.c34
-rw-r--r--drivers/acpi/acpica/utresrc.c9
2 files changed, 25 insertions, 18 deletions
diff --git a/drivers/acpi/acpica/tbutils.c b/drivers/acpi/acpica/tbutils.c
index 7abe66505739..0d2e98920069 100644
--- a/drivers/acpi/acpica/tbutils.c
+++ b/drivers/acpi/acpica/tbutils.c
@@ -416,9 +416,18 @@ acpi_tb_get_table(struct acpi_table_desc *table_desc,
}
}
- table_desc->validation_count++;
- if (table_desc->validation_count == 0) {
- table_desc->validation_count--;
+ if (table_desc->validation_count < ACPI_MAX_TABLE_VALIDATIONS) {
+ table_desc->validation_count++;
+
+ /*
+ * Detect validation_count overflows to ensure that the warning
+ * message will only be printed once.
+ */
+ if (table_desc->validation_count >= ACPI_MAX_TABLE_VALIDATIONS) {
+ ACPI_WARNING((AE_INFO,
+ "Table %p, Validation count overflows\n",
+ table_desc));
+ }
}
*out_table = table_desc->pointer;
@@ -445,13 +454,20 @@ void acpi_tb_put_table(struct acpi_table_desc *table_desc)
ACPI_FUNCTION_TRACE(acpi_tb_put_table);
- if (table_desc->validation_count == 0) {
- ACPI_WARNING((AE_INFO,
- "Table %p, Validation count is zero before decrement\n",
- table_desc));
- return_VOID;
+ if (table_desc->validation_count < ACPI_MAX_TABLE_VALIDATIONS) {
+ table_desc->validation_count--;
+
+ /*
+ * Detect validation_count underflows to ensure that the warning
+ * message will only be printed once.
+ */
+ if (table_desc->validation_count >= ACPI_MAX_TABLE_VALIDATIONS) {
+ ACPI_WARNING((AE_INFO,
+ "Table %p, Validation count underflows\n",
+ table_desc));
+ return_VOID;
+ }
}
- table_desc->validation_count--;
if (table_desc->validation_count == 0) {
diff --git a/drivers/acpi/acpica/utresrc.c b/drivers/acpi/acpica/utresrc.c
index e0587c85bafd..ff096d9755b9 100644
--- a/drivers/acpi/acpica/utresrc.c
+++ b/drivers/acpi/acpica/utresrc.c
@@ -474,15 +474,6 @@ acpi_ut_walk_aml_resources(struct acpi_walk_state *walk_state,
return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);
}
- /*
- * The end_tag opcode must be followed by a zero byte.
- * Although this byte is technically defined to be a checksum,
- * in practice, all ASL compilers set this byte to zero.
- */
- if (*(aml + 1) != 0) {
- return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);
- }
-
/* Return the pointer to the end_tag if requested */
if (!user_function) {