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authorBob Moore <robert.moore@intel.com>2017-04-26 10:17:43 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2017-04-27 00:30:58 +0200
commitda28e1955d7fc228870f437693cfae8ce486ad9f (patch)
treef40b3ef5f511eeb696729e37202e5ae7f293ab87 /drivers/acpi
parentMerge back ACPICA changes for v4.12. (diff)
downloadlinux-da28e1955d7fc228870f437693cfae8ce486ad9f.tar.xz
linux-da28e1955d7fc228870f437693cfae8ce486ad9f.zip
ACPICA: Disassembler: Enhance resource descriptor detection
ACPICA commit ba5020b2dbe1538e4ccd7ac2dfd8843a690c007f This change enhances the detection of resource descriptors within a buffer object. For the end_tag opcode, the second byte is defined to be either a checksum or zero. All known ASL compilers insert a zero for this byte. The disassembler now ensures this byte is zero before deciding that a buffer should be disassembled to a resource descriptor. This helps eliminate incorrect decisions when attempting to disassemble a buffer to a resource descriptor. Link: https://github.com/acpica/acpica/commit/ba5020b2 Signed-off-by: Bob Moore <robert.moore@intel.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/acpica/utresrc.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/acpi/acpica/utresrc.c b/drivers/acpi/acpica/utresrc.c
index ff096d9755b9..e0587c85bafd 100644
--- a/drivers/acpi/acpica/utresrc.c
+++ b/drivers/acpi/acpica/utresrc.c
@@ -474,6 +474,15 @@ 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) {