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| author |   Bob Moore <robert.moore@intel.com> | 2017-04-26 16:17:43 +0800 |
|---|---|---|
| committer |   Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2017-04-27 00:30:58 +0200 |
| commit | da28e1955d7fc228870f437693cfae8ce486ad9f (patch) | |
| tree | f40b3ef5f511eeb696729e37202e5ae7f293ab87 /drivers/acpi | |
| parent | Merge back ACPICA changes for v4.12. (diff) | |
| download | linux-dev-da28e1955d7fc228870f437693cfae8ce486ad9f.tar.xz linux-dev-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.c | 9 |
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) { |