Version 20190509

09 May 2019. Summary of changes for version 20190509:

This release is available at https://acpica.org/downloads

1) ACPICA kernel-resident subsystem:

Revert commit 6c43e1a ("ACPICA: Clear status of GPEs before enabling them") that causes problems with Thunderbolt controllers to occur if a dock device is connected at init time (the xhci_hcd and thunderbolt modules crash which prevents peripherals connected through them from working). Commit 6c43e1a effectively causes commit ecc1165b8b74 ("ACPICA: Dispatch active GPEs at init time") to get undone, so the problem addressed by commit ecc1165b8b74 appears again as a result of it.

2) iASL Compiler/Disassembler and ACPICA tools:

Reverted iASL: Additional forward reference detection. This change reverts forward reference detection for field declarations. The feature unintentionally emitted AML bytecode with incorrect package lengths for some ASL code related to Fields and OperationRegions. This malformed AML can cause systems to crash
during boot. The malformed AML bytecode is emitted in iASL version 20190329 and 20190405.

iASL: improve forward reference detection. This change improves forward reference detection for named objects inside of scopes. If a parse object has the OP_NOT_FOUND_DURING_LOAD set, it means that Op is a reference to a named object that is declared later in the AML bytecode. This is allowed if the reference is inside of a method and the declaration is outside of a method like so:

DefinitionBlock(...)
{
Method (TEST)
{
Return (NUM0)
}
Name (NUM0,0)
}

However, if the declaration and reference are both in the same method or outside any methods, this is a forward reference and should be marked as an error because it would result in runtime errors.

DefinitionBlock(...)
{
Name (BUFF, Buffer (NUM0) {}) // Forward reference
Name (NUM0, 0x0)

Method (TEST)
{
Local0 = NUM1
Name (NUM1, 0x1) // Forward reference
return (Local0)
}
}

iASL: Implemented additional buffer overflow analysis for BufferField declarations. Check if a buffer index argument to a create buffer field operation is beyond the end of the target buffer.

This affects these AML operators:

AML_CREATE_FIELD_OP
AML_CREATE_BIT_FIELD_OP
AML_CREATE_BYTE_FIELD_OP
AML_CREATE_WORD_FIELD_OP
AML_CREATE_DWORD_FIELD_OP
AML_CREATE_QWORD_FIELD_OP

There are three conditions that must be satisfied in order to allow this validation at compile time:

1) The length of the target buffer must be an integer constant
2) The index specified in the create* must be an integer constant
3) For CreateField, the bit length argument must be non-zero.

Example:
Name (BUF1, Buffer() {1,2})
CreateField (BUF1, 7, 9, CF03) // 3: ERR

dsdt.asl 14: CreateField (BUF1, 7, 9, CF03) // 3: ERR
Error 6165 - ^ Buffer index beyond end of target buffer