Thumb ELFs with `.gnu_debugdata` can result in functions being created with incorrect platform

[zznop]

Version and Platform (required):

• Binary Ninja Version: 5.3
• CPU Architecture: Thumb-2

Bug Description:
Thumb-2 ELF files containing thumb function pointers in .gnu_debugdata result in those functions being incorrectly created as ARM functions

Steps To Reproduce:
Please provide all steps required to reproduce the behavior:

1. Open the attached binary
2. Navigate to android::(anonymous namespace)::CreateRelroFile at 0x11c8c
3. Observe that the function was created as ARM, resulting in bad decompilation

>>> current_function
<func: armv7@0x11c8c>

Expected Behavior:
A thumb-2 function should be created instead

Screenshots/Video Recording:

Additional Information:

Parsing the debug info ends up calling DefineAutoSymbolAndVariableOrFunction to add functions to the debug view. Platform::GetAssociatedPlatformByAddress strips the LSB and adds the symbol to the symbol queue with the adjusted address. The symbol queue is iterated to create functions and DefineAutoSymbolAndVariableOrFunction is called a second time - this time with the already adjusted address. This results in the function platform being identified as ARM.

We should not use symbol addresses to resolve the function platform as the symbol addresses should always have the lsb stripped. All DefineAutoSymbolAndVariableOrFunction(GetDefaultPlatform(), symbol, type); calls in elfview.cpp are wrong for function symbols for thumb-2 functions.

libwebviewchromium_loader.so.zip

Currently, the only workaround is to undefine the functions and recreate them from the right-click menu and manually set the thumb-2 platform.