objtool warning when compiling modules on linux-6.1 onwards

geetz · 01-31-2023, 01:07 AM

Hi Team,

We are getting objtool warning while compiling our module with latest Linux Kernel 6.1.3 onwards.

warning: objtool: VNetCsumCopyDatagram+0x4e: call to csum_partial_copy_nocheck() with UACCESS enabled

Our code does exactly what csum_and_copy_to_user() does, unfortunately recent kernels do not export csum_and_copy_to_user or csum_partial_copy_generic, only csum_partial_copy_nocheck. So that's what we call.

Could someone please help to resolve the issue.

business_kid · 01-31-2023, 07:55 AM

Hello, geetz & welcome to LQ.

So someone was delegated from your team to join LQ and post the question, and you drew the short straw?
If you post again, provide proper details. How_To_Ask_a_Question

Try

Reading the kernel ChangeLog for changes affecting objtool.
Updating the relevant package, in case that helps.

changes like this are usually well flagged so people have time to get their ducks in a neat row before they take effect. So if 'we' are using linux commercially, 'we' should stay more in touch. There's probably a security issue behind it.