#593 gelf_getsymshndx errors when second parameter is NULL

[Ethan Sommer]

elfutils gelf_getsymshndx does not error when the second parameter is non-NULL, and as of linux kernel 5.8, this seems to be a way that function is used. elfutils has this comment: "The user is not required to pass a data descriptor for an extended section index table." which I think is about not requiring the second parameter to be non-NULL, would it be possible for gelf_getsymshndx to be changed to support that behaviour, so that elftoolchain's libelf can continue to be used to build the kernel?

[Ethan Sommer]

I have attached a patch that I believe resolves this issue, and only retrieves the extended section index when the 2nd parameter is non-NULL.

[Ethan Sommer]

ping?

[Michael Forney]

FWIW, I also ran into this issue and Ethan's patch looks good to me. I just made a slight tweak to remove the impossible lid == NULL check in the subsequent if statement.

I attached my patch variation.

[Joseph Koshy]

I'll be taking this up shortly.

The manual needs to be changed along with this code change.

The libelf test suite doesn't have tests for gelf_getsymshndx() currently. I'll need to add those later.

[Joseph Koshy]

Fixed in [r3873].

[Joseph Koshy]

Could you please confirm that the fix works for you?