llvm dev - May 2020 - [lld] dynamic section question.

This program:

.global _start

_start:

  movl $1, %eax

  movl $42, %ebx

  int $0x80

 

“./clang -nostdlib x.s”

 

Will not get a dynamic section unless -E passed to lld and because of that will
segfault.  If the .interp section is omitted (static) then the dynamic section
isn’t needed and the program will run.

 

Can lld recognize that an .interp is not needed (no DT_NEEDED) and omit the
section even when the user/driver adds –dynamic-linker=xxx?  Or should the
.dynamic section be present as in the case when -E is used?

 

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On 2020-05-22, sidneym at codeaurora.org wrote:
>This program:
>
>.global _start
>
>_start:
>
>  movl $1, %eax
>
>  movl $42, %ebx
>
>  int $0x80
>
>
>
>“./clang -nostdlib x.s”
>
>
>
>Will not get a dynamic section unless -E passed to lld and because of that
will segfault.  If the .interp section is omitted (static) then the dynamic
section isn’t needed and the program will run.
>
>
>
>Can lld recognize that an .interp is not needed (no DT_NEEDED) and omit the
section even when the user/driver adds –dynamic-linker=xxx?  Or should the
.dynamic section be present as in the case when -E is used?
clang passes --dynamic-linker to the linker. GNU ld has quite involved logic not
to create .interp
It is not at all clear to me that LLD should adopt that.

clang -static -nostdlib a.s -o a  # is probably more correct.
-static suppresses --dynamic-linker