rtld: add a test for RTLD_DEEPBIND

[kevans]

Summary

This tests that with RTLD_DEEPBIND, symbols are looked up in all of the
object's needed objects before the global object.

PR: 275393
Sponsored by: NetApp, Inc.
Sponsored by: Klara, Inc.

[kib]

libexec/rtld-elf/tests/Makefile

16

Do you new tests require lower warn level than 6?

libexec/rtld-elf/tests/libdeep/Makefile

12

Can this be some construct with $ORIGIN, to avoid abs path recording into DT_RUNPATH?

libexec/rtld-elf/tests/libdeep/libdeep.c

15

externs are not needed

libexec/rtld-elf/tests/libval/libval.c

13

extern's are not needed

[kevans]

libexec/rtld-elf/tests/libdeep/Makefile

12

lld doesn't seem to accept $ORIGIN for -rpath, unfortunately. I also couldn't figure out how to get it smuggled through bmake properly; $$ORIGIN would get through just fine as $ORIGIN, but somewhere between bmake rendering it and lld using it, it was transformed into -zrelro. I bypassed bmake and tried just linking it manually, and it gets angry because $ORIGIN's not a path.

[kevans]

libexec/rtld-elf/tests/Makefile

16

Nope, they're fine at the default (6)

[kevans]

Use -rpath $ORIGIN, thanks jrtc27
Drop redundant extern

[kib]

Did you checked, does the test pass with the D42841 applied?

[kevans]

In D42843#977270, @kib wrote:

Did you checked, does the test pass with the D42841 applied?

Yup, it's quite happy now, thanks!

[kevans]

libexec/rtld-elf/tests/rtld_deepbind/Makefile

3

This ends up clobbering Kyuafile from the other rtld tests. I can't push it to the directory above because it needs libval to build first, so I think I'll just push it to /usr/tests/libexec/rtld-elf/rtld_deepbind