glibc 2.22 or prior have a bug that the dynamic linker (ld-linux.so.2)
crashes on `dlopen` if .rela.dyn and .rela.plt are not contiguous in
the `dlopen`-ed file and RTLD_NOW is specified. That bug was fixed in
fa19d5c48a.
glibc 2.23 which includes the fix for the bug was released on 2016-02-18.
So, unless you are using glibc that is more than 5 years old, mold-
generated shared object files work fine with `dlopen`. But it is easy
to make the sections contiguous in file, so I'll commit this change as a
workaround for the bug.
Fixes https://github.com/rui314/mold/issues/120
Previously, mold created two or more ".rodata" sections if input files
contain regular .rodata sections as well as .rodata.str* or .rodata.cst*
sections. This is because .rodata.str* and .rodata.cst* contains mergeable
section contents (i.e. string constants and constant pools, respectively),
and they are handled in a special way.
In ELF, section names are not significant, so nothing is wrong with
creating multiple .rodata. However, valgrind unfortunately doesn't like
such executable.
With this change, mold keeps ".rodata.str" and ".rodata.cst" prefixes
to avoid creating multiple ".rodata" sections.
Fixes https://github.com/rui314/mold/issues/118
mold used to emit a spurious "recompile with -fPIC" error when creating
a position-dependent executable. This is because we alwyas create
dynamic relocations for importe symbols. If the relocated place is
read-only, we can't apply a dynamic relocation, and we printed out the
error message.
This patch fixes the issue by creating copy relocations and PLTs for
such symbols.
Fixes https://github.com/rui314/mold/issues/116
