freebsd-skq/libexec/rtld-elf/mips
John Baldwin b4e9a36bf7 Handle relocations for newer non-PIC MIPS ABI.
Newer binutils supports extensions to the MIPS ABI for non-PIC code
that is used when compiling O32 binaries with clang 5 (but not used
for N64 oddly enough).  These extensions require support for
R_MIPS_COPY relocations as well as a second PLT GOT using
R_MIPS_JUMP_SLOT relocations.

For R_MIPS_COPY, use the same approach as on other architectures where
fixups are deferred to the MD do_copy_relocations.

The additional PLT GOT for jump slots is located in a .got.plt section
which is identified by a DT_MIPS_PLTGOT dynamic entry.  This GOT also
requires fixups for the first two GOT entries just as the normal GOT.
However, the entry point for this second GOT uses a different calling
convention. Rather than passing an offset into the GOT, it passes an
offset into the .rel.plt section.  This requires a second entry point
(_rtld_pltbind_start) which calls the normal _rtld_bind() rather than
_mips_rtld_bind().  This also means providing a real version of
reloc_jmpslot() which is used by _rtld_bind().

In addition, add real implementions of reloc_plt() and
reloc_jmpslots() which walk .rel.plt handling R_MIPS_JUMP_SLOT
relocations.

Reviewed by:	kib
Sponsored by:	DARPA / AFRL
Differential Revision:	https://reviews.freebsd.org/D12326
2017-09-12 17:46:30 +00:00
..
reloc.c Handle relocations for newer non-PIC MIPS ABI. 2017-09-12 17:46:30 +00:00
rtld_machdep.h rtld: fix warnings about redundant declarations 2017-05-26 15:55:03 +00:00
rtld_start.S Handle relocations for newer non-PIC MIPS ABI. 2017-09-12 17:46:30 +00:00