We can generate i386 TLS code sequences for general and local dynamic
models without PLT, which uses indirect call via GOT:
call *___tls_get_addr@GOT(%reg)
where EBX register isn't required as GOT base, instead of direct call:
call ___tls_get_addr[@PLT]
which requires EBX register as GOT base.
Since direct call is 4-byte long and indirect call, is 5-byte long, the
extra one byte must be handled properly.
For general dynamic model, 7-byte lea instruction before call instruction
is replaced by 6-byte one to make room for indirect call. For local
dynamic model, we simply use 5-byte indirect call.
TLS linker optimization is updated to recognize new instruction patterns.
For local dynamic model to local exec model transition, we generate
a 6-byte lea instruction as nop, instead of a 1-byte nop plus a 4-byte
lea instruction. Since linker may convert
call ___tls_get_addr[@PLT]
to
addr32 call ____tls_get_addr
when producing static executable, both patterns are recognized.
bfd/
* elf64-i386.c (elf_i386_link_hash_entry): Add tls_get_addr.
(elf_i386_link_hash_newfunc): Initialize tls_get_addr to 2.
(elf_i386_check_tls_transition): Check indirect call and direct
call with the addr32 prefix for general and local dynamic models.
Set the tls_get_addr feild.
(elf_i386_convert_load_reloc): Always use addr32 prefix for
indirect ___tls_get_addr call via GOT.
(elf_i386_relocate_section): Handle GD->LE, GD->IE and LD->LE
transitions with indirect call and direct call with the addr32
prefix.
ld/
* testsuite/ld-i386/i386.exp: Run libtlspic2.so, tlsbin2,
tlsgd3, tlsld2, tlsgd4, tlspie3a, tlspie3b and tlspie3c.
* testsuite/ld-i386/pass.out: New file.
* testsuite/ld-i386/tls-def1.c: Likewise.
* testsuite/ld-i386/tls-gd1.S: Likewise.
* testsuite/ld-i386/tls-ld1.S: Likewise.
* testsuite/ld-i386/tls-main1.c: Likewise.
* testsuite/ld-i386/tls.exp: Likewise.
* testsuite/ld-i386/tlsbin2-nacl.rd: Likewise.
* testsuite/ld-i386/tlsbin2.dd: Likewise.
* testsuite/ld-i386/tlsbin2.rd: Likewise.
* testsuite/ld-i386/tlsbin2.sd: Likewise.
* testsuite/ld-i386/tlsbin2.td: Likewise.
* testsuite/ld-i386/tlsbinpic2.s: Likewise.
* testsuite/ld-i386/tlsgd3.dd: Likewise.
* testsuite/ld-i386/tlsgd3.s: Likewise.
* testsuite/ld-i386/tlsgd4.d: Likewise.
* testsuite/ld-i386/tlsgd4.s: Likewise.
* testsuite/ld-i386/tlsld2.s: Likewise.
* testsuite/ld-i386/tlspic2-nacl.rd: Likewise.
* testsuite/ld-i386/tlspic2.dd: Likewise.
* testsuite/ld-i386/tlspic2.rd: Likewise.
* testsuite/ld-i386/tlspic2.sd: Likewise.
* testsuite/ld-i386/tlspic2.td: Likewise.
* testsuite/ld-i386/tlspic3.s: Likewise.
* testsuite/ld-i386/tlspie3.s: Likewise.
* testsuite/ld-i386/tlspie3a.d: Likewise.
* testsuite/ld-i386/tlspie3b.d: Likewise.
* testsuite/ld-i386/tlspie3c.d: Likewise.
H.J. Lu