"Unambiguous" is is in particular taking as reference the assembler,
which also accepts certain insns - despite them allowing for varying
operand size, and hence in principle being ambiguous - without any
suffix. For example, from the very beginning of the life of x86-64 I had
trouble understanding why a plain and simple RET had to be printed as
RETQ. In case someone really used the 16-bit form, RETW disambiguates
the two quite fine.
We can generate x86-64 TLS code sequences for general and local dynamic
models without PLT, which uses indirect call via GOT:
call *__tls_get_addr@GOTPCREL(%rip)
instead of direct call:
call __tls_get_addr[@PLT]
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, one 0x66 prefix before call instruction is
removed 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
4 0x66 prefixes, instead of 3, before mov instruction in 64-bit and
generate a 5-byte nop, instead of 4-byte, before mov instruction in
32-bit. Since linker may convert
call *__tls_get_addr@GOTPCREL(%rip)
to
addr32 call __tls_get_addr
when producing static executable, both patterns are recognized.
bfd/
* elf64-x86-64.c (elf_x86_64_link_hash_entry): Add tls_get_addr.
(elf_x86_64_link_hash_newfunc): Initialize tls_get_addr to 2.
(elf_x86_64_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_x86_64_convert_load_reloc): Always use addr32 prefix for
indirect __tls_get_addr call via GOT.
(elf_x86_64_relocate_section): Handle GD->LE, GD->IE and LD->LE
transitions with indirect call and direct call with the addr32
prefix.
ld/
* testsuite/ld-x86-64/pass.out: New file.
* testsuite/ld-x86-64/tls-def1.c: Likewise.
* testsuite/ld-x86-64/tls-gd1.S: Likewise.
* testsuite/ld-x86-64/tls-ld1.S: Likewise.
* testsuite/ld-x86-64/tls-main1.c: Likewise.
* testsuite/ld-x86-64/tls.exp: Likewise.
* testsuite/ld-x86-64/tlsbin2-nacl.rd: Likewise.
* testsuite/ld-x86-64/tlsbin2.dd: Likewise.
* testsuite/ld-x86-64/tlsbin2.rd: Likewise.
* testsuite/ld-x86-64/tlsbin2.sd: Likewise.
* testsuite/ld-x86-64/tlsbin2.td: Likewise.
* testsuite/ld-x86-64/tlsbinpic2.s: Likewise.
* testsuite/ld-x86-64/tlsgd10.dd: Likewise.
* testsuite/ld-x86-64/tlsgd10.s: Likewise.
* testsuite/ld-x86-64/tlsgd11.dd: Likewise.
* testsuite/ld-x86-64/tlsgd11.s: Likewise.
* testsuite/ld-x86-64/tlsgd12.d: Likewise.
* testsuite/ld-x86-64/tlsgd12.s: Likewise.
* testsuite/ld-x86-64/tlsgd13.d: Likewise.
* testsuite/ld-x86-64/tlsgd13.s: Likewise.
* testsuite/ld-x86-64/tlsgd14.dd: Likewise.
* testsuite/ld-x86-64/tlsgd14.s: Likewise.
* testsuite/ld-x86-64/tlsgd5c.s: Likewise.
* testsuite/ld-x86-64/tlsgd6c.s: Likewise.
* testsuite/ld-x86-64/tlsgd9.dd: Likewise.
* testsuite/ld-x86-64/tlsgd9.s: Likewise.
* testsuite/ld-x86-64/tlsld4.dd: Likewise.
* testsuite/ld-x86-64/tlsld4.s: Likewise.
* testsuite/ld-x86-64/tlsld5.dd: Likewise.
* testsuite/ld-x86-64/tlsld5.s: Likewise.
* testsuite/ld-x86-64/tlsld6.dd: Likewise.
* testsuite/ld-x86-64/tlsld6.s: Likewise.
* testsuite/ld-x86-64/tlspic2-nacl.rd: Likewise.
* testsuite/ld-x86-64/tlspic2.dd: Likewise.
* testsuite/ld-x86-64/tlspic2.rd: Likewise.
* testsuite/ld-x86-64/tlspic2.sd: Likewise.
* testsuite/ld-x86-64/tlspic2.td: Likewise.
* testsuite/ld-x86-64/tlspic3.s: Likewise.
* testsuite/ld-x86-64/tlspie2.s: Likewise.
* testsuite/ld-x86-64/tlspie2a.d: Likewise.
* testsuite/ld-x86-64/tlspie2b.d: Likewise.
* testsuite/ld-x86-64/tlspie2c.d: Likewise.
* testsuite/ld-x86-64/tlsgd5.dd: Updated.
* testsuite/ld-x86-64/tlsgd6.dd: Likewise.
* testsuite/ld-x86-64/x86-64.exp: Run libtlspic2.so, tlsbin2,
tlsgd5b, tlsgd6b, tlsld4, tlsld5, tlsld6, tlsgd9, tlsgd10,
tlsgd11, tlsgd14, tlsgd12, tlsgd13, tlspie2a, tlspie2b and
tlspie2c.
