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| author | Alan Modra <amodra@gmail.com> | 2018-04-09 09:11:44 +0930 |
|---|---|---|
| committer | Alan Modra <amodra@gmail.com> | 2018-04-09 16:53:05 +0930 |
| commit | 37da22e5c85375b30e1211ecff1b261f425375f0 (patch) | |
| tree | 7df19745933aff7448284642e17d626b5270358c /bfd/ChangeLog | |
| parent | 51066b93507b79e46bcd6c998b760a2fd4b3d0a9 (diff) | |
| download | gdb-37da22e5c85375b30e1211ecff1b261f425375f0.zip gdb-37da22e5c85375b30e1211ecff1b261f425375f0.tar.gz gdb-37da22e5c85375b30e1211ecff1b261f425375f0.tar.bz2 | |
PowerPC indirect calls to __tls_get_addr
It is possible to construct indirect calls to __tls_get_addr in
assembly that confuse TLS optimization. (PowerPC gcc doesn't support
such calls, ignoring -mlongcall for __tls_get_addr.) This patch fixes
the problem by requiring a TLSLD or TLSGD marker reloc before any insn
in an indirect call to __tls_get_addr will be optimized. They also
need additional marker relocs defined in a later patch, so don't
expect the optimization to work just yet. The point here is to
prevent mis-optimization of indirect calls without any marker relocs.
The presense of a marker reloc is tracked by a new bit in the tls_mask
field of ppc_link_hash_entry and the corresponding lgot_masks unsigned
char array for local symbols. Since the field is only 8 bits, we've
run out of space. However, tracking TLS use for variables, and
tracking IFUNC for functions are independent, and bits can be reused.
TLS_TLS is always set for TLS usage, so can be used to select the
meaning of the other bits. This patch does that even for elf32-ppc.c
which hasn't yet run out of space in the field.
* elf64-ppc.c (TLS_TLS, TLS_GD, TLS_LD, TLS_TPREL, TLS_DTPREL,
TLS_TPRELGD, TLS_EXPLICIT): Renumber. Test TLS_TLS throughout
file when other TLS flags are tested in a mask.
(TLS_MARK, NON_GOT): Define.
(PLT_IFUNC): Redefine, and test TLS_TLS throughout file as well.
(update_local_sym_info): Don't create got entry when NON_GOT.
(ppc64_elf_check_relocs): Pass NON_GOT with PLT_IFUNC.
Set TLS_MARK.
(get_tls_mask): Do toc lookup if tls_mask is just TLS_MARK.
(ppc64_elf_relocate_section): Likewise.
(ppc64_elf_tls_optimize): Don't attempt to optimize indirect
__tls_get_addr calls lacking a marker reloc.
* elf32-ppc.c (TLS_TLS, TLS_GD, TLS_LD, TLS_TPREL, TLS_DTPREL,
TLS_TPRELGD): Renumber. Update comment.
(TLS_MARK, NON_GOT): Define.
(PLT_IFUNC): Redefine, and test TLS_TLS throughout file as well.
(update_local_sym_info): Don't create got entry when NON_GOT.
(ppc_elf_check_relocs): Pass NON_GOT with PLT_IFUNC.
Set TLS_MARK.
(ppc_elf_tls_optimize): Don't attempt to optimize indirect
__tls_get_addr calls lacking a marker reloc.
Diffstat (limited to 'bfd/ChangeLog')
| -rw-r--r-- | bfd/ChangeLog | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/bfd/ChangeLog b/bfd/ChangeLog index a8eaebb..99f5639 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,27 @@ +2018-04-09 Alan Modra <amodra@gmail.com> + + * elf64-ppc.c (TLS_TLS, TLS_GD, TLS_LD, TLS_TPREL, TLS_DTPREL, + TLS_TPRELGD, TLS_EXPLICIT): Renumber. Test TLS_TLS throughout + file when other TLS flags are tested in a mask. + (TLS_MARK, NON_GOT): Define. + (PLT_IFUNC): Redefine, and test TLS_TLS throughout file as well. + (update_local_sym_info): Don't create got entry when NON_GOT. + (ppc64_elf_check_relocs): Pass NON_GOT with PLT_IFUNC. + Set TLS_MARK. + (get_tls_mask): Do toc lookup if tls_mask is just TLS_MARK. + (ppc64_elf_relocate_section): Likewise. + (ppc64_elf_tls_optimize): Don't attempt to optimize indirect + __tls_get_addr calls lacking a marker reloc. + * elf32-ppc.c (TLS_TLS, TLS_GD, TLS_LD, TLS_TPREL, TLS_DTPREL, + TLS_TPRELGD): Renumber. Update comment. + (TLS_MARK, NON_GOT): Define. + (PLT_IFUNC): Redefine, and test TLS_TLS throughout file as well. + (update_local_sym_info): Don't create got entry when NON_GOT. + (ppc_elf_check_relocs): Pass NON_GOT with PLT_IFUNC. + Set TLS_MARK. + (ppc_elf_tls_optimize): Don't attempt to optimize indirect + __tls_get_addr calls lacking a marker reloc. + 2018-04-06 H.J. Lu <hongjiu.lu@intel.com> * elf64-x86-64.c (elf_x86_64_info_to_howto): Don't mask out |