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| author | Alan Modra <amodra@gmail.com> | 2014-02-12 21:04:32 +1030 |
|---|---|---|
| committer | Alan Modra <amodra@gmail.com> | 2014-02-12 22:10:09 +1030 |
| commit | 9f7552cff4367fc58246f72223d7a1de84c660b7 (patch) | |
| tree | a37cb13f33379a021514dd739f7a5301d3634e85 /bfd | |
| parent | 795bc6b3eac9e3f80279df69c05d70fc44eaaa4c (diff) | |
| download | gdb-9f7552cff4367fc58246f72223d7a1de84c660b7.zip gdb-9f7552cff4367fc58246f72223d7a1de84c660b7.tar.gz gdb-9f7552cff4367fc58246f72223d7a1de84c660b7.tar.bz2 | |
Fix bad interaction between --relax and tls optimisation
Adding long-branch stubs for __tls_get_addr calls that are optimised
away is silly. It also causes assertion failures on newer object files
that use R_PPC_TLSGD and R_PPC_TLSLD marker relocs, and half-optimised
(ie. broken) code for older object files.
PR 16546
* elf32-ppc.c (ppc_elf_relax_section): Don't build long-branch
stubs for calls to __tls_get_addr that we know will later be
optimised away.
Diffstat (limited to 'bfd')
| -rw-r--r-- | bfd/ChangeLog | 6 | ||||
| -rw-r--r-- | bfd/elf32-ppc.c | 56 |
2 files changed, 62 insertions, 0 deletions
diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 120a2f5..39d9def 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,5 +1,11 @@ 2014-02-12 Alan Modra <amodra@gmail.com> + * elf32-ppc.c (ppc_elf_relax_section): Don't build long-branch + stubs for calls to __tls_get_addr that we know will later be + optimised away. + +2014-02-12 Alan Modra <amodra@gmail.com> + * elf32-ppc.c (ppc_elf_relax_section): Enable ppc476 workaround for ld -r, when code sections are sufficiently aligned. * elf32-ppc.h (struct ppc_elf_params): Delete pagesize. Add diff --git a/bfd/elf32-ppc.c b/bfd/elf32-ppc.c index f7c0366..d8e6108 100644 --- a/bfd/elf32-ppc.c +++ b/bfd/elf32-ppc.c @@ -6831,6 +6831,62 @@ ppc_elf_relax_section (bfd *abfd, else continue; + /* If this branch is to __tls_get_addr then we may later + optimise away the call. We won't be needing a long- + branch stub in that case. */ + if (link_info->executable + && !link_info->relocatable + && h == htab->tls_get_addr + && irel != internal_relocs) + { + unsigned long t_symndx = ELF32_R_SYM (irel[-1].r_info); + unsigned long t_rtype = ELF32_R_TYPE (irel[-1].r_info); + unsigned int tls_mask = 0; + + /* The previous reloc should be one of R_PPC_TLSGD or + R_PPC_TLSLD, or for older object files, a reloc + on the __tls_get_addr arg setup insn. Get tls + mask bits from the symbol on that reloc. */ + if (t_symndx < symtab_hdr->sh_info) + { + bfd_vma *local_got_offsets = elf_local_got_offsets (abfd); + + if (local_got_offsets != NULL) + { + struct plt_entry **local_plt = (struct plt_entry **) + (local_got_offsets + symtab_hdr->sh_info); + char *lgot_masks = (char *) + (local_plt + symtab_hdr->sh_info); + tls_mask = lgot_masks[t_symndx]; + } + } + else + { + struct elf_link_hash_entry *th + = elf_sym_hashes (abfd)[t_symndx - symtab_hdr->sh_info]; + + while (th->root.type == bfd_link_hash_indirect + || th->root.type == bfd_link_hash_warning) + th = (struct elf_link_hash_entry *) th->root.u.i.link; + + tls_mask + = ((struct ppc_elf_link_hash_entry *) th)->tls_mask; + } + + /* The mask bits tell us if the call will be + optimised away. */ + if ((tls_mask & TLS_TLS) != 0 && (tls_mask & TLS_GD) == 0 + && (t_rtype == R_PPC_TLSGD + || t_rtype == R_PPC_GOT_TLSGD16 + || t_rtype == R_PPC_GOT_TLSGD16_LO)) + continue; + if ((tls_mask & TLS_TLS) != 0 && (tls_mask & TLS_LD) == 0 + && (t_rtype == R_PPC_TLSLD + || t_rtype == R_PPC_GOT_TLSLD16 + || t_rtype == R_PPC_GOT_TLSLD16_LO)) + continue; + } + sym_type = h->type; } |