diff options
| author | Alan Modra <amodra@gmail.com> | 2017-07-31 10:18:46 +0930 |
|---|---|---|
| committer | Alan Modra <amodra@gmail.com> | 2017-07-31 13:20:44 +0930 |
| commit | d44c746aedeb31aacd867edc2da30dedc1e63e15 (patch) | |
| tree | 2e8e6f68db504b37e84bfc8644321e4ccfc983c5 | |
| parent | 93e0a1eab1c7963d77513aa503b129ea03cd6d39 (diff) | |
| download | binutils-gdb-d44c746aedeb31aacd867edc2da30dedc1e63e15.tar.gz | |
PR 21847, PowerPC64 --plt-localentry again
This makes ld warn about --plt-localentry if a version of glibc
without the necessary ld.so checks is detected, and revises the
documentation.
bfd/
* elf64-ppc.c (ppc64_elf_tls_setup): Warn on --plt-localentry
without ld.so checks.
gold/
* powerpc.cc (Target_powerpc::scan_relocs): Warn on --plt-localentry
without ld.so checks.
ld/
* ld.texinfo (plt-localentry): Revise.
| -rw-r--r-- | bfd/ChangeLog | 5 | ||||
| -rw-r--r-- | bfd/elf64-ppc.c | 6 | ||||
| -rw-r--r-- | gold/ChangeLog | 5 | ||||
| -rw-r--r-- | gold/powerpc.cc | 4 | ||||
| -rw-r--r-- | ld/ChangeLog | 4 | ||||
| -rw-r--r-- | ld/ld.texinfo | 7 |
6 files changed, 29 insertions, 2 deletions
diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 41c935dd0d8..9839a3487f5 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,8 @@ +2017-07-31 Alan Modra <amodra@gmail.com> + + * elf64-ppc.c (ppc64_elf_tls_setup): Warn on --plt-localentry + without ld.so checks. + 2017-07-29 Alan Modra <amodra@gmail.com> PR 21847 diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c index 5f3c79f8111..7f4f7b6b86f 100644 --- a/bfd/elf64-ppc.c +++ b/bfd/elf64-ppc.c @@ -8372,6 +8372,12 @@ ppc64_elf_tls_setup (struct bfd_link_info *info) --plt-localentry can cause trouble. */ if (htab->params->plt_localentry0 < 0) htab->params->plt_localentry0 = 0; + if (htab->params->plt_localentry0 + && elf_link_hash_lookup (&htab->elf, "GLIBC_2.26", + FALSE, FALSE, FALSE) == NULL) + info->callbacks->einfo + (_("%P: warning: --plt-localentry is especially dangerous without " + "ld.so support to detect ABI violations.\n")); htab->tls_get_addr = ((struct ppc_link_hash_entry *) elf_link_hash_lookup (&htab->elf, ".__tls_get_addr", diff --git a/gold/ChangeLog b/gold/ChangeLog index a0193937001..e7567e65926 100644 --- a/gold/ChangeLog +++ b/gold/ChangeLog @@ -1,3 +1,8 @@ +2017-07-31 Alan Modra <amodra@gmail.com> + + * powerpc.cc (Target_powerpc::scan_relocs): Warn on --plt-localentry + without ld.so checks. + 2017-07-29 Alan Modra <amodra@gmail.com> PR 21847 diff --git a/gold/powerpc.cc b/gold/powerpc.cc index e322d6f8836..14e56d88f9d 100644 --- a/gold/powerpc.cc +++ b/gold/powerpc.cc @@ -7660,6 +7660,10 @@ Target_powerpc<size, big_endian>::scan_relocs( { if (parameters->options().user_set_plt_localentry()) plt_localentry0 = parameters->options().plt_localentry(); + if (plt_localentry0 + && symtab->lookup("GLIBC_2.26", NULL) == NULL) + gold_warning(_("--plt-localentry is especially dangerous without " + "ld.so support to detect ABI violations")); } this->plt_localentry0_ = plt_localentry0; this->plt_localentry0_init_ = true; diff --git a/ld/ChangeLog b/ld/ChangeLog index 2a371b9c250..3c918e6c583 100644 --- a/ld/ChangeLog +++ b/ld/ChangeLog @@ -1,3 +1,7 @@ +2017-07-31 Alan Modra <amodra@gmail.com> + + * ld.texinfo (plt-localentry): Revise. + 2017-07-29 Alan Modra <amodra@gmail.com> * ld.texinfo (plt-localentry): Document. diff --git a/ld/ld.texinfo b/ld/ld.texinfo index 172c1ddd9fa..ebe7e7b7bdf 100644 --- a/ld/ld.texinfo +++ b/ld/ld.texinfo @@ -7613,8 +7613,11 @@ Such an external function can be called via the PLT without saving r2 or restoring it on return, avoiding a common load-hit-store for small functions. The optimization is attractive, with up to 40% reduction in execution time for a small function, but can result in symbol -interposition failures. Use with care. @option{--no-plt-localentry} -is the default. +interposition failures. Also, minor changes in a shared library, +including system libraries, can cause a function that was localentry:0 +to become localentry:8. This will result in a dynamic loader +complaint and failure to run. The option is experimental, use with +care. @option{--no-plt-localentry} is the default. @end table @ifclear GENERIC |