diff options
Diffstat (limited to 'bfd/elf64-ppc.c')
| -rw-r--r-- | bfd/elf64-ppc.c | 48 |
1 files changed, 29 insertions, 19 deletions
diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c index a451c47..8319a21 100644 --- a/bfd/elf64-ppc.c +++ b/bfd/elf64-ppc.c @@ -2788,20 +2788,20 @@ must_be_dyn_reloc (struct bfd_link_info *info, } /* If ELIMINATE_COPY_RELOCS is non-zero, the linker will try to avoid - copying dynamic variables from a shared lib into an app's dynbss + copying dynamic variables from a shared lib into an app's .dynbss section, and instead use a dynamic relocation to point into the - shared lib. With code that gcc generates, it's vital that this be - enabled; In the PowerPC64 ABI, the address of a function is actually - the address of a function descriptor, which resides in the .opd - section. gcc uses the descriptor directly rather than going via the - GOT as some other ABI's do, which means that initialized function - pointers must reference the descriptor. Thus, a function pointer - initialized to the address of a function in a shared library will - either require a copy reloc, or a dynamic reloc. Using a copy reloc - redefines the function descriptor symbol to point to the copy. This - presents a problem as a plt entry for that function is also - initialized from the function descriptor symbol and the copy reloc - may not be initialized first. */ + shared lib. With code that gcc generates it is vital that this be + enabled; In the PowerPC64 ELFv1 ABI the address of a function is + actually the address of a function descriptor which resides in the + .opd section. gcc uses the descriptor directly rather than going + via the GOT as some other ABIs do, which means that initialized + function pointers reference the descriptor. Thus, a function + pointer initialized to the address of a function in a shared + library will either require a .dynbss copy and a copy reloc, or a + dynamic reloc. Using a .dynbss copy redefines the function + descriptor symbol to point to the copy. This presents a problem as + a PLT entry for that function is also initialized from the function + descriptor symbol and the copy may not be initialized first. */ #define ELIMINATE_COPY_RELOCS 1 /* Section name for stubs is the associated section name plus this @@ -6462,13 +6462,23 @@ ppc64_elf_adjust_dynamic_symbol (struct bfd_link_info *info, || h->protected_def) return TRUE; - if (h->plt.plist != NULL) + if (h->type == STT_FUNC + || h->type == STT_GNU_IFUNC) { - /* We should never get here, but unfortunately there are versions - of gcc out there that improperly (for this ABI) put initialized - function pointers, vtable refs and suchlike in read-only - sections. Allow them to proceed, but warn that this might - break at runtime. */ + /* .dynbss copies of function symbols only work if we have + ELFv1 dot-symbols. ELFv1 compilers since 2004 default to not + use dot-symbols and set the function symbol size to the text + size of the function rather than the size of the descriptor. + That's wrong for copying a descriptor. */ + if (((struct ppc_link_hash_entry *) h)->oh == NULL + || !(h->size == 24 || h->size == 16)) + return TRUE; + + /* We should never get here, but unfortunately there are old + versions of gcc (circa gcc-3.2) that improperly for the + ELFv1 ABI put initialized function pointers, vtable refs and + suchlike in read-only sections. Allow them to proceed, but + warn that this might break at runtime. */ info->callbacks->einfo (_("%P: copy reloc against `%pT' requires lazy plt linking; " "avoid setting LD_BIND_NOW=1 or upgrade gcc\n"), |