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aarch64: Enable ifunc support. 

Add support for handling the R_AARCH64_IRELATIVE relocation and
STT_GNU_IFUNC symbols to the aarch64 port.

ports/ChangeLog.aarch64:

2013-11-26  Will Newton  <will.newton@linaro.org>

	* sysdeps/aarch64/dl-irel.h: Include ldsodefs.h.
	(ELF_MACHINE_IRELA): Define.  (elf_ifunc_invoke): Pass
	hwcap to ifunc resolver function.  (elf_irela): New function.
	* sysdeps/aarch64/dl-machine.h: Include dl-irel.h.
	(elf_machine_rela) Handle STT_GNU_IFUNC symbols and
	R_AARCH64_IRELATIVE relocations.  (elf_machine_lazy_rel):
	Handle R_AARCH64_IRELATIVE relocations.
This commit is contained in:
Will Newton 2013-11-25 14:56:28 +00:00
parent 6f476861be
commit 7520ff8c74
3 changed files with 49 additions and 3 deletions
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10
ports/ChangeLog.aarch64
View File

@ -1,3 +1,13 @@
2013-11-26 Will Newton <will.newton@linaro.org>
* sysdeps/aarch64/dl-irel.h: Include ldsodefs.h.
(ELF_MACHINE_IRELA): Define. (elf_ifunc_invoke): Pass
hwcap to ifunc resolver function. (elf_irela): New function.
* sysdeps/aarch64/dl-machine.h: Include dl-irel.h.
(elf_machine_rela) Handle STT_GNU_IFUNC symbols and
R_AARCH64_IRELATIVE relocations. (elf_machine_lazy_rel):
Handle R_AARCH64_IRELATIVE relocations.
2013-10-30 Mike Frysinger <vapier@gentoo.org>
* sysdeps/unix/sysv/linux/aarch64/configure.in: Moved to ...

22
ports/sysdeps/aarch64/dl-irel.h
View File

@ -22,15 +22,31 @@
#include <stdio.h>
#include <unistd.h>
#include <ldsodefs.h>
/* AArch64 does not yet implement IFUNC support. However since
2011-06-20 provision of a elf_ifunc_invoke has been mandatory. */
#define ELF_MACHINE_IRELA 1
static inline ElfW(Addr)
__attribute ((always_inline))
elf_ifunc_invoke (ElfW(Addr) addr)
{
return ((ElfW(Addr) (*) (void)) (addr)) ();
return ((ElfW(Addr) (*) (unsigned long int)) (addr)) (GLRO(dl_hwcap));
}
static inline void
__attribute ((always_inline))
elf_irela (const ElfW(Rela) *reloc)
{
ElfW(Addr) *const reloc_addr = (void *) reloc->r_offset;
const unsigned long int r_type = ELFW(R_TYPE) (reloc->r_info);
if (__glibc_likely (r_type == R_AARCH64_IRELATIVE))
{
ElfW(Addr) value = elf_ifunc_invoke (reloc->r_addend);
*reloc_addr = value;
}
else
__libc_fatal ("unexpected reloc type in static binary");
}
#endif

20
ports/sysdeps/aarch64/dl-machine.h
View File

@ -23,6 +23,7 @@
#include <tls.h>
#include <dl-tlsdesc.h>
#include <dl-irel.h>
/* Return nonzero iff ELF header is compatible with the running host. */
static inline int __attribute__ ((unused))
@ -243,6 +244,12 @@ elf_machine_rela (struct link_map *map, const ElfW(Rela) *reloc,
struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type);
ElfW(Addr) value = sym_map == NULL ? 0 : sym_map->l_addr + sym->st_value;
if (sym != NULL
&& __glibc_unlikely (ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC)
&& __glibc_likely (sym->st_shndx != SHN_UNDEF)
&& __glibc_likely (!skip_ifunc))
value = elf_ifunc_invoke (value);
switch (r_type)
{
case R_AARCH64_COPY:
@ -331,6 +338,12 @@ elf_machine_rela (struct link_map *map, const ElfW(Rela) *reloc,
}
break;
case R_AARCH64_IRELATIVE:
value = map->l_addr + reloc->r_addend;
value = elf_ifunc_invoke (value);
*reloc_addr = value;
break;
default:
_dl_reloc_bad_type (map, r_type, 0);
break;
@ -374,6 +387,13 @@ elf_machine_lazy_rel (struct link_map *map,
td->entry = (void*)(D_PTR (map, l_info[ADDRIDX (DT_TLSDESC_PLT)])
+ map->l_addr);
}
else if (__glibc_unlikely (r_type == R_AARCH64_IRELATIVE))
{
ElfW(Addr) value = map->l_addr + reloc->r_addend;
if (__glibc_likely (!skip_ifunc))
value = elf_ifunc_invoke (value);
*reloc_addr = value;
}
else
_dl_reloc_bad_type (map, r_type, 1);
}