@@ -1653,8 +1653,9 @@ typedef struct
#define R_MIPS_GLOB_DAT 51
#define R_MIPS_COPY 126
#define R_MIPS_JUMP_SLOT 127
+#define R_MIPS_IRELATIVE 128
/* Keep this the last entry. */
-#define R_MIPS_NUM 128
+#define R_MIPS_NUM 129
/* Legal values for p_type field of Elf32_Phdr. */
@@ -1731,7 +1732,9 @@ typedef struct
in a PIE as it stores a relative offset from the address of the tag
rather than an absolute address. */
#define DT_MIPS_RLD_MAP_REL 0x70000035
-#define DT_MIPS_NUM 0x36
+ /* Number of explicitly relocated GOT entries */
+#define DT_MIPS_GENERAL_GOTNO 0x70000036
+#define DT_MIPS_NUM 0x37
/* Legal values for DT_MIPS_FLAGS Elf32_Dyn entry. */
new file mode 100644
@@ -0,0 +1,63 @@
+/* Machine-dependent ELF indirect relocation inline functions.
+ MIPS version.
+ Copyright (C) 2015 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library. If not, see
+ <http://www.gnu.org/licenses/>. */
+
+#ifndef _DL_IREL_H
+#define _DL_IREL_H
+
+#include <stdio.h>
+#include <unistd.h>
+#include <sgidefs.h>
+#include <link.h>
+#include <elf.h>
+#include <ldsodefs.h>
+
+#define ELF_MACHINE_IREL 1
+
+static inline ElfW(Addr)
+__attribute ((always_inline))
+elf_ifunc_invoke (ElfW(Addr) addr)
+{
+ /* Print some debugging info if wanted. */
+ if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_SYMBOLS))
+ {
+ ElfW(Addr) t_addr =
+ ((ElfW(Addr) (*) (unsigned long int)) (addr)) (GLRO(dl_hwcap));
+ GLRO(dl_debug_printf) ("In elf_ifunc_invoke(0x%lx), return(0x%lx)\n",
+ (unsigned long int)addr,
+ (unsigned long int)t_addr);
+ }
+
+ return ((ElfW(Addr) (*) (unsigned long int)) (addr)) (GLRO(dl_hwcap));
+}
+
+/* Allow either R_MIPS_RELATIVE or the nop R_MIPS_NONE. */
+static inline void
+__attribute ((always_inline))
+elf_irel (const ElfW(Rel) *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_MIPS_IRELATIVE))
+ *reloc_addr = elf_ifunc_invoke (*reloc_addr);
+ else if (r_type)
+ __libc_fatal ("unexpected reloc type in static binary");
+}
+
+#endif /* dl-irel.h */
@@ -33,6 +33,7 @@
#include <sysdep.h>
#include <sys/asm.h>
#include <dl-tls.h>
+#include <dl-irel.h>
/* The offset of gp from GOT might be system-dependent. It's set by
ld. The same value is also */
@@ -200,10 +201,13 @@ do { \
if (__builtin_expect (map->l_addr == 0, 1)) \
break; \
\
- /* got[0] is reserved. got[1] is also reserved for the dynamic object \
- generated by gnu ld. Skip these reserved entries from \
- relocation. */ \
- i = (got[1] & ELF_MIPS_GNU_GOT1_MASK)? 2 : 1; \
+ if (map->l_info[DT_MIPS (GENERAL_GOTNO)] != NULL) \
+ i = map->l_info[DT_MIPS (GENERAL_GOTNO)]->d_un.d_val; \
+ else \
+ /* got[0] is reserved. got[1] is also reserved for the dynamic \
+ object generated by gnu ld. Skip these reserved entries from \
+ relocation. */ \
+ i = (got[1] & ELF_MIPS_GNU_GOT1_MASK)? 2 : 1; \
n = map->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val; \
\
/* Add the run-time displacement to all local got entries. */ \
@@ -493,7 +497,8 @@ auto inline void
__attribute__ ((always_inline))
elf_machine_reloc (struct link_map *map, ElfW(Addr) r_info,
const ElfW(Sym) *sym, const struct r_found_version *version,
- void *reloc_addr, ElfW(Addr) r_addend, int inplace_p)
+ void *reloc_addr, ElfW(Addr) r_addend, int inplace_p,
+ int skip_ifunc)
{
const unsigned long int r_type = ELFW(R_TYPE) (r_info);
ElfW(Addr) *addr_field = (ElfW(Addr) *) reloc_addr;
@@ -579,25 +584,31 @@ elf_machine_reloc (struct link_map *map, ElfW(Addr) r_info,
if ((ElfW(Word))symidx < gotsym)
{
- /* This wouldn't work for a symbol imported from other
- libraries for which there's no GOT entry, but MIPS
- requires every symbol referenced in a dynamic
- relocation to have a GOT entry in the primary GOT,
- so we only get here for locally-defined symbols.
- For section symbols, we should *NOT* be adding
- sym->st_value (per the definition of the meaning of
- S in reloc expressions in the ELF64 MIPS ABI),
- since it should have already been added to
- reloc_value by the linker, but older versions of
- GNU ld didn't add it, and newer versions don't emit
- useless relocations to section symbols any more, so
- it is safe to keep on adding sym->st_value, even
- though it's not ABI compliant. Some day we should
- bite the bullet and stop doing this. */
+ /* Linker will not normally emit symbolic relocations for
+ locally-defined global symbols. If we reach here, we must
+ be dealing with relocation to a global symbols which is
+ explicitly relocated via the general GOT region and
+ pre-emptible. */
#ifndef RTLD_BOOTSTRAP
- if (map != &GL(dl_rtld_map))
+ if (map->l_info[DT_MIPS (GENERAL_GOTNO)] == NULL)
+ {
+ const char *strtab;
+ strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
+
+ _dl_error_printf ("\
+%s: Explicitly relocated symbol `%s' requires dynamic tag MIPS_GENERAL_GOTNO\n",
+ RTLD_PROGNAME, strtab + sym->st_name);
+ }
+ else
+ {
+ struct link_map *rmap = RESOLVE_MAP (&sym, version, r_type);
+ if ((ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC))
+ reloc_value = elf_ifunc_invoke (sym->st_value
+ + rmap->l_addr);
+ else
+ reloc_value = sym->st_value + rmap->l_addr;
+ }
#endif
- reloc_value += sym->st_value + map->l_addr;
}
else
{
@@ -698,6 +709,14 @@ elf_machine_reloc (struct link_map *map, ElfW(Addr) r_info,
break;
}
+ case R_MIPS_IRELATIVE:
+ /* The resolver routine is the symbol referenced by this relocation.
+ To get the address of the function to use at runtime, the resolver
+ routine is called and its return value is the address of the target
+ functon which is final relocation value. */
+ *addr_field = elf_ifunc_invoke (map->l_addr + *addr_field);
+ break;
+
#if _MIPS_SIM == _ABI64
case R_MIPS_64:
/* For full compliance with the ELF64 ABI, one must precede the
@@ -727,7 +746,8 @@ elf_machine_rel (struct link_map *map, const ElfW(Rel) *reloc,
const ElfW(Sym) *sym, const struct r_found_version *version,
void *const reloc_addr, int skip_ifunc)
{
- elf_machine_reloc (map, reloc->r_info, sym, version, reloc_addr, 0, 1);
+ elf_machine_reloc (map, reloc->r_info, sym, version, reloc_addr, 0, 1,
+ skip_ifunc);
}
auto inline void
@@ -768,7 +788,7 @@ elf_machine_rela (struct link_map *map, const ElfW(Rela) *reloc,
void *const reloc_addr, int skip_ifunc)
{
elf_machine_reloc (map, reloc->r_info, sym, version, reloc_addr,
- reloc->r_addend, 0);
+ reloc->r_addend, 0, skip_ifunc);
}
auto inline void
@@ -795,8 +815,16 @@ elf_machine_got_rel (struct link_map *map, int lazy)
const struct r_found_version *version __attribute__ ((unused)) \
= vernum ? &map->l_versions[vernum[sym_index] & 0x7fff] : NULL; \
struct link_map *sym_map; \
+ ElfW(Addr) value = 0; \
sym_map = RESOLVE_MAP (&ref, version, reloc); \
- ref ? sym_map->l_addr + ref->st_value : 0; \
+ if (__glibc_likely (ref != NULL)) \
+ { \
+ value = sym_map->l_addr + ref->st_value; \
+ if (__glibc_unlikely (ELFW(ST_TYPE) (ref->st_info) \
+ == STT_GNU_IFUNC)) \
+ value = elf_ifunc_invoke (value); \
+ } \
+ value; \
})
if (map->l_info[VERSYMIDX (DT_VERSYM)] != NULL)
@@ -810,9 +838,12 @@ elf_machine_got_rel (struct link_map *map, int lazy)
/* The dynamic linker's local got entries have already been relocated. */
if (map != &GL(dl_rtld_map))
{
- /* got[0] is reserved. got[1] is also reserved for the dynamic object
- generated by gnu ld. Skip these reserved entries from relocation. */
- i = (got[1] & ELF_MIPS_GNU_GOT1_MASK)? 2 : 1;
+ if (map->l_info[DT_MIPS (GENERAL_GOTNO)] != NULL)
+ i = map->l_info[DT_MIPS (GENERAL_GOTNO)]->d_un.d_val;
+ else
+ /* got[0] is reserved. got[1] is also reserved for the dynamic object
+ generated by gnu ld. Skip these reserved entries from relocation. */
+ i = (got[1] & ELF_MIPS_GNU_GOT1_MASK)? 2 : 1;
/* Add the run-time displacement to all local got entries if
needed. */
@@ -193,6 +193,9 @@ __dl_runtime_resolve (ElfW(Word) sym_index,
/* Currently value contains the base load address of the object
that defines sym. Now add in the symbol offset. */
value = (sym ? sym_map->l_addr + sym->st_value : 0);
+ if (sym != NULL
+ && __glibc_unlikely (ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC))
+ value = elf_ifunc_invoke (DL_FIXUP_VALUE_ADDR (value));
}
else
/* We already found the symbol. The module (and therefore its load
@@ -34,7 +34,7 @@ extern void _dl_static_init (struct link_map *map);
#undef VALID_ELF_ABIVERSION
#define VALID_ELF_ABIVERSION(osabi,ver) \
(ver == 0 \
- || (osabi == ELFOSABI_SYSV && ver < 4) \
+ || (osabi == ELFOSABI_SYSV && ver < 5) \
|| (osabi == ELFOSABI_GNU && ver < LIBC_ABI_MAX))
#endif /* ldsodefs.h */
@@ -14,3 +14,6 @@ UNIQUE
#
# MIPS O32 FP64
MIPS_O32_FP64 mips*-*-linux*
+#
+# MIPS IFUNC
+IFUNC mips*-*-linux*