/* Inline functions for dynamic linking.
- Copyright (C) 1995,96,97,98,99,2000 Free Software Foundation, Inc.
+ Copyright (C) 1995-2019 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
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, write to the Free
- Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
- 02111-1307 USA. */
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+/* This macro is used as a callback from elf_machine_rel{a,} when a
+ static TLS reloc is about to be performed. Since (in dl-load.c) we
+ permit dynamic loading of objects that might use such relocs, we
+ have to check whether each use is actually doable. If the object
+ whose TLS segment the reference resolves to was allocated space in
+ the static TLS block at startup, then it's ok. Otherwise, we make
+ an attempt to allocate it in surplus space on the fly. If that
+ can't be done, we fall back to the error that DF_STATIC_TLS is
+ intended to produce. */
+#define HAVE_STATIC_TLS(map, sym_map) \
+ (__builtin_expect ((sym_map)->l_tls_offset != NO_TLS_OFFSET \
+ && ((sym_map)->l_tls_offset \
+ != FORCED_DYNAMIC_TLS_OFFSET), 1))
+
+#define CHECK_STATIC_TLS(map, sym_map) \
+ do { \
+ if (!HAVE_STATIC_TLS (map, sym_map)) \
+ _dl_allocate_static_tls (sym_map); \
+ } while (0)
+
+#define TRY_STATIC_TLS(map, sym_map) \
+ (__builtin_expect ((sym_map)->l_tls_offset \
+ != FORCED_DYNAMIC_TLS_OFFSET, 1) \
+ && (__builtin_expect ((sym_map)->l_tls_offset != NO_TLS_OFFSET, 1) \
+ || _dl_try_allocate_static_tls (sym_map) == 0))
+
+int _dl_try_allocate_static_tls (struct link_map *map) attribute_hidden;
#include <elf.h>
-#include <dl-machine.h>
-#include <assert.h>
-
-#ifndef VERSYMIDX
-# define VERSYMIDX(sym) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (sym))
-#endif
-
-/* Global read-only variable defined in rtld.c which is nonzero if we
- shall give more warning messages. */
-extern int _dl_verbose __attribute__ ((unused));
-
-
-/* Read the dynamic section at DYN and fill in INFO with indices DT_*. */
-
-static inline void __attribute__ ((unused))
-elf_get_dynamic_info (struct link_map *l)
-{
- ElfW(Dyn) *dyn = l->l_ld;
- ElfW(Addr) l_addr;
- ElfW(Dyn) **info;
-
- if (! dyn)
- return;
-
- l_addr = l->l_addr;
- info = l->l_info;
-
- while (dyn->d_tag != DT_NULL)
- {
- if (dyn->d_tag < DT_NUM)
- info[dyn->d_tag] = dyn;
- else if (dyn->d_tag >= DT_LOPROC &&
- dyn->d_tag < DT_LOPROC + DT_THISPROCNUM)
- info[dyn->d_tag - DT_LOPROC + DT_NUM] = dyn;
- else if ((Elf32_Word) DT_VERSIONTAGIDX (dyn->d_tag) < DT_VERSIONTAGNUM)
- info[VERSYMIDX (dyn->d_tag)] = dyn;
- else if ((Elf32_Word) DT_EXTRATAGIDX (dyn->d_tag) < DT_EXTRANUM)
- info[DT_EXTRATAGIDX (dyn->d_tag) + DT_NUM + DT_THISPROCNUM
- + DT_VERSIONTAGNUM] = dyn;
- else
- assert (! "bad dynamic tag");
- ++dyn;
- }
-#ifndef DL_RO_DYN_SECTION
- if (info[DT_PLTGOT] != NULL)
- info[DT_PLTGOT]->d_un.d_ptr += l_addr;
- if (info[DT_STRTAB] != NULL)
- info[DT_STRTAB]->d_un.d_ptr += l_addr;
- if (info[DT_SYMTAB] != NULL)
- info[DT_SYMTAB]->d_un.d_ptr += l_addr;
+#ifdef RESOLVE_MAP
+/* We pass reloc_addr as a pointer to void, as opposed to a pointer to
+ ElfW(Addr), because not all architectures can assume that the
+ relocated address is properly aligned, whereas the compiler is
+ entitled to assume that a pointer to a type is properly aligned for
+ the type. Even if we cast the pointer back to some other type with
+ less strict alignment requirements, the compiler might still
+ remember that the pointer was originally more aligned, thereby
+ optimizing away alignment tests or using word instructions for
+ copying memory, breaking the very code written to handle the
+ unaligned cases. */
+# if ! ELF_MACHINE_NO_REL
+auto inline void __attribute__((always_inline))
+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);
+auto inline void __attribute__((always_inline))
+elf_machine_rel_relative (ElfW(Addr) l_addr, const ElfW(Rel) *reloc,
+ void *const reloc_addr);
+# endif
# if ! ELF_MACHINE_NO_RELA
- if (info[DT_RELA] != NULL)
- {
- assert (info[DT_RELAENT]->d_un.d_val == sizeof (ElfW(Rela)));
- info[DT_RELA]->d_un.d_ptr += l_addr;
- }
+auto inline void __attribute__((always_inline))
+elf_machine_rela (struct link_map *map, const ElfW(Rela) *reloc,
+ const ElfW(Sym) *sym, const struct r_found_version *version,
+ void *const reloc_addr, int skip_ifunc);
+auto inline void __attribute__((always_inline))
+elf_machine_rela_relative (ElfW(Addr) l_addr, const ElfW(Rela) *reloc,
+ void *const reloc_addr);
# endif
-# if ! ELF_MACHINE_NO_REL
- if (info[DT_REL] != NULL)
- {
- assert (info[DT_RELENT]->d_un.d_val == sizeof (ElfW(Rel)));
- info[DT_REL]->d_un.d_ptr += l_addr;
- }
+# if ELF_MACHINE_NO_RELA || defined ELF_MACHINE_PLT_REL
+auto inline void __attribute__((always_inline))
+elf_machine_lazy_rel (struct link_map *map,
+ ElfW(Addr) l_addr, const ElfW(Rel) *reloc,
+ int skip_ifunc);
+# else
+auto inline void __attribute__((always_inline))
+elf_machine_lazy_rel (struct link_map *map,
+ ElfW(Addr) l_addr, const ElfW(Rela) *reloc,
+ int skip_ifunc);
# endif
#endif
- if (info[DT_PLTREL] != NULL)
- {
-# if ELF_MACHINE_NO_RELA
- assert (info[DT_PLTREL]->d_un.d_val == DT_REL);
-# elif ELF_MACHINE_NO_REL
- assert (info[DT_PLTREL]->d_un.d_val == DT_RELA);
+
+#include <dl-machine.h>
+
+#include "get-dynamic-info.h"
+
+#ifdef RESOLVE_MAP
+
+# if defined RTLD_BOOTSTRAP || defined STATIC_PIE_BOOTSTRAP
+# define ELF_DURING_STARTUP (1)
# else
- assert (info[DT_PLTREL]->d_un.d_val == DT_REL
- || info[DT_PLTREL]->d_un.d_val == DT_RELA);
+# define ELF_DURING_STARTUP (0)
# endif
- }
-#ifndef DL_RO_DYN_SECTION
- if (info[DT_JMPREL] != NULL)
- info[DT_JMPREL]->d_un.d_ptr += l_addr;
- if (info[VERSYMIDX (DT_VERSYM)] != NULL)
- info[VERSYMIDX (DT_VERSYM)]->d_un.d_ptr += l_addr;
-#endif
- if (info[DT_FLAGS] != NULL)
- {
- /* Flags are used. Translate to the old form where available.
- Since these l_info entries are only tested for NULL pointers it
- is ok if they point to the DT_FLAGS entry. */
- ElfW(Word) flags = info[DT_FLAGS]->d_un.d_val;
- if (flags & DF_SYMBOLIC)
- info[DT_SYMBOLIC] = info[DT_FLAGS];
- if (flags & DF_TEXTREL)
- info[DT_TEXTREL] = info[DT_FLAGS];
- if (flags & DF_BIND_NOW)
- info[DT_BIND_NOW] = info[DT_FLAGS];
- }
- if (info[VERSYMIDX (DT_FLAGS_1)] != NULL)
- l->l_flags_1 = info[VERSYMIDX (DT_FLAGS_1)]->d_un.d_val;
- if (info[DT_RUNPATH] != NULL)
- /* If both RUNPATH and RPATH are given, the latter is ignored. */
- info[DT_RPATH] = NULL;
-}
-
-#ifdef RESOLVE
/* Get the definitions of `elf_dynamic_do_rel' and `elf_dynamic_do_rela'.
These functions are almost identical, so we use cpp magic to avoid
/* On some machines, notably SPARC, DT_REL* includes DT_JMPREL in its
range. Note that according to the ELF spec, this is completely legal!
- But conditionally define things so that on machines we know this will
- not happen we do something more optimal. */
-# ifdef ELF_MACHINE_PLTREL_OVERLAP
-# define _ELF_DYNAMIC_DO_RELOC(RELOC, reloc, map, do_lazy, test_rel) \
+ We are guarenteed that we have one of three situations. Either DT_JMPREL
+ comes immediately after DT_REL*, or there is overlap and DT_JMPREL
+ consumes precisely the very end of the DT_REL*, or DT_JMPREL and DT_REL*
+ are completely separate and there is a gap between them. */
+
+# define _ELF_DYNAMIC_DO_RELOC(RELOC, reloc, map, do_lazy, skip_ifunc, test_rel) \
do { \
- struct { ElfW(Addr) start, size; int lazy; } ranges[3]; \
- int ranges_index; \
- \
- ranges[0].lazy = ranges[2].lazy = 0; \
- ranges[1].lazy = 1; \
- ranges[0].size = ranges[1].size = ranges[2].size = 0; \
+ struct { ElfW(Addr) start, size; \
+ __typeof (((ElfW(Dyn) *) 0)->d_un.d_val) nrelative; int lazy; } \
+ ranges[2] = { { 0, 0, 0, 0 }, { 0, 0, 0, 0 } }; \
\
if ((map)->l_info[DT_##RELOC]) \
{ \
ranges[0].start = D_PTR ((map), l_info[DT_##RELOC]); \
ranges[0].size = (map)->l_info[DT_##RELOC##SZ]->d_un.d_val; \
- } \
- \
- if ((do_lazy) \
- && (map)->l_info[DT_PLTREL] \
- && (!test_rel || (map)->l_info[DT_PLTREL]->d_un.d_val == DT_##RELOC)) \
- { \
- ranges[1].start = D_PTR ((map), l_info[DT_JMPREL]); \
- ranges[1].size = (map)->l_info[DT_PLTRELSZ]->d_un.d_val; \
- ranges[2].start = ranges[1].start + ranges[1].size; \
- ranges[2].size = ranges[0].start + ranges[0].size - ranges[2].start; \
- ranges[0].size = ranges[1].start - ranges[0].start; \
- } \
- \
- for (ranges_index = 0; ranges_index < 3; ++ranges_index) \
- elf_dynamic_do_##reloc ((map), \
- ranges[ranges_index].start, \
- ranges[ranges_index].size, \
- ranges[ranges_index].lazy); \
- } while (0)
-# else
-# define _ELF_DYNAMIC_DO_RELOC(RELOC, reloc, map, do_lazy, test_rel) \
- do { \
- struct { ElfW(Addr) start, size; int lazy; } ranges[2]; \
- int ranges_index; \
- ranges[0].lazy = 0; \
- ranges[0].size = ranges[1].size = 0; \
- ranges[0].start = 0; \
- \
- if ((map)->l_info[DT_##RELOC]) \
- { \
- ranges[0].start = D_PTR ((map), l_info[DT_##RELOC]); \
- ranges[0].size = (map)->l_info[DT_##RELOC##SZ]->d_un.d_val; \
+ if (map->l_info[VERSYMIDX (DT_##RELOC##COUNT)] != NULL) \
+ ranges[0].nrelative \
+ = map->l_info[VERSYMIDX (DT_##RELOC##COUNT)]->d_un.d_val; \
} \
if ((map)->l_info[DT_PLTREL] \
&& (!test_rel || (map)->l_info[DT_PLTREL]->d_un.d_val == DT_##RELOC)) \
{ \
ElfW(Addr) start = D_PTR ((map), l_info[DT_JMPREL]); \
+ ElfW(Addr) size = (map)->l_info[DT_PLTRELSZ]->d_un.d_val; \
\
- if ((do_lazy) \
- /* This test does not only detect whether the relocation \
- sections are in the right order, it also checks whether \
- there is a DT_REL/DT_RELA section. */ \
- || ranges[0].start + ranges[0].size != start) \
+ if (ranges[0].start + ranges[0].size == (start + size)) \
+ ranges[0].size -= size; \
+ if (ELF_DURING_STARTUP \
+ || (!(do_lazy) \
+ && (ranges[0].start + ranges[0].size) == start)) \
+ { \
+ /* Combine processing the sections. */ \
+ ranges[0].size += size; \
+ } \
+ else \
{ \
ranges[1].start = start; \
- ranges[1].size = (map)->l_info[DT_PLTRELSZ]->d_un.d_val; \
+ ranges[1].size = size; \
ranges[1].lazy = (do_lazy); \
} \
- else \
- /* Combine processing the sections. */ \
- ranges[0].size += (map)->l_info[DT_PLTRELSZ]->d_un.d_val; \
} \
\
- for (ranges_index = 0; ranges_index < 2; ++ranges_index) \
- elf_dynamic_do_##reloc ((map), \
- ranges[ranges_index].start, \
- ranges[ranges_index].size, \
- ranges[ranges_index].lazy); \
+ if (ELF_DURING_STARTUP) \
+ elf_dynamic_do_##reloc ((map), ranges[0].start, ranges[0].size, \
+ ranges[0].nrelative, 0, skip_ifunc); \
+ else \
+ { \
+ int ranges_index; \
+ for (ranges_index = 0; ranges_index < 2; ++ranges_index) \
+ elf_dynamic_do_##reloc ((map), \
+ ranges[ranges_index].start, \
+ ranges[ranges_index].size, \
+ ranges[ranges_index].nrelative, \
+ ranges[ranges_index].lazy, \
+ skip_ifunc); \
+ } \
} while (0)
-# endif
# if ELF_MACHINE_NO_REL || ELF_MACHINE_NO_RELA
# define _ELF_CHECK_REL 0
# if ! ELF_MACHINE_NO_REL
# include "do-rel.h"
-# define ELF_DYNAMIC_DO_REL(map, lazy) \
- _ELF_DYNAMIC_DO_RELOC (REL, rel, map, lazy, _ELF_CHECK_REL)
+# define ELF_DYNAMIC_DO_REL(map, lazy, skip_ifunc) \
+ _ELF_DYNAMIC_DO_RELOC (REL, Rel, map, lazy, skip_ifunc, _ELF_CHECK_REL)
# else
-# define ELF_DYNAMIC_DO_REL(map, lazy) /* Nothing to do. */
+# define ELF_DYNAMIC_DO_REL(map, lazy, skip_ifunc) /* Nothing to do. */
# endif
# if ! ELF_MACHINE_NO_RELA
# define DO_RELA
# include "do-rel.h"
-# define ELF_DYNAMIC_DO_RELA(map, lazy) \
- _ELF_DYNAMIC_DO_RELOC (RELA, rela, map, lazy, _ELF_CHECK_REL)
+# define ELF_DYNAMIC_DO_RELA(map, lazy, skip_ifunc) \
+ _ELF_DYNAMIC_DO_RELOC (RELA, Rela, map, lazy, skip_ifunc, _ELF_CHECK_REL)
# else
-# define ELF_DYNAMIC_DO_RELA(map, lazy) /* Nothing to do. */
+# define ELF_DYNAMIC_DO_RELA(map, lazy, skip_ifunc) /* Nothing to do. */
# endif
/* This can't just be an inline function because GCC is too dumb
to inline functions containing inlines themselves. */
-# define ELF_DYNAMIC_RELOCATE(map, lazy, consider_profile) \
+# define ELF_DYNAMIC_RELOCATE(map, lazy, consider_profile, skip_ifunc) \
do { \
int edr_lazy = elf_machine_runtime_setup ((map), (lazy), \
(consider_profile)); \
- ELF_DYNAMIC_DO_REL ((map), edr_lazy); \
- ELF_DYNAMIC_DO_RELA ((map), edr_lazy); \
+ ELF_DYNAMIC_DO_REL ((map), edr_lazy, skip_ifunc); \
+ ELF_DYNAMIC_DO_RELA ((map), edr_lazy, skip_ifunc); \
} while (0)
#endif
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