From 9cee55856438b714fa1efa45d8b7c1857467f4ca Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Fri, 5 Oct 2012 10:20:39 -0700 Subject: [PATCH] Set up the data structures for vDSO in libc.a --- ChangeLog | 15 +++++ elf/dl-support.c | 9 +++ elf/dynamic-link.h | 145 +------------------------------------------- elf/get-dynamic-info.h | 161 +++++++++++++++++++++++++++++++++++++++++++++++++ elf/rtld.c | 96 +---------------------------- elf/setup-vdso.h | 119 ++++++++++++++++++++++++++++++++++++ 6 files changed, 307 insertions(+), 238 deletions(-) create mode 100644 elf/get-dynamic-info.h create mode 100644 elf/setup-vdso.h diff --git a/ChangeLog b/ChangeLog index 3d3fa6ddf1..090efd0de4 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,18 @@ +2012-10-05 H.J. Lu + + [BZ #14557] + * elf/dl-support.c (_dl_sysinfo_map): New. + Include "get-dynamic-info.h" and "setup-vdso.h". + (_dl_non_dynamic_init): Call setup_vdso. + * elf/dynamic-link.h: Don't include . + (elf_get_dynamic_info): Moved to ... + * elf/get-dynamic-info.h: Here. New file. + * elf/dynamic-link.h: Include "get-dynamic-info.h". + * elf/rtld.c (dl_main): Break out vDSO setup code into ... + * elf/setup-vdso.h: Here. New file. + * elf/rtld.c: Include "setup-vdso.h". + (dl_main): Call setup_vdso. + 2012-10-05 Joseph Myers * math/libm-test.inc: List nexttoward, cimag, clog10, conf and diff --git a/elf/dl-support.c b/elf/dl-support.c index 2bb468a5fb..424ca6ddea 100644 --- a/elf/dl-support.c +++ b/elf/dl-support.c @@ -161,6 +161,11 @@ uintptr_t _dl_sysinfo = DL_SYSINFO_DEFAULT; #if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO /* Address of the ELF headers in the vsyscall page. */ const ElfW(Ehdr) *_dl_sysinfo_dso; + +struct link_map *_dl_sysinfo_map; + +# include "get-dynamic-info.h" +# include "setup-vdso.h" #endif /* During the program run we must not modify the global data of @@ -266,6 +271,10 @@ _dl_non_dynamic_init (void) _dl_verbose = *(getenv ("LD_WARN") ?: "") == '\0' ? 0 : 1; + /* Set up the data structures for the system-supplied DSO early, + so they can influence _dl_init_paths. */ + setup_vdso (NULL, NULL); + /* Initialize the data structures for the search paths for shared objects. */ _dl_init_paths (getenv ("LD_LIBRARY_PATH")); diff --git a/elf/dynamic-link.h b/elf/dynamic-link.h index d982c52ed3..ad30d23a7f 100644 --- a/elf/dynamic-link.h +++ b/elf/dynamic-link.h @@ -42,7 +42,6 @@ int internal_function _dl_try_allocate_static_tls (struct link_map *map); #include -#include #ifdef RESOLVE_MAP /* We pass reloc_addr as a pointer to void, as opposed to a pointer to @@ -88,149 +87,7 @@ elf_machine_lazy_rel (struct link_map *map, #include - -/* Read the dynamic section at DYN and fill in INFO with indices DT_*. */ -#ifndef RESOLVE_MAP -static -#else -auto -#endif -inline void __attribute__ ((unused, always_inline)) -elf_get_dynamic_info (struct link_map *l, ElfW(Dyn) *temp) -{ - ElfW(Dyn) *dyn = l->l_ld; - ElfW(Dyn) **info; -#if __ELF_NATIVE_CLASS == 32 - typedef Elf32_Word d_tag_utype; -#elif __ELF_NATIVE_CLASS == 64 - typedef Elf64_Xword d_tag_utype; -#endif - -#ifndef RTLD_BOOTSTRAP - if (dyn == NULL) - return; -#endif - - info = l->l_info; - - while (dyn->d_tag != DT_NULL) - { - if ((d_tag_utype) 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 ((d_tag_utype) DT_VERSIONTAGIDX (dyn->d_tag) < DT_VERSIONTAGNUM) - info[VERSYMIDX (dyn->d_tag)] = dyn; - else if ((d_tag_utype) DT_EXTRATAGIDX (dyn->d_tag) < DT_EXTRANUM) - info[DT_EXTRATAGIDX (dyn->d_tag) + DT_NUM + DT_THISPROCNUM - + DT_VERSIONTAGNUM] = dyn; - else if ((d_tag_utype) DT_VALTAGIDX (dyn->d_tag) < DT_VALNUM) - info[DT_VALTAGIDX (dyn->d_tag) + DT_NUM + DT_THISPROCNUM - + DT_VERSIONTAGNUM + DT_EXTRANUM] = dyn; - else if ((d_tag_utype) DT_ADDRTAGIDX (dyn->d_tag) < DT_ADDRNUM) - info[DT_ADDRTAGIDX (dyn->d_tag) + DT_NUM + DT_THISPROCNUM - + DT_VERSIONTAGNUM + DT_EXTRANUM + DT_VALNUM] = dyn; - ++dyn; - } - -#define DL_RO_DYN_TEMP_CNT 8 - -#ifndef DL_RO_DYN_SECTION - /* Don't adjust .dynamic unnecessarily. */ - if (l->l_addr != 0) - { - ElfW(Addr) l_addr = l->l_addr; - int cnt = 0; - -# define ADJUST_DYN_INFO(tag) \ - do \ - if (info[tag] != NULL) \ - { \ - if (temp) \ - { \ - temp[cnt].d_tag = info[tag]->d_tag; \ - temp[cnt].d_un.d_ptr = info[tag]->d_un.d_ptr + l_addr; \ - info[tag] = temp + cnt++; \ - } \ - else \ - info[tag]->d_un.d_ptr += l_addr; \ - } \ - while (0) - - ADJUST_DYN_INFO (DT_HASH); - ADJUST_DYN_INFO (DT_PLTGOT); - ADJUST_DYN_INFO (DT_STRTAB); - ADJUST_DYN_INFO (DT_SYMTAB); -# if ! ELF_MACHINE_NO_RELA - ADJUST_DYN_INFO (DT_RELA); -# endif -# if ! ELF_MACHINE_NO_REL - ADJUST_DYN_INFO (DT_REL); -# endif - ADJUST_DYN_INFO (DT_JMPREL); - ADJUST_DYN_INFO (VERSYMIDX (DT_VERSYM)); - ADJUST_DYN_INFO (DT_ADDRTAGIDX (DT_GNU_HASH) + DT_NUM + DT_THISPROCNUM - + DT_VERSIONTAGNUM + DT_EXTRANUM + DT_VALNUM); -# undef ADJUST_DYN_INFO - assert (cnt <= DL_RO_DYN_TEMP_CNT); - } -#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); -#else - assert (info[DT_PLTREL]->d_un.d_val == DT_REL - || info[DT_PLTREL]->d_un.d_val == DT_RELA); -#endif - } -#if ! ELF_MACHINE_NO_RELA - if (info[DT_RELA] != NULL) - assert (info[DT_RELAENT]->d_un.d_val == sizeof (ElfW(Rela))); -# endif -# if ! ELF_MACHINE_NO_REL - if (info[DT_REL] != NULL) - assert (info[DT_RELENT]->d_un.d_val == sizeof (ElfW(Rel))); -#endif -#ifdef RTLD_BOOTSTRAP - /* Only the bind now flags are allowed. */ - assert (info[VERSYMIDX (DT_FLAGS_1)] == NULL - || (info[VERSYMIDX (DT_FLAGS_1)]->d_un.d_val & ~DF_1_NOW) == 0); - assert (info[DT_FLAGS] == NULL - || (info[DT_FLAGS]->d_un.d_val & ~DF_BIND_NOW) == 0); - /* Flags must not be set for ld.so. */ - assert (info[DT_RUNPATH] == NULL); - assert (info[DT_RPATH] == NULL); -#else - 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. */ - l->l_flags = info[DT_FLAGS]->d_un.d_val; - - if (l->l_flags & DF_SYMBOLIC) - info[DT_SYMBOLIC] = info[DT_FLAGS]; - if (l->l_flags & DF_TEXTREL) - info[DT_TEXTREL] = info[DT_FLAGS]; - if (l->l_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 (l->l_flags_1 & DF_1_NOW) - info[DT_BIND_NOW] = info[VERSYMIDX (DT_FLAGS_1)]; - } - if (info[DT_RUNPATH] != NULL) - /* If both RUNPATH and RPATH are given, the latter is ignored. */ - info[DT_RPATH] = NULL; -#endif -} +#include "get-dynamic-info.h" #ifdef RESOLVE_MAP diff --git a/elf/get-dynamic-info.h b/elf/get-dynamic-info.h new file mode 100644 index 0000000000..ffac75f635 --- /dev/null +++ b/elf/get-dynamic-info.h @@ -0,0 +1,161 @@ +/* Read the dynamic section at DYN and fill in INFO with indices DT_*. + Copyright (C) 2012 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 + . */ + +#include + +#ifndef RESOLVE_MAP +static +#else +auto +#endif +inline void __attribute__ ((unused, always_inline)) +elf_get_dynamic_info (struct link_map *l, ElfW(Dyn) *temp) +{ + ElfW(Dyn) *dyn = l->l_ld; + ElfW(Dyn) **info; +#if __ELF_NATIVE_CLASS == 32 + typedef Elf32_Word d_tag_utype; +#elif __ELF_NATIVE_CLASS == 64 + typedef Elf64_Xword d_tag_utype; +#endif + +#ifndef RTLD_BOOTSTRAP + if (dyn == NULL) + return; +#endif + + info = l->l_info; + + while (dyn->d_tag != DT_NULL) + { + if ((d_tag_utype) 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 ((d_tag_utype) DT_VERSIONTAGIDX (dyn->d_tag) < DT_VERSIONTAGNUM) + info[VERSYMIDX (dyn->d_tag)] = dyn; + else if ((d_tag_utype) DT_EXTRATAGIDX (dyn->d_tag) < DT_EXTRANUM) + info[DT_EXTRATAGIDX (dyn->d_tag) + DT_NUM + DT_THISPROCNUM + + DT_VERSIONTAGNUM] = dyn; + else if ((d_tag_utype) DT_VALTAGIDX (dyn->d_tag) < DT_VALNUM) + info[DT_VALTAGIDX (dyn->d_tag) + DT_NUM + DT_THISPROCNUM + + DT_VERSIONTAGNUM + DT_EXTRANUM] = dyn; + else if ((d_tag_utype) DT_ADDRTAGIDX (dyn->d_tag) < DT_ADDRNUM) + info[DT_ADDRTAGIDX (dyn->d_tag) + DT_NUM + DT_THISPROCNUM + + DT_VERSIONTAGNUM + DT_EXTRANUM + DT_VALNUM] = dyn; + ++dyn; + } + +#define DL_RO_DYN_TEMP_CNT 8 + +#ifndef DL_RO_DYN_SECTION + /* Don't adjust .dynamic unnecessarily. */ + if (l->l_addr != 0) + { + ElfW(Addr) l_addr = l->l_addr; + int cnt = 0; + +# define ADJUST_DYN_INFO(tag) \ + do \ + if (info[tag] != NULL) \ + { \ + if (temp) \ + { \ + temp[cnt].d_tag = info[tag]->d_tag; \ + temp[cnt].d_un.d_ptr = info[tag]->d_un.d_ptr + l_addr; \ + info[tag] = temp + cnt++; \ + } \ + else \ + info[tag]->d_un.d_ptr += l_addr; \ + } \ + while (0) + + ADJUST_DYN_INFO (DT_HASH); + ADJUST_DYN_INFO (DT_PLTGOT); + ADJUST_DYN_INFO (DT_STRTAB); + ADJUST_DYN_INFO (DT_SYMTAB); +# if ! ELF_MACHINE_NO_RELA + ADJUST_DYN_INFO (DT_RELA); +# endif +# if ! ELF_MACHINE_NO_REL + ADJUST_DYN_INFO (DT_REL); +# endif + ADJUST_DYN_INFO (DT_JMPREL); + ADJUST_DYN_INFO (VERSYMIDX (DT_VERSYM)); + ADJUST_DYN_INFO (DT_ADDRTAGIDX (DT_GNU_HASH) + DT_NUM + DT_THISPROCNUM + + DT_VERSIONTAGNUM + DT_EXTRANUM + DT_VALNUM); +# undef ADJUST_DYN_INFO + assert (cnt <= DL_RO_DYN_TEMP_CNT); + } +#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); +#else + assert (info[DT_PLTREL]->d_un.d_val == DT_REL + || info[DT_PLTREL]->d_un.d_val == DT_RELA); +#endif + } +#if ! ELF_MACHINE_NO_RELA + if (info[DT_RELA] != NULL) + assert (info[DT_RELAENT]->d_un.d_val == sizeof (ElfW(Rela))); +# endif +# if ! ELF_MACHINE_NO_REL + if (info[DT_REL] != NULL) + assert (info[DT_RELENT]->d_un.d_val == sizeof (ElfW(Rel))); +#endif +#ifdef RTLD_BOOTSTRAP + /* Only the bind now flags are allowed. */ + assert (info[VERSYMIDX (DT_FLAGS_1)] == NULL + || (info[VERSYMIDX (DT_FLAGS_1)]->d_un.d_val & ~DF_1_NOW) == 0); + assert (info[DT_FLAGS] == NULL + || (info[DT_FLAGS]->d_un.d_val & ~DF_BIND_NOW) == 0); + /* Flags must not be set for ld.so. */ + assert (info[DT_RUNPATH] == NULL); + assert (info[DT_RPATH] == NULL); +#else + 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. */ + l->l_flags = info[DT_FLAGS]->d_un.d_val; + + if (l->l_flags & DF_SYMBOLIC) + info[DT_SYMBOLIC] = info[DT_FLAGS]; + if (l->l_flags & DF_TEXTREL) + info[DT_TEXTREL] = info[DT_FLAGS]; + if (l->l_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 (l->l_flags_1 & DF_1_NOW) + info[DT_BIND_NOW] = info[VERSYMIDX (DT_FLAGS_1)]; + } + if (info[DT_RUNPATH] != NULL) + /* If both RUNPATH and RPATH are given, the latter is ignored. */ + info[DT_RPATH] = NULL; +#endif +} diff --git a/elf/rtld.c b/elf/rtld.c index 8a0264504b..b0126e51af 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -873,6 +873,7 @@ security_init (void) _dl_random = NULL; } +#include "setup-vdso.h" /* The library search path. */ static const char *library_path attribute_relro; @@ -1329,102 +1330,9 @@ of this helper program; chances are you did not intend to run this program.\n\ } struct link_map **first_preload = &GL(dl_rtld_map).l_next; -#if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO /* Set up the data structures for the system-supplied DSO early, so they can influence _dl_init_paths. */ - if (GLRO(dl_sysinfo_dso) != NULL) - { - /* Do an abridged version of the work _dl_map_object_from_fd would do - to map in the object. It's already mapped and prelinked (and - better be, since it's read-only and so we couldn't relocate it). - We just want our data structures to describe it as if we had just - mapped and relocated it normally. */ - struct link_map *l = _dl_new_object ((char *) "", "", lt_library, NULL, - 0, LM_ID_BASE); - if (__builtin_expect (l != NULL, 1)) - { - static ElfW(Dyn) dyn_temp[DL_RO_DYN_TEMP_CNT] attribute_relro; - - l->l_phdr = ((const void *) GLRO(dl_sysinfo_dso) - + GLRO(dl_sysinfo_dso)->e_phoff); - l->l_phnum = GLRO(dl_sysinfo_dso)->e_phnum; - for (uint_fast16_t i = 0; i < l->l_phnum; ++i) - { - const ElfW(Phdr) *const ph = &l->l_phdr[i]; - if (ph->p_type == PT_DYNAMIC) - { - l->l_ld = (void *) ph->p_vaddr; - l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn)); - } - else if (ph->p_type == PT_LOAD) - { - if (! l->l_addr) - l->l_addr = ph->p_vaddr; - if (ph->p_vaddr + ph->p_memsz >= l->l_map_end) - l->l_map_end = ph->p_vaddr + ph->p_memsz; - if ((ph->p_flags & PF_X) - && ph->p_vaddr + ph->p_memsz >= l->l_text_end) - l->l_text_end = ph->p_vaddr + ph->p_memsz; - } - else - /* There must be no TLS segment. */ - assert (ph->p_type != PT_TLS); - } - l->l_map_start = (ElfW(Addr)) GLRO(dl_sysinfo_dso); - l->l_addr = l->l_map_start - l->l_addr; - l->l_map_end += l->l_addr; - l->l_text_end += l->l_addr; - l->l_ld = (void *) ((ElfW(Addr)) l->l_ld + l->l_addr); - elf_get_dynamic_info (l, dyn_temp); - _dl_setup_hash (l); - l->l_relocated = 1; - - /* The vDSO is always used. */ - l->l_used = 1; - - /* Initialize l_local_scope to contain just this map. This allows - the use of dl_lookup_symbol_x to resolve symbols within the vdso. - So we create a single entry list pointing to l_real as its only - element */ - l->l_local_scope[0]->r_nlist = 1; - l->l_local_scope[0]->r_list = &l->l_real; - - /* Now that we have the info handy, use the DSO image's soname - so this object can be looked up by name. Note that we do not - set l_name here. That field gives the file name of the DSO, - and this DSO is not associated with any file. */ - if (l->l_info[DT_SONAME] != NULL) - { - /* Work around a kernel problem. The kernel cannot handle - addresses in the vsyscall DSO pages in writev() calls. */ - const char *dsoname = ((char *) D_PTR (l, l_info[DT_STRTAB]) - + l->l_info[DT_SONAME]->d_un.d_val); - size_t len = strlen (dsoname); - char *copy = malloc (len); - if (copy == NULL) - _dl_fatal_printf ("out of memory\n"); - l->l_libname->name = l->l_name = memcpy (copy, dsoname, len); - } - - /* Add the vDSO to the object list. */ - _dl_add_to_namespace_list (l, LM_ID_BASE); - - /* Rearrange the list so this DSO appears after rtld_map. */ - assert (l->l_next == NULL); - assert (l->l_prev == main_map); - GL(dl_rtld_map).l_next = l; - l->l_prev = &GL(dl_rtld_map); - first_preload = &l->l_next; - - /* We have a prelinked DSO preloaded by the system. */ - GLRO(dl_sysinfo_map) = l; -# ifdef NEED_DL_SYSINFO - if (GLRO(dl_sysinfo) == DL_SYSINFO_DEFAULT) - GLRO(dl_sysinfo) = GLRO(dl_sysinfo_dso)->e_entry + l->l_addr; -# endif - } - } -#endif + setup_vdso (main_map, &first_preload); #ifdef DL_SYSDEP_OSCHECK DL_SYSDEP_OSCHECK (_dl_fatal_printf); diff --git a/elf/setup-vdso.h b/elf/setup-vdso.h new file mode 100644 index 0000000000..1b969a0718 --- /dev/null +++ b/elf/setup-vdso.h @@ -0,0 +1,119 @@ +/* Set up the data structures for the system-supplied DSO. + Copyright (C) 2012 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 + . */ + +static inline void __attribute__ ((always_inline)) +setup_vdso (struct link_map *main_map __attribute__ ((unused)), + struct link_map ***first_preload __attribute__ ((unused))) +{ +#if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO + if (GLRO(dl_sysinfo_dso) == NULL) + return; + + /* Do an abridged version of the work _dl_map_object_from_fd would do + to map in the object. It's already mapped and prelinked (and + better be, since it's read-only and so we couldn't relocate it). + We just want our data structures to describe it as if we had just + mapped and relocated it normally. */ + struct link_map *l = _dl_new_object ((char *) "", "", lt_library, NULL, + 0, LM_ID_BASE); + if (__builtin_expect (l != NULL, 1)) + { + static ElfW(Dyn) dyn_temp[DL_RO_DYN_TEMP_CNT] attribute_relro; + + l->l_phdr = ((const void *) GLRO(dl_sysinfo_dso) + + GLRO(dl_sysinfo_dso)->e_phoff); + l->l_phnum = GLRO(dl_sysinfo_dso)->e_phnum; + for (uint_fast16_t i = 0; i < l->l_phnum; ++i) + { + const ElfW(Phdr) *const ph = &l->l_phdr[i]; + if (ph->p_type == PT_DYNAMIC) + { + l->l_ld = (void *) ph->p_vaddr; + l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn)); + } + else if (ph->p_type == PT_LOAD) + { + if (! l->l_addr) + l->l_addr = ph->p_vaddr; + if (ph->p_vaddr + ph->p_memsz >= l->l_map_end) + l->l_map_end = ph->p_vaddr + ph->p_memsz; + if ((ph->p_flags & PF_X) + && ph->p_vaddr + ph->p_memsz >= l->l_text_end) + l->l_text_end = ph->p_vaddr + ph->p_memsz; + } + else + /* There must be no TLS segment. */ + assert (ph->p_type != PT_TLS); + } + l->l_map_start = (ElfW(Addr)) GLRO(dl_sysinfo_dso); + l->l_addr = l->l_map_start - l->l_addr; + l->l_map_end += l->l_addr; + l->l_text_end += l->l_addr; + l->l_ld = (void *) ((ElfW(Addr)) l->l_ld + l->l_addr); + elf_get_dynamic_info (l, dyn_temp); + _dl_setup_hash (l); + l->l_relocated = 1; + + /* The vDSO is always used. */ + l->l_used = 1; + + /* Initialize l_local_scope to contain just this map. This allows + the use of dl_lookup_symbol_x to resolve symbols within the vdso. + So we create a single entry list pointing to l_real as its only + element */ + l->l_local_scope[0]->r_nlist = 1; + l->l_local_scope[0]->r_list = &l->l_real; + + /* Now that we have the info handy, use the DSO image's soname + so this object can be looked up by name. Note that we do not + set l_name here. That field gives the file name of the DSO, + and this DSO is not associated with any file. */ + if (l->l_info[DT_SONAME] != NULL) + { + /* Work around a kernel problem. The kernel cannot handle + addresses in the vsyscall DSO pages in writev() calls. */ + const char *dsoname = ((char *) D_PTR (l, l_info[DT_STRTAB]) + + l->l_info[DT_SONAME]->d_un.d_val); + size_t len = strlen (dsoname); + char *copy = malloc (len); + if (copy == NULL) + _dl_fatal_printf ("out of memory\n"); + l->l_libname->name = l->l_name = memcpy (copy, dsoname, len); + } + + /* Add the vDSO to the object list. */ + _dl_add_to_namespace_list (l, LM_ID_BASE); + +# ifdef IS_IN_rtld + /* Rearrange the list so this DSO appears after rtld_map. */ + assert (l->l_next == NULL); + assert (l->l_prev == main_map); + GL(dl_rtld_map).l_next = l; + l->l_prev = &GL(dl_rtld_map); + *first_preload = &l->l_next; +# endif + + /* We have a prelinked DSO preloaded by the system. */ + GLRO(dl_sysinfo_map) = l; +# ifdef NEED_DL_SYSINFO + if (GLRO(dl_sysinfo) == DL_SYSINFO_DEFAULT) + GLRO(dl_sysinfo) = GLRO(dl_sysinfo_dso)->e_entry + l->l_addr; +# endif + } +#endif +} -- 2.11.4.GIT