diff options
Diffstat (limited to 'REORG.TODO/elf/dl-support.c')
| -rw-r--r-- | REORG.TODO/elf/dl-support.c | 389 |
1 files changed, 389 insertions, 0 deletions
diff --git a/REORG.TODO/elf/dl-support.c b/REORG.TODO/elf/dl-support.c new file mode 100644 index 0000000000..c22be854f4 --- /dev/null +++ b/REORG.TODO/elf/dl-support.c @@ -0,0 +1,389 @@ +/* Support for dynamic linking code in static libc. + Copyright (C) 1996-2017 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/>. */ + +/* This file defines some things that for the dynamic linker are defined in + rtld.c and dl-sysdep.c in ways appropriate to bootstrap dynamic linking. */ + +#include <errno.h> +#include <libintl.h> +#include <stdlib.h> +#include <unistd.h> +#include <sys/param.h> +#include <stdint.h> +#include <ldsodefs.h> +#include <dl-machine.h> +#include <libc-lock.h> +#include <dl-cache.h> +#include <dl-librecon.h> +#include <dl-procinfo.h> +#include <unsecvars.h> +#include <hp-timing.h> +#include <stackinfo.h> + +extern char *__progname; +char **_dl_argv = &__progname; /* This is checked for some error messages. */ + +/* Name of the architecture. */ +const char *_dl_platform; +size_t _dl_platformlen; + +int _dl_debug_mask; +int _dl_lazy; +ElfW(Addr) _dl_use_load_bias = -2; +int _dl_dynamic_weak; + +/* If nonzero print warnings about problematic situations. */ +int _dl_verbose; + +/* We never do profiling. */ +const char *_dl_profile; +const char *_dl_profile_output; + +/* Names of shared object for which the RUNPATHs and RPATHs should be + ignored. */ +const char *_dl_inhibit_rpath; + +/* The map for the object we will profile. */ +struct link_map *_dl_profile_map; + +/* This is the address of the last stack address ever used. */ +void *__libc_stack_end; + +/* Path where the binary is found. */ +const char *_dl_origin_path; + +/* Nonzero if runtime lookup should not update the .got/.plt. */ +int _dl_bind_not; + +/* A dummy link map for the executable, used by dlopen to access the global + scope. We don't export any symbols ourselves, so this can be minimal. */ +static struct link_map _dl_main_map = + { + .l_name = (char *) "", + .l_real = &_dl_main_map, + .l_ns = LM_ID_BASE, + .l_libname = &(struct libname_list) { .name = "", .dont_free = 1 }, + .l_searchlist = + { + .r_list = &(struct link_map *) { &_dl_main_map }, + .r_nlist = 1, + }, + .l_symbolic_searchlist = { .r_list = &(struct link_map *) { NULL } }, + .l_type = lt_executable, + .l_scope_mem = { &_dl_main_map.l_searchlist }, + .l_scope_max = (sizeof (_dl_main_map.l_scope_mem) + / sizeof (_dl_main_map.l_scope_mem[0])), + .l_scope = _dl_main_map.l_scope_mem, + .l_local_scope = { &_dl_main_map.l_searchlist }, + .l_used = 1, + .l_tls_offset = NO_TLS_OFFSET, + .l_serial = 1, + }; + +/* Namespace information. */ +struct link_namespaces _dl_ns[DL_NNS] = + { + [LM_ID_BASE] = + { + ._ns_loaded = &_dl_main_map, + ._ns_nloaded = 1, + ._ns_main_searchlist = &_dl_main_map.l_searchlist, + } + }; +size_t _dl_nns = 1; + +/* Incremented whenever something may have been added to dl_loaded. */ +unsigned long long _dl_load_adds = 1; + +/* Fake scope of the main application. */ +struct r_scope_elem _dl_initial_searchlist = + { + .r_list = &(struct link_map *) { &_dl_main_map }, + .r_nlist = 1, + }; + +#ifndef HAVE_INLINED_SYSCALLS +/* Nonzero during startup. */ +int _dl_starting_up = 1; +#endif + +/* Random data provided by the kernel. */ +void *_dl_random; + +/* Get architecture specific initializer. */ +#include <dl-procinfo.c> + +/* Initial value of the CPU clock. */ +#ifndef HP_TIMING_NONAVAIL +hp_timing_t _dl_cpuclock_offset; +#endif + +void (*_dl_init_static_tls) (struct link_map *) = &_dl_nothread_init_static_tls; + +size_t _dl_pagesize = EXEC_PAGESIZE; + +int _dl_inhibit_cache; + +unsigned int _dl_osversion; + +/* All known directories in sorted order. */ +struct r_search_path_elem *_dl_all_dirs; + +/* All directories after startup. */ +struct r_search_path_elem *_dl_init_all_dirs; + +/* The object to be initialized first. */ +struct link_map *_dl_initfirst; + +/* Descriptor to write debug messages to. */ +int _dl_debug_fd = STDERR_FILENO; + +int _dl_correct_cache_id = _DL_CACHE_DEFAULT_ID; + +ElfW(auxv_t) *_dl_auxv; +const ElfW(Phdr) *_dl_phdr; +size_t _dl_phnum; +uint64_t _dl_hwcap __attribute__ ((nocommon)); +uint64_t _dl_hwcap2 __attribute__ ((nocommon)); + +/* The value of the FPU control word the kernel will preset in hardware. */ +fpu_control_t _dl_fpu_control = _FPU_DEFAULT; + +#if !HAVE_TUNABLES +/* This is not initialized to HWCAP_IMPORTANT, matching the definition + of _dl_important_hwcaps, below, where no hwcap strings are ever + used. This mask is still used to mediate the lookups in the cache + file. Since there is no way to set this nonzero (we don't grok the + LD_HWCAP_MASK environment variable here), there is no real point in + setting _dl_hwcap nonzero below, but we do anyway. */ +uint64_t _dl_hwcap_mask __attribute__ ((nocommon)); +#endif + +/* Prevailing state of the stack. Generally this includes PF_X, indicating it's + * executable but this isn't true for all platforms. */ +ElfW(Word) _dl_stack_flags = DEFAULT_STACK_PERMS; + +/* If loading a shared object requires that we make the stack executable + when it was not, we do it by calling this function. + It returns an errno code or zero on success. */ +int (*_dl_make_stack_executable_hook) (void **) internal_function + = _dl_make_stack_executable; + + +/* Function in libpthread to wait for termination of lookups. */ +void (*_dl_wait_lookup_done) (void); + +struct dl_scope_free_list *_dl_scope_free_list; + +#ifdef NEED_DL_SYSINFO +/* Needed for improved syscall handling on at least x86/Linux. */ +uintptr_t _dl_sysinfo = DL_SYSINFO_DEFAULT; +#endif +#ifdef 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" +#endif +#include "setup-vdso.h" + +/* During the program run we must not modify the global data of + loaded shared object simultanously in two threads. Therefore we + protect `_dl_open' and `_dl_close' in dl-close.c. + + This must be a recursive lock since the initializer function of + the loaded object might as well require a call to this function. + At this time it is not anymore a problem to modify the tables. */ +__rtld_lock_define_initialized_recursive (, _dl_load_lock) +/* This lock is used to keep __dl_iterate_phdr from inspecting the + list of loaded objects while an object is added to or removed from + that list. */ +__rtld_lock_define_initialized_recursive (, _dl_load_write_lock) + + +#ifdef HAVE_AUX_VECTOR +int _dl_clktck; + +void +internal_function +_dl_aux_init (ElfW(auxv_t) *av) +{ + int seen = 0; + uid_t uid = 0; + gid_t gid = 0; + + _dl_auxv = av; + for (; av->a_type != AT_NULL; ++av) + switch (av->a_type) + { + case AT_PAGESZ: + if (av->a_un.a_val != 0) + GLRO(dl_pagesize) = av->a_un.a_val; + break; + case AT_CLKTCK: + GLRO(dl_clktck) = av->a_un.a_val; + break; + case AT_PHDR: + GL(dl_phdr) = (const void *) av->a_un.a_val; + break; + case AT_PHNUM: + GL(dl_phnum) = av->a_un.a_val; + break; + case AT_PLATFORM: + GLRO(dl_platform) = (void *) av->a_un.a_val; + break; + case AT_HWCAP: + GLRO(dl_hwcap) = (unsigned long int) av->a_un.a_val; + break; + case AT_HWCAP2: + GLRO(dl_hwcap2) = (unsigned long int) av->a_un.a_val; + break; + case AT_FPUCW: + GLRO(dl_fpu_control) = av->a_un.a_val; + break; +#ifdef NEED_DL_SYSINFO + case AT_SYSINFO: + GL(dl_sysinfo) = av->a_un.a_val; + break; +#endif +#ifdef NEED_DL_SYSINFO_DSO + case AT_SYSINFO_EHDR: + GL(dl_sysinfo_dso) = (void *) av->a_un.a_val; + break; +#endif + case AT_UID: + uid ^= av->a_un.a_val; + seen |= 1; + break; + case AT_EUID: + uid ^= av->a_un.a_val; + seen |= 2; + break; + case AT_GID: + gid ^= av->a_un.a_val; + seen |= 4; + break; + case AT_EGID: + gid ^= av->a_un.a_val; + seen |= 8; + break; + case AT_SECURE: + seen = -1; + __libc_enable_secure = av->a_un.a_val; + __libc_enable_secure_decided = 1; + break; + case AT_RANDOM: + _dl_random = (void *) av->a_un.a_val; + break; +# ifdef DL_PLATFORM_AUXV + DL_PLATFORM_AUXV +# endif + } + if (seen == 0xf) + { + __libc_enable_secure = uid != 0 || gid != 0; + __libc_enable_secure_decided = 1; + } +} +#endif + + +void +internal_function +_dl_non_dynamic_init (void) +{ + _dl_main_map.l_origin = _dl_get_origin (); + _dl_main_map.l_phdr = GL(dl_phdr); + _dl_main_map.l_phnum = GL(dl_phnum); + + if (HP_SMALL_TIMING_AVAIL) + HP_TIMING_NOW (_dl_cpuclock_offset); + + _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")); + + /* Remember the last search directory added at startup. */ + _dl_init_all_dirs = GL(dl_all_dirs); + + _dl_lazy = *(getenv ("LD_BIND_NOW") ?: "") == '\0'; + + _dl_bind_not = *(getenv ("LD_BIND_NOT") ?: "") != '\0'; + + _dl_dynamic_weak = *(getenv ("LD_DYNAMIC_WEAK") ?: "") == '\0'; + + _dl_profile_output = getenv ("LD_PROFILE_OUTPUT"); + if (_dl_profile_output == NULL || _dl_profile_output[0] == '\0') + _dl_profile_output + = &"/var/tmp\0/var/profile"[__libc_enable_secure ? 9 : 0]; + + if (__libc_enable_secure) + { + static const char unsecure_envvars[] = + UNSECURE_ENVVARS +#ifdef EXTRA_UNSECURE_ENVVARS + EXTRA_UNSECURE_ENVVARS +#endif + ; + const char *cp = unsecure_envvars; + + while (cp < unsecure_envvars + sizeof (unsecure_envvars)) + { + __unsetenv (cp); + cp = (const char *) __rawmemchr (cp, '\0') + 1; + } + +#if !HAVE_TUNABLES + if (__access ("/etc/suid-debug", F_OK) != 0) + __unsetenv ("MALLOC_CHECK_"); +#endif + } + +#ifdef DL_PLATFORM_INIT + DL_PLATFORM_INIT; +#endif + +#ifdef DL_OSVERSION_INIT + DL_OSVERSION_INIT; +#endif + + /* Now determine the length of the platform string. */ + if (_dl_platform != NULL) + _dl_platformlen = strlen (_dl_platform); + + /* Scan for a program header telling us the stack is nonexecutable. */ + if (_dl_phdr != NULL) + for (uint_fast16_t i = 0; i < _dl_phnum; ++i) + if (_dl_phdr[i].p_type == PT_GNU_STACK) + { + _dl_stack_flags = _dl_phdr[i].p_flags; + break; + } +} + +#ifdef DL_SYSINFO_IMPLEMENTATION +DL_SYSINFO_IMPLEMENTATION +#endif |