diff options
Diffstat (limited to 'elf/rtld.c')
| -rw-r--r-- | elf/rtld.c | 110 |
1 files changed, 63 insertions, 47 deletions
diff --git a/elf/rtld.c b/elf/rtld.c index 87a86bed32..943901f56b 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -95,14 +95,6 @@ struct rtld_global _rtld_global = /* Get architecture specific initializer. */ #include <dl-procinfo.c> ._dl_debug_fd = STDERR_FILENO, -#ifdef NEED_DL_SYSINFO - ._dl_sysinfo = DL_SYSINFO_DEFAULT, -#endif - ._dl_lazy = 1, - ._dl_use_load_bias = -2, - ._dl_fpu_control = _FPU_DEFAULT, - ._dl_correct_cache_id = _DL_CACHE_DEFAULT_ID, - ._dl_hwcap_mask = HWCAP_IMPORTANT, /* Default presumption without further information is executable stack. */ ._dl_stack_flags = PF_R|PF_W|PF_X, #ifdef _LIBC_REENTRANT @@ -116,6 +108,28 @@ struct rtld_global _rtld_global = extern struct rtld_global _rtld_local __attribute__ ((alias ("_rtld_global"), visibility ("hidden"))); + +/* This variable is similar to _rtld_local, but all values are + read-only after relocation. */ +struct rtld_global_ro _rtld_global_ro attribute_relro = + { +#ifdef NEED_DL_SYSINFO + ._dl_sysinfo = DL_SYSINFO_DEFAULT, +#endif + ._dl_use_load_bias = -2, + ._dl_correct_cache_id = _DL_CACHE_DEFAULT_ID, + ._dl_hwcap_mask = HWCAP_IMPORTANT, + ._dl_lazy = 1, + ._dl_fpu_control = _FPU_DEFAULT, + }; +/* If we would use strong_alias here the compiler would see a + non-hidden definition. This would undo the effect of the previous + declaration. So spell out was strong_alias does plus add the + visibility attribute. */ +extern struct rtld_global_ro _rtld_local_ro + __attribute__ ((alias ("_rtld_global_ro"), visibility ("hidden"))); + + static void dl_main (const ElfW(Phdr) *phdr, ElfW(Word) phnum, ElfW(Addr) *user_entry); @@ -280,7 +294,7 @@ _dl_start_final (void *arg, struct dl_start_final_info *info) } #endif - if (__builtin_expect (GL(dl_debug_mask) & DL_DEBUG_STATISTICS, 0)) + if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_STATISTICS, 0)) { #ifndef HP_TIMING_NONAVAIL print_statistics (&rtld_total_time); @@ -712,7 +726,7 @@ dl_main (const ElfW(Phdr) *phdr, if (! strcmp (INTUSE(_dl_argv)[1], "--list")) { mode = list; - GL(dl_lazy) = -1; /* This means do no dependency analysis. */ + GLRO(dl_lazy) = -1; /* This means do no dependency analysis. */ ++_dl_skip_args; --_dl_argc; @@ -738,7 +752,7 @@ dl_main (const ElfW(Phdr) *phdr, else if (! strcmp (INTUSE(_dl_argv)[1], "--inhibit-rpath") && _dl_argc > 2) { - GL(dl_inhibit_rpath) = INTUSE(_dl_argv)[2]; + GLRO(dl_inhibit_rpath) = INTUSE(_dl_argv)[2]; _dl_skip_args += 2; _dl_argc -= 2; @@ -1035,8 +1049,8 @@ of this helper program; chances are you did not intend to run this program.\n\ /* If LD_USE_LOAD_BIAS env variable has not been seen, default to not using bias for non-prelinked PIEs and libraries and using it for executables or prelinked PIEs or libraries. */ - if (GL(dl_use_load_bias) == (ElfW(Addr)) -2) - GL(dl_use_load_bias) = (GL(dl_loaded)->l_addr == 0) ? -1 : 0; + if (GLRO(dl_use_load_bias) == (ElfW(Addr)) -2) + GLRO(dl_use_load_bias) = (GL(dl_loaded)->l_addr == 0) ? -1 : 0; /* Set up the program header information for the dynamic linker itself. It is needed in the dl_iterate_phdr() callbacks. */ @@ -1212,7 +1226,7 @@ ERROR: ld.so: object '%s' from %s cannot be preloaded: ignored.\n", #ifdef NEED_DL_SYSINFO struct link_map *sysinfo_map = NULL; - if (GL(dl_sysinfo_dso) != NULL) + 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 @@ -1224,9 +1238,9 @@ ERROR: ld.so: object '%s' from %s cannot be preloaded: ignored.\n", { static ElfW(Dyn) dyn_temp[DL_RO_DYN_TEMP_CNT]; - l->l_phdr = ((const void *) GL(dl_sysinfo_dso) - + GL(dl_sysinfo_dso)->e_phoff); - l->l_phnum = GL(dl_sysinfo_dso)->e_phnum; + 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]; @@ -1243,7 +1257,7 @@ ERROR: ld.so: object '%s' from %s cannot be preloaded: ignored.\n", l->l_map_end = ph->p_vaddr + ph->p_memsz; } } - l->l_map_start = (ElfW(Addr)) GL(dl_sysinfo_dso); + 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_ld = (void *) ((ElfW(Addr)) l->l_ld + l->l_addr); @@ -1269,8 +1283,8 @@ ERROR: ld.so: object '%s' from %s cannot be preloaded: ignored.\n", } /* We have a prelinked DSO preloaded by the system. */ - if (GL(dl_sysinfo) == DL_SYSINFO_DEFAULT) - GL(dl_sysinfo) = GL(dl_sysinfo_dso)->e_entry + l->l_addr; + if (GLRO(dl_sysinfo) == DL_SYSINFO_DEFAULT) + GLRO(dl_sysinfo) = GLRO(dl_sysinfo_dso)->e_entry + l->l_addr; sysinfo_map = l; } } @@ -1437,7 +1451,7 @@ cannot allocate TLS data structures for initial thread"); after relocation. */ struct link_map *l; - if (GL(dl_debug_mask) & DL_DEBUG_PRELINK) + if (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK) { struct r_scope_elem *scope = &GL(dl_loaded)->l_searchlist; @@ -1449,8 +1463,8 @@ cannot allocate TLS data structures for initial thread"); _dl_printf ("\t%s => not found\n", l->l_libname->name); continue; } - if (_dl_name_match_p (GL(dl_trace_prelink), l)) - GL(dl_trace_prelink_map) = l; + if (_dl_name_match_p (GLRO(dl_trace_prelink), l)) + GLRO(dl_trace_prelink_map) = l; _dl_printf ("\t%s => %s (0x%0*Zx, 0x%0*Zx)", l->l_libname->name[0] ? l->l_libname->name : rtld_progname ?: "<main program>", @@ -1507,13 +1521,13 @@ cannot allocate TLS data structures for initial thread"); else { /* If LD_WARN is set warn about undefined symbols. */ - if (GL(dl_lazy) >= 0 && GL(dl_verbose)) + if (GLRO(dl_lazy) >= 0 && GLRO(dl_verbose)) { /* We have to do symbol dependency testing. */ struct relocate_args args; struct link_map *l; - args.lazy = GL(dl_lazy); + args.lazy = GLRO(dl_lazy); l = GL(dl_loaded); while (l->l_next) @@ -1529,7 +1543,7 @@ cannot allocate TLS data structures for initial thread"); l = l->l_prev; } while (l); - if ((GL(dl_debug_mask) & DL_DEBUG_PRELINK) + if ((GLRO(dl_debug_mask) & DL_DEBUG_PRELINK) && GL(dl_rtld_map).l_opencount > 1) INTUSE(_dl_relocate_object) (&GL(dl_rtld_map), GL(dl_loaded)->l_scope, 0, 0); @@ -1612,7 +1626,7 @@ cannot allocate TLS data structures for initial thread"); } if (GL(dl_loaded)->l_info [ADDRIDX (DT_GNU_LIBLIST)] - && ! __builtin_expect (GL(dl_profile) != NULL, 0)) + && ! __builtin_expect (GLRO(dl_profile) != NULL, 0)) { ElfW(Lib) *liblist, *liblistend; struct link_map **r_list, **r_listend, *l; @@ -1660,7 +1674,7 @@ cannot allocate TLS data structures for initial thread"); if (r_list == r_listend && liblist == liblistend) prelinked = true; - if (__builtin_expect (GL(dl_debug_mask) & DL_DEBUG_LIBS, 0)) + if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_LIBS, 0)) _dl_printf ("\nprelink checking: %s\n", prelinked ? "ok" : "failed"); } @@ -1740,7 +1754,7 @@ cannot allocate TLS data structures for initial thread"); know that because it is self-contained). */ struct link_map *l; - int consider_profiling = GL(dl_profile) != NULL; + int consider_profiling = GLRO(dl_profile) != NULL; #ifndef HP_TIMING_NONAVAIL hp_timing_t start; hp_timing_t stop; @@ -1748,7 +1762,7 @@ cannot allocate TLS data structures for initial thread"); #endif /* If we are profiling we also must do lazy reloaction. */ - GL(dl_lazy) |= consider_profiling; + GLRO(dl_lazy) |= consider_profiling; l = GL(dl_loaded); while (l->l_next) @@ -1769,7 +1783,7 @@ cannot allocate TLS data structures for initial thread"); } if (l != &GL(dl_rtld_map)) - INTUSE(_dl_relocate_object) (l, l->l_scope, GL(dl_lazy), + INTUSE(_dl_relocate_object) (l, l->l_scope, GLRO(dl_lazy), consider_profiling); l = l->l_prev; @@ -1792,7 +1806,8 @@ cannot allocate TLS data structures for initial thread"); needs to have _dl_profile_map set up by the relocator. */ if (__builtin_expect (GL(dl_profile_map) != NULL, 0)) /* We must prepare the profiling. */ - INTUSE(_dl_start_profile) (GL(dl_profile_map), GL(dl_profile_output)); + INTUSE(_dl_start_profile) (GL(dl_profile_map), + GLRO(dl_profile_output)); if (GL(dl_rtld_map).l_opencount > 1) { @@ -1928,7 +1943,7 @@ process_dl_debug (const char *dl_debug) if (debopts[cnt].len == len && memcmp (dl_debug, debopts[cnt].name, len) == 0) { - GL(dl_debug_mask) |= debopts[cnt].mask; + GLRO(dl_debug_mask) |= debopts[cnt].mask; any_debug = 1; break; } @@ -1949,7 +1964,7 @@ warning: debug option `%s' unknown; try LD_DEBUG=help\n", copy); ++dl_debug; } - if (GL(dl_debug_mask) & DL_DEBUG_HELP) + if (GLRO(dl_debug_mask) & DL_DEBUG_HELP) { size_t cnt; @@ -1983,7 +1998,7 @@ process_envvars (enum mode *modep) char *debug_output = NULL; /* This is the default place for profiling data file. */ - GL(dl_profile_output) + GLRO(dl_profile_output) = &"/var/tmp\0/var/profile"[INTUSE(__libc_enable_secure) ? 9 : 0]; while ((envline = _dl_next_ld_env_entry (&runp)) != NULL) @@ -2004,7 +2019,7 @@ process_envvars (enum mode *modep) case 4: /* Warning level, verbose or not. */ if (memcmp (envline, "WARN", 4) == 0) - GL(dl_verbose) = envline[5] != '\0'; + GLRO(dl_verbose) = envline[5] != '\0'; break; case 5: @@ -2030,18 +2045,18 @@ process_envvars (enum mode *modep) /* Which shared object shall be profiled. */ if (memcmp (envline, "PROFILE", 7) == 0 && envline[8] != '\0') - GL(dl_profile) = &envline[8]; + GLRO(dl_profile) = &envline[8]; break; case 8: /* Do we bind early? */ if (memcmp (envline, "BIND_NOW", 8) == 0) { - GL(dl_lazy) = envline[9] == '\0'; + GLRO(dl_lazy) = envline[9] == '\0'; break; } if (memcmp (envline, "BIND_NOT", 8) == 0) - GL(dl_bind_not) = envline[9] != '\0'; + GLRO(dl_bind_not) = envline[9] != '\0'; break; case 9: @@ -2054,14 +2069,15 @@ process_envvars (enum mode *modep) case 10: /* Mask for the important hardware capabilities. */ if (memcmp (envline, "HWCAP_MASK", 10) == 0) - GL(dl_hwcap_mask) = __strtoul_internal (&envline[11], NULL, 0, 0); + GLRO(dl_hwcap_mask) = __strtoul_internal (&envline[11], NULL, + 0, 0); break; case 11: /* Path where the binary is found. */ if (!INTUSE(__libc_enable_secure) && memcmp (envline, "ORIGIN_PATH", 11) == 0) - GL(dl_origin_path) = &envline[12]; + GLRO(dl_origin_path) = &envline[12]; break; case 12: @@ -2080,7 +2096,7 @@ process_envvars (enum mode *modep) } if (memcmp (envline, "DYNAMIC_WEAK", 12) == 0) - GL(dl_dynamic_weak) = 1; + GLRO(dl_dynamic_weak) = 1; break; case 13: @@ -2091,7 +2107,7 @@ process_envvars (enum mode *modep) #endif if (!INTUSE(__libc_enable_secure) && memcmp (envline, "USE_LOAD_BIAS", 13) == 0) - GL(dl_use_load_bias) = envline[14] == '1' ? -1 : 0; + GLRO(dl_use_load_bias) = envline[14] == '1' ? -1 : 0; break; case 14: @@ -2099,7 +2115,7 @@ process_envvars (enum mode *modep) if (!INTUSE(__libc_enable_secure) && memcmp (envline, "PROFILE_OUTPUT", 14) == 0 && envline[15] != '\0') - GL(dl_profile_output) = &envline[15]; + GLRO(dl_profile_output) = &envline[15]; break; case 16: @@ -2107,9 +2123,9 @@ process_envvars (enum mode *modep) if (memcmp (envline, "TRACE_PRELINKING", 16) == 0) { mode = trace; - GL(dl_verbose) = 1; - GL(dl_debug_mask) |= DL_DEBUG_PRELINK; - GL(dl_trace_prelink) = &envline[17]; + GLRO(dl_verbose) = 1; + GLRO(dl_debug_mask) |= DL_DEBUG_PRELINK; + GLRO(dl_trace_prelink) = &envline[17]; } break; |