| commit 2bf9e641fd50ec34b04b70829679abf64fc0ed78 |
| Author: Florian Weimer <fweimer@redhat.com> |
| Date: Thu Oct 8 10:57:09 2020 +0200 |
| |
| elf: Extract command-line/environment variables state from rtld.c |
| |
| Introduce struct dl_main_state and move it to <dl-main.h>. Rename |
| enum mode to enum rtld_mode and add the rtld_mode_ prefix to the enum |
| constants. |
| |
| This avoids the need for putting state that is only needed during |
| startup into the ld.so data segment. |
| |
| Conflicts: |
| elf/rtld.c |
| (Caused by glibc-fedora-__libc_multiple_libcs.patch.) |
| |
| diff --git a/elf/dl-main.h b/elf/dl-main.h |
| new file mode 100644 |
| index 0000000000000000..bcc9bcf2e8fee6e7 |
| |
| |
| @@ -0,0 +1,98 @@ |
| +/* Information collection during ld.so startup. |
| + Copyright (C) 1995-2020 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 |
| + <https://www.gnu.org/licenses/>. */ |
| + |
| +#ifndef _DL_MAIN |
| +#define _DL_MAIN |
| + |
| +#include <limits.h> |
| + |
| +/* Length limits for names and paths, to protect the dynamic linker, |
| + particularly when __libc_enable_secure is active. */ |
| +#ifdef NAME_MAX |
| +# define SECURE_NAME_LIMIT NAME_MAX |
| +#else |
| +# define SECURE_NAME_LIMIT 255 |
| +#endif |
| +#ifdef PATH_MAX |
| +# define SECURE_PATH_LIMIT PATH_MAX |
| +#else |
| +# define SECURE_PATH_LIMIT 1024 |
| +#endif |
| + |
| +/* Strings containing colon-separated lists of audit modules. */ |
| +struct audit_list |
| +{ |
| + /* Array of strings containing colon-separated path lists. Each |
| + audit module needs its own namespace, so pre-allocate the largest |
| + possible list. */ |
| + const char *audit_strings[DL_NNS]; |
| + |
| + /* Number of entries added to audit_strings. */ |
| + size_t length; |
| + |
| + /* Index into the audit_strings array (for the iteration phase). */ |
| + size_t current_index; |
| + |
| + /* Tail of audit_strings[current_index] which still needs |
| + processing. */ |
| + const char *current_tail; |
| + |
| + /* Scratch buffer for returning a name which is part of the strings |
| + in audit_strings. */ |
| + char fname[SECURE_NAME_LIMIT]; |
| +}; |
| + |
| +/* This is a list of all the modes the dynamic loader can be in. */ |
| +enum rtld_mode |
| + { |
| + rtld_mode_normal, rtld_mode_list, rtld_mode_verify, rtld_mode_trace, |
| + }; |
| + |
| +/* Aggregated state information extracted from environment variables |
| + and the ld.so command line. */ |
| +struct dl_main_state |
| +{ |
| + struct audit_list audit_list; |
| + |
| + /* The library search path. */ |
| + const char *library_path; |
| + |
| + /* The list preloaded objects from LD_PRELOAD. */ |
| + const char *preloadlist; |
| + |
| + /* The preload list passed as a command argument. */ |
| + const char *preloadarg; |
| + |
| + enum rtld_mode mode; |
| + |
| + /* True if any of the debugging options is enabled. */ |
| + bool any_debug; |
| + |
| + /* True if information about versions has to be printed. */ |
| + bool version_info; |
| +}; |
| + |
| +/* Helper function to invoke _dl_init_paths with the right arguments |
| + from *STATE. */ |
| +static inline void |
| +call_init_paths (const struct dl_main_state *state) |
| +{ |
| + _dl_init_paths (state->library_path); |
| +} |
| + |
| +#endif /* _DL_MAIN */ |
| diff --git a/elf/rtld.c b/elf/rtld.c |
| index 4107a215abd554f4..fbfa441bf3b050ff 100644 |
| |
| |
| @@ -45,6 +45,7 @@ |
| #include <not-cancel.h> |
| #include <array_length.h> |
| #include <libc-early-init.h> |
| +#include <dl-main.h> |
| |
| #include <assert.h> |
| |
| @@ -109,42 +110,6 @@ static void print_missing_version (int errcode, const char *objname, |
| /* Print the various times we collected. */ |
| static void print_statistics (const hp_timing_t *total_timep); |
| |
| -/* Length limits for names and paths, to protect the dynamic linker, |
| - particularly when __libc_enable_secure is active. */ |
| -#ifdef NAME_MAX |
| -# define SECURE_NAME_LIMIT NAME_MAX |
| -#else |
| -# define SECURE_NAME_LIMIT 255 |
| -#endif |
| -#ifdef PATH_MAX |
| -# define SECURE_PATH_LIMIT PATH_MAX |
| -#else |
| -# define SECURE_PATH_LIMIT 1024 |
| -#endif |
| - |
| -/* Strings containing colon-separated lists of audit modules. */ |
| -struct audit_list |
| -{ |
| - /* Array of strings containing colon-separated path lists. Each |
| - audit module needs its own namespace, so pre-allocate the largest |
| - possible list. */ |
| - const char *audit_strings[DL_NNS]; |
| - |
| - /* Number of entries added to audit_strings. */ |
| - size_t length; |
| - |
| - /* Index into the audit_strings array (for the iteration phase). */ |
| - size_t current_index; |
| - |
| - /* Tail of audit_strings[current_index] which still needs |
| - processing. */ |
| - const char *current_tail; |
| - |
| - /* Scratch buffer for returning a name which is part of the strings |
| - in audit_strings. */ |
| - char fname[SECURE_NAME_LIMIT]; |
| -}; |
| - |
| /* Creates an empty audit list. */ |
| static void audit_list_init (struct audit_list *); |
| |
| @@ -165,13 +130,13 @@ static void audit_list_add_dynamic_tag (struct audit_list *, |
| audit_list_add_dynamic_tags calls. */ |
| static const char *audit_list_next (struct audit_list *); |
| |
| -/* This is a list of all the modes the dynamic loader can be in. */ |
| -enum mode { normal, list, verify, trace }; |
| +/* Initialize *STATE with the defaults. */ |
| +static void dl_main_state_init (struct dl_main_state *state); |
| |
| /* Process all environments variables the dynamic linker must recognize. |
| Since all of them start with `LD_' we are a bit smarter while finding |
| all the entries. */ |
| -static void process_envvars (enum mode *modep, struct audit_list *); |
| +static void process_envvars (struct dl_main_state *state); |
| |
| #ifdef DL_ARGV_NOT_RELRO |
| int _dl_argc attribute_hidden; |
| @@ -314,6 +279,18 @@ audit_list_count (struct audit_list *list) |
| return naudit; |
| } |
| |
| +static void |
| +dl_main_state_init (struct dl_main_state *state) |
| +{ |
| + audit_list_init (&state->audit_list); |
| + state->library_path = NULL; |
| + state->preloadlist = NULL; |
| + state->preloadarg = NULL; |
| + state->mode = rtld_mode_normal; |
| + state->any_debug = false; |
| + state->version_info = false; |
| +} |
| + |
| /* Set nonzero during loading and initialization of executable and |
| libraries, cleared before the executable's entry point runs. This |
| must not be initialized to nonzero, because the unused dynamic |
| @@ -896,15 +873,6 @@ security_init (void) |
| |
| #include "setup-vdso.h" |
| |
| -/* The library search path. */ |
| -static const char *library_path attribute_relro; |
| -/* The list preloaded objects. */ |
| -static const char *preloadlist attribute_relro; |
| -/* Nonzero if information about versions has to be printed. */ |
| -static int version_info attribute_relro; |
| -/* The preload list passed as a command argument. */ |
| -static const char *preloadarg attribute_relro; |
| - |
| /* The LD_PRELOAD environment variable gives list of libraries |
| separated by white space or colons that are loaded before the |
| executable's dependencies and prepended to the global scope list. |
| @@ -1146,7 +1114,6 @@ dl_main (const ElfW(Phdr) *phdr, |
| ElfW(auxv_t) *auxv) |
| { |
| const ElfW(Phdr) *ph; |
| - enum mode mode; |
| struct link_map *main_map; |
| size_t file_size; |
| char *file; |
| @@ -1156,8 +1123,8 @@ dl_main (const ElfW(Phdr) *phdr, |
| bool rtld_is_main = false; |
| void *tcbp = NULL; |
| |
| - struct audit_list audit_list; |
| - audit_list_init (&audit_list); |
| + struct dl_main_state state; |
| + dl_main_state_init (&state); |
| |
| GL(dl_init_static_tls) = &_dl_nothread_init_static_tls; |
| |
| @@ -1172,7 +1139,7 @@ dl_main (const ElfW(Phdr) *phdr, |
| GL(dl_make_stack_executable_hook) = &_dl_make_stack_executable; |
| |
| /* Process the environment variable which control the behaviour. */ |
| - process_envvars (&mode, &audit_list); |
| + process_envvars (&state); |
| |
| /* Set up a flag which tells we are just starting. */ |
| _dl_starting_up = 1; |
| @@ -1204,7 +1171,7 @@ dl_main (const ElfW(Phdr) *phdr, |
| while (_dl_argc > 1) |
| if (! strcmp (_dl_argv[1], "--list")) |
| { |
| - mode = list; |
| + state.mode = rtld_mode_list; |
| GLRO(dl_lazy) = -1; /* This means do no dependency analysis. */ |
| |
| ++_dl_skip_args; |
| @@ -1213,7 +1180,7 @@ dl_main (const ElfW(Phdr) *phdr, |
| } |
| else if (! strcmp (_dl_argv[1], "--verify")) |
| { |
| - mode = verify; |
| + state.mode = rtld_mode_verify; |
| |
| ++_dl_skip_args; |
| --_dl_argc; |
| @@ -1229,7 +1196,7 @@ dl_main (const ElfW(Phdr) *phdr, |
| else if (! strcmp (_dl_argv[1], "--library-path") |
| && _dl_argc > 2) |
| { |
| - library_path = _dl_argv[2]; |
| + state.library_path = _dl_argv[2]; |
| |
| _dl_skip_args += 2; |
| _dl_argc -= 2; |
| @@ -1246,7 +1213,7 @@ dl_main (const ElfW(Phdr) *phdr, |
| } |
| else if (! strcmp (_dl_argv[1], "--audit") && _dl_argc > 2) |
| { |
| - audit_list_add_string (&audit_list, _dl_argv[2]); |
| + audit_list_add_string (&state.audit_list, _dl_argv[2]); |
| |
| _dl_skip_args += 2; |
| _dl_argc -= 2; |
| @@ -1254,7 +1221,7 @@ dl_main (const ElfW(Phdr) *phdr, |
| } |
| else if (! strcmp (_dl_argv[1], "--preload") && _dl_argc > 2) |
| { |
| - preloadarg = _dl_argv[2]; |
| + state.preloadarg = _dl_argv[2]; |
| _dl_skip_args += 2; |
| _dl_argc -= 2; |
| _dl_argv += 2; |
| @@ -1322,7 +1289,7 @@ of this helper program; chances are you did not intend to run this program.\n\ |
| break; |
| } |
| |
| - if (__builtin_expect (mode, normal) == verify) |
| + if (__glibc_unlikely (state.mode == rtld_mode_verify)) |
| { |
| const char *objname; |
| const char *err_str = NULL; |
| @@ -1351,7 +1318,7 @@ of this helper program; chances are you did not intend to run this program.\n\ |
| /* Now the map for the main executable is available. */ |
| main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded; |
| |
| - if (__builtin_expect (mode, normal) == normal |
| + if (__glibc_likely (state.mode == rtld_mode_normal) |
| && GL(dl_rtld_map).l_info[DT_SONAME] != NULL |
| && main_map->l_info[DT_SONAME] != NULL |
| && strcmp ((const char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB]) |
| @@ -1592,7 +1559,7 @@ ERROR: '%s': cannot process note segment.\n", _dl_argv[0]); |
| _dl_setup_hash (main_map); |
| } |
| |
| - if (__builtin_expect (mode, normal) == verify) |
| + if (__glibc_unlikely (state.mode == rtld_mode_verify)) |
| { |
| /* We were called just to verify that this is a dynamic |
| executable using us as the program interpreter. Exit with an |
| @@ -1619,7 +1586,7 @@ ERROR: '%s': cannot process note segment.\n", _dl_argv[0]); |
| |
| /* Initialize the data structures for the search paths for shared |
| objects. */ |
| - _dl_init_paths (library_path); |
| + call_init_paths (&state); |
| |
| /* Initialize _r_debug. */ |
| struct r_debug *r = _dl_debug_initialize (GL(dl_rtld_map).l_addr, |
| @@ -1684,14 +1651,14 @@ ERROR: '%s': cannot process note segment.\n", _dl_argv[0]); |
| /* Assign a module ID. Do this before loading any audit modules. */ |
| GL(dl_rtld_map).l_tls_modid = _dl_next_tls_modid (); |
| |
| - audit_list_add_dynamic_tag (&audit_list, main_map, DT_AUDIT); |
| - audit_list_add_dynamic_tag (&audit_list, main_map, DT_DEPAUDIT); |
| + audit_list_add_dynamic_tag (&state.audit_list, main_map, DT_AUDIT); |
| + audit_list_add_dynamic_tag (&state.audit_list, main_map, DT_DEPAUDIT); |
| |
| /* If we have auditing DSOs to load, do it now. */ |
| bool need_security_init = true; |
| - if (audit_list.length > 0) |
| + if (state.audit_list.length > 0) |
| { |
| - size_t naudit = audit_list_count (&audit_list); |
| + size_t naudit = audit_list_count (&state.audit_list); |
| |
| /* Since we start using the auditing DSOs right away we need to |
| initialize the data structures now. */ |
| @@ -1704,7 +1671,7 @@ ERROR: '%s': cannot process note segment.\n", _dl_argv[0]); |
| security_init (); |
| need_security_init = false; |
| |
| - load_audit_modules (main_map, &audit_list); |
| + load_audit_modules (main_map, &state.audit_list); |
| |
| /* The count based on audit strings may overestimate the number |
| of audit modules that got loaded, but not underestimate. */ |
| @@ -1759,19 +1726,21 @@ ERROR: '%s': cannot process note segment.\n", _dl_argv[0]); |
| struct link_map **preloads = NULL; |
| unsigned int npreloads = 0; |
| |
| - if (__glibc_unlikely (preloadlist != NULL)) |
| + if (__glibc_unlikely (state.preloadlist != NULL)) |
| { |
| RTLD_TIMING_VAR (start); |
| rtld_timer_start (&start); |
| - npreloads += handle_preload_list (preloadlist, main_map, "LD_PRELOAD"); |
| + npreloads += handle_preload_list (state.preloadlist, main_map, |
| + "LD_PRELOAD"); |
| rtld_timer_accum (&load_time, start); |
| } |
| |
| - if (__glibc_unlikely (preloadarg != NULL)) |
| + if (__glibc_unlikely (state.preloadarg != NULL)) |
| { |
| RTLD_TIMING_VAR (start); |
| rtld_timer_start (&start); |
| - npreloads += handle_preload_list (preloadarg, main_map, "--preload"); |
| + npreloads += handle_preload_list (state.preloadarg, main_map, |
| + "--preload"); |
| rtld_timer_accum (&load_time, start); |
| } |
| |
| @@ -1878,7 +1847,8 @@ ERROR: '%s': cannot process note segment.\n", _dl_argv[0]); |
| { |
| RTLD_TIMING_VAR (start); |
| rtld_timer_start (&start); |
| - _dl_map_object_deps (main_map, preloads, npreloads, mode == trace, 0); |
| + _dl_map_object_deps (main_map, preloads, npreloads, |
| + state.mode == rtld_mode_trace, 0); |
| rtld_timer_accum (&load_time, start); |
| } |
| |
| @@ -1905,7 +1875,7 @@ ERROR: '%s': cannot process note segment.\n", _dl_argv[0]); |
| rtld_multiple_ref = true; |
| |
| GL(dl_rtld_map).l_prev = main_map->l_searchlist.r_list[i - 1]; |
| - if (__builtin_expect (mode, normal) == normal) |
| + if (__glibc_likely (state.mode == rtld_mode_normal)) |
| { |
| GL(dl_rtld_map).l_next = (i + 1 < main_map->l_searchlist.r_nlist |
| ? main_map->l_searchlist.r_list[i + 1] |
| @@ -1938,8 +1908,8 @@ ERROR: '%s': cannot process note segment.\n", _dl_argv[0]); |
| versions we need. */ |
| { |
| struct version_check_args args; |
| - args.doexit = mode == normal; |
| - args.dotrace = mode == trace; |
| + args.doexit = state.mode == rtld_mode_normal; |
| + args.dotrace = state.mode == rtld_mode_trace; |
| _dl_receive_error (print_missing_version, version_check_doit, &args); |
| } |
| |
| @@ -1959,7 +1929,7 @@ ERROR: '%s': cannot process note segment.\n", _dl_argv[0]); |
| earlier. */ |
| security_init (); |
| |
| - if (__builtin_expect (mode, normal) != normal) |
| + if (__glibc_unlikely (state.mode != rtld_mode_normal)) |
| { |
| /* We were run just to list the shared libraries. It is |
| important that we do this before real relocation, because the |
| @@ -2061,7 +2031,7 @@ ERROR: '%s': cannot process note segment.\n", _dl_argv[0]); |
| (size_t) l->l_map_start); |
| } |
| |
| - if (__builtin_expect (mode, trace) != trace) |
| + if (__glibc_unlikely (state.mode != rtld_mode_trace)) |
| for (i = 1; i < (unsigned int) _dl_argc; ++i) |
| { |
| const ElfW(Sym) *ref = NULL; |
| @@ -2115,7 +2085,7 @@ ERROR: '%s': cannot process note segment.\n", _dl_argv[0]); |
| } |
| } |
| #define VERNEEDTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERNEED)) |
| - if (version_info) |
| + if (state.version_info) |
| { |
| /* Print more information. This means here, print information |
| about the versions needed. */ |
| @@ -2477,13 +2447,10 @@ print_missing_version (int errcode __attribute__ ((unused)), |
| objname, errstring); |
| } |
| |
| -/* Nonzero if any of the debugging options is enabled. */ |
| -static int any_debug attribute_relro; |
| - |
| /* Process the string given as the parameter which explains which debugging |
| options are enabled. */ |
| static void |
| -process_dl_debug (const char *dl_debug) |
| +process_dl_debug (struct dl_main_state *state, const char *dl_debug) |
| { |
| /* When adding new entries make sure that the maximal length of a name |
| is correctly handled in the LD_DEBUG_HELP code below. */ |
| @@ -2540,7 +2507,7 @@ process_dl_debug (const char *dl_debug) |
| && memcmp (dl_debug, debopts[cnt].name, len) == 0) |
| { |
| GLRO(dl_debug_mask) |= debopts[cnt].mask; |
| - any_debug = 1; |
| + state->any_debug = true; |
| break; |
| } |
| |
| @@ -2594,11 +2561,10 @@ extern char **_environ attribute_hidden; |
| |
| |
| static void |
| -process_envvars (enum mode *modep, struct audit_list *audit_list) |
| +process_envvars (struct dl_main_state *state) |
| { |
| char **runp = _environ; |
| char *envline; |
| - enum mode mode = normal; |
| char *debug_output = NULL; |
| |
| /* This is the default place for profiling data file. */ |
| @@ -2630,25 +2596,25 @@ process_envvars (enum mode *modep, struct audit_list *audit_list) |
| /* Debugging of the dynamic linker? */ |
| if (memcmp (envline, "DEBUG", 5) == 0) |
| { |
| - process_dl_debug (&envline[6]); |
| + process_dl_debug (state, &envline[6]); |
| break; |
| } |
| if (memcmp (envline, "AUDIT", 5) == 0) |
| - audit_list_add_string (audit_list, &envline[6]); |
| + audit_list_add_string (&state->audit_list, &envline[6]); |
| break; |
| |
| case 7: |
| /* Print information about versions. */ |
| if (memcmp (envline, "VERBOSE", 7) == 0) |
| { |
| - version_info = envline[8] != '\0'; |
| + state->version_info = envline[8] != '\0'; |
| break; |
| } |
| |
| /* List of objects to be preloaded. */ |
| if (memcmp (envline, "PRELOAD", 7) == 0) |
| { |
| - preloadlist = &envline[8]; |
| + state->preloadlist = &envline[8]; |
| break; |
| } |
| |
| @@ -2697,7 +2663,7 @@ process_envvars (enum mode *modep, struct audit_list *audit_list) |
| if (!__libc_enable_secure |
| && memcmp (envline, "LIBRARY_PATH", 12) == 0) |
| { |
| - library_path = &envline[13]; |
| + state->library_path = &envline[13]; |
| break; |
| } |
| |
| @@ -2739,7 +2705,7 @@ process_envvars (enum mode *modep, struct audit_list *audit_list) |
| /* The mode of the dynamic linker can be set. */ |
| if (memcmp (envline, "TRACE_PRELINKING", 16) == 0) |
| { |
| - mode = trace; |
| + state->mode = rtld_mode_trace; |
| GLRO(dl_verbose) = 1; |
| GLRO(dl_debug_mask) |= DL_DEBUG_PRELINK; |
| GLRO(dl_trace_prelink) = &envline[17]; |
| @@ -2749,7 +2715,7 @@ process_envvars (enum mode *modep, struct audit_list *audit_list) |
| case 20: |
| /* The mode of the dynamic linker can be set. */ |
| if (memcmp (envline, "TRACE_LOADED_OBJECTS", 20) == 0) |
| - mode = trace; |
| + state->mode = rtld_mode_trace; |
| break; |
| |
| /* We might have some extra environment variable to handle. This |
| @@ -2762,9 +2728,6 @@ process_envvars (enum mode *modep, struct audit_list *audit_list) |
| } |
| } |
| |
| - /* The caller wants this information. */ |
| - *modep = mode; |
| - |
| /* Extra security for SUID binaries. Remove all dangerous environment |
| variables. */ |
| if (__builtin_expect (__libc_enable_secure, 0)) |
| @@ -2793,13 +2756,13 @@ process_envvars (enum mode *modep, struct audit_list *audit_list) |
| GLRO(dl_debug_mask) = 0; |
| } |
| |
| - if (mode != normal) |
| + if (state->mode != rtld_mode_normal) |
| _exit (5); |
| } |
| /* If we have to run the dynamic linker in debugging mode and the |
| LD_DEBUG_OUTPUT environment variable is given, we write the debug |
| messages to this file. */ |
| - else if (any_debug && debug_output != NULL) |
| + else if (state->any_debug && debug_output != NULL) |
| { |
| const int flags = O_WRONLY | O_APPEND | O_CREAT | O_NOFOLLOW; |
| size_t name_len = strlen (debug_output); |