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

--- /dev/null

+++ b/elf/dl-main.h

@@ -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

--- a/elf/rtld.c

+++ b/elf/rtld.c

@@ -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);