commit 851f32cf7bf7067f73b991610778915edd57d7b4

Author: Florian Weimer <fweimer@redhat.com>

Date:   Tue Mar 2 14:38:42 2021 +0100

    ld.so: Implement the --list-diagnostics option

diff --git a/elf/Makefile b/elf/Makefile

index aa65ec59f143bccf..d246f1c0d9e019fd 100644

--- a/elf/Makefile

+++ b/elf/Makefile

@@ -64,7 +64,7 @@ elide-routines.os = $(all-dl-routines) dl-support enbl-secure dl-origin \

 # interpreter and operating independent of libc.

 rtld-routines	= rtld $(all-dl-routines) dl-sysdep dl-environ dl-minimal \

   dl-error-minimal dl-conflict dl-hwcaps dl-hwcaps_split dl-hwcaps-subdirs \

-  dl-usage

+  dl-usage dl-diagnostics dl-diagnostics-kernel dl-diagnostics-cpu

 all-rtld-routines = $(rtld-routines) $(sysdep-rtld-routines)

 CFLAGS-dl-runtime.c += -fexceptions -fasynchronous-unwind-tables

@@ -672,6 +672,9 @@ CFLAGS-cache.c += $(SYSCONF-FLAGS)

 CFLAGS-rtld.c += $(SYSCONF-FLAGS)

 CFLAGS-dl-usage.c += $(SYSCONF-FLAGS) \

   -D'RTLD="$(rtlddir)/$(rtld-installed-name)"'

+CFLAGS-dl-diagnostics.c += $(SYSCONF-FLAGS) \

+  -D'PREFIX="$(prefix)"' \

+  -D'RTLD="$(rtlddir)/$(rtld-installed-name)"'

 cpp-srcs-left := $(all-rtld-routines:=.os)

 lib := rtld

diff --git a/elf/dl-diagnostics-cpu.c b/elf/dl-diagnostics-cpu.c

new file mode 100644

index 0000000000000000..f7d149764bcb35a1

--- /dev/null

+++ b/elf/dl-diagnostics-cpu.c

@@ -0,0 +1,24 @@

+/* Print CPU diagnostics data in ld.so.  Stub version.

+   Copyright (C) 2021 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/>.  */

+

+#include <dl-diagnostics.h>

+

+void

+_dl_diagnostics_cpu (void)

+{

+}

diff --git a/elf/dl-diagnostics-kernel.c b/elf/dl-diagnostics-kernel.c

new file mode 100644

index 0000000000000000..831c358f1463cbf4

--- /dev/null

+++ b/elf/dl-diagnostics-kernel.c

@@ -0,0 +1,24 @@

+/* Print kernel diagnostics data in ld.so.  Stub version.

+   Copyright (C) 2021 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/>.  */

+

+#include <dl-diagnostics.h>

+

+void

+_dl_diagnostics_kernel (void)

+{

+}

diff --git a/elf/dl-diagnostics.c b/elf/dl-diagnostics.c

new file mode 100644

index 0000000000000000..bef224b36cbf5fc3

--- /dev/null

+++ b/elf/dl-diagnostics.c

@@ -0,0 +1,265 @@

+/* Print diagnostics data in ld.so.

+   Copyright (C) 2021 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/>.  */

+

+#include <gnu/lib-names.h>

+#include <stdbool.h>

+#include <stddef.h>

+#include <unistd.h>

+

+#include <dl-diagnostics.h>

+#include <dl-hwcaps.h>

+#include <dl-main.h>

+#include <dl-procinfo.h>

+#include <dl-sysdep.h>

+#include <ldsodefs.h>

+#include "trusted-dirs.h"

+#include "version.h"

+

+/* Write CH to standard output.  */

+static void

+_dl_putc (char ch)

+{

+  _dl_write (STDOUT_FILENO, &ch, 1);

+}

+

+/* Print CH to standard output, quoting it if necessary.  */

+static void

+print_quoted_char (char ch)

+{

+  if (ch < ' ' || ch > '~')

+    {

+      char buf[4];

+      buf[0] = '\\';

+      buf[1] = '0' + ((ch >> 6) & 7);

+      buf[2] = '0' + ((ch >> 6) & 7);

+      buf[3] = '0' + (ch & 7);

+      _dl_write (STDOUT_FILENO, buf, 4);

+    }

+  else

+    {

+      if (ch == '\\' || ch == '"')

+        _dl_putc ('\\');

+      _dl_putc (ch);

+    }

+}

+

+/* Print S of LEN bytes to standard output, quoting characters as

+   needed.  */

+static void

+print_string_length (const char *s, size_t len)

+{

+  _dl_putc ('"');

+  for (size_t i = 0; i < len; ++i)

+    print_quoted_char (s[i]);

+  _dl_putc ('"');

+}

+

+void

+_dl_diagnostics_print_string (const char *s)

+{

+  if (s == NULL)

+    {

+      _dl_printf ("0x0");

+      return;

+    }

+

+  _dl_putc ('"');

+  while (*s != '\0')

+    {

+      print_quoted_char (*s);

+      ++s;

+    }

+  _dl_putc ('"');

+}

+

+void

+_dl_diagnostics_print_labeled_string (const char *label, const char *s)

+{

+  _dl_printf ("%s=", label);

+  _dl_diagnostics_print_string (s);

+  _dl_putc ('\n');

+}

+

+void

+_dl_diagnostics_print_labeled_value (const char *label, uint64_t value)

+{

+  if (sizeof (value) == sizeof (unsigned long int))

+    /* _dl_printf can print 64-bit values directly.  */

+    _dl_printf ("%s=0x%lx\n", label, (unsigned long int) value);

+  else

+    {

+      uint32_t high = value >> 32;

+      uint32_t low = value;

+      if (high == 0)

+        _dl_printf ("%s=0x%x\n", label, low);

+      else

+        _dl_printf ("%s=0x%x%08x\n", label, high, low);

+    }

+}

+

+/* Return true if ENV is an unfiltered environment variable.  */

+static bool

+unfiltered_envvar (const char *env, size_t *name_length)

+{

+  char *env_equal = strchr (env, '=');

+  if (env_equal == NULL)

+    {

+      /* Always dump malformed entries.  */

+      *name_length = strlen (env);

+      return true;

+    }

+  size_t envname_length = env_equal - env;

+  *name_length = envname_length;

+

+  /* LC_ and LD_ variables.  */

+  if (env[0] == 'L' && (env[1] == 'C' || env[1] == 'D')

+      && env[2] == '_')

+    return true;

+

+  /* MALLOC_ variables.  */

+  if (strncmp (env, "MALLOC_", strlen ("MALLOC_")) == 0)

+    return true;

+

+  static const char unfiltered[] =

+    "DATEMSK\0"

+    "GCONV_PATH\0"

+    "GETCONF_DIR\0"

+    "GETCONF_DIR\0"

+    "GLIBC_TUNABLES\0"

+    "GMON_OUTPUT_PREFIX\0"

+    "HESIOD_CONFIG\0"

+    "HES_DOMAIN\0"

+    "HOSTALIASES\0"

+    "I18NPATH\0"

+    "IFS\0"

+    "LANG\0"

+    "LOCALDOMAIN\0"

+    "LOCPATH\0"

+    "MSGVERB\0"

+    "NIS_DEFAULTS\0"

+    "NIS_GROUP\0"

+    "NIS_PATH\0"

+    "NLSPATH\0"

+    "PATH\0"

+    "POSIXLY_CORRECT\0"

+    "RESOLV_HOST_CONF\0"

+    "RES_OPTIONS\0"

+    "SEV_LEVEL\0"

+    "TMPDIR\0"

+    "TZ\0"

+    "TZDIR\0"

+    /* Two null bytes at the end to mark the end of the list via an

+       empty substring.  */

+    ;

+  for (const char *candidate = unfiltered; *candidate != '\0'; )

+    {

+      size_t candidate_length = strlen (candidate);

+      if (candidate_length == envname_length

+          && memcmp (candidate, env, candidate_length) == 0)

+        return true;

+      candidate += candidate_length + 1;

+    }

+

+  return false;

+}

+

+/* Dump the process environment.  */

+static void

+print_environ (char **environ)

+{

+  unsigned int index = 0;

+  for (char **envp = environ; *envp != NULL; ++envp)

+    {

+      char *env = *envp;

+      size_t name_length;

+      bool unfiltered = unfiltered_envvar (env, &name_length);

+      _dl_printf ("env%s[0x%x]=",

+                  unfiltered ? "" : "_filtered", index);

+      if (unfiltered)

+        _dl_diagnostics_print_string (env);

+      else

+        print_string_length (env, name_length);

+      _dl_putc ('\n');

+      ++index;

+    }

+}

+

+/* Print configured paths and the built-in search path.  */

+static void

+print_paths (void)

+{

+  _dl_diagnostics_print_labeled_string ("path.prefix", PREFIX);

+  _dl_diagnostics_print_labeled_string ("path.rtld", RTLD);

+  _dl_diagnostics_print_labeled_string ("path.sysconfdir", SYSCONFDIR);

+

+  unsigned int index = 0;

+  static const char *system_dirs = SYSTEM_DIRS "\0";

+  for (const char *e = system_dirs; *e != '\0'; )

+    {

+      size_t len = strlen (e);

+      _dl_printf ("path.system_dirs[0x%x]=", index);

+      print_string_length (e, len);

+      _dl_putc ('\n');

+      ++index;

+      e += len + 1;

+    }

+}

+

+/* Print information about the glibc version.  */

+static void

+print_version (void)

+{

+  _dl_diagnostics_print_labeled_string ("version.release", RELEASE);

+  _dl_diagnostics_print_labeled_string ("version.version", VERSION);

+}

+

+void

+_dl_print_diagnostics (char **environ)

+{

+#ifdef HAVE_DL_DISCOVER_OSVERSION

+  _dl_diagnostics_print_labeled_value

+    ("dl_discover_osversion", _dl_discover_osversion ());

+#endif

+  _dl_diagnostics_print_labeled_string ("dl_dst_lib", DL_DST_LIB);

+  _dl_diagnostics_print_labeled_value ("dl_hwcap", GLRO (dl_hwcap));

+  _dl_diagnostics_print_labeled_value ("dl_hwcap_important", HWCAP_IMPORTANT);

+  _dl_diagnostics_print_labeled_value ("dl_hwcap2", GLRO (dl_hwcap2));

+  _dl_diagnostics_print_labeled_string

+    ("dl_hwcaps_subdirs", _dl_hwcaps_subdirs);

+  _dl_diagnostics_print_labeled_value

+    ("dl_hwcaps_subdirs_active", _dl_hwcaps_subdirs_active ());

+  _dl_diagnostics_print_labeled_value ("dl_osversion", GLRO (dl_osversion));

+  _dl_diagnostics_print_labeled_value ("dl_pagesize", GLRO (dl_pagesize));

+  _dl_diagnostics_print_labeled_string ("dl_platform", GLRO (dl_platform));

+  _dl_diagnostics_print_labeled_string

+    ("dl_profile_output", GLRO (dl_profile_output));

+  _dl_diagnostics_print_labeled_value

+    ("dl_string_platform", _dl_string_platform ( GLRO (dl_platform)));

+

+  _dl_diagnostics_print_labeled_string ("dso.ld", LD_SO);

+  _dl_diagnostics_print_labeled_string ("dso.libc", LIBC_SO);

+

+  print_environ (environ);

+  print_paths ();

+  print_version ();

+

+  _dl_diagnostics_kernel ();

+  _dl_diagnostics_cpu ();

+

+  _exit (EXIT_SUCCESS);

+}

diff --git a/elf/dl-diagnostics.h b/elf/dl-diagnostics.h

new file mode 100644

index 0000000000000000..27dcb12bca12e5b6

--- /dev/null

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

@@ -0,0 +1,46 @@

+/* Interfaces for printing diagnostics in ld.so.

+   Copyright (C) 2021 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_DIAGNOSTICS_H

+#define _DL_DIAGNOSTICS_H

+

+#include <stdint.h>

+

+/* Write the null-terminated string to standard output, surrounded in

+   quotation marks.  */

+void _dl_diagnostics_print_string (const char *s) attribute_hidden;

+

+/* Like _dl_diagnostics_print_string, but add a LABEL= prefix, and a

+   newline character as a suffix.  */

+void _dl_diagnostics_print_labeled_string (const char *label, const char *s)

+  attribute_hidden;

+

+/* Print LABEL=VALUE to standard output, followed by a newline

+   character.  */

+void _dl_diagnostics_print_labeled_value (const char *label, uint64_t value)

+  attribute_hidden;

+

+/* Print diagnostics data for the kernel.  Called from

+   _dl_print_diagnostics.  */

+void _dl_diagnostics_kernel (void) attribute_hidden;

+

+/* Print diagnostics data for the CPU(s).  Called from

+   _dl_print_diagnostics.  */

+void _dl_diagnostics_cpu (void) attribute_hidden;

+

+#endif /* _DL_DIAGNOSTICS_H */

diff --git a/elf/dl-main.h b/elf/dl-main.h

index 9e7b51d8f010e904..9fbbdb0fac09adf3 100644

--- a/elf/dl-main.h

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

@@ -63,7 +63,7 @@ struct audit_list

 enum rtld_mode

   {

     rtld_mode_normal, rtld_mode_list, rtld_mode_verify, rtld_mode_trace,

-    rtld_mode_list_tunables, rtld_mode_help,

+    rtld_mode_list_tunables, rtld_mode_list_diagnostics, rtld_mode_help,

   };

 /* Aggregated state information extracted from environment variables

@@ -121,4 +121,7 @@ _Noreturn void _dl_version (void) attribute_hidden;

 _Noreturn void _dl_help (const char *argv0, struct dl_main_state *state)

   attribute_hidden;

+/* Print a diagnostics dump.  */

+_Noreturn void _dl_print_diagnostics (char **environ) attribute_hidden;

+

 #endif /* _DL_MAIN */

diff --git a/elf/dl-usage.c b/elf/dl-usage.c

index 908b4894b3014b2d..e19e1791d9169da2 100644

--- a/elf/dl-usage.c

+++ b/elf/dl-usage.c

@@ -261,6 +261,7 @@ setting environment variables (which would be inherited by subprocesses).\n\

   --list-tunables       list all tunables with minimum and maximum values\n"

 #endif

 "\

+  --list-diagnostics    list diagnostics information\n\

   --help                display this help and exit\n\

   --version             output version information and exit\n\

 \n\

diff --git a/elf/rtld.c b/elf/rtld.c

index 54b621ec5ca014fa..d14c388f548d6d51 100644

--- a/elf/rtld.c

+++ b/elf/rtld.c

@@ -138,6 +138,7 @@ 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.  */

+extern char **_environ attribute_hidden;

 static void process_envvars (struct dl_main_state *state);

 #ifdef DL_ARGV_NOT_RELRO

@@ -1273,6 +1274,14 @@ dl_main (const ElfW(Phdr) *phdr,

 	    ++_dl_argv;

 	  }

 #endif

+	else if (! strcmp (_dl_argv[1], "--list-diagnostics"))

+	  {

+	    state.mode = rtld_mode_list_diagnostics;

+

+	    ++_dl_skip_args;

+	    --_dl_argc;

+	    ++_dl_argv;

+	  }

 	else if (strcmp (_dl_argv[1], "--help") == 0)

 	  {

 	    state.mode = rtld_mode_help;

@@ -1301,6 +1310,9 @@ dl_main (const ElfW(Phdr) *phdr,

 	}

 #endif

+      if (state.mode == rtld_mode_list_diagnostics)

+	_dl_print_diagnostics (_environ);

+

       /* If we have no further argument the program was called incorrectly.

 	 Grant the user some education.  */

       if (_dl_argc < 2)

@@ -2623,12 +2635,6 @@ a filename can be specified using the LD_DEBUG_OUTPUT environment variable.\n");

     }

 }

-/* 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.  */

-extern char **_environ attribute_hidden;

-

-

 static void

 process_envvars (struct dl_main_state *state)

 {

diff --git a/sysdeps/unix/sysv/linux/dl-diagnostics-kernel.c b/sysdeps/unix/sysv/linux/dl-diagnostics-kernel.c

new file mode 100644

index 0000000000000000..59f6402c547ba590

--- /dev/null

+++ b/sysdeps/unix/sysv/linux/dl-diagnostics-kernel.c

@@ -0,0 +1,77 @@

+/* Print kernel diagnostics data in ld.so.  Linux version.

+   Copyright (C) 2021 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/>.  */

+

+#include <dl-diagnostics.h>

+#include <ldsodefs.h>

+#include <sys/utsname.h>

+

+/* Dump the auxiliary vector to standard output.  */

+static void

+print_auxv (void)

+{

+  /* See _dl_show_auxv.  The code below follows the general output

+     format for diagnostic dumps.  */

+  unsigned int index = 0;

+  for (ElfW(auxv_t) *av = GLRO(dl_auxv); av->a_type != AT_NULL; ++av)

+    {

+      _dl_printf ("auxv[0x%x].a_type=0x%lx\n"

+                  "auxv[0x%x].a_val=",

+                  index, (unsigned long int) av->a_type, index);

+      if (av->a_type == AT_EXECFN

+          || av->a_type == AT_PLATFORM

+          || av->a_type == AT_BASE_PLATFORM)

+        /* The address of the strings is not useful at all, so print

+           the strings themselvs.  */

+        _dl_diagnostics_print_string ((const char *) av->a_un.a_val);

+      else

+        _dl_printf ("0x%lx", (unsigned long int) av->a_un.a_val);

+      _dl_printf ("\n");

+      ++index;

+    }

+}

+

+/* Print one uname entry.  */

+static void

+print_utsname_entry (const char *field, const char *value)

+{

+  _dl_printf ("uname.");

+  _dl_diagnostics_print_labeled_string (field, value);

+}

+

+/* Print information from uname, including the kernel version.  */

+static void

+print_uname (void)

+{

+  struct utsname uts;

+  if (__uname (&uts) == 0)

+    {

+      print_utsname_entry ("sysname", uts.sysname);

+      print_utsname_entry ("nodename", uts.nodename);

+      print_utsname_entry ("release", uts.release);

+      print_utsname_entry ("version", uts.version);

+      print_utsname_entry ("machine", uts.machine);

+      print_utsname_entry ("domainname", uts.domainname);

+    }

+}

+

+void

+_dl_diagnostics_kernel (void)

+{

+  print_auxv ();

+  print_uname ();

+}