commit be9240c84c67de44959905a829141576965a0588

Author: Fangrui Song <maskray@google.com>

Date:   Tue Apr 19 15:52:27 2022 -0700

    elf: Remove __libc_init_secure

    After 73fc4e28b9464f0e13edc719a5372839970e7ddb,

    __libc_enable_secure_decided is always 0 and a statically linked

    executable may overwrite __libc_enable_secure without considering

    AT_SECURE.

    The __libc_enable_secure has been correctly initialized in _dl_aux_init,

    so just remove __libc_enable_secure_decided and __libc_init_secure.

    This allows us to remove some startup_get*id functions from

    22b79ed7f413cd980a7af0cf258da5bf82b6d5e5.

    Reviewed-by: Florian Weimer <fweimer@redhat.com>

    (cherry picked from commit 3e9acce8c50883b6cd8a3fb653363d9fa21e1608)

diff --git a/csu/libc-start.c b/csu/libc-start.c

index d01e57ea59ceb880..a2fc2f6f9665a48f 100644

--- a/csu/libc-start.c

+++ b/csu/libc-start.c

@@ -285,9 +285,6 @@ LIBC_START_MAIN (int (*main) (int, char **, char ** MAIN_AUXVEC_DECL),

         }

     }

-  /* Initialize very early so that tunables can use it.  */

-  __libc_init_secure ();

-

   __tunables_init (__environ);

   ARCH_INIT_CPU_FEATURES ();

diff --git a/elf/enbl-secure.c b/elf/enbl-secure.c

index 9e47526bd3e444e1..1208610bd0670c74 100644

--- a/elf/enbl-secure.c

+++ b/elf/enbl-secure.c

@@ -26,15 +26,5 @@

 #include <startup.h>

 #include <libc-internal.h>

-/* If nonzero __libc_enable_secure is already set.  */

-int __libc_enable_secure_decided;

 /* Safest assumption, if somehow the initializer isn't run.  */

 int __libc_enable_secure = 1;

-

-void

-__libc_init_secure (void)

-{

-  if (__libc_enable_secure_decided == 0)

-    __libc_enable_secure = (startup_geteuid () != startup_getuid ()

-			    || startup_getegid () != startup_getgid ());

-}

diff --git a/include/libc-internal.h b/include/libc-internal.h

index 749dfb919ce4a62d..44fcb6bdf8751c1c 100644

--- a/include/libc-internal.h

+++ b/include/libc-internal.h

@@ -21,9 +21,6 @@

 #include <hp-timing.h>

-/* Initialize the `__libc_enable_secure' flag.  */

-extern void __libc_init_secure (void);

-

 /* Discover the tick frequency of the machine if something goes wrong,

    we return 0, an impossible hertz.  */

 extern int __profile_frequency (void);

diff --git a/include/unistd.h b/include/unistd.h

index 7849562c4272e2c9..5824485629793ccb 100644

--- a/include/unistd.h

+++ b/include/unistd.h

@@ -180,7 +180,6 @@ libc_hidden_proto (__sbrk)

    and some functions contained in the C library ignore various

    environment variables that normally affect them.  */

 extern int __libc_enable_secure attribute_relro;

-extern int __libc_enable_secure_decided;

 rtld_hidden_proto (__libc_enable_secure)

diff --git a/sysdeps/generic/startup.h b/sysdeps/generic/startup.h

index 04f20cde474cea89..c3be5430bd8bbaa6 100644

--- a/sysdeps/generic/startup.h

+++ b/sysdeps/generic/startup.h

@@ -23,27 +23,3 @@

 /* Use macro instead of inline function to avoid including <stdio.h>.  */

 #define _startup_fatal(message) __libc_fatal ((message))

-

-static inline uid_t

-startup_getuid (void)

-{

-  return __getuid ();

-}

-

-static inline uid_t

-startup_geteuid (void)

-{

-  return __geteuid ();

-}

-

-static inline gid_t

-startup_getgid (void)

-{

-  return __getgid ();

-}

-

-static inline gid_t

-startup_getegid (void)

-{

-  return __getegid ();

-}

diff --git a/sysdeps/mach/hurd/enbl-secure.c b/sysdeps/mach/hurd/enbl-secure.c

deleted file mode 100644

index 3e9a6b888d56754b..0000000000000000

--- a/sysdeps/mach/hurd/enbl-secure.c

+++ /dev/null

@@ -1,30 +0,0 @@

-/* Define and initialize the `__libc_enable_secure' flag.  Hurd version.

-   Copyright (C) 1998-2021 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/>.  */

-

-/* There is no need for this file in the Hurd; it is just a placeholder

-   to prevent inclusion of the sysdeps/generic version.

-   In the shared library, the `__libc_enable_secure' variable is defined

-   by the dynamic linker in dl-sysdep.c and set there.

-   In the static library, it is defined in init-first.c and set there.  */

-

-#include <libc-internal.h>

-

-void

-__libc_init_secure (void)

-{

-}

diff --git a/sysdeps/mach/hurd/i386/init-first.c b/sysdeps/mach/hurd/i386/init-first.c

index a430aae085527163..4dc9017ec8754a1a 100644

--- a/sysdeps/mach/hurd/i386/init-first.c

+++ b/sysdeps/mach/hurd/i386/init-first.c

@@ -38,10 +38,6 @@ extern void __init_misc (int, char **, char **);

 unsigned long int __hurd_threadvar_stack_offset;

 unsigned long int __hurd_threadvar_stack_mask;

-#ifndef SHARED

-int __libc_enable_secure;

-#endif

-

 extern int __libc_argc attribute_hidden;

 extern char **__libc_argv attribute_hidden;

 extern char **_dl_argv;

diff --git a/sysdeps/unix/sysv/linux/i386/startup.h b/sysdeps/unix/sysv/linux/i386/startup.h

index dee7a4f1d3d420be..192c765361c17ed1 100644

--- a/sysdeps/unix/sysv/linux/i386/startup.h

+++ b/sysdeps/unix/sysv/linux/i386/startup.h

@@ -32,30 +32,6 @@ _startup_fatal (const char *message __attribute__ ((unused)))

   ABORT_INSTRUCTION;

   __builtin_unreachable ();

 }

-

-static inline uid_t

-startup_getuid (void)

-{

-  return (uid_t) INTERNAL_SYSCALL_CALL (getuid32);

-}

-

-static inline uid_t

-startup_geteuid (void)

-{

-  return (uid_t) INTERNAL_SYSCALL_CALL (geteuid32);

-}

-

-static inline gid_t

-startup_getgid (void)

-{

-  return (gid_t) INTERNAL_SYSCALL_CALL (getgid32);

-}

-

-static inline gid_t

-startup_getegid (void)

-{

-  return (gid_t) INTERNAL_SYSCALL_CALL (getegid32);

-}

 #else

 # include_next <startup.h>

 #endif