1  /* Copyright (C) 2015-2023 Free Software Foundation, Inc.
       2     This file is part of the GNU C Library.
       3  
       4     The GNU C Library is free software; you can redistribute it and/or
       5     modify it under the terms of the GNU Lesser General Public
       6     License as published by the Free Software Foundation; either
       7     version 2.1 of the License, or (at your option) any later version.
       8  
       9     The GNU C Library is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      12     Lesser General Public License for more details.
      13  
      14     You should have received a copy of the GNU Lesser General Public
      15     License along with the GNU C Library; if not, see
      16     <https://www.gnu.org/licenses/>.  */
      17  
      18  #include <sys/personality.h>
      19  #include <sysdep.h>
      20  
      21  extern __typeof (personality) __personality;
      22  
      23  int
      24  __personality (unsigned long persona)
      25  {
      26  #ifdef PERSONALITY_TRUNCATE_ARGUMENT
      27    /* Starting with kernel commit v2.6.21-3117-g97dc32c, the type of
      28       task_struct->pesonality is "unsigned int".
      29       Starting with kernel commit v2.6.35-rc1-372-g485d527, the personality
      30       syscall accepts "unsigned int" instead of "long unsigned int".
      31       In between, a personality argument that does not fit into "unsigned int"
      32       would result to system call returning -EINVAL.
      33       We explicitly truncate the personality argument to "unsigned int"
      34       to eliminate the uncertainty.  */
      35    persona = (unsigned int) persona;
      36  #endif
      37  
      38    long int ret = INTERNAL_SYSCALL_CALL (personality, persona);
      39  
      40    /* Starting with kernel commit v2.6.29-6609-g11d06b2, the personality syscall
      41       never fails.  However, 32-bit kernels might flag valid values as errors, so
      42       we need to reverse the error setting.  We can't use the raw result as some
      43       arches split the return/error values.  */
      44    if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (ret)))
      45      ret = -INTERNAL_SYSCALL_ERRNO (ret);
      46    return ret;
      47  }
      48  weak_alias (__personality, personality)