| /* arch_prctl call for Linux/x32. |
| Copyright (C) 2012-2014 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 |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <errno.h> |
| #include <sys/prctl.h> |
| #include <sys/syscall.h> |
| #include <sysdep.h> |
| #include <stdint.h> |
| |
| /* Since x32 arch_prctl stores 32-bit base address of segment registers |
| %fs and %gs as unsigned 64-bit value via ARCH_GET_FS and ARCH_GET_GS, |
| we use an unsigned 64-bit variable to hold the base address and copy |
| it to ADDR after the system call returns. */ |
| |
| int |
| __arch_prctl (int code, uintptr_t *addr) |
| { |
| int res; |
| uint64_t addr64; |
| void *prctl_arg = addr; |
| |
| switch (code) |
| { |
| case ARCH_GET_FS: |
| case ARCH_GET_GS: |
| prctl_arg = &addr64; |
| break; |
| } |
| |
| res = INLINE_SYSCALL (arch_prctl, 2, code, prctl_arg); |
| if (res == 0) |
| switch (code) |
| { |
| case ARCH_GET_FS: |
| case ARCH_GET_GS: |
| /* Check for a large value that overflows. */ |
| if ((uintptr_t) addr64 != addr64) |
| { |
| __set_errno (EOVERFLOW); |
| return -1; |
| } |
| *addr = (uintptr_t) addr64; |
| break; |
| } |
| |
| return res; |
| } |
| weak_alias (__arch_prctl, arch_prctl) |
