63 lines
1.7 KiB
C
63 lines
1.7 KiB
C
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/* arch_prctl call for Linux/x32.
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Copyright (C) 2012 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <errno.h>
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#include <sys/prctl.h>
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#include <sys/syscall.h>
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#include <sysdep.h>
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/* Since x32 arch_prctl stores 32-bit base address of segment registers
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%fs and %gs as unsigned 64-bit value via ARCH_GET_FS and ARCH_GET_GS,
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we use an unsigned 64-bit variable to hold the base address and copy
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it to ADDR after the system call returns. */
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int
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__arch_prctl (int code, uintptr_t *addr)
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{
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int res;
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uint64_t addr64;
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void *prctl_arg = addr;
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switch (code)
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{
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case ARCH_GET_FS:
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case ARCH_GET_GS:
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prctl_arg = &addr64;
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break;
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}
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res = INLINE_SYSCALL (arch_prctl, 2, code, prctl_arg);
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if (res == 0)
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switch (code)
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{
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case ARCH_GET_FS:
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case ARCH_GET_GS:
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/* Check for a large value that overflows. */
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if ((uintptr_t) addr64 != addr64)
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{
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__set_errno (EOVERFLOW);
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return -1;
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}
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*addr = (uintptr_t) addr64;
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break;
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}
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return res;
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}
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weak_alias (__arch_prctl, arch_prctl)
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