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a803367bab
The 32-bit protection key behavior is somewhat unclear on 32-bit powerpc, so this change is restricted to the 64-bit variants. Flag translation is needed because of hardware differences between the POWER implementation (read and write flags) and the Intel implementation (write and read+write flags).
49 lines
1.5 KiB
C
49 lines
1.5 KiB
C
/* Changing the per-thread memory protection key, powerpc64 version.
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Copyright (C) 2017-2020 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 <arch-pkey.h>
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#include <errno.h>
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#include <sys/mman.h>
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int
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pkey_set (int key, unsigned int rights)
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{
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if (key < 0 || key > PKEY_MAX || rights > 3)
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{
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__set_errno (EINVAL);
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return -1;
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}
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/* Translate to AMR bit values. */
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unsigned long int bits;
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if (rights & PKEY_DISABLE_ACCESS)
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/* The PKEY_DISABLE_WRITE bit does not matter. */
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bits = PKEY_AMR_READ | PKEY_AMR_WRITE;
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else if (rights == PKEY_DISABLE_WRITE)
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bits = PKEY_AMR_WRITE;
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else
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bits = 0;
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unsigned int index = pkey_index (key);
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unsigned long int mask = 3UL << index;
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unsigned long int amr = pkey_read ();
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amr = (amr & ~mask) | (bits << index);
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pkey_write (amr);
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return 0;
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}
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