From a803367bab167f5ec4fde1f0d0ec447707c29520 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Fri, 14 Feb 2020 20:55:39 +0100 Subject: powerpc64: Add memory protection key support [BZ #23202] 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). --- .../unix/sysv/linux/powerpc/powerpc64/pkey_set.c | 48 ++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 sysdeps/unix/sysv/linux/powerpc/powerpc64/pkey_set.c (limited to 'sysdeps/unix/sysv/linux/powerpc/powerpc64/pkey_set.c') diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/pkey_set.c b/sysdeps/unix/sysv/linux/powerpc/powerpc64/pkey_set.c new file mode 100644 index 0000000000..20b372ee29 --- /dev/null +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/pkey_set.c @@ -0,0 +1,48 @@ +/* Changing the per-thread memory protection key, powerpc64 version. + Copyright (C) 2017-2020 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 + . */ + +#include +#include +#include + +int +pkey_set (int key, unsigned int rights) +{ + if (key < 0 || key > PKEY_MAX || rights > 3) + { + __set_errno (EINVAL); + return -1; + } + + /* Translate to AMR bit values. */ + unsigned long int bits; + if (rights & PKEY_DISABLE_ACCESS) + /* The PKEY_DISABLE_WRITE bit does not matter. */ + bits = PKEY_AMR_READ | PKEY_AMR_WRITE; + else if (rights == PKEY_DISABLE_WRITE) + bits = PKEY_AMR_WRITE; + else + bits = 0; + + unsigned int index = pkey_index (key); + unsigned long int mask = 3UL << index; + unsigned long int amr = pkey_read (); + amr = (amr & ~mask) | (bits << index); + pkey_write (amr); + return 0; +} -- cgit 1.4.1