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_get.c | 42 ++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 sysdeps/unix/sysv/linux/powerpc/powerpc64/pkey_get.c (limited to 'sysdeps/unix/sysv/linux/powerpc/powerpc64/pkey_get.c') diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/pkey_get.c b/sysdeps/unix/sysv/linux/powerpc/powerpc64/pkey_get.c new file mode 100644 index 0000000000..856ba061b9 --- /dev/null +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/pkey_get.c @@ -0,0 +1,42 @@ +/* Reading 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_get (int key) +{ + if (key < 0 || key > PKEY_MAX) + { + __set_errno (EINVAL); + return -1; + } + unsigned int index = pkey_index (key); + unsigned long int amr = pkey_read (); + unsigned int bits = (amr >> index) & 3; + + /* Translate from AMR values. PKEY_AMR_READ standing alone is not + currently representable. */ + if (bits & PKEY_AMR_READ) + return PKEY_DISABLE_ACCESS; + else if (bits == PKEY_AMR_WRITE) + return PKEY_DISABLE_WRITE; + return 0; +} -- cgit 1.4.1