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authorKonstantin Belousov <kib@FreeBSD.org>2019-02-20 09:56:23 +0000
committerKonstantin Belousov <kib@FreeBSD.org>2019-02-20 09:56:23 +0000
commita2d95495ee82f3ed36051f231e0eedcff708e6d6 (patch)
treebdef8465783eb600ca32f87594cb36eb627fd871 /lib/libc/x86/sys
parente7a9df16e6541a68ab21e51a5d0badb5feef1894 (diff)
downloadsrc-a2d95495ee82f3ed36051f231e0eedcff708e6d6.tar.gz
src-a2d95495ee82f3ed36051f231e0eedcff708e6d6.zip
Add usermode helpers for for Intel userspace protection keys feature.
Reviewed by: markj Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 2 weeks Differential revision: https://reviews.freebsd.org/D18893
Notes
Notes: svn path=/head/; revision=344354
Diffstat (limited to 'lib/libc/x86/sys')
-rw-r--r--lib/libc/x86/sys/Makefile.inc3
-rw-r--r--lib/libc/x86/sys/pkru.c138
2 files changed, 140 insertions, 1 deletions
diff --git a/lib/libc/x86/sys/Makefile.inc b/lib/libc/x86/sys/Makefile.inc
index 0e8026ae47c2..640fbf02c21b 100644
--- a/lib/libc/x86/sys/Makefile.inc
+++ b/lib/libc/x86/sys/Makefile.inc
@@ -3,7 +3,8 @@
.PATH: ${LIBC_SRCTOP}/x86/sys
SRCS+= \
- __vdso_gettc.c
+ __vdso_gettc.c \
+ pkru.c
.if ${MACHINE_CPUARCH} == "amd64" && ${MK_HYPERV} != "no"
CFLAGS+= -DWANT_HYPERV
diff --git a/lib/libc/x86/sys/pkru.c b/lib/libc/x86/sys/pkru.c
new file mode 100644
index 000000000000..6aa3cbf95767
--- /dev/null
+++ b/lib/libc/x86/sys/pkru.c
@@ -0,0 +1,138 @@
+/*-
+ * Copyright (c) 2019 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <machine/cpufunc.h>
+#include <machine/specialreg.h>
+#include <machine/sysarch.h>
+#include <x86/ifunc.h>
+#include <errno.h>
+#include <string.h>
+
+#define MAX_PKRU_IDX 0xf
+#ifdef __i386__
+#define X86_SET_PKRU I386_SET_PKRU
+#define X86_CLEAR_PKRU I386_CLEAR_PKRU
+#else
+#define X86_SET_PKRU AMD64_SET_PKRU
+#define X86_CLEAR_PKRU AMD64_CLEAR_PKRU
+#endif
+
+static int
+x86_pkru_get_perm_unsup(u_int keyidx, int *access, int *modify)
+{
+
+ errno = EOPNOTSUPP;
+ return (-1);
+}
+
+static int
+x86_pkru_get_perm_hw(u_int keyidx, int *access, int *modify)
+{
+ uint32_t pkru;
+
+ if (keyidx > MAX_PKRU_IDX) {
+ errno = EINVAL;
+ return (-1);
+ }
+ keyidx *= 2;
+ pkru = rdpkru();
+ *access = (pkru & (1 << keyidx)) == 0;
+ *modify = (pkru & (2 << keyidx)) == 0;
+ return (0);
+}
+
+DEFINE_UIFUNC(, int, x86_pkru_get_perm, (u_int, int *, int *), static)
+{
+
+ return ((cpu_stdext_feature2 & CPUID_STDEXT2_OSPKE) == 0 ?
+ x86_pkru_get_perm_unsup : x86_pkru_get_perm_hw);
+}
+
+static int
+x86_pkru_set_perm_unsup(u_int keyidx, int access, int modify)
+{
+
+ errno = EOPNOTSUPP;
+ return (-1);
+}
+
+static int
+x86_pkru_set_perm_hw(u_int keyidx, int access, int modify)
+{
+ uint32_t pkru;
+
+ if (keyidx > MAX_PKRU_IDX) {
+ errno = EINVAL;
+ return (-1);
+ }
+ keyidx *= 2;
+ pkru = rdpkru();
+ pkru &= ~(3 << keyidx);
+ if (!access)
+ pkru |= 1 << keyidx;
+ if (!modify)
+ pkru |= 2 << keyidx;
+ wrpkru(pkru);
+ return (0);
+}
+
+DEFINE_UIFUNC(, int, x86_pkru_set_perm, (u_int, int, int), static)
+{
+
+ return ((cpu_stdext_feature2 & CPUID_STDEXT2_OSPKE) == 0 ?
+ x86_pkru_set_perm_unsup : x86_pkru_set_perm_hw);
+}
+
+int
+x86_pkru_protect_range(void *addr, unsigned long len, u_int keyidx, int flags)
+{
+ struct amd64_set_pkru a64pkru;
+
+ memset(&a64pkru, 0, sizeof(a64pkru));
+ a64pkru.addr = addr;
+ a64pkru.len = len;
+ a64pkru.keyidx = keyidx;
+ a64pkru.flags = flags;
+ return (sysarch(X86_SET_PKRU, &a64pkru));
+}
+
+int
+x86_pkru_unprotect_range(void *addr, unsigned long len)
+{
+ struct amd64_set_pkru a64pkru;
+
+ memset(&a64pkru, 0, sizeof(a64pkru));
+ a64pkru.addr = addr;
+ a64pkru.len = len;
+ return (sysarch(X86_CLEAR_PKRU, &a64pkru));
+}