diff options
Diffstat (limited to 'lib/libc/x86/sys/pkru.c')
| -rw-r--r-- | lib/libc/x86/sys/pkru.c | 138 |
1 files changed, 138 insertions, 0 deletions
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)); +} |