1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2011 Konstantin Belousov <kib@FreeBSD.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/types.h> 33 #include <sys/ucontext.h> 34 #include <errno.h> 35 #include <stdarg.h> 36 #include <stdlib.h> 37 #include <machine/cpufunc.h> 38 #include <machine/specialreg.h> 39 #include <machine/sysarch.h> 40 #include <x86/ifunc.h> 41 #include <x86/fpu.h> 42 43 #if defined __i386__ 44 #define X86_GET_XFPUSTATE I386_GET_XFPUSTATE 45 typedef struct savexmm savex86_t ; 46 typedef struct i386_get_xfpustate x86_get_xfpustate_t; 47 #elif defined __amd64__ 48 #define X86_GET_XFPUSTATE AMD64_GET_XFPUSTATE 49 typedef struct savefpu savex86_t; 50 typedef struct amd64_get_xfpustate x86_get_xfpustate_t; 51 #else 52 #error "Wrong arch" 53 #endif 54 55 static int xstate_sz = 0; 56 57 static int 58 __getcontextx_size_xfpu(void) 59 { 60 61 return (sizeof(ucontext_t) + xstate_sz); 62 } 63 64 DEFINE_UIFUNC(, int, __getcontextx_size, (void), static) 65 { 66 u_int p[4]; 67 68 if ((cpu_feature2 & CPUID2_OSXSAVE) != 0) { 69 cpuid_count(0xd, 0x0, p); 70 xstate_sz = p[1] - sizeof(savex86_t); 71 } 72 return (__getcontextx_size_xfpu); 73 } 74 75 static int 76 __fillcontextx2_xfpu(char *ctx) 77 { 78 x86_get_xfpustate_t xfpu; 79 ucontext_t *ucp; 80 81 ucp = (ucontext_t *)ctx; 82 xfpu.addr = (char *)(ucp + 1); 83 xfpu.len = xstate_sz; 84 if (sysarch(X86_GET_XFPUSTATE, &xfpu) == -1) 85 return (-1); 86 ucp->uc_mcontext.mc_xfpustate = (__register_t)xfpu.addr; 87 ucp->uc_mcontext.mc_xfpustate_len = xstate_sz; 88 ucp->uc_mcontext.mc_flags |= _MC_HASFPXSTATE; 89 return (0); 90 } 91 92 static int 93 __fillcontextx2_noxfpu(char *ctx) 94 { 95 ucontext_t *ucp; 96 97 ucp = (ucontext_t *)ctx; 98 ucp->uc_mcontext.mc_xfpustate = 0; 99 ucp->uc_mcontext.mc_xfpustate_len = 0; 100 return (0); 101 } 102 103 DEFINE_UIFUNC(, int, __fillcontextx2, (char *), static) 104 { 105 106 return ((cpu_feature2 & CPUID2_OSXSAVE) != 0 ? __fillcontextx2_xfpu : 107 __fillcontextx2_noxfpu); 108 } 109 110 int 111 __fillcontextx(char *ctx) 112 { 113 ucontext_t *ucp; 114 115 ucp = (ucontext_t *)ctx; 116 if (getcontext(ucp) == -1) 117 return (-1); 118 __fillcontextx2(ctx); 119 return (0); 120 } 121 122 __weak_reference(__getcontextx, getcontextx); 123 124 ucontext_t * 125 __getcontextx(void) 126 { 127 char *ctx; 128 int error; 129 130 ctx = malloc(__getcontextx_size()); 131 if (ctx == NULL) 132 return (NULL); 133 if (__fillcontextx(ctx) == -1) { 134 error = errno; 135 free(ctx); 136 errno = error; 137 return (NULL); 138 } 139 return ((ucontext_t *)ctx); 140 } 141