1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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 #include <sys/types.h> 31 #include <sys/ucontext.h> 32 #include <errno.h> 33 #include <stdarg.h> 34 #include <stdlib.h> 35 #include <machine/cpufunc.h> 36 #include <machine/specialreg.h> 37 #include <machine/sysarch.h> 38 #include <x86/ifunc.h> 39 #include <x86/fpu.h> 40 41 #if defined __i386__ 42 #define X86_GET_XFPUSTATE I386_GET_XFPUSTATE 43 typedef struct savexmm savex86_t ; 44 typedef struct i386_get_xfpustate x86_get_xfpustate_t; 45 #elif defined __amd64__ 46 #define X86_GET_XFPUSTATE AMD64_GET_XFPUSTATE 47 typedef struct savefpu savex86_t; 48 typedef struct amd64_get_xfpustate x86_get_xfpustate_t; 49 #else 50 #error "Wrong arch" 51 #endif 52 53 static int xstate_sz = 0; 54 55 static int 56 __getcontextx_size_xfpu(void) 57 { 58 59 return (sizeof(ucontext_t) + xstate_sz); 60 } 61 62 DEFINE_UIFUNC(, int, __getcontextx_size, (void)) 63 { 64 u_int p[4]; 65 66 if ((cpu_feature2 & CPUID2_OSXSAVE) != 0) { 67 cpuid_count(0xd, 0x0, p); 68 xstate_sz = p[1] - sizeof(savex86_t); 69 } 70 return (__getcontextx_size_xfpu); 71 } 72 73 static int 74 __fillcontextx2_xfpu(char *ctx) 75 { 76 x86_get_xfpustate_t xfpu; 77 ucontext_t *ucp; 78 79 ucp = (ucontext_t *)ctx; 80 xfpu.addr = (char *)(ucp + 1); 81 xfpu.len = xstate_sz; 82 if (sysarch(X86_GET_XFPUSTATE, &xfpu) == -1) 83 return (-1); 84 ucp->uc_mcontext.mc_xfpustate = (__register_t)xfpu.addr; 85 ucp->uc_mcontext.mc_xfpustate_len = xstate_sz; 86 ucp->uc_mcontext.mc_flags |= _MC_HASFPXSTATE; 87 return (0); 88 } 89 90 static int 91 __fillcontextx2_noxfpu(char *ctx) 92 { 93 ucontext_t *ucp; 94 95 ucp = (ucontext_t *)ctx; 96 ucp->uc_mcontext.mc_xfpustate = 0; 97 ucp->uc_mcontext.mc_xfpustate_len = 0; 98 return (0); 99 } 100 101 DEFINE_UIFUNC(, int, __fillcontextx2, (char *)) 102 { 103 104 return ((cpu_feature2 & CPUID2_OSXSAVE) != 0 ? __fillcontextx2_xfpu : 105 __fillcontextx2_noxfpu); 106 } 107 108 int 109 __fillcontextx(char *ctx) 110 { 111 ucontext_t *ucp; 112 113 ucp = (ucontext_t *)ctx; 114 if (getcontext(ucp) == -1) 115 return (-1); 116 __fillcontextx2(ctx); 117 return (0); 118 } 119 120 __weak_reference(__getcontextx, getcontextx); 121 122 ucontext_t * 123 __getcontextx(void) 124 { 125 char *ctx; 126 int error; 127 128 ctx = malloc(__getcontextx_size()); 129 if (ctx == NULL) 130 return (NULL); 131 if (__fillcontextx(ctx) == -1) { 132 error = errno; 133 free(ctx); 134 errno = error; 135 return (NULL); 136 } 137 return ((ucontext_t *)ctx); 138 } 139