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/types.h> 30 #include <sys/ucontext.h> 31 #include <errno.h> 32 #include <stdarg.h> 33 #include <stdlib.h> 34 #include <machine/cpufunc.h> 35 #include <machine/specialreg.h> 36 #include <machine/sysarch.h> 37 #include <x86/ifunc.h> 38 #include <x86/fpu.h> 39 40 #if defined __i386__ 41 #define X86_GET_XFPUSTATE I386_GET_XFPUSTATE 42 typedef struct savexmm savex86_t ; 43 typedef struct i386_get_xfpustate x86_get_xfpustate_t; 44 #elif defined __amd64__ 45 #define X86_GET_XFPUSTATE AMD64_GET_XFPUSTATE 46 typedef struct savefpu savex86_t; 47 typedef struct amd64_get_xfpustate x86_get_xfpustate_t; 48 #else 49 #error "Wrong arch" 50 #endif 51 52 static int xstate_sz = 0; 53 54 static int 55 __getcontextx_size_xfpu(void) 56 { 57 58 return (sizeof(ucontext_t) + xstate_sz); 59 } 60 61 DEFINE_UIFUNC(, int, __getcontextx_size, (void)) 62 { 63 u_int p[4]; 64 65 if ((cpu_feature2 & CPUID2_OSXSAVE) != 0) { 66 cpuid_count(0xd, 0x0, p); 67 xstate_sz = p[1] - sizeof(savex86_t); 68 } 69 return (__getcontextx_size_xfpu); 70 } 71 72 static int 73 __fillcontextx2_xfpu(char *ctx) 74 { 75 x86_get_xfpustate_t xfpu; 76 ucontext_t *ucp; 77 78 ucp = (ucontext_t *)ctx; 79 xfpu.addr = (char *)(ucp + 1); 80 xfpu.len = xstate_sz; 81 if (sysarch(X86_GET_XFPUSTATE, &xfpu) == -1) 82 return (-1); 83 ucp->uc_mcontext.mc_xfpustate = (__register_t)xfpu.addr; 84 ucp->uc_mcontext.mc_xfpustate_len = xstate_sz; 85 ucp->uc_mcontext.mc_flags |= _MC_HASFPXSTATE; 86 return (0); 87 } 88 89 static int 90 __fillcontextx2_noxfpu(char *ctx) 91 { 92 ucontext_t *ucp; 93 94 ucp = (ucontext_t *)ctx; 95 ucp->uc_mcontext.mc_xfpustate = 0; 96 ucp->uc_mcontext.mc_xfpustate_len = 0; 97 return (0); 98 } 99 100 DEFINE_UIFUNC(, int, __fillcontextx2, (char *)) 101 { 102 103 return ((cpu_feature2 & CPUID2_OSXSAVE) != 0 ? __fillcontextx2_xfpu : 104 __fillcontextx2_noxfpu); 105 } 106 107 int 108 __fillcontextx(char *ctx) 109 { 110 ucontext_t *ucp; 111 112 ucp = (ucontext_t *)ctx; 113 if (getcontext(ucp) == -1) 114 return (-1); 115 __fillcontextx2(ctx); 116 return (0); 117 } 118 119 __weak_reference(__getcontextx, getcontextx); 120 121 ucontext_t * 122 __getcontextx(void) 123 { 124 char *ctx; 125 int error; 126 127 ctx = malloc(__getcontextx_size()); 128 if (ctx == NULL) 129 return (NULL); 130 if (__fillcontextx(ctx) == -1) { 131 error = errno; 132 free(ctx); 133 errno = error; 134 return (NULL); 135 } 136 return ((ucontext_t *)ctx); 137 } 138