1 /* $NetBSD: csan.h,v 1.3 2019/11/08 12:36:11 maxv Exp $ */ 2 3 /* 4 * Copyright (c) 2019 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Maxime Villard. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/ksyms.h> 33 #include <uvm/uvm.h> 34 #include <amd64/pmap.h> 35 #include <x86/cpufunc.h> 36 37 static inline bool 38 kcsan_md_unsupported(vaddr_t addr) 39 { 40 return (addr >= (vaddr_t)PTE_BASE && 41 addr < ((vaddr_t)PTE_BASE + NBPD_L4)); 42 } 43 44 static inline bool 45 kcsan_md_is_avail(void) 46 { 47 return true; 48 } 49 50 static inline void 51 kcsan_md_disable_intrs(uint64_t *state) 52 { 53 *state = x86_read_psl(); 54 x86_disable_intr(); 55 } 56 57 static inline void 58 kcsan_md_enable_intrs(uint64_t *state) 59 { 60 x86_write_psl(*state); 61 } 62 63 static inline void 64 kcsan_md_delay(uint64_t us) 65 { 66 DELAY(us); 67 } 68 69 static inline bool 70 __md_unwind_end(const char *name) 71 { 72 if (!strcmp(name, "syscall") || 73 !strcmp(name, "alltraps") || 74 !strcmp(name, "handle_syscall") || 75 !strncmp(name, "Xtrap", 5) || 76 !strncmp(name, "Xintr", 5) || 77 !strncmp(name, "Xhandle", 7) || 78 !strncmp(name, "Xresume", 7) || 79 !strncmp(name, "Xstray", 6) || 80 !strncmp(name, "Xhold", 5) || 81 !strncmp(name, "Xrecurse", 8) || 82 !strcmp(name, "Xdoreti") || 83 !strncmp(name, "Xsoft", 5)) { 84 return true; 85 } 86 87 return false; 88 } 89 90 static void 91 kcsan_md_unwind(void) 92 { 93 uint64_t *rbp, rip; 94 const char *mod; 95 const char *sym; 96 size_t nsym; 97 int error; 98 99 rbp = (uint64_t *)__builtin_frame_address(0); 100 nsym = 0; 101 102 while (1) { 103 /* 8(%rbp) contains the saved %rip. */ 104 rip = *(rbp + 1); 105 106 if (rip < KERNBASE) { 107 break; 108 } 109 error = ksyms_getname(&mod, &sym, (vaddr_t)rip, KSYMS_PROC); 110 if (error) { 111 break; 112 } 113 printf("#%zu %p in %s <%s>\n", nsym, (void *)rip, sym, mod); 114 if (__md_unwind_end(sym)) { 115 break; 116 } 117 118 rbp = (uint64_t *)*(rbp); 119 if (rbp == 0) { 120 break; 121 } 122 nsym++; 123 124 if (nsym >= 15) { 125 break; 126 } 127 } 128 } 129