1 /* $NetBSD: csan.h,v 1.4 2020/09/10 14:04:45 maxv Exp $ */ 2 3 /* 4 * Copyright (c) 2019-2020 Maxime Villard, m00nbsd.net 5 * All rights reserved. 6 * 7 * This code is part of the KCSAN subsystem of the NetBSD kernel. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 23 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 24 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 25 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 26 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #include <sys/ksyms.h> 32 #include <uvm/uvm.h> 33 #include <amd64/pmap.h> 34 #include <x86/cpufunc.h> 35 36 static inline bool 37 kcsan_md_unsupported(vaddr_t addr) 38 { 39 return (addr >= (vaddr_t)PTE_BASE && 40 addr < ((vaddr_t)PTE_BASE + NBPD_L4)); 41 } 42 43 static inline bool 44 kcsan_md_is_avail(void) 45 { 46 return true; 47 } 48 49 static inline void 50 kcsan_md_disable_intrs(uint64_t *state) 51 { 52 *state = x86_read_psl(); 53 x86_disable_intr(); 54 } 55 56 static inline void 57 kcsan_md_enable_intrs(uint64_t *state) 58 { 59 x86_write_psl(*state); 60 } 61 62 static inline void 63 kcsan_md_delay(uint64_t us) 64 { 65 DELAY(us); 66 } 67 68 static inline bool 69 __md_unwind_end(const char *name) 70 { 71 if (!strcmp(name, "syscall") || 72 !strcmp(name, "alltraps") || 73 !strcmp(name, "handle_syscall") || 74 !strncmp(name, "Xtrap", 5) || 75 !strncmp(name, "Xintr", 5) || 76 !strncmp(name, "Xhandle", 7) || 77 !strncmp(name, "Xresume", 7) || 78 !strncmp(name, "Xstray", 6) || 79 !strncmp(name, "Xhold", 5) || 80 !strncmp(name, "Xrecurse", 8) || 81 !strcmp(name, "Xdoreti") || 82 !strncmp(name, "Xsoft", 5)) { 83 return true; 84 } 85 86 return false; 87 } 88 89 static void 90 kcsan_md_unwind(void) 91 { 92 uint64_t *rbp, rip; 93 const char *mod; 94 const char *sym; 95 size_t nsym; 96 int error; 97 98 rbp = (uint64_t *)__builtin_frame_address(0); 99 nsym = 0; 100 101 while (1) { 102 /* 8(%rbp) contains the saved %rip. */ 103 rip = *(rbp + 1); 104 105 if (rip < KERNBASE) { 106 break; 107 } 108 error = ksyms_getname(&mod, &sym, (vaddr_t)rip, KSYMS_PROC); 109 if (error) { 110 break; 111 } 112 printf("#%zu %p in %s <%s>\n", nsym, (void *)rip, sym, mod); 113 if (__md_unwind_end(sym)) { 114 break; 115 } 116 117 rbp = (uint64_t *)*(rbp); 118 if (rbp == 0) { 119 break; 120 } 121 nsym++; 122 123 if (nsym >= 15) { 124 break; 125 } 126 } 127 } 128