1 /* $NetBSD: kgdb_machdep.c,v 1.5 2024/09/08 09:36:49 rillig Exp $ */ 2 3 /* 4 * Copyright (c) 1996 Matthias Pfaller. 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 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __KERNEL_RCSID(0, "$NetBSD: kgdb_machdep.c,v 1.5 2024/09/08 09:36:49 rillig Exp $"); 30 31 #include "opt_ddb.h" 32 #include "opt_kgdb.h" 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/kgdb.h> 37 #include <sys/socket.h> 38 39 #include <uvm/uvm_extern.h> 40 41 //#include <machine/frame.h> 42 #include <machine/reg.h> 43 #include <machine/trap.h> 44 #include <machine/db_machdep.h> 45 #include <machine/thunk.h> 46 #include <netinet/in.h> 47 48 49 /* 50 * Determine if the memory at va..(va+len) is valid. 51 */ 52 int 53 kgdb_acc(vaddr_t va, size_t len) 54 { 55 vaddr_t last_va; 56 57 last_va = va + len; 58 va &= ~PGOFSET; 59 last_va &= ~PGOFSET; 60 61 thunk_printf_debug("%s: [%p .. %p]\n", __func__, 62 (void *) va, (void *) last_va); 63 do { 64 if (db_validate_address(va)) 65 return (0); 66 va += PAGE_SIZE; 67 } while (va < last_va); 68 69 return (1); 70 } 71 72 /* 73 * Translate a trap number into a unix compatible signal value. 74 * (gdb only understands unix signal numbers). 75 */ 76 int 77 kgdb_signal(int type) 78 { 79 return type; 80 81 // panic("%s", __func__); 82 #if 0 83 switch (type) { 84 case T_BREAKPOINT: 85 return(SIGTRAP); 86 case -1: 87 return(SIGSEGV); 88 default: 89 return(SIGINT); 90 } 91 #endif 92 } 93 94 /* 95 * Definitions exported from gdb. 96 */ 97 98 /* 99 * Translate the values stored in the kernel regs struct to the format 100 * understood by gdb. 101 */ 102 void 103 kgdb_getregs(db_regs_t *regs, kgdb_reg_t *gdb_regs) 104 { 105 #ifdef __x86_64__ 106 kgdb_reg_t *gregs = regs->uc_mcontext.__gregs; 107 108 gdb_regs[ 0] = gregs[_REG_RAX]; 109 gdb_regs[ 1] = gregs[_REG_RBX]; 110 gdb_regs[ 2] = gregs[_REG_RCX]; 111 gdb_regs[ 3] = gregs[_REG_RDX]; 112 gdb_regs[ 4] = gregs[_REG_RSI]; 113 gdb_regs[ 5] = gregs[_REG_RDI]; 114 gdb_regs[ 6] = gregs[_REG_RBP]; 115 gdb_regs[ 7] = gregs[_REG_RSP]; 116 gdb_regs[ 8] = gregs[_REG_R8]; 117 gdb_regs[ 9] = gregs[_REG_R9]; 118 gdb_regs[10] = gregs[_REG_R10]; 119 gdb_regs[11] = gregs[_REG_R11]; 120 gdb_regs[12] = gregs[_REG_R12]; 121 gdb_regs[13] = gregs[_REG_R13]; 122 gdb_regs[14] = gregs[_REG_R14]; 123 gdb_regs[15] = gregs[_REG_R15]; 124 gdb_regs[16] = gregs[_REG_RIP]; 125 gdb_regs[17] = gregs[_REG_RFLAGS]; 126 gdb_regs[18] = gregs[_REG_CS]; 127 gdb_regs[19] = gregs[_REG_SS]; 128 129 #elif defined(__i386) 130 kgdb_reg_t *gregs = regs->uc_mcontext.__gregs; 131 132 gdb_regs[ 0] = gregs[_REG_EAX]; 133 gdb_regs[ 1] = gregs[_REG_ECX]; 134 gdb_regs[ 2] = gregs[_REG_EDX]; 135 gdb_regs[ 3] = gregs[_REG_EBX]; 136 gdb_regs[ 4] = gregs[_REG_ESP]; 137 gdb_regs[ 5] = gregs[_REG_EBP]; 138 gdb_regs[ 6] = gregs[_REG_ESI]; 139 gdb_regs[ 7] = gregs[_REG_EDI]; 140 gdb_regs[ 8] = gregs[_REG_EIP]; 141 gdb_regs[ 9] = gregs[_REG_EFL]; 142 gdb_regs[10] = gregs[_REG_CS]; 143 gdb_regs[11] = gregs[_REG_SS]; 144 gdb_regs[12] = gregs[_REG_DS]; 145 gdb_regs[13] = gregs[_REG_ES]; 146 gdb_regs[14] = gregs[_REG_FS]; 147 gdb_regs[15] = gregs[_REG_GS]; 148 149 #else 150 #error port kgdb_machdep.c kgdb_getregs 151 #endif 152 } 153 154 /* 155 * And the reverse. 156 */ 157 158 void 159 kgdb_setregs(db_regs_t *regs, kgdb_reg_t *gdb_regs) 160 { 161 #ifdef __x86_64__ 162 kgdb_reg_t *gregs = regs->uc_mcontext.__gregs; 163 164 gregs[_REG_RAX] = gdb_regs[ 0]; 165 gregs[_REG_RBX] = gdb_regs[ 1]; 166 gregs[_REG_RCX] = gdb_regs[ 2]; 167 gregs[_REG_RDX] = gdb_regs[ 3]; 168 gregs[_REG_RSI] = gdb_regs[ 4]; 169 gregs[_REG_RDI] = gdb_regs[ 5]; 170 gregs[_REG_RBP] = gdb_regs[ 6]; 171 gregs[_REG_RSP] = gdb_regs[ 7]; 172 gregs[_REG_R8 ] = gdb_regs[ 8]; 173 gregs[_REG_R9 ] = gdb_regs[ 9]; 174 gregs[_REG_R10] = gdb_regs[10]; 175 gregs[_REG_R11] = gdb_regs[11]; 176 gregs[_REG_R12] = gdb_regs[12]; 177 gregs[_REG_R13] = gdb_regs[13]; 178 gregs[_REG_R14] = gdb_regs[14]; 179 gregs[_REG_R15] = gdb_regs[15]; 180 gregs[_REG_RIP] = gdb_regs[16]; 181 gregs[_REG_RFLAGS] = gdb_regs[17]; 182 gregs[_REG_CS ] = gdb_regs[18]; 183 gregs[_REG_SS ] = gdb_regs[19]; 184 #elif defined(__i386) 185 panic("%s", __func__); 186 kgdb_reg_t *gregs = regs->uc_mcontext.__gregs; 187 188 gregs[_REG_EAX] = gdb_regs[ 0]; 189 gregs[_REG_ECX] = gdb_regs[ 1]; 190 gregs[_REG_EDX] = gdb_regs[ 2]; 191 gregs[_REG_EBX] = gdb_regs[ 3]; 192 gregs[_REG_EBP] = gdb_regs[ 5]; 193 gregs[_REG_ESI] = gdb_regs[ 6]; 194 gregs[_REG_EDI] = gdb_regs[ 7]; 195 gregs[_REG_EIP] = gdb_regs[ 8]; 196 gregs[_REG_EFL] = gdb_regs[ 9]; 197 gregs[_REG_CS] = gdb_regs[10]; 198 gregs[_REG_DS] = gdb_regs[12]; 199 gregs[_REG_ES] = gdb_regs[13]; 200 201 #else 202 panic("%s", __func__); 203 #endif 204 } 205 206 /* 207 * Trap into kgdb to wait for debugger to connect, 208 * noting on the console why nothing else is going on. 209 */ 210 void 211 kgdb_connect(int verbose) 212 { 213 if (kgdb_dev == NODEV) 214 return; 215 216 if (verbose) 217 printf("kgdb waiting..."); 218 219 breakpoint(); 220 221 if (verbose) 222 printf("connected.\n"); 223 224 kgdb_debug_panic = 1; 225 } 226 227 /* 228 * Decide what to do on panic. 229 * (This is called by panic, like Debugger()) 230 */ 231 void 232 kgdb_panic(void) 233 { 234 if (kgdb_dev != NODEV && kgdb_debug_panic) { 235 printf("entering kgdb\n"); 236 kgdb_connect(kgdb_active == 0); 237 } 238 } 239 240 static int kgdb_socket, kgdb_fd; 241 static int kgdb_connected; 242 243 244 static void 245 kgdb_get_connection(void) 246 { 247 while (!kgdb_connected) { 248 thunk_printf("...[kgdb connecting]..."); 249 kgdb_fd = thunk_gdb_accept(kgdb_socket); 250 if (kgdb_fd) 251 kgdb_connected = 1; 252 } 253 kgdb_active = 1; 254 } 255 256 static int 257 kgdb_getc(void *arg) 258 { 259 char ch; 260 261 while (thunk_kgdb_getc(kgdb_fd, &ch) < 0) { 262 kgdb_connected = 0; 263 kgdb_get_connection(); 264 } 265 //thunk_printf("[<%c]", ch); 266 return (int) ch; 267 } 268 269 270 static void 271 kgdb_putc(void *arg, int ch_in) 272 { 273 char ch = (char) ch_in; 274 while (thunk_kgdb_putc(kgdb_fd, ch) < 0) { 275 kgdb_connected = 0; 276 kgdb_get_connection(); 277 } 278 //thunk_printf("[>%c]", ch); 279 } 280 281 void 282 kgdb_port_init(void) 283 { 284 kgdb_connected = 0; 285 286 /* open our socket */ 287 kgdb_socket = thunk_gdb_open(); 288 if (kgdb_socket == 0) { 289 kgdb_dev = 0; 290 printf("aborting kgdb\n"); 291 return; 292 } 293 294 /* signal we have a connection `dev' */ 295 kgdb_dev = 0x123; 296 kgdb_attach(kgdb_getc, kgdb_putc, 0); 297 } 298 299 /* 300 * handle a trap instruction encountered from KGDB 301 */ 302 void 303 kgdb_kernel_trap(int signo, vaddr_t pc, vaddr_t va, ucontext_t *ucp) 304 { 305 kgdb_get_connection(); 306 307 thunk_printf("entering trap\n"); 308 thunk_printf(" signo %d, pc %p, va %p\n", signo, (void *) pc, (void *) va); 309 kgdb_trap(signo, ucp); 310 } 311 312
Indexes created Sat Sep 20 22:09:52 GMT 2025