Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 1 | /* |
| 2 | * This program is free software; you can redistribute it and/or modify it |
| 3 | * under the terms of the GNU General Public License as published by the |
| 4 | * Free Software Foundation; either version 2, or (at your option) any |
| 5 | * later version. |
| 6 | * |
| 7 | * This program is distributed in the hope that it will be useful, but |
| 8 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 9 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 10 | * General Public License for more details. |
| 11 | * |
| 12 | */ |
| 13 | |
| 14 | /* |
| 15 | * Copyright (C) 2004 Amit S. Kale <amitkale@linsyssoft.com> |
| 16 | * Copyright (C) 2000-2001 VERITAS Software Corporation. |
| 17 | * Copyright (C) 2002 Andi Kleen, SuSE Labs |
| 18 | * Copyright (C) 2004 LinSysSoft Technologies Pvt. Ltd. |
| 19 | * Copyright (C) 2007 MontaVista Software, Inc. |
| 20 | * Copyright (C) 2007-2008 Jason Wessel, Wind River Systems, Inc. |
| 21 | */ |
| 22 | /**************************************************************************** |
| 23 | * Contributor: Lake Stevens Instrument Division$ |
| 24 | * Written by: Glenn Engel $ |
| 25 | * Updated by: Amit Kale<akale@veritas.com> |
| 26 | * Updated by: Tom Rini <trini@kernel.crashing.org> |
| 27 | * Updated by: Jason Wessel <jason.wessel@windriver.com> |
| 28 | * Modified for 386 by Jim Kingdon, Cygnus Support. |
| 29 | * Origianl kgdb, compatibility with 2.1.xx kernel by |
| 30 | * David Grothe <dave@gcom.com> |
| 31 | * Integrated into 2.2.5 kernel by Tigran Aivazian <tigran@sco.com> |
| 32 | * X86_64 changes from Andi Kleen's patch merged by Jim Houston |
| 33 | */ |
| 34 | #include <linux/spinlock.h> |
| 35 | #include <linux/kdebug.h> |
| 36 | #include <linux/string.h> |
| 37 | #include <linux/kernel.h> |
| 38 | #include <linux/ptrace.h> |
| 39 | #include <linux/sched.h> |
| 40 | #include <linux/delay.h> |
| 41 | #include <linux/kgdb.h> |
| 42 | #include <linux/init.h> |
| 43 | #include <linux/smp.h> |
Jason Wessel | d359752 | 2008-02-15 14:55:53 -0600 | [diff] [blame] | 44 | #include <linux/nmi.h> |
Jason Wessel | cc09674 | 2010-01-28 17:04:42 -0600 | [diff] [blame^] | 45 | #include <linux/hw_breakpoint.h> |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 46 | |
K.Prasad | 62edab9 | 2009-06-01 23:47:06 +0530 | [diff] [blame] | 47 | #include <asm/debugreg.h> |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 48 | #include <asm/apicdef.h> |
| 49 | #include <asm/system.h> |
| 50 | |
Ingo Molnar | 7b6aa33 | 2009-02-17 13:58:15 +0100 | [diff] [blame] | 51 | #include <asm/apic.h> |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 52 | |
| 53 | /* |
| 54 | * Put the error code here just in case the user cares: |
| 55 | */ |
| 56 | static int gdb_x86errcode; |
| 57 | |
| 58 | /* |
| 59 | * Likewise, the vector number here (since GDB only gets the signal |
| 60 | * number through the usual means, and that's not very specific): |
| 61 | */ |
| 62 | static int gdb_x86vector = -1; |
| 63 | |
| 64 | /** |
| 65 | * pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs |
| 66 | * @gdb_regs: A pointer to hold the registers in the order GDB wants. |
| 67 | * @regs: The &struct pt_regs of the current process. |
| 68 | * |
| 69 | * Convert the pt_regs in @regs into the format for registers that |
| 70 | * GDB expects, stored in @gdb_regs. |
| 71 | */ |
| 72 | void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs) |
| 73 | { |
Jason Wessel | 703a1ed | 2008-09-26 10:36:42 -0500 | [diff] [blame] | 74 | #ifndef CONFIG_X86_32 |
| 75 | u32 *gdb_regs32 = (u32 *)gdb_regs; |
| 76 | #endif |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 77 | gdb_regs[GDB_AX] = regs->ax; |
| 78 | gdb_regs[GDB_BX] = regs->bx; |
| 79 | gdb_regs[GDB_CX] = regs->cx; |
| 80 | gdb_regs[GDB_DX] = regs->dx; |
| 81 | gdb_regs[GDB_SI] = regs->si; |
| 82 | gdb_regs[GDB_DI] = regs->di; |
| 83 | gdb_regs[GDB_BP] = regs->bp; |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 84 | gdb_regs[GDB_PC] = regs->ip; |
| 85 | #ifdef CONFIG_X86_32 |
Jason Wessel | 703a1ed | 2008-09-26 10:36:42 -0500 | [diff] [blame] | 86 | gdb_regs[GDB_PS] = regs->flags; |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 87 | gdb_regs[GDB_DS] = regs->ds; |
| 88 | gdb_regs[GDB_ES] = regs->es; |
| 89 | gdb_regs[GDB_CS] = regs->cs; |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 90 | gdb_regs[GDB_FS] = 0xFFFF; |
| 91 | gdb_regs[GDB_GS] = 0xFFFF; |
Jason Wessel | cf6f196 | 2009-12-11 08:43:16 -0600 | [diff] [blame] | 92 | if (user_mode_vm(regs)) { |
| 93 | gdb_regs[GDB_SS] = regs->ss; |
| 94 | gdb_regs[GDB_SP] = regs->sp; |
| 95 | } else { |
| 96 | gdb_regs[GDB_SS] = __KERNEL_DS; |
| 97 | gdb_regs[GDB_SP] = kernel_stack_pointer(regs); |
| 98 | } |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 99 | #else |
| 100 | gdb_regs[GDB_R8] = regs->r8; |
| 101 | gdb_regs[GDB_R9] = regs->r9; |
| 102 | gdb_regs[GDB_R10] = regs->r10; |
| 103 | gdb_regs[GDB_R11] = regs->r11; |
| 104 | gdb_regs[GDB_R12] = regs->r12; |
| 105 | gdb_regs[GDB_R13] = regs->r13; |
| 106 | gdb_regs[GDB_R14] = regs->r14; |
| 107 | gdb_regs[GDB_R15] = regs->r15; |
Jason Wessel | 703a1ed | 2008-09-26 10:36:42 -0500 | [diff] [blame] | 108 | gdb_regs32[GDB_PS] = regs->flags; |
| 109 | gdb_regs32[GDB_CS] = regs->cs; |
| 110 | gdb_regs32[GDB_SS] = regs->ss; |
H. Peter Anvin | 5ca6c0c | 2009-10-12 14:12:18 -0700 | [diff] [blame] | 111 | gdb_regs[GDB_SP] = kernel_stack_pointer(regs); |
Jason Wessel | cf6f196 | 2009-12-11 08:43:16 -0600 | [diff] [blame] | 112 | #endif |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 113 | } |
| 114 | |
| 115 | /** |
| 116 | * sleeping_thread_to_gdb_regs - Convert ptrace regs to GDB regs |
| 117 | * @gdb_regs: A pointer to hold the registers in the order GDB wants. |
| 118 | * @p: The &struct task_struct of the desired process. |
| 119 | * |
| 120 | * Convert the register values of the sleeping process in @p to |
| 121 | * the format that GDB expects. |
| 122 | * This function is called when kgdb does not have access to the |
| 123 | * &struct pt_regs and therefore it should fill the gdb registers |
| 124 | * @gdb_regs with what has been saved in &struct thread_struct |
| 125 | * thread field during switch_to. |
| 126 | */ |
| 127 | void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p) |
| 128 | { |
Jason Wessel | 703a1ed | 2008-09-26 10:36:42 -0500 | [diff] [blame] | 129 | #ifndef CONFIG_X86_32 |
| 130 | u32 *gdb_regs32 = (u32 *)gdb_regs; |
| 131 | #endif |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 132 | gdb_regs[GDB_AX] = 0; |
| 133 | gdb_regs[GDB_BX] = 0; |
| 134 | gdb_regs[GDB_CX] = 0; |
| 135 | gdb_regs[GDB_DX] = 0; |
| 136 | gdb_regs[GDB_SI] = 0; |
| 137 | gdb_regs[GDB_DI] = 0; |
| 138 | gdb_regs[GDB_BP] = *(unsigned long *)p->thread.sp; |
| 139 | #ifdef CONFIG_X86_32 |
| 140 | gdb_regs[GDB_DS] = __KERNEL_DS; |
| 141 | gdb_regs[GDB_ES] = __KERNEL_DS; |
| 142 | gdb_regs[GDB_PS] = 0; |
| 143 | gdb_regs[GDB_CS] = __KERNEL_CS; |
| 144 | gdb_regs[GDB_PC] = p->thread.ip; |
| 145 | gdb_regs[GDB_SS] = __KERNEL_DS; |
| 146 | gdb_regs[GDB_FS] = 0xFFFF; |
| 147 | gdb_regs[GDB_GS] = 0xFFFF; |
| 148 | #else |
Jason Wessel | 703a1ed | 2008-09-26 10:36:42 -0500 | [diff] [blame] | 149 | gdb_regs32[GDB_PS] = *(unsigned long *)(p->thread.sp + 8); |
| 150 | gdb_regs32[GDB_CS] = __KERNEL_CS; |
| 151 | gdb_regs32[GDB_SS] = __KERNEL_DS; |
Alexey Dobriyan | 0c23590 | 2009-05-04 03:30:15 +0400 | [diff] [blame] | 152 | gdb_regs[GDB_PC] = 0; |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 153 | gdb_regs[GDB_R8] = 0; |
| 154 | gdb_regs[GDB_R9] = 0; |
| 155 | gdb_regs[GDB_R10] = 0; |
| 156 | gdb_regs[GDB_R11] = 0; |
| 157 | gdb_regs[GDB_R12] = 0; |
| 158 | gdb_regs[GDB_R13] = 0; |
| 159 | gdb_regs[GDB_R14] = 0; |
| 160 | gdb_regs[GDB_R15] = 0; |
| 161 | #endif |
| 162 | gdb_regs[GDB_SP] = p->thread.sp; |
| 163 | } |
| 164 | |
| 165 | /** |
| 166 | * gdb_regs_to_pt_regs - Convert GDB regs to ptrace regs. |
| 167 | * @gdb_regs: A pointer to hold the registers we've received from GDB. |
| 168 | * @regs: A pointer to a &struct pt_regs to hold these values in. |
| 169 | * |
| 170 | * Convert the GDB regs in @gdb_regs into the pt_regs, and store them |
| 171 | * in @regs. |
| 172 | */ |
| 173 | void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs) |
| 174 | { |
Jason Wessel | 703a1ed | 2008-09-26 10:36:42 -0500 | [diff] [blame] | 175 | #ifndef CONFIG_X86_32 |
| 176 | u32 *gdb_regs32 = (u32 *)gdb_regs; |
| 177 | #endif |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 178 | regs->ax = gdb_regs[GDB_AX]; |
| 179 | regs->bx = gdb_regs[GDB_BX]; |
| 180 | regs->cx = gdb_regs[GDB_CX]; |
| 181 | regs->dx = gdb_regs[GDB_DX]; |
| 182 | regs->si = gdb_regs[GDB_SI]; |
| 183 | regs->di = gdb_regs[GDB_DI]; |
| 184 | regs->bp = gdb_regs[GDB_BP]; |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 185 | regs->ip = gdb_regs[GDB_PC]; |
| 186 | #ifdef CONFIG_X86_32 |
Jason Wessel | 703a1ed | 2008-09-26 10:36:42 -0500 | [diff] [blame] | 187 | regs->flags = gdb_regs[GDB_PS]; |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 188 | regs->ds = gdb_regs[GDB_DS]; |
| 189 | regs->es = gdb_regs[GDB_ES]; |
| 190 | regs->cs = gdb_regs[GDB_CS]; |
| 191 | #else |
| 192 | regs->r8 = gdb_regs[GDB_R8]; |
| 193 | regs->r9 = gdb_regs[GDB_R9]; |
| 194 | regs->r10 = gdb_regs[GDB_R10]; |
| 195 | regs->r11 = gdb_regs[GDB_R11]; |
| 196 | regs->r12 = gdb_regs[GDB_R12]; |
| 197 | regs->r13 = gdb_regs[GDB_R13]; |
| 198 | regs->r14 = gdb_regs[GDB_R14]; |
| 199 | regs->r15 = gdb_regs[GDB_R15]; |
Jason Wessel | 703a1ed | 2008-09-26 10:36:42 -0500 | [diff] [blame] | 200 | regs->flags = gdb_regs32[GDB_PS]; |
| 201 | regs->cs = gdb_regs32[GDB_CS]; |
| 202 | regs->ss = gdb_regs32[GDB_SS]; |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 203 | #endif |
| 204 | } |
| 205 | |
Jason Wessel | 64e9ee3 | 2008-02-15 14:55:56 -0600 | [diff] [blame] | 206 | static struct hw_breakpoint { |
| 207 | unsigned enabled; |
Jason Wessel | 64e9ee3 | 2008-02-15 14:55:56 -0600 | [diff] [blame] | 208 | unsigned long addr; |
Jason Wessel | cc09674 | 2010-01-28 17:04:42 -0600 | [diff] [blame^] | 209 | int len; |
| 210 | int type; |
| 211 | struct perf_event **pev; |
Jason Wessel | 64e9ee3 | 2008-02-15 14:55:56 -0600 | [diff] [blame] | 212 | } breakinfo[4]; |
| 213 | |
| 214 | static void kgdb_correct_hw_break(void) |
| 215 | { |
Jason Wessel | 64e9ee3 | 2008-02-15 14:55:56 -0600 | [diff] [blame] | 216 | int breakno; |
| 217 | |
Jason Wessel | 64e9ee3 | 2008-02-15 14:55:56 -0600 | [diff] [blame] | 218 | for (breakno = 0; breakno < 4; breakno++) { |
Jason Wessel | cc09674 | 2010-01-28 17:04:42 -0600 | [diff] [blame^] | 219 | struct perf_event *bp; |
| 220 | struct arch_hw_breakpoint *info; |
| 221 | int val; |
| 222 | int cpu = raw_smp_processor_id(); |
| 223 | if (!breakinfo[breakno].enabled) |
| 224 | continue; |
| 225 | bp = *per_cpu_ptr(breakinfo[breakno].pev, cpu); |
| 226 | info = counter_arch_bp(bp); |
| 227 | if (bp->attr.disabled != 1) |
| 228 | continue; |
| 229 | bp->attr.bp_addr = breakinfo[breakno].addr; |
| 230 | bp->attr.bp_len = breakinfo[breakno].len; |
| 231 | bp->attr.bp_type = breakinfo[breakno].type; |
| 232 | info->address = breakinfo[breakno].addr; |
| 233 | info->len = breakinfo[breakno].len; |
| 234 | info->type = breakinfo[breakno].type; |
| 235 | val = arch_install_hw_breakpoint(bp); |
| 236 | if (!val) |
| 237 | bp->attr.disabled = 0; |
Jason Wessel | 64e9ee3 | 2008-02-15 14:55:56 -0600 | [diff] [blame] | 238 | } |
Jason Wessel | cc09674 | 2010-01-28 17:04:42 -0600 | [diff] [blame^] | 239 | hw_breakpoint_restore(); |
Jason Wessel | 64e9ee3 | 2008-02-15 14:55:56 -0600 | [diff] [blame] | 240 | } |
| 241 | |
| 242 | static int |
| 243 | kgdb_remove_hw_break(unsigned long addr, int len, enum kgdb_bptype bptype) |
| 244 | { |
| 245 | int i; |
| 246 | |
| 247 | for (i = 0; i < 4; i++) |
| 248 | if (breakinfo[i].addr == addr && breakinfo[i].enabled) |
| 249 | break; |
| 250 | if (i == 4) |
| 251 | return -1; |
| 252 | |
| 253 | breakinfo[i].enabled = 0; |
| 254 | |
| 255 | return 0; |
| 256 | } |
| 257 | |
| 258 | static void kgdb_remove_all_hw_break(void) |
| 259 | { |
| 260 | int i; |
Jason Wessel | cc09674 | 2010-01-28 17:04:42 -0600 | [diff] [blame^] | 261 | int cpu = raw_smp_processor_id(); |
| 262 | struct perf_event *bp; |
Jason Wessel | 64e9ee3 | 2008-02-15 14:55:56 -0600 | [diff] [blame] | 263 | |
Jason Wessel | cc09674 | 2010-01-28 17:04:42 -0600 | [diff] [blame^] | 264 | for (i = 0; i < 4; i++) { |
| 265 | if (!breakinfo[i].enabled) |
| 266 | continue; |
| 267 | bp = *per_cpu_ptr(breakinfo[i].pev, cpu); |
| 268 | if (bp->attr.disabled == 1) |
| 269 | continue; |
| 270 | arch_uninstall_hw_breakpoint(bp); |
| 271 | bp->attr.disabled = 1; |
| 272 | } |
Jason Wessel | 64e9ee3 | 2008-02-15 14:55:56 -0600 | [diff] [blame] | 273 | } |
| 274 | |
| 275 | static int |
| 276 | kgdb_set_hw_break(unsigned long addr, int len, enum kgdb_bptype bptype) |
| 277 | { |
Jason Wessel | 64e9ee3 | 2008-02-15 14:55:56 -0600 | [diff] [blame] | 278 | int i; |
| 279 | |
| 280 | for (i = 0; i < 4; i++) |
| 281 | if (!breakinfo[i].enabled) |
| 282 | break; |
| 283 | if (i == 4) |
| 284 | return -1; |
| 285 | |
| 286 | switch (bptype) { |
| 287 | case BP_HARDWARE_BREAKPOINT: |
Jason Wessel | cc09674 | 2010-01-28 17:04:42 -0600 | [diff] [blame^] | 288 | len = 1; |
| 289 | breakinfo[i].type = X86_BREAKPOINT_EXECUTE; |
Jason Wessel | 64e9ee3 | 2008-02-15 14:55:56 -0600 | [diff] [blame] | 290 | break; |
| 291 | case BP_WRITE_WATCHPOINT: |
Jason Wessel | cc09674 | 2010-01-28 17:04:42 -0600 | [diff] [blame^] | 292 | breakinfo[i].type = X86_BREAKPOINT_WRITE; |
Jason Wessel | 64e9ee3 | 2008-02-15 14:55:56 -0600 | [diff] [blame] | 293 | break; |
| 294 | case BP_ACCESS_WATCHPOINT: |
Jason Wessel | cc09674 | 2010-01-28 17:04:42 -0600 | [diff] [blame^] | 295 | breakinfo[i].type = X86_BREAKPOINT_RW; |
Jason Wessel | 64e9ee3 | 2008-02-15 14:55:56 -0600 | [diff] [blame] | 296 | break; |
| 297 | default: |
| 298 | return -1; |
| 299 | } |
Jason Wessel | cc09674 | 2010-01-28 17:04:42 -0600 | [diff] [blame^] | 300 | switch (len) { |
| 301 | case 1: |
| 302 | breakinfo[i].len = X86_BREAKPOINT_LEN_1; |
| 303 | break; |
| 304 | case 2: |
| 305 | breakinfo[i].len = X86_BREAKPOINT_LEN_2; |
| 306 | break; |
| 307 | case 4: |
| 308 | breakinfo[i].len = X86_BREAKPOINT_LEN_4; |
| 309 | break; |
| 310 | #ifdef CONFIG_X86_64 |
| 311 | case 8: |
| 312 | breakinfo[i].len = X86_BREAKPOINT_LEN_8; |
| 313 | break; |
| 314 | #endif |
| 315 | default: |
Jason Wessel | 64e9ee3 | 2008-02-15 14:55:56 -0600 | [diff] [blame] | 316 | return -1; |
Jason Wessel | cc09674 | 2010-01-28 17:04:42 -0600 | [diff] [blame^] | 317 | } |
Jason Wessel | 64e9ee3 | 2008-02-15 14:55:56 -0600 | [diff] [blame] | 318 | breakinfo[i].addr = addr; |
Jason Wessel | cc09674 | 2010-01-28 17:04:42 -0600 | [diff] [blame^] | 319 | breakinfo[i].enabled = 1; |
Jason Wessel | 64e9ee3 | 2008-02-15 14:55:56 -0600 | [diff] [blame] | 320 | |
| 321 | return 0; |
| 322 | } |
| 323 | |
| 324 | /** |
| 325 | * kgdb_disable_hw_debug - Disable hardware debugging while we in kgdb. |
| 326 | * @regs: Current &struct pt_regs. |
| 327 | * |
| 328 | * This function will be called if the particular architecture must |
| 329 | * disable hardware debugging while it is processing gdb packets or |
| 330 | * handling exception. |
| 331 | */ |
| 332 | void kgdb_disable_hw_debug(struct pt_regs *regs) |
| 333 | { |
Jason Wessel | cc09674 | 2010-01-28 17:04:42 -0600 | [diff] [blame^] | 334 | int i; |
| 335 | int cpu = raw_smp_processor_id(); |
| 336 | struct perf_event *bp; |
| 337 | |
Jason Wessel | 64e9ee3 | 2008-02-15 14:55:56 -0600 | [diff] [blame] | 338 | /* Disable hardware debugging while we are in kgdb: */ |
| 339 | set_debugreg(0UL, 7); |
Jason Wessel | cc09674 | 2010-01-28 17:04:42 -0600 | [diff] [blame^] | 340 | for (i = 0; i < 4; i++) { |
| 341 | if (!breakinfo[i].enabled) |
| 342 | continue; |
| 343 | bp = *per_cpu_ptr(breakinfo[i].pev, cpu); |
| 344 | if (bp->attr.disabled == 1) |
| 345 | continue; |
| 346 | arch_uninstall_hw_breakpoint(bp); |
| 347 | bp->attr.disabled = 1; |
| 348 | } |
Jason Wessel | 64e9ee3 | 2008-02-15 14:55:56 -0600 | [diff] [blame] | 349 | } |
| 350 | |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 351 | /** |
| 352 | * kgdb_post_primary_code - Save error vector/code numbers. |
| 353 | * @regs: Original pt_regs. |
| 354 | * @e_vector: Original error vector. |
| 355 | * @err_code: Original error code. |
| 356 | * |
| 357 | * This is needed on architectures which support SMP and KGDB. |
| 358 | * This function is called after all the slave cpus have been put |
| 359 | * to a know spin state and the primary CPU has control over KGDB. |
| 360 | */ |
| 361 | void kgdb_post_primary_code(struct pt_regs *regs, int e_vector, int err_code) |
| 362 | { |
| 363 | /* primary processor is completely in the debugger */ |
| 364 | gdb_x86vector = e_vector; |
| 365 | gdb_x86errcode = err_code; |
| 366 | } |
| 367 | |
| 368 | #ifdef CONFIG_SMP |
| 369 | /** |
| 370 | * kgdb_roundup_cpus - Get other CPUs into a holding pattern |
| 371 | * @flags: Current IRQ state |
| 372 | * |
| 373 | * On SMP systems, we need to get the attention of the other CPUs |
| 374 | * and get them be in a known state. This should do what is needed |
| 375 | * to get the other CPUs to call kgdb_wait(). Note that on some arches, |
| 376 | * the NMI approach is not used for rounding up all the CPUs. For example, |
| 377 | * in case of MIPS, smp_call_function() is used to roundup CPUs. In |
| 378 | * this case, we have to make sure that interrupts are enabled before |
| 379 | * calling smp_call_function(). The argument to this function is |
| 380 | * the flags that will be used when restoring the interrupts. There is |
| 381 | * local_irq_save() call before kgdb_roundup_cpus(). |
| 382 | * |
| 383 | * On non-SMP systems, this is not called. |
| 384 | */ |
| 385 | void kgdb_roundup_cpus(unsigned long flags) |
| 386 | { |
Ingo Molnar | dac5f41 | 2009-01-28 15:42:24 +0100 | [diff] [blame] | 387 | apic->send_IPI_allbutself(APIC_DM_NMI); |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 388 | } |
| 389 | #endif |
| 390 | |
| 391 | /** |
| 392 | * kgdb_arch_handle_exception - Handle architecture specific GDB packets. |
| 393 | * @vector: The error vector of the exception that happened. |
| 394 | * @signo: The signal number of the exception that happened. |
| 395 | * @err_code: The error code of the exception that happened. |
| 396 | * @remcom_in_buffer: The buffer of the packet we have read. |
| 397 | * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into. |
| 398 | * @regs: The &struct pt_regs of the current process. |
| 399 | * |
| 400 | * This function MUST handle the 'c' and 's' command packets, |
| 401 | * as well packets to set / remove a hardware breakpoint, if used. |
| 402 | * If there are additional packets which the hardware needs to handle, |
| 403 | * they are handled here. The code should return -1 if it wants to |
| 404 | * process more packets, and a %0 or %1 if it wants to exit from the |
| 405 | * kgdb callback. |
| 406 | */ |
| 407 | int kgdb_arch_handle_exception(int e_vector, int signo, int err_code, |
| 408 | char *remcomInBuffer, char *remcomOutBuffer, |
| 409 | struct pt_regs *linux_regs) |
| 410 | { |
| 411 | unsigned long addr; |
| 412 | char *ptr; |
| 413 | int newPC; |
| 414 | |
| 415 | switch (remcomInBuffer[0]) { |
| 416 | case 'c': |
| 417 | case 's': |
| 418 | /* try to read optional parameter, pc unchanged if no parm */ |
| 419 | ptr = &remcomInBuffer[1]; |
| 420 | if (kgdb_hex2long(&ptr, &addr)) |
| 421 | linux_regs->ip = addr; |
Jason Wessel | 737a460 | 2008-03-07 16:34:16 -0600 | [diff] [blame] | 422 | case 'D': |
| 423 | case 'k': |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 424 | newPC = linux_regs->ip; |
| 425 | |
| 426 | /* clear the trace bit */ |
Harvey Harrison | fda31d7 | 2008-04-18 09:54:38 -0700 | [diff] [blame] | 427 | linux_regs->flags &= ~X86_EFLAGS_TF; |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 428 | atomic_set(&kgdb_cpu_doing_single_step, -1); |
| 429 | |
| 430 | /* set the trace bit if we're stepping */ |
| 431 | if (remcomInBuffer[0] == 's') { |
Harvey Harrison | fda31d7 | 2008-04-18 09:54:38 -0700 | [diff] [blame] | 432 | linux_regs->flags |= X86_EFLAGS_TF; |
Jason Wessel | d7161a6 | 2008-09-26 10:36:41 -0500 | [diff] [blame] | 433 | atomic_set(&kgdb_cpu_doing_single_step, |
| 434 | raw_smp_processor_id()); |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 435 | } |
| 436 | |
Jason Wessel | 64e9ee3 | 2008-02-15 14:55:56 -0600 | [diff] [blame] | 437 | kgdb_correct_hw_break(); |
| 438 | |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 439 | return 0; |
| 440 | } |
| 441 | |
| 442 | /* this means that we do not want to exit from the handler: */ |
| 443 | return -1; |
| 444 | } |
| 445 | |
| 446 | static inline int |
| 447 | single_step_cont(struct pt_regs *regs, struct die_args *args) |
| 448 | { |
| 449 | /* |
| 450 | * Single step exception from kernel space to user space so |
| 451 | * eat the exception and continue the process: |
| 452 | */ |
| 453 | printk(KERN_ERR "KGDB: trap/step from kernel to user space, " |
| 454 | "resuming...\n"); |
| 455 | kgdb_arch_handle_exception(args->trapnr, args->signr, |
| 456 | args->err, "c", "", regs); |
K.Prasad | 62edab9 | 2009-06-01 23:47:06 +0530 | [diff] [blame] | 457 | /* |
| 458 | * Reset the BS bit in dr6 (pointed by args->err) to |
| 459 | * denote completion of processing |
| 460 | */ |
| 461 | (*(unsigned long *)ERR_PTR(args->err)) &= ~DR_STEP; |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 462 | |
| 463 | return NOTIFY_STOP; |
| 464 | } |
| 465 | |
Jason Wessel | d359752 | 2008-02-15 14:55:53 -0600 | [diff] [blame] | 466 | static int was_in_debug_nmi[NR_CPUS]; |
| 467 | |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 468 | static int __kgdb_notify(struct die_args *args, unsigned long cmd) |
| 469 | { |
| 470 | struct pt_regs *regs = args->regs; |
| 471 | |
| 472 | switch (cmd) { |
| 473 | case DIE_NMI: |
| 474 | if (atomic_read(&kgdb_active) != -1) { |
| 475 | /* KGDB CPU roundup */ |
| 476 | kgdb_nmicallback(raw_smp_processor_id(), regs); |
Jason Wessel | d359752 | 2008-02-15 14:55:53 -0600 | [diff] [blame] | 477 | was_in_debug_nmi[raw_smp_processor_id()] = 1; |
| 478 | touch_nmi_watchdog(); |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 479 | return NOTIFY_STOP; |
| 480 | } |
| 481 | return NOTIFY_DONE; |
| 482 | |
| 483 | case DIE_NMI_IPI: |
Jan Kiszka | e85ceae | 2008-10-06 13:50:59 -0500 | [diff] [blame] | 484 | /* Just ignore, we will handle the roundup on DIE_NMI. */ |
Jason Wessel | d359752 | 2008-02-15 14:55:53 -0600 | [diff] [blame] | 485 | return NOTIFY_DONE; |
| 486 | |
| 487 | case DIE_NMIUNKNOWN: |
| 488 | if (was_in_debug_nmi[raw_smp_processor_id()]) { |
| 489 | was_in_debug_nmi[raw_smp_processor_id()] = 0; |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 490 | return NOTIFY_STOP; |
| 491 | } |
| 492 | return NOTIFY_DONE; |
| 493 | |
| 494 | case DIE_NMIWATCHDOG: |
| 495 | if (atomic_read(&kgdb_active) != -1) { |
| 496 | /* KGDB CPU roundup: */ |
| 497 | kgdb_nmicallback(raw_smp_processor_id(), regs); |
| 498 | return NOTIFY_STOP; |
| 499 | } |
| 500 | /* Enter debugger: */ |
| 501 | break; |
| 502 | |
| 503 | case DIE_DEBUG: |
Jason Wessel | cc09674 | 2010-01-28 17:04:42 -0600 | [diff] [blame^] | 504 | if (atomic_read(&kgdb_cpu_doing_single_step) != -1) { |
Jason Wessel | d7161a6 | 2008-09-26 10:36:41 -0500 | [diff] [blame] | 505 | if (user_mode(regs)) |
| 506 | return single_step_cont(regs, args); |
| 507 | break; |
| 508 | } else if (test_thread_flag(TIF_SINGLESTEP)) |
| 509 | /* This means a user thread is single stepping |
| 510 | * a system call which should be ignored |
| 511 | */ |
| 512 | return NOTIFY_DONE; |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 513 | /* fall through */ |
| 514 | default: |
| 515 | if (user_mode(regs)) |
| 516 | return NOTIFY_DONE; |
| 517 | } |
| 518 | |
| 519 | if (kgdb_handle_exception(args->trapnr, args->signr, args->err, regs)) |
| 520 | return NOTIFY_DONE; |
| 521 | |
Jason Wessel | 737a460 | 2008-03-07 16:34:16 -0600 | [diff] [blame] | 522 | /* Must touch watchdog before return to normal operation */ |
| 523 | touch_nmi_watchdog(); |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 524 | return NOTIFY_STOP; |
| 525 | } |
| 526 | |
| 527 | static int |
| 528 | kgdb_notify(struct notifier_block *self, unsigned long cmd, void *ptr) |
| 529 | { |
| 530 | unsigned long flags; |
| 531 | int ret; |
| 532 | |
| 533 | local_irq_save(flags); |
| 534 | ret = __kgdb_notify(ptr, cmd); |
| 535 | local_irq_restore(flags); |
| 536 | |
| 537 | return ret; |
| 538 | } |
| 539 | |
| 540 | static struct notifier_block kgdb_notifier = { |
| 541 | .notifier_call = kgdb_notify, |
| 542 | |
| 543 | /* |
| 544 | * Lowest-prio notifier priority, we want to be notified last: |
| 545 | */ |
| 546 | .priority = -INT_MAX, |
| 547 | }; |
| 548 | |
| 549 | /** |
| 550 | * kgdb_arch_init - Perform any architecture specific initalization. |
| 551 | * |
| 552 | * This function will handle the initalization of any architecture |
| 553 | * specific callbacks. |
| 554 | */ |
| 555 | int kgdb_arch_init(void) |
| 556 | { |
Jason Wessel | cc09674 | 2010-01-28 17:04:42 -0600 | [diff] [blame^] | 557 | int i, cpu; |
| 558 | int ret; |
| 559 | struct perf_event_attr attr; |
| 560 | struct perf_event **pevent; |
| 561 | |
| 562 | ret = register_die_notifier(&kgdb_notifier); |
| 563 | if (ret != 0) |
| 564 | return ret; |
| 565 | /* |
| 566 | * Pre-allocate the hw breakpoint structions in the non-atomic |
| 567 | * portion of kgdb because this operation requires mutexs to |
| 568 | * complete. |
| 569 | */ |
| 570 | attr.bp_addr = (unsigned long)kgdb_arch_init; |
| 571 | attr.type = PERF_TYPE_BREAKPOINT; |
| 572 | attr.bp_len = HW_BREAKPOINT_LEN_1; |
| 573 | attr.bp_type = HW_BREAKPOINT_W; |
| 574 | attr.disabled = 1; |
| 575 | for (i = 0; i < 4; i++) { |
| 576 | breakinfo[i].pev = register_wide_hw_breakpoint(&attr, NULL); |
| 577 | if (IS_ERR(breakinfo[i].pev)) { |
| 578 | printk(KERN_ERR "kgdb: Could not allocate hw breakpoints\n"); |
| 579 | breakinfo[i].pev = NULL; |
| 580 | kgdb_arch_exit(); |
| 581 | return -1; |
| 582 | } |
| 583 | for_each_online_cpu(cpu) { |
| 584 | pevent = per_cpu_ptr(breakinfo[i].pev, cpu); |
| 585 | pevent[0]->hw.sample_period = 1; |
| 586 | if (pevent[0]->destroy != NULL) { |
| 587 | pevent[0]->destroy = NULL; |
| 588 | release_bp_slot(*pevent); |
| 589 | } |
| 590 | } |
| 591 | } |
| 592 | return ret; |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 593 | } |
| 594 | |
| 595 | /** |
| 596 | * kgdb_arch_exit - Perform any architecture specific uninitalization. |
| 597 | * |
| 598 | * This function will handle the uninitalization of any architecture |
| 599 | * specific callbacks, for dynamic registration and unregistration. |
| 600 | */ |
| 601 | void kgdb_arch_exit(void) |
| 602 | { |
Jason Wessel | cc09674 | 2010-01-28 17:04:42 -0600 | [diff] [blame^] | 603 | int i; |
| 604 | for (i = 0; i < 4; i++) { |
| 605 | if (breakinfo[i].pev) { |
| 606 | unregister_wide_hw_breakpoint(breakinfo[i].pev); |
| 607 | breakinfo[i].pev = NULL; |
| 608 | } |
| 609 | } |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 610 | unregister_die_notifier(&kgdb_notifier); |
| 611 | } |
| 612 | |
| 613 | /** |
| 614 | * |
| 615 | * kgdb_skipexception - Bail out of KGDB when we've been triggered. |
| 616 | * @exception: Exception vector number |
| 617 | * @regs: Current &struct pt_regs. |
| 618 | * |
| 619 | * On some architectures we need to skip a breakpoint exception when |
| 620 | * it occurs after a breakpoint has been removed. |
| 621 | * |
| 622 | * Skip an int3 exception when it occurs after a breakpoint has been |
| 623 | * removed. Backtrack eip by 1 since the int3 would have caused it to |
| 624 | * increment by 1. |
| 625 | */ |
| 626 | int kgdb_skipexception(int exception, struct pt_regs *regs) |
| 627 | { |
| 628 | if (exception == 3 && kgdb_isremovedbreak(regs->ip - 1)) { |
| 629 | regs->ip -= 1; |
| 630 | return 1; |
| 631 | } |
| 632 | return 0; |
| 633 | } |
| 634 | |
| 635 | unsigned long kgdb_arch_pc(int exception, struct pt_regs *regs) |
| 636 | { |
| 637 | if (exception == 3) |
| 638 | return instruction_pointer(regs) - 1; |
| 639 | return instruction_pointer(regs); |
| 640 | } |
| 641 | |
| 642 | struct kgdb_arch arch_kgdb_ops = { |
| 643 | /* Breakpoint instruction: */ |
| 644 | .gdb_bpt_instr = { 0xcc }, |
Jason Wessel | 64e9ee3 | 2008-02-15 14:55:56 -0600 | [diff] [blame] | 645 | .flags = KGDB_HW_BREAKPOINT, |
| 646 | .set_hw_breakpoint = kgdb_set_hw_break, |
| 647 | .remove_hw_breakpoint = kgdb_remove_hw_break, |
| 648 | .remove_all_hw_break = kgdb_remove_all_hw_break, |
| 649 | .correct_hw_break = kgdb_correct_hw_break, |
Ingo Molnar | 82da3ff | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 650 | }; |