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
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.
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.
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
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>
45 #include <asm/apicdef.h>
46 #include <asm/system.h>
49 # include <mach_ipi.h>
51 # include <asm/mach_apic.h>
55 * Put the error code here just in case the user cares:
57 static int gdb_x86errcode
;
60 * Likewise, the vector number here (since GDB only gets the signal
61 * number through the usual means, and that's not very specific):
63 static int gdb_x86vector
= -1;
66 * pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs
67 * @gdb_regs: A pointer to hold the registers in the order GDB wants.
68 * @regs: The &struct pt_regs of the current process.
70 * Convert the pt_regs in @regs into the format for registers that
71 * GDB expects, stored in @gdb_regs.
73 void pt_regs_to_gdb_regs(unsigned long *gdb_regs
, struct pt_regs
*regs
)
75 gdb_regs
[GDB_AX
] = regs
->ax
;
76 gdb_regs
[GDB_BX
] = regs
->bx
;
77 gdb_regs
[GDB_CX
] = regs
->cx
;
78 gdb_regs
[GDB_DX
] = regs
->dx
;
79 gdb_regs
[GDB_SI
] = regs
->si
;
80 gdb_regs
[GDB_DI
] = regs
->di
;
81 gdb_regs
[GDB_BP
] = regs
->bp
;
82 gdb_regs
[GDB_PS
] = regs
->flags
;
83 gdb_regs
[GDB_PC
] = regs
->ip
;
85 gdb_regs
[GDB_DS
] = regs
->ds
;
86 gdb_regs
[GDB_ES
] = regs
->es
;
87 gdb_regs
[GDB_CS
] = regs
->cs
;
88 gdb_regs
[GDB_SS
] = __KERNEL_DS
;
89 gdb_regs
[GDB_FS
] = 0xFFFF;
90 gdb_regs
[GDB_GS
] = 0xFFFF;
92 gdb_regs
[GDB_R8
] = regs
->r8
;
93 gdb_regs
[GDB_R9
] = regs
->r9
;
94 gdb_regs
[GDB_R10
] = regs
->r10
;
95 gdb_regs
[GDB_R11
] = regs
->r11
;
96 gdb_regs
[GDB_R12
] = regs
->r12
;
97 gdb_regs
[GDB_R13
] = regs
->r13
;
98 gdb_regs
[GDB_R14
] = regs
->r14
;
99 gdb_regs
[GDB_R15
] = regs
->r15
;
101 gdb_regs
[GDB_SP
] = regs
->sp
;
105 * sleeping_thread_to_gdb_regs - Convert ptrace regs to GDB regs
106 * @gdb_regs: A pointer to hold the registers in the order GDB wants.
107 * @p: The &struct task_struct of the desired process.
109 * Convert the register values of the sleeping process in @p to
110 * the format that GDB expects.
111 * This function is called when kgdb does not have access to the
112 * &struct pt_regs and therefore it should fill the gdb registers
113 * @gdb_regs with what has been saved in &struct thread_struct
114 * thread field during switch_to.
116 void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs
, struct task_struct
*p
)
118 gdb_regs
[GDB_AX
] = 0;
119 gdb_regs
[GDB_BX
] = 0;
120 gdb_regs
[GDB_CX
] = 0;
121 gdb_regs
[GDB_DX
] = 0;
122 gdb_regs
[GDB_SI
] = 0;
123 gdb_regs
[GDB_DI
] = 0;
124 gdb_regs
[GDB_BP
] = *(unsigned long *)p
->thread
.sp
;
126 gdb_regs
[GDB_DS
] = __KERNEL_DS
;
127 gdb_regs
[GDB_ES
] = __KERNEL_DS
;
128 gdb_regs
[GDB_PS
] = 0;
129 gdb_regs
[GDB_CS
] = __KERNEL_CS
;
130 gdb_regs
[GDB_PC
] = p
->thread
.ip
;
131 gdb_regs
[GDB_SS
] = __KERNEL_DS
;
132 gdb_regs
[GDB_FS
] = 0xFFFF;
133 gdb_regs
[GDB_GS
] = 0xFFFF;
135 gdb_regs
[GDB_PS
] = *(unsigned long *)(p
->thread
.sp
+ 8);
136 gdb_regs
[GDB_PC
] = 0;
137 gdb_regs
[GDB_R8
] = 0;
138 gdb_regs
[GDB_R9
] = 0;
139 gdb_regs
[GDB_R10
] = 0;
140 gdb_regs
[GDB_R11
] = 0;
141 gdb_regs
[GDB_R12
] = 0;
142 gdb_regs
[GDB_R13
] = 0;
143 gdb_regs
[GDB_R14
] = 0;
144 gdb_regs
[GDB_R15
] = 0;
146 gdb_regs
[GDB_SP
] = p
->thread
.sp
;
150 * gdb_regs_to_pt_regs - Convert GDB regs to ptrace regs.
151 * @gdb_regs: A pointer to hold the registers we've received from GDB.
152 * @regs: A pointer to a &struct pt_regs to hold these values in.
154 * Convert the GDB regs in @gdb_regs into the pt_regs, and store them
157 void gdb_regs_to_pt_regs(unsigned long *gdb_regs
, struct pt_regs
*regs
)
159 regs
->ax
= gdb_regs
[GDB_AX
];
160 regs
->bx
= gdb_regs
[GDB_BX
];
161 regs
->cx
= gdb_regs
[GDB_CX
];
162 regs
->dx
= gdb_regs
[GDB_DX
];
163 regs
->si
= gdb_regs
[GDB_SI
];
164 regs
->di
= gdb_regs
[GDB_DI
];
165 regs
->bp
= gdb_regs
[GDB_BP
];
166 regs
->flags
= gdb_regs
[GDB_PS
];
167 regs
->ip
= gdb_regs
[GDB_PC
];
169 regs
->ds
= gdb_regs
[GDB_DS
];
170 regs
->es
= gdb_regs
[GDB_ES
];
171 regs
->cs
= gdb_regs
[GDB_CS
];
173 regs
->r8
= gdb_regs
[GDB_R8
];
174 regs
->r9
= gdb_regs
[GDB_R9
];
175 regs
->r10
= gdb_regs
[GDB_R10
];
176 regs
->r11
= gdb_regs
[GDB_R11
];
177 regs
->r12
= gdb_regs
[GDB_R12
];
178 regs
->r13
= gdb_regs
[GDB_R13
];
179 regs
->r14
= gdb_regs
[GDB_R14
];
180 regs
->r15
= gdb_regs
[GDB_R15
];
185 * kgdb_post_primary_code - Save error vector/code numbers.
186 * @regs: Original pt_regs.
187 * @e_vector: Original error vector.
188 * @err_code: Original error code.
190 * This is needed on architectures which support SMP and KGDB.
191 * This function is called after all the slave cpus have been put
192 * to a know spin state and the primary CPU has control over KGDB.
194 void kgdb_post_primary_code(struct pt_regs
*regs
, int e_vector
, int err_code
)
196 /* primary processor is completely in the debugger */
197 gdb_x86vector
= e_vector
;
198 gdb_x86errcode
= err_code
;
203 * kgdb_roundup_cpus - Get other CPUs into a holding pattern
204 * @flags: Current IRQ state
206 * On SMP systems, we need to get the attention of the other CPUs
207 * and get them be in a known state. This should do what is needed
208 * to get the other CPUs to call kgdb_wait(). Note that on some arches,
209 * the NMI approach is not used for rounding up all the CPUs. For example,
210 * in case of MIPS, smp_call_function() is used to roundup CPUs. In
211 * this case, we have to make sure that interrupts are enabled before
212 * calling smp_call_function(). The argument to this function is
213 * the flags that will be used when restoring the interrupts. There is
214 * local_irq_save() call before kgdb_roundup_cpus().
216 * On non-SMP systems, this is not called.
218 void kgdb_roundup_cpus(unsigned long flags
)
220 send_IPI_allbutself(APIC_DM_NMI
);
225 * kgdb_arch_handle_exception - Handle architecture specific GDB packets.
226 * @vector: The error vector of the exception that happened.
227 * @signo: The signal number of the exception that happened.
228 * @err_code: The error code of the exception that happened.
229 * @remcom_in_buffer: The buffer of the packet we have read.
230 * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into.
231 * @regs: The &struct pt_regs of the current process.
233 * This function MUST handle the 'c' and 's' command packets,
234 * as well packets to set / remove a hardware breakpoint, if used.
235 * If there are additional packets which the hardware needs to handle,
236 * they are handled here. The code should return -1 if it wants to
237 * process more packets, and a %0 or %1 if it wants to exit from the
240 int kgdb_arch_handle_exception(int e_vector
, int signo
, int err_code
,
241 char *remcomInBuffer
, char *remcomOutBuffer
,
242 struct pt_regs
*linux_regs
)
248 switch (remcomInBuffer
[0]) {
251 /* try to read optional parameter, pc unchanged if no parm */
252 ptr
= &remcomInBuffer
[1];
253 if (kgdb_hex2long(&ptr
, &addr
))
254 linux_regs
->ip
= addr
;
255 newPC
= linux_regs
->ip
;
257 /* clear the trace bit */
258 linux_regs
->flags
&= ~TF_MASK
;
259 atomic_set(&kgdb_cpu_doing_single_step
, -1);
261 /* set the trace bit if we're stepping */
262 if (remcomInBuffer
[0] == 's') {
263 linux_regs
->flags
|= TF_MASK
;
264 kgdb_single_step
= 1;
265 if (kgdb_contthread
) {
266 atomic_set(&kgdb_cpu_doing_single_step
,
267 raw_smp_processor_id());
274 /* this means that we do not want to exit from the handler: */
279 single_step_cont(struct pt_regs
*regs
, struct die_args
*args
)
282 * Single step exception from kernel space to user space so
283 * eat the exception and continue the process:
285 printk(KERN_ERR
"KGDB: trap/step from kernel to user space, "
287 kgdb_arch_handle_exception(args
->trapnr
, args
->signr
,
288 args
->err
, "c", "", regs
);
293 static int __kgdb_notify(struct die_args
*args
, unsigned long cmd
)
295 struct pt_regs
*regs
= args
->regs
;
299 if (atomic_read(&kgdb_active
) != -1) {
300 /* KGDB CPU roundup */
301 kgdb_nmicallback(raw_smp_processor_id(), regs
);
307 if (atomic_read(&kgdb_active
) != -1) {
308 /* KGDB CPU roundup: */
309 if (kgdb_nmicallback(raw_smp_processor_id(), regs
))
315 case DIE_NMIWATCHDOG
:
316 if (atomic_read(&kgdb_active
) != -1) {
317 /* KGDB CPU roundup: */
318 kgdb_nmicallback(raw_smp_processor_id(), regs
);
321 /* Enter debugger: */
325 if (atomic_read(&kgdb_cpu_doing_single_step
) ==
326 raw_smp_processor_id() &&
328 return single_step_cont(regs
, args
);
335 if (kgdb_handle_exception(args
->trapnr
, args
->signr
, args
->err
, regs
))
342 kgdb_notify(struct notifier_block
*self
, unsigned long cmd
, void *ptr
)
347 local_irq_save(flags
);
348 ret
= __kgdb_notify(ptr
, cmd
);
349 local_irq_restore(flags
);
354 static struct notifier_block kgdb_notifier
= {
355 .notifier_call
= kgdb_notify
,
358 * Lowest-prio notifier priority, we want to be notified last:
360 .priority
= -INT_MAX
,
364 * kgdb_arch_init - Perform any architecture specific initalization.
366 * This function will handle the initalization of any architecture
367 * specific callbacks.
369 int kgdb_arch_init(void)
371 return register_die_notifier(&kgdb_notifier
);
375 * kgdb_arch_exit - Perform any architecture specific uninitalization.
377 * This function will handle the uninitalization of any architecture
378 * specific callbacks, for dynamic registration and unregistration.
380 void kgdb_arch_exit(void)
382 unregister_die_notifier(&kgdb_notifier
);
387 * kgdb_skipexception - Bail out of KGDB when we've been triggered.
388 * @exception: Exception vector number
389 * @regs: Current &struct pt_regs.
391 * On some architectures we need to skip a breakpoint exception when
392 * it occurs after a breakpoint has been removed.
394 * Skip an int3 exception when it occurs after a breakpoint has been
395 * removed. Backtrack eip by 1 since the int3 would have caused it to
398 int kgdb_skipexception(int exception
, struct pt_regs
*regs
)
400 if (exception
== 3 && kgdb_isremovedbreak(regs
->ip
- 1)) {
407 unsigned long kgdb_arch_pc(int exception
, struct pt_regs
*regs
)
410 return instruction_pointer(regs
) - 1;
411 return instruction_pointer(regs
);
414 struct kgdb_arch arch_kgdb_ops
= {
415 /* Breakpoint instruction: */
416 .gdb_bpt_instr
= { 0xcc },