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v4.17
  1/*
  2 * PowerPC backend to the KGDB stub.
  3 *
  4 * 1998 (c) Michael AK Tesch (tesch@cs.wisc.edu)
  5 * Copyright (C) 2003 Timesys Corporation.
  6 * Copyright (C) 2004-2006 MontaVista Software, Inc.
  7 * PPC64 Mods (C) 2005 Frank Rowand (frowand@mvista.com)
  8 * PPC32 support restored by Vitaly Wool <vwool@ru.mvista.com> and
  9 * Sergei Shtylyov <sshtylyov@ru.mvista.com>
 10 * Copyright (C) 2007-2008 Wind River Systems, Inc.
 11 *
 12 * This file is licensed under the terms of the GNU General Public License
 13 * version 2. This program as licensed "as is" without any warranty of any
 14 * kind, whether express or implied.
 15 */
 16
 17#include <linux/kernel.h>
 18#include <linux/kgdb.h>
 19#include <linux/smp.h>
 20#include <linux/signal.h>
 21#include <linux/ptrace.h>
 22#include <linux/kdebug.h>
 23#include <asm/current.h>
 24#include <asm/processor.h>
 25#include <asm/machdep.h>
 26#include <asm/debug.h>
 
 27#include <linux/slab.h>
 
 28
 29/*
 30 * This table contains the mapping between PowerPC hardware trap types, and
 31 * signals, which are primarily what GDB understands.  GDB and the kernel
 32 * don't always agree on values, so we use constants taken from gdb-6.2.
 33 */
 34static struct hard_trap_info
 35{
 36	unsigned int tt;		/* Trap type code for powerpc */
 37	unsigned char signo;		/* Signal that we map this trap into */
 38} hard_trap_info[] = {
 39	{ 0x0100, 0x02 /* SIGINT */  },		/* system reset */
 40	{ 0x0200, 0x0b /* SIGSEGV */ },		/* machine check */
 41	{ 0x0300, 0x0b /* SIGSEGV */ },		/* data access */
 42	{ 0x0400, 0x0b /* SIGSEGV */ },		/* instruction access */
 43	{ 0x0500, 0x02 /* SIGINT */  },		/* external interrupt */
 44	{ 0x0600, 0x0a /* SIGBUS */  },		/* alignment */
 45	{ 0x0700, 0x05 /* SIGTRAP */ },		/* program check */
 46	{ 0x0800, 0x08 /* SIGFPE */  },		/* fp unavailable */
 47	{ 0x0900, 0x0e /* SIGALRM */ },		/* decrementer */
 48	{ 0x0c00, 0x14 /* SIGCHLD */ },		/* system call */
 49#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
 50	{ 0x2002, 0x05 /* SIGTRAP */ },		/* debug */
 51#if defined(CONFIG_FSL_BOOKE)
 52	{ 0x2010, 0x08 /* SIGFPE */  },		/* spe unavailable */
 53	{ 0x2020, 0x08 /* SIGFPE */  },		/* spe unavailable */
 54	{ 0x2030, 0x08 /* SIGFPE */  },		/* spe fp data */
 55	{ 0x2040, 0x08 /* SIGFPE */  },		/* spe fp data */
 56	{ 0x2050, 0x08 /* SIGFPE */  },		/* spe fp round */
 57	{ 0x2060, 0x0e /* SIGILL */  },		/* performance monitor */
 58	{ 0x2900, 0x08 /* SIGFPE */  },		/* apu unavailable */
 59	{ 0x3100, 0x0e /* SIGALRM */ },		/* fixed interval timer */
 60	{ 0x3200, 0x02 /* SIGINT */  }, 	/* watchdog */
 61#else /* ! CONFIG_FSL_BOOKE */
 62	{ 0x1000, 0x0e /* SIGALRM */ },		/* prog interval timer */
 63	{ 0x1010, 0x0e /* SIGALRM */ },		/* fixed interval timer */
 64	{ 0x1020, 0x02 /* SIGINT */  }, 	/* watchdog */
 65	{ 0x2010, 0x08 /* SIGFPE */  },		/* fp unavailable */
 66	{ 0x2020, 0x08 /* SIGFPE */  },		/* ap unavailable */
 67#endif
 68#else /* ! (defined(CONFIG_40x) || defined(CONFIG_BOOKE)) */
 69	{ 0x0d00, 0x05 /* SIGTRAP */ },		/* single-step */
 70#if defined(CONFIG_PPC_8xx)
 71	{ 0x1000, 0x04 /* SIGILL */  },		/* software emulation */
 72#else /* ! CONFIG_PPC_8xx */
 73	{ 0x0f00, 0x04 /* SIGILL */  },		/* performance monitor */
 74	{ 0x0f20, 0x08 /* SIGFPE */  },		/* altivec unavailable */
 75	{ 0x1300, 0x05 /* SIGTRAP */ }, 	/* instruction address break */
 76#if defined(CONFIG_PPC64)
 77	{ 0x1200, 0x05 /* SIGILL */  },		/* system error */
 78	{ 0x1500, 0x04 /* SIGILL */  },		/* soft patch */
 79	{ 0x1600, 0x04 /* SIGILL */  },		/* maintenance */
 80	{ 0x1700, 0x08 /* SIGFPE */  },		/* altivec assist */
 81	{ 0x1800, 0x04 /* SIGILL */  },		/* thermal */
 82#else /* ! CONFIG_PPC64 */
 83	{ 0x1400, 0x02 /* SIGINT */  },		/* SMI */
 84	{ 0x1600, 0x08 /* SIGFPE */  },		/* altivec assist */
 85	{ 0x1700, 0x04 /* SIGILL */  },		/* TAU */
 86	{ 0x2000, 0x05 /* SIGTRAP */ },		/* run mode */
 87#endif
 88#endif
 89#endif
 90	{ 0x0000, 0x00 }			/* Must be last */
 91};
 92
 93static int computeSignal(unsigned int tt)
 94{
 95	struct hard_trap_info *ht;
 96
 97	for (ht = hard_trap_info; ht->tt && ht->signo; ht++)
 98		if (ht->tt == tt)
 99			return ht->signo;
100
101	return SIGHUP;		/* default for things we don't know about */
102}
103
104/**
105 *
106 *	kgdb_skipexception - Bail out of KGDB when we've been triggered.
107 *	@exception: Exception vector number
108 *	@regs: Current &struct pt_regs.
109 *
110 *	On some architectures we need to skip a breakpoint exception when
111 *	it occurs after a breakpoint has been removed.
112 *
113 */
114int kgdb_skipexception(int exception, struct pt_regs *regs)
115{
116	return kgdb_isremovedbreak(regs->nip);
117}
118
119static int kgdb_call_nmi_hook(struct pt_regs *regs)
120{
121	kgdb_nmicallback(raw_smp_processor_id(), regs);
122	return 0;
123}
124
125#ifdef CONFIG_SMP
126void kgdb_roundup_cpus(unsigned long flags)
127{
128	smp_send_debugger_break();
129}
130#endif
131
132/* KGDB functions to use existing PowerPC64 hooks. */
133static int kgdb_debugger(struct pt_regs *regs)
134{
135	return !kgdb_handle_exception(1, computeSignal(TRAP(regs)),
136				      DIE_OOPS, regs);
137}
138
139static int kgdb_handle_breakpoint(struct pt_regs *regs)
140{
141	if (user_mode(regs))
142		return 0;
143
144	if (kgdb_handle_exception(1, SIGTRAP, 0, regs) != 0)
145		return 0;
146
147	if (*(u32 *) (regs->nip) == *(u32 *) (&arch_kgdb_ops.gdb_bpt_instr))
148		regs->nip += BREAK_INSTR_SIZE;
149
150	return 1;
151}
152
153static DEFINE_PER_CPU(struct thread_info, kgdb_thread_info);
154static int kgdb_singlestep(struct pt_regs *regs)
155{
156	struct thread_info *thread_info, *exception_thread_info;
157	struct thread_info *backup_current_thread_info =
158		this_cpu_ptr(&kgdb_thread_info);
159
160	if (user_mode(regs))
161		return 0;
162
163	/*
164	 * On Book E and perhaps other processors, singlestep is handled on
165	 * the critical exception stack.  This causes current_thread_info()
166	 * to fail, since it it locates the thread_info by masking off
167	 * the low bits of the current stack pointer.  We work around
168	 * this issue by copying the thread_info from the kernel stack
169	 * before calling kgdb_handle_exception, and copying it back
170	 * afterwards.  On most processors the copy is avoided since
171	 * exception_thread_info == thread_info.
172	 */
173	thread_info = (struct thread_info *)(regs->gpr[1] & ~(THREAD_SIZE-1));
174	exception_thread_info = current_thread_info();
175
176	if (thread_info != exception_thread_info) {
177		/* Save the original current_thread_info. */
178		memcpy(backup_current_thread_info, exception_thread_info, sizeof *thread_info);
179		memcpy(exception_thread_info, thread_info, sizeof *thread_info);
180	}
181
182	kgdb_handle_exception(0, SIGTRAP, 0, regs);
183
184	if (thread_info != exception_thread_info)
185		/* Restore current_thread_info lastly. */
186		memcpy(exception_thread_info, backup_current_thread_info, sizeof *thread_info);
187
188	return 1;
189}
190
191static int kgdb_iabr_match(struct pt_regs *regs)
192{
193	if (user_mode(regs))
194		return 0;
195
196	if (kgdb_handle_exception(0, computeSignal(TRAP(regs)), 0, regs) != 0)
197		return 0;
198	return 1;
199}
200
201static int kgdb_break_match(struct pt_regs *regs)
202{
203	if (user_mode(regs))
204		return 0;
205
206	if (kgdb_handle_exception(0, computeSignal(TRAP(regs)), 0, regs) != 0)
207		return 0;
208	return 1;
209}
210
211#define PACK64(ptr, src) do { *(ptr++) = (src); } while (0)
212
213#define PACK32(ptr, src) do {          \
214	u32 *ptr32;                   \
215	ptr32 = (u32 *)ptr;           \
216	*(ptr32++) = (src);           \
217	ptr = (unsigned long *)ptr32; \
218	} while (0)
219
220void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
221{
222	struct pt_regs *regs = (struct pt_regs *)(p->thread.ksp +
223						  STACK_FRAME_OVERHEAD);
224	unsigned long *ptr = gdb_regs;
225	int reg;
226
227	memset(gdb_regs, 0, NUMREGBYTES);
228
229	/* Regs GPR0-2 */
230	for (reg = 0; reg < 3; reg++)
231		PACK64(ptr, regs->gpr[reg]);
232
233	/* Regs GPR3-13 are caller saved, not in regs->gpr[] */
234	ptr += 11;
235
236	/* Regs GPR14-31 */
237	for (reg = 14; reg < 32; reg++)
238		PACK64(ptr, regs->gpr[reg]);
239
240#ifdef CONFIG_FSL_BOOKE
241#ifdef CONFIG_SPE
242	for (reg = 0; reg < 32; reg++)
243		PACK64(ptr, p->thread.evr[reg]);
244#else
245	ptr += 32;
246#endif
247#else
248	/* fp registers not used by kernel, leave zero */
249	ptr += 32 * 8 / sizeof(long);
250#endif
251
252	PACK64(ptr, regs->nip);
253	PACK64(ptr, regs->msr);
254	PACK32(ptr, regs->ccr);
255	PACK64(ptr, regs->link);
256	PACK64(ptr, regs->ctr);
257	PACK32(ptr, regs->xer);
258
259	BUG_ON((unsigned long)ptr >
260	       (unsigned long)(((void *)gdb_regs) + NUMREGBYTES));
261}
262
263#define GDB_SIZEOF_REG sizeof(unsigned long)
264#define GDB_SIZEOF_REG_U32 sizeof(u32)
265
266#ifdef CONFIG_FSL_BOOKE
267#define GDB_SIZEOF_FLOAT_REG sizeof(unsigned long)
268#else
269#define GDB_SIZEOF_FLOAT_REG sizeof(u64)
270#endif
271
272struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
273{
274	{ "r0", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[0]) },
275	{ "r1", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[1]) },
276	{ "r2", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[2]) },
277	{ "r3", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[3]) },
278	{ "r4", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[4]) },
279	{ "r5", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[5]) },
280	{ "r6", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[6]) },
281	{ "r7", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[7]) },
282	{ "r8", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[8]) },
283	{ "r9", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[9]) },
284	{ "r10", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[10]) },
285	{ "r11", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[11]) },
286	{ "r12", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[12]) },
287	{ "r13", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[13]) },
288	{ "r14", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[14]) },
289	{ "r15", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[15]) },
290	{ "r16", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[16]) },
291	{ "r17", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[17]) },
292	{ "r18", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[18]) },
293	{ "r19", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[19]) },
294	{ "r20", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[20]) },
295	{ "r21", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[21]) },
296	{ "r22", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[22]) },
297	{ "r23", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[23]) },
298	{ "r24", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[24]) },
299	{ "r25", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[25]) },
300	{ "r26", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[26]) },
301	{ "r27", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[27]) },
302	{ "r28", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[28]) },
303	{ "r29", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[29]) },
304	{ "r30", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[30]) },
305	{ "r31", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[31]) },
306
307	{ "f0", GDB_SIZEOF_FLOAT_REG, 0 },
308	{ "f1", GDB_SIZEOF_FLOAT_REG, 1 },
309	{ "f2", GDB_SIZEOF_FLOAT_REG, 2 },
310	{ "f3", GDB_SIZEOF_FLOAT_REG, 3 },
311	{ "f4", GDB_SIZEOF_FLOAT_REG, 4 },
312	{ "f5", GDB_SIZEOF_FLOAT_REG, 5 },
313	{ "f6", GDB_SIZEOF_FLOAT_REG, 6 },
314	{ "f7", GDB_SIZEOF_FLOAT_REG, 7 },
315	{ "f8", GDB_SIZEOF_FLOAT_REG, 8 },
316	{ "f9", GDB_SIZEOF_FLOAT_REG, 9 },
317	{ "f10", GDB_SIZEOF_FLOAT_REG, 10 },
318	{ "f11", GDB_SIZEOF_FLOAT_REG, 11 },
319	{ "f12", GDB_SIZEOF_FLOAT_REG, 12 },
320	{ "f13", GDB_SIZEOF_FLOAT_REG, 13 },
321	{ "f14", GDB_SIZEOF_FLOAT_REG, 14 },
322	{ "f15", GDB_SIZEOF_FLOAT_REG, 15 },
323	{ "f16", GDB_SIZEOF_FLOAT_REG, 16 },
324	{ "f17", GDB_SIZEOF_FLOAT_REG, 17 },
325	{ "f18", GDB_SIZEOF_FLOAT_REG, 18 },
326	{ "f19", GDB_SIZEOF_FLOAT_REG, 19 },
327	{ "f20", GDB_SIZEOF_FLOAT_REG, 20 },
328	{ "f21", GDB_SIZEOF_FLOAT_REG, 21 },
329	{ "f22", GDB_SIZEOF_FLOAT_REG, 22 },
330	{ "f23", GDB_SIZEOF_FLOAT_REG, 23 },
331	{ "f24", GDB_SIZEOF_FLOAT_REG, 24 },
332	{ "f25", GDB_SIZEOF_FLOAT_REG, 25 },
333	{ "f26", GDB_SIZEOF_FLOAT_REG, 26 },
334	{ "f27", GDB_SIZEOF_FLOAT_REG, 27 },
335	{ "f28", GDB_SIZEOF_FLOAT_REG, 28 },
336	{ "f29", GDB_SIZEOF_FLOAT_REG, 29 },
337	{ "f30", GDB_SIZEOF_FLOAT_REG, 30 },
338	{ "f31", GDB_SIZEOF_FLOAT_REG, 31 },
339
340	{ "pc", GDB_SIZEOF_REG, offsetof(struct pt_regs, nip) },
341	{ "msr", GDB_SIZEOF_REG, offsetof(struct pt_regs, msr) },
342	{ "cr", GDB_SIZEOF_REG_U32, offsetof(struct pt_regs, ccr) },
343	{ "lr", GDB_SIZEOF_REG, offsetof(struct pt_regs, link) },
344	{ "ctr", GDB_SIZEOF_REG_U32, offsetof(struct pt_regs, ctr) },
345	{ "xer", GDB_SIZEOF_REG, offsetof(struct pt_regs, xer) },
346};
347
348char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
349{
350	if (regno >= DBG_MAX_REG_NUM || regno < 0)
351		return NULL;
352
353	if (regno < 32 || regno >= 64)
354		/* First 0 -> 31 gpr registers*/
355		/* pc, msr, ls... registers 64 -> 69 */
356		memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
357				dbg_reg_def[regno].size);
358
359	if (regno >= 32 && regno < 64) {
360		/* FP registers 32 -> 63 */
361#if defined(CONFIG_FSL_BOOKE) && defined(CONFIG_SPE)
362		if (current)
363			memcpy(mem, &current->thread.evr[regno-32],
364					dbg_reg_def[regno].size);
365#else
366		/* fp registers not used by kernel, leave zero */
367		memset(mem, 0, dbg_reg_def[regno].size);
368#endif
369	}
370
371	return dbg_reg_def[regno].name;
372}
373
374int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
375{
376	if (regno >= DBG_MAX_REG_NUM || regno < 0)
377		return -EINVAL;
378
379	if (regno < 32 || regno >= 64)
380		/* First 0 -> 31 gpr registers*/
381		/* pc, msr, ls... registers 64 -> 69 */
382		memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
383				dbg_reg_def[regno].size);
384
385	if (regno >= 32 && regno < 64) {
386		/* FP registers 32 -> 63 */
387#if defined(CONFIG_FSL_BOOKE) && defined(CONFIG_SPE)
388		memcpy(&current->thread.evr[regno-32], mem,
389				dbg_reg_def[regno].size);
390#else
391		/* fp registers not used by kernel, leave zero */
392		return 0;
393#endif
394	}
395
396	return 0;
397}
398
399void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
400{
401	regs->nip = pc;
402}
403
404/*
405 * This function does PowerPC specific procesing for interfacing to gdb.
406 */
407int kgdb_arch_handle_exception(int vector, int signo, int err_code,
408			       char *remcom_in_buffer, char *remcom_out_buffer,
409			       struct pt_regs *linux_regs)
410{
411	char *ptr = &remcom_in_buffer[1];
412	unsigned long addr;
413
414	switch (remcom_in_buffer[0]) {
415		/*
416		 * sAA..AA   Step one instruction from AA..AA
417		 * This will return an error to gdb ..
418		 */
419	case 's':
420	case 'c':
421		/* handle the optional parameter */
422		if (kgdb_hex2long(&ptr, &addr))
423			linux_regs->nip = addr;
424
425		atomic_set(&kgdb_cpu_doing_single_step, -1);
426		/* set the trace bit if we're stepping */
427		if (remcom_in_buffer[0] == 's') {
428#ifdef CONFIG_PPC_ADV_DEBUG_REGS
429			mtspr(SPRN_DBCR0,
430			      mfspr(SPRN_DBCR0) | DBCR0_IC | DBCR0_IDM);
431			linux_regs->msr |= MSR_DE;
432#else
433			linux_regs->msr |= MSR_SE;
434#endif
435			atomic_set(&kgdb_cpu_doing_single_step,
436				   raw_smp_processor_id());
437		}
438		return 0;
439	}
440
441	return -1;
442}
443
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
444/*
445 * Global data
446 */
447struct kgdb_arch arch_kgdb_ops = {
448#ifdef __LITTLE_ENDIAN__
449	.gdb_bpt_instr = {0x08, 0x10, 0x82, 0x7d},
450#else
451	.gdb_bpt_instr = {0x7d, 0x82, 0x10, 0x08},
452#endif
453};
454
455static int kgdb_not_implemented(struct pt_regs *regs)
456{
457	return 0;
458}
459
460static void *old__debugger_ipi;
461static void *old__debugger;
462static void *old__debugger_bpt;
463static void *old__debugger_sstep;
464static void *old__debugger_iabr_match;
465static void *old__debugger_break_match;
466static void *old__debugger_fault_handler;
467
468int kgdb_arch_init(void)
469{
470	old__debugger_ipi = __debugger_ipi;
471	old__debugger = __debugger;
472	old__debugger_bpt = __debugger_bpt;
473	old__debugger_sstep = __debugger_sstep;
474	old__debugger_iabr_match = __debugger_iabr_match;
475	old__debugger_break_match = __debugger_break_match;
476	old__debugger_fault_handler = __debugger_fault_handler;
477
478	__debugger_ipi = kgdb_call_nmi_hook;
479	__debugger = kgdb_debugger;
480	__debugger_bpt = kgdb_handle_breakpoint;
481	__debugger_sstep = kgdb_singlestep;
482	__debugger_iabr_match = kgdb_iabr_match;
483	__debugger_break_match = kgdb_break_match;
484	__debugger_fault_handler = kgdb_not_implemented;
485
486	return 0;
487}
488
489void kgdb_arch_exit(void)
490{
491	__debugger_ipi = old__debugger_ipi;
492	__debugger = old__debugger;
493	__debugger_bpt = old__debugger_bpt;
494	__debugger_sstep = old__debugger_sstep;
495	__debugger_iabr_match = old__debugger_iabr_match;
496	__debugger_break_match = old__debugger_break_match;
497	__debugger_fault_handler = old__debugger_fault_handler;
498}
v5.9
  1/*
  2 * PowerPC backend to the KGDB stub.
  3 *
  4 * 1998 (c) Michael AK Tesch (tesch@cs.wisc.edu)
  5 * Copyright (C) 2003 Timesys Corporation.
  6 * Copyright (C) 2004-2006 MontaVista Software, Inc.
  7 * PPC64 Mods (C) 2005 Frank Rowand (frowand@mvista.com)
  8 * PPC32 support restored by Vitaly Wool <vwool@ru.mvista.com> and
  9 * Sergei Shtylyov <sshtylyov@ru.mvista.com>
 10 * Copyright (C) 2007-2008 Wind River Systems, Inc.
 11 *
 12 * This file is licensed under the terms of the GNU General Public License
 13 * version 2. This program as licensed "as is" without any warranty of any
 14 * kind, whether express or implied.
 15 */
 16
 17#include <linux/kernel.h>
 18#include <linux/kgdb.h>
 19#include <linux/smp.h>
 20#include <linux/signal.h>
 21#include <linux/ptrace.h>
 22#include <linux/kdebug.h>
 23#include <asm/current.h>
 24#include <asm/processor.h>
 25#include <asm/machdep.h>
 26#include <asm/debug.h>
 27#include <asm/code-patching.h>
 28#include <linux/slab.h>
 29#include <asm/inst.h>
 30
 31/*
 32 * This table contains the mapping between PowerPC hardware trap types, and
 33 * signals, which are primarily what GDB understands.  GDB and the kernel
 34 * don't always agree on values, so we use constants taken from gdb-6.2.
 35 */
 36static struct hard_trap_info
 37{
 38	unsigned int tt;		/* Trap type code for powerpc */
 39	unsigned char signo;		/* Signal that we map this trap into */
 40} hard_trap_info[] = {
 41	{ 0x0100, 0x02 /* SIGINT */  },		/* system reset */
 42	{ 0x0200, 0x0b /* SIGSEGV */ },		/* machine check */
 43	{ 0x0300, 0x0b /* SIGSEGV */ },		/* data access */
 44	{ 0x0400, 0x0b /* SIGSEGV */ },		/* instruction access */
 45	{ 0x0500, 0x02 /* SIGINT */  },		/* external interrupt */
 46	{ 0x0600, 0x0a /* SIGBUS */  },		/* alignment */
 47	{ 0x0700, 0x05 /* SIGTRAP */ },		/* program check */
 48	{ 0x0800, 0x08 /* SIGFPE */  },		/* fp unavailable */
 49	{ 0x0900, 0x0e /* SIGALRM */ },		/* decrementer */
 50	{ 0x0c00, 0x14 /* SIGCHLD */ },		/* system call */
 51#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
 52	{ 0x2002, 0x05 /* SIGTRAP */ },		/* debug */
 53#if defined(CONFIG_FSL_BOOKE)
 54	{ 0x2010, 0x08 /* SIGFPE */  },		/* spe unavailable */
 55	{ 0x2020, 0x08 /* SIGFPE */  },		/* spe unavailable */
 56	{ 0x2030, 0x08 /* SIGFPE */  },		/* spe fp data */
 57	{ 0x2040, 0x08 /* SIGFPE */  },		/* spe fp data */
 58	{ 0x2050, 0x08 /* SIGFPE */  },		/* spe fp round */
 59	{ 0x2060, 0x0e /* SIGILL */  },		/* performance monitor */
 60	{ 0x2900, 0x08 /* SIGFPE */  },		/* apu unavailable */
 61	{ 0x3100, 0x0e /* SIGALRM */ },		/* fixed interval timer */
 62	{ 0x3200, 0x02 /* SIGINT */  }, 	/* watchdog */
 63#else /* ! CONFIG_FSL_BOOKE */
 64	{ 0x1000, 0x0e /* SIGALRM */ },		/* prog interval timer */
 65	{ 0x1010, 0x0e /* SIGALRM */ },		/* fixed interval timer */
 66	{ 0x1020, 0x02 /* SIGINT */  }, 	/* watchdog */
 67	{ 0x2010, 0x08 /* SIGFPE */  },		/* fp unavailable */
 68	{ 0x2020, 0x08 /* SIGFPE */  },		/* ap unavailable */
 69#endif
 70#else /* ! (defined(CONFIG_40x) || defined(CONFIG_BOOKE)) */
 71	{ 0x0d00, 0x05 /* SIGTRAP */ },		/* single-step */
 72#if defined(CONFIG_PPC_8xx)
 73	{ 0x1000, 0x04 /* SIGILL */  },		/* software emulation */
 74#else /* ! CONFIG_PPC_8xx */
 75	{ 0x0f00, 0x04 /* SIGILL */  },		/* performance monitor */
 76	{ 0x0f20, 0x08 /* SIGFPE */  },		/* altivec unavailable */
 77	{ 0x1300, 0x05 /* SIGTRAP */ }, 	/* instruction address break */
 78#if defined(CONFIG_PPC64)
 79	{ 0x1200, 0x05 /* SIGILL */  },		/* system error */
 80	{ 0x1500, 0x04 /* SIGILL */  },		/* soft patch */
 81	{ 0x1600, 0x04 /* SIGILL */  },		/* maintenance */
 82	{ 0x1700, 0x08 /* SIGFPE */  },		/* altivec assist */
 83	{ 0x1800, 0x04 /* SIGILL */  },		/* thermal */
 84#else /* ! CONFIG_PPC64 */
 85	{ 0x1400, 0x02 /* SIGINT */  },		/* SMI */
 86	{ 0x1600, 0x08 /* SIGFPE */  },		/* altivec assist */
 87	{ 0x1700, 0x04 /* SIGILL */  },		/* TAU */
 88	{ 0x2000, 0x05 /* SIGTRAP */ },		/* run mode */
 89#endif
 90#endif
 91#endif
 92	{ 0x0000, 0x00 }			/* Must be last */
 93};
 94
 95static int computeSignal(unsigned int tt)
 96{
 97	struct hard_trap_info *ht;
 98
 99	for (ht = hard_trap_info; ht->tt && ht->signo; ht++)
100		if (ht->tt == tt)
101			return ht->signo;
102
103	return SIGHUP;		/* default for things we don't know about */
104}
105
106/**
107 *
108 *	kgdb_skipexception - Bail out of KGDB when we've been triggered.
109 *	@exception: Exception vector number
110 *	@regs: Current &struct pt_regs.
111 *
112 *	On some architectures we need to skip a breakpoint exception when
113 *	it occurs after a breakpoint has been removed.
114 *
115 */
116int kgdb_skipexception(int exception, struct pt_regs *regs)
117{
118	return kgdb_isremovedbreak(regs->nip);
119}
120
121static int kgdb_debugger_ipi(struct pt_regs *regs)
122{
123	kgdb_nmicallback(raw_smp_processor_id(), regs);
124	return 0;
125}
126
127#ifdef CONFIG_SMP
128void kgdb_roundup_cpus(void)
129{
130	smp_send_debugger_break();
131}
132#endif
133
134/* KGDB functions to use existing PowerPC64 hooks. */
135static int kgdb_debugger(struct pt_regs *regs)
136{
137	return !kgdb_handle_exception(1, computeSignal(TRAP(regs)),
138				      DIE_OOPS, regs);
139}
140
141static int kgdb_handle_breakpoint(struct pt_regs *regs)
142{
143	if (user_mode(regs))
144		return 0;
145
146	if (kgdb_handle_exception(1, SIGTRAP, 0, regs) != 0)
147		return 0;
148
149	if (*(u32 *)regs->nip == BREAK_INSTR)
150		regs->nip += BREAK_INSTR_SIZE;
151
152	return 1;
153}
154
 
155static int kgdb_singlestep(struct pt_regs *regs)
156{
 
 
 
 
157	if (user_mode(regs))
158		return 0;
159
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
160	kgdb_handle_exception(0, SIGTRAP, 0, regs);
161
 
 
 
 
162	return 1;
163}
164
165static int kgdb_iabr_match(struct pt_regs *regs)
166{
167	if (user_mode(regs))
168		return 0;
169
170	if (kgdb_handle_exception(0, computeSignal(TRAP(regs)), 0, regs) != 0)
171		return 0;
172	return 1;
173}
174
175static int kgdb_break_match(struct pt_regs *regs)
176{
177	if (user_mode(regs))
178		return 0;
179
180	if (kgdb_handle_exception(0, computeSignal(TRAP(regs)), 0, regs) != 0)
181		return 0;
182	return 1;
183}
184
185#define PACK64(ptr, src) do { *(ptr++) = (src); } while (0)
186
187#define PACK32(ptr, src) do {          \
188	u32 *ptr32;                   \
189	ptr32 = (u32 *)ptr;           \
190	*(ptr32++) = (src);           \
191	ptr = (unsigned long *)ptr32; \
192	} while (0)
193
194void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
195{
196	struct pt_regs *regs = (struct pt_regs *)(p->thread.ksp +
197						  STACK_FRAME_OVERHEAD);
198	unsigned long *ptr = gdb_regs;
199	int reg;
200
201	memset(gdb_regs, 0, NUMREGBYTES);
202
203	/* Regs GPR0-2 */
204	for (reg = 0; reg < 3; reg++)
205		PACK64(ptr, regs->gpr[reg]);
206
207	/* Regs GPR3-13 are caller saved, not in regs->gpr[] */
208	ptr += 11;
209
210	/* Regs GPR14-31 */
211	for (reg = 14; reg < 32; reg++)
212		PACK64(ptr, regs->gpr[reg]);
213
214#ifdef CONFIG_FSL_BOOKE
215#ifdef CONFIG_SPE
216	for (reg = 0; reg < 32; reg++)
217		PACK64(ptr, p->thread.evr[reg]);
218#else
219	ptr += 32;
220#endif
221#else
222	/* fp registers not used by kernel, leave zero */
223	ptr += 32 * 8 / sizeof(long);
224#endif
225
226	PACK64(ptr, regs->nip);
227	PACK64(ptr, regs->msr);
228	PACK32(ptr, regs->ccr);
229	PACK64(ptr, regs->link);
230	PACK64(ptr, regs->ctr);
231	PACK32(ptr, regs->xer);
232
233	BUG_ON((unsigned long)ptr >
234	       (unsigned long)(((void *)gdb_regs) + NUMREGBYTES));
235}
236
237#define GDB_SIZEOF_REG sizeof(unsigned long)
238#define GDB_SIZEOF_REG_U32 sizeof(u32)
239
240#ifdef CONFIG_FSL_BOOKE
241#define GDB_SIZEOF_FLOAT_REG sizeof(unsigned long)
242#else
243#define GDB_SIZEOF_FLOAT_REG sizeof(u64)
244#endif
245
246struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
247{
248	{ "r0", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[0]) },
249	{ "r1", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[1]) },
250	{ "r2", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[2]) },
251	{ "r3", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[3]) },
252	{ "r4", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[4]) },
253	{ "r5", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[5]) },
254	{ "r6", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[6]) },
255	{ "r7", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[7]) },
256	{ "r8", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[8]) },
257	{ "r9", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[9]) },
258	{ "r10", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[10]) },
259	{ "r11", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[11]) },
260	{ "r12", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[12]) },
261	{ "r13", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[13]) },
262	{ "r14", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[14]) },
263	{ "r15", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[15]) },
264	{ "r16", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[16]) },
265	{ "r17", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[17]) },
266	{ "r18", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[18]) },
267	{ "r19", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[19]) },
268	{ "r20", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[20]) },
269	{ "r21", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[21]) },
270	{ "r22", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[22]) },
271	{ "r23", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[23]) },
272	{ "r24", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[24]) },
273	{ "r25", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[25]) },
274	{ "r26", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[26]) },
275	{ "r27", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[27]) },
276	{ "r28", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[28]) },
277	{ "r29", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[29]) },
278	{ "r30", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[30]) },
279	{ "r31", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[31]) },
280
281	{ "f0", GDB_SIZEOF_FLOAT_REG, 0 },
282	{ "f1", GDB_SIZEOF_FLOAT_REG, 1 },
283	{ "f2", GDB_SIZEOF_FLOAT_REG, 2 },
284	{ "f3", GDB_SIZEOF_FLOAT_REG, 3 },
285	{ "f4", GDB_SIZEOF_FLOAT_REG, 4 },
286	{ "f5", GDB_SIZEOF_FLOAT_REG, 5 },
287	{ "f6", GDB_SIZEOF_FLOAT_REG, 6 },
288	{ "f7", GDB_SIZEOF_FLOAT_REG, 7 },
289	{ "f8", GDB_SIZEOF_FLOAT_REG, 8 },
290	{ "f9", GDB_SIZEOF_FLOAT_REG, 9 },
291	{ "f10", GDB_SIZEOF_FLOAT_REG, 10 },
292	{ "f11", GDB_SIZEOF_FLOAT_REG, 11 },
293	{ "f12", GDB_SIZEOF_FLOAT_REG, 12 },
294	{ "f13", GDB_SIZEOF_FLOAT_REG, 13 },
295	{ "f14", GDB_SIZEOF_FLOAT_REG, 14 },
296	{ "f15", GDB_SIZEOF_FLOAT_REG, 15 },
297	{ "f16", GDB_SIZEOF_FLOAT_REG, 16 },
298	{ "f17", GDB_SIZEOF_FLOAT_REG, 17 },
299	{ "f18", GDB_SIZEOF_FLOAT_REG, 18 },
300	{ "f19", GDB_SIZEOF_FLOAT_REG, 19 },
301	{ "f20", GDB_SIZEOF_FLOAT_REG, 20 },
302	{ "f21", GDB_SIZEOF_FLOAT_REG, 21 },
303	{ "f22", GDB_SIZEOF_FLOAT_REG, 22 },
304	{ "f23", GDB_SIZEOF_FLOAT_REG, 23 },
305	{ "f24", GDB_SIZEOF_FLOAT_REG, 24 },
306	{ "f25", GDB_SIZEOF_FLOAT_REG, 25 },
307	{ "f26", GDB_SIZEOF_FLOAT_REG, 26 },
308	{ "f27", GDB_SIZEOF_FLOAT_REG, 27 },
309	{ "f28", GDB_SIZEOF_FLOAT_REG, 28 },
310	{ "f29", GDB_SIZEOF_FLOAT_REG, 29 },
311	{ "f30", GDB_SIZEOF_FLOAT_REG, 30 },
312	{ "f31", GDB_SIZEOF_FLOAT_REG, 31 },
313
314	{ "pc", GDB_SIZEOF_REG, offsetof(struct pt_regs, nip) },
315	{ "msr", GDB_SIZEOF_REG, offsetof(struct pt_regs, msr) },
316	{ "cr", GDB_SIZEOF_REG_U32, offsetof(struct pt_regs, ccr) },
317	{ "lr", GDB_SIZEOF_REG, offsetof(struct pt_regs, link) },
318	{ "ctr", GDB_SIZEOF_REG_U32, offsetof(struct pt_regs, ctr) },
319	{ "xer", GDB_SIZEOF_REG, offsetof(struct pt_regs, xer) },
320};
321
322char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
323{
324	if (regno >= DBG_MAX_REG_NUM || regno < 0)
325		return NULL;
326
327	if (regno < 32 || regno >= 64)
328		/* First 0 -> 31 gpr registers*/
329		/* pc, msr, ls... registers 64 -> 69 */
330		memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
331				dbg_reg_def[regno].size);
332
333	if (regno >= 32 && regno < 64) {
334		/* FP registers 32 -> 63 */
335#if defined(CONFIG_FSL_BOOKE) && defined(CONFIG_SPE)
336		if (current)
337			memcpy(mem, &current->thread.evr[regno-32],
338					dbg_reg_def[regno].size);
339#else
340		/* fp registers not used by kernel, leave zero */
341		memset(mem, 0, dbg_reg_def[regno].size);
342#endif
343	}
344
345	return dbg_reg_def[regno].name;
346}
347
348int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
349{
350	if (regno >= DBG_MAX_REG_NUM || regno < 0)
351		return -EINVAL;
352
353	if (regno < 32 || regno >= 64)
354		/* First 0 -> 31 gpr registers*/
355		/* pc, msr, ls... registers 64 -> 69 */
356		memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
357				dbg_reg_def[regno].size);
358
359	if (regno >= 32 && regno < 64) {
360		/* FP registers 32 -> 63 */
361#if defined(CONFIG_FSL_BOOKE) && defined(CONFIG_SPE)
362		memcpy(&current->thread.evr[regno-32], mem,
363				dbg_reg_def[regno].size);
364#else
365		/* fp registers not used by kernel, leave zero */
366		return 0;
367#endif
368	}
369
370	return 0;
371}
372
373void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
374{
375	regs->nip = pc;
376}
377
378/*
379 * This function does PowerPC specific procesing for interfacing to gdb.
380 */
381int kgdb_arch_handle_exception(int vector, int signo, int err_code,
382			       char *remcom_in_buffer, char *remcom_out_buffer,
383			       struct pt_regs *linux_regs)
384{
385	char *ptr = &remcom_in_buffer[1];
386	unsigned long addr;
387
388	switch (remcom_in_buffer[0]) {
389		/*
390		 * sAA..AA   Step one instruction from AA..AA
391		 * This will return an error to gdb ..
392		 */
393	case 's':
394	case 'c':
395		/* handle the optional parameter */
396		if (kgdb_hex2long(&ptr, &addr))
397			linux_regs->nip = addr;
398
399		atomic_set(&kgdb_cpu_doing_single_step, -1);
400		/* set the trace bit if we're stepping */
401		if (remcom_in_buffer[0] == 's') {
402#ifdef CONFIG_PPC_ADV_DEBUG_REGS
403			mtspr(SPRN_DBCR0,
404			      mfspr(SPRN_DBCR0) | DBCR0_IC | DBCR0_IDM);
405			linux_regs->msr |= MSR_DE;
406#else
407			linux_regs->msr |= MSR_SE;
408#endif
409			atomic_set(&kgdb_cpu_doing_single_step,
410				   raw_smp_processor_id());
411		}
412		return 0;
413	}
414
415	return -1;
416}
417
418int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt)
419{
420	int err;
421	unsigned int instr;
422	struct ppc_inst *addr = (struct ppc_inst *)bpt->bpt_addr;
423
424	err = get_kernel_nofault(instr, (unsigned *) addr);
425	if (err)
426		return err;
427
428	err = patch_instruction(addr, ppc_inst(BREAK_INSTR));
429	if (err)
430		return -EFAULT;
431
432	*(unsigned int *)bpt->saved_instr = instr;
433
434	return 0;
435}
436
437int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt)
438{
439	int err;
440	unsigned int instr = *(unsigned int *)bpt->saved_instr;
441	struct ppc_inst *addr = (struct ppc_inst *)bpt->bpt_addr;
442
443	err = patch_instruction(addr, ppc_inst(instr));
444	if (err)
445		return -EFAULT;
446
447	return 0;
448}
449
450/*
451 * Global data
452 */
453const struct kgdb_arch arch_kgdb_ops;
 
 
 
 
 
 
454
455static int kgdb_not_implemented(struct pt_regs *regs)
456{
457	return 0;
458}
459
460static void *old__debugger_ipi;
461static void *old__debugger;
462static void *old__debugger_bpt;
463static void *old__debugger_sstep;
464static void *old__debugger_iabr_match;
465static void *old__debugger_break_match;
466static void *old__debugger_fault_handler;
467
468int kgdb_arch_init(void)
469{
470	old__debugger_ipi = __debugger_ipi;
471	old__debugger = __debugger;
472	old__debugger_bpt = __debugger_bpt;
473	old__debugger_sstep = __debugger_sstep;
474	old__debugger_iabr_match = __debugger_iabr_match;
475	old__debugger_break_match = __debugger_break_match;
476	old__debugger_fault_handler = __debugger_fault_handler;
477
478	__debugger_ipi = kgdb_debugger_ipi;
479	__debugger = kgdb_debugger;
480	__debugger_bpt = kgdb_handle_breakpoint;
481	__debugger_sstep = kgdb_singlestep;
482	__debugger_iabr_match = kgdb_iabr_match;
483	__debugger_break_match = kgdb_break_match;
484	__debugger_fault_handler = kgdb_not_implemented;
485
486	return 0;
487}
488
489void kgdb_arch_exit(void)
490{
491	__debugger_ipi = old__debugger_ipi;
492	__debugger = old__debugger;
493	__debugger_bpt = old__debugger_bpt;
494	__debugger_sstep = old__debugger_sstep;
495	__debugger_iabr_match = old__debugger_iabr_match;
496	__debugger_break_match = old__debugger_break_match;
497	__debugger_fault_handler = old__debugger_fault_handler;
498}