[PATCH] i386/x86-64: fall back to old-style call trace if no unwinding

If no unwinding is possible at all for a certain exception instance, fall back to the old style call trace instead of not showing any trace at all. Also, allow setting the stack trace mode at the command line.

Jan Beulich committed 20 years ago

Commit c33bd9a1 parent fe7cacc6 files · +83 −45Browse files

Unified · Split

6 files

arch/i386/kernel/traps.c +33 −13
arch/x86_64/kernel/traps.c +35 −16
include/asm-i386/unwind.h +4 −4
include/asm-x86_64/unwind.h +4 −4
include/linux/unwind.h +4 −4
kernel/unwind.c +3 −4

arch/i386/kernel/traps.c+33−13

@@ -93,6 +93,7 @@ asmlinkage void spurious_interrupt_bug(void); · 92 unmodified lines
93	asmlinkage void machine_check(void);	93	asmlinkage void machine_check(void);
94		94
95	static int kstack_depth_to_print = 24;	95	static int kstack_depth_to_print = 24;
		96	static int call_trace = 1;
96	ATOMIC_NOTIFIER_HEAD(i386die_chain);	97	ATOMIC_NOTIFIER_HEAD(i386die_chain);
97		98
98	int register_die_notifier(struct notifier_block *nb)	99	int register_die_notifier(struct notifier_block *nb)
@@ -171,40 +172,47 @@ static inline unsigned long print_context_stack(struct thread_info *tinfo, · 72 unmodified lines
171	return ebp;	172	return ebp;
172	}	173	}
173		174
174	static asmlinkage void show_trace_unwind(struct unwind_frame_info info, void log_lvl)	175	static asmlinkage int show_trace_unwind(struct unwind_frame_info info, void log_lvl)
175	{	176	{
		177	int n = 0;
176	int printed = 0; /* nr of entries already printed on current line */	178	int printed = 0; /* nr of entries already printed on current line */
177		179
178	while (unwind(info) == 0 && UNW_PC(info)) {	180	while (unwind(info) == 0 && UNW_PC(info)) {
		181	++n;
179	printed = print_addr_and_symbol(UNW_PC(info), log_lvl, printed);	182	printed = print_addr_and_symbol(UNW_PC(info), log_lvl, printed);
180	if (arch_unw_user_mode(info))	183	if (arch_unw_user_mode(info))
181	break;	184	break;
182	}	185	}
183	if (printed)	186	if (printed)
184	printk("\n");	187	printk("\n");
		188	return n;
185	}	189	}
186		190
187	static void show_trace_log_lvl(struct task_struct task, struct pt_regs regs,	191	static void show_trace_log_lvl(struct task_struct task, struct pt_regs regs,
188	unsigned long stack, char log_lvl)	192	unsigned long stack, char log_lvl)
189	{	193	{
190	unsigned long ebp;	194	unsigned long ebp;
191	struct unwind_frame_info info;
192		195
193	if (!task)	196	if (!task)
194	task = current;	197	task = current;
195		198
196	if (regs) {	199	if (call_trace >= 0) {
197	if (unwind_init_frame_info(&info, task, regs) == 0) {	200	int unw_ret = 0;
198	show_trace_unwind(&info, log_lvl);	201	struct unwind_frame_info info;
199	return;	202
		203	if (regs) {
		204	if (unwind_init_frame_info(&info, task, regs) == 0)
		205	unw_ret = show_trace_unwind(&info, log_lvl);
		206	} else if (task == current)
		207	unw_ret = unwind_init_running(&info, show_trace_unwind, log_lvl);
		208	else {
		209	if (unwind_init_blocked(&info, task) == 0)
		210	unw_ret = show_trace_unwind(&info, log_lvl);
200	}	211	}
201	} else if (task == current) {	212	if (unw_ret > 0) {
202	if (unwind_init_running(&info, show_trace_unwind, log_lvl) == 0)	213	if (call_trace > 0)
203	return;	214	return;
204	} else {	215	printk("%sLegacy call trace:\n", log_lvl);
205	if (unwind_init_blocked(&info, task) == 0) {
206	show_trace_unwind(&info, log_lvl);
207	return;
208	}	216	}
209	}	217	}
210		218
@@ -1245,3 +1253,15 @@ static int __init kstack_setup(char *s) · 1034 unmodified lines
1245	return 1;	1253	return 1;
1246	}	1254	}
1247	__setup("kstack=", kstack_setup);	1255	__setup("kstack=", kstack_setup);
		1256
		1257	static int __init call_trace_setup(char *s)
		1258	{
		1259	if (strcmp(s, "old") == 0)
		1260	call_trace = -1;
		1261	else if (strcmp(s, "both") == 0)
		1262	call_trace = 0;
		1263	else if (strcmp(s, "new") == 0)
		1264	call_trace = 1;
		1265	return 1;
		1266	}
		1267	__setup("call_trace=", call_trace_setup);

arch/x86_64/kernel/traps.c+35−16

@@ -107,6 +107,7 @@ static inline void preempt_conditional_cli(struct pt_regs *regs) · 106 unmodified lines
107	}	107	}
108		108
109	static int kstack_depth_to_print = 10;	109	static int kstack_depth_to_print = 10;
		110	static int call_trace = 1;
110		111
111	#ifdef CONFIG_KALLSYMS	112	#ifdef CONFIG_KALLSYMS
112	#include <linux/kallsyms.h>	113	#include <linux/kallsyms.h>
@@ -190,11 +191,12 @@ static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack, · 77 unmodified lines
190	return NULL;	191	return NULL;
191	}	192	}
192		193
193	static void show_trace_unwind(struct unwind_frame_info info, void context)	194	static int show_trace_unwind(struct unwind_frame_info info, void context)
194	{	195	{
195	int i = 11;	196	int i = 11, n = 0;
196		197
197	while (unwind(info) == 0 && UNW_PC(info)) {	198	while (unwind(info) == 0 && UNW_PC(info)) {
		199	++n;
198	if (i > 50) {	200	if (i > 50) {
199	printk("\n ");	201	printk("\n ");
200	i = 7;	202	i = 7;
@@ -205,6 +207,7 @@ static void show_trace_unwind(struct unwind_frame_info info, void context) · 4 unmodified lines
205	break;	207	break;
206	}	208	}
207	printk("\n");	209	printk("\n");
		210	return n;
208	}	211	}
209		212
210	/*	213	/*
@@ -218,27 +221,32 @@ void show_trace(struct task_struct tsk, struct pt_regs regs, unsigned long * s · 7 unmodified lines
218	{	221	{
219	const unsigned cpu = safe_smp_processor_id();	222	const unsigned cpu = safe_smp_processor_id();
220	unsigned long irqstack_end = (unsigned long )cpu_pda(cpu)->irqstackptr;	223	unsigned long irqstack_end = (unsigned long )cpu_pda(cpu)->irqstackptr;
221	int i;	224	int i = 11;
222	unsigned used = 0;	225	unsigned used = 0;
223	struct unwind_frame_info info;
224		226
225	printk("\nCall Trace:");	227	printk("\nCall Trace:");
226		228
227	if (!tsk)	229	if (!tsk)
228	tsk = current;	230	tsk = current;
229		231
230	if (regs) {	232	if (call_trace >= 0) {
231	if (unwind_init_frame_info(&info, tsk, regs) == 0) {	233	int unw_ret = 0;
232	show_trace_unwind(&info, NULL);	234	struct unwind_frame_info info;
233	return;	235
		236	if (regs) {
		237	if (unwind_init_frame_info(&info, tsk, regs) == 0)
		238	unw_ret = show_trace_unwind(&info, NULL);
		239	} else if (tsk == current)
		240	unw_ret = unwind_init_running(&info, show_trace_unwind, NULL);
		241	else {
		242	if (unwind_init_blocked(&info, tsk) == 0)
		243	unw_ret = show_trace_unwind(&info, NULL);
234	}	244	}
235	} else if (tsk == current) {	245	if (unw_ret > 0) {
236	if (unwind_init_running(&info, show_trace_unwind, NULL) == 0)	246	if (call_trace > 0)
237	return;	247	return;
238	} else {	248	printk("Legacy call trace:");
239	if (unwind_init_blocked(&info, tsk) == 0) {	249	i = 18;
240	show_trace_unwind(&info, NULL);
241	return;
242	}	250	}
243	}	251	}
244		252
@@ -264,7 +272,7 @@ void show_trace(struct task_struct tsk, struct pt_regs regs, unsigned long * s · 19 unmodified lines
264	} \	272	} \
265	} while (0)	273	} while (0)
266		274
267	for(i = 11; ; ) {	275	for(; ; ) {
268	const char *id;	276	const char *id;
269	unsigned long *estack_end;	277	unsigned long *estack_end;
270	estack_end = in_exception_stack(cpu, (unsigned long)stack,	278	estack_end = in_exception_stack(cpu, (unsigned long)stack,
@@ -1052,3 +1060,14 @@ static int __init kstack_setup(char *s) · 781 unmodified lines
1052	}	1060	}
1053	__setup("kstack=", kstack_setup);	1061	__setup("kstack=", kstack_setup);
1054		1062
		1063	static int __init call_trace_setup(char *s)
		1064	{
		1065	if (strcmp(s, "old") == 0)
		1066	call_trace = -1;
		1067	else if (strcmp(s, "both") == 0)
		1068	call_trace = 0;
		1069	else if (strcmp(s, "new") == 0)
		1070	call_trace = 1;
		1071	return 1;
		1072	}
		1073	__setup("call_trace=", call_trace_setup);

include/asm-i386/unwind.h+4−4

@@ -66,10 +66,10 @@ static inline void arch_unw_init_blocked(struct unwind_frame_info *info) · 65 unmodified lines
66	info->regs.xes = __USER_DS;	66	info->regs.xes = __USER_DS;
67	}	67	}
68		68
69	extern asmlinkage void arch_unwind_init_running(struct unwind_frame_info *,	69	extern asmlinkage int arch_unwind_init_running(struct unwind_frame_info *,
70	asmlinkage void (callback)(struct unwind_frame_info ,	70	asmlinkage int (callback)(struct unwind_frame_info ,
71	void *arg),	71	void *arg),
72	void *arg);	72	void *arg);
73		73
74	static inline int arch_unw_user_mode(const struct unwind_frame_info *info)	74	static inline int arch_unw_user_mode(const struct unwind_frame_info *info)
75	{	75	{

include/asm-x86_64/unwind.h+4−4

@@ -75,10 +75,10 @@ static inline void arch_unw_init_blocked(struct unwind_frame_info *info) · 74 unmodified lines
75	info->regs.ss = __KERNEL_DS;	75	info->regs.ss = __KERNEL_DS;
76	}	76	}
77		77
78	extern void arch_unwind_init_running(struct unwind_frame_info *,	78	extern int arch_unwind_init_running(struct unwind_frame_info *,
79	void (callback)(struct unwind_frame_info ,	79	int (callback)(struct unwind_frame_info ,
80	void *arg),	80	void *arg),
81	void *arg);	81	void *arg);
82		82
83	static inline int arch_unw_user_mode(const struct unwind_frame_info *info)	83	static inline int arch_unw_user_mode(const struct unwind_frame_info *info)
84	{	84	{

include/linux/unwind.h+4−4

@@ -49,8 +49,8 @@ extern int unwind_init_blocked(struct unwind_frame_info *, · 48 unmodified lines
49	* Prepare to unwind the currently running thread.	49	* Prepare to unwind the currently running thread.
50	*/	50	*/
51	extern int unwind_init_running(struct unwind_frame_info *,	51	extern int unwind_init_running(struct unwind_frame_info *,
52	asmlinkage void (callback)(struct unwind_frame_info ,	52	asmlinkage int (callback)(struct unwind_frame_info ,
53	void *arg),	53	void *arg),
54	void *arg);	54	void *arg);
55		55
56	/*	56	/*
@@ -97,8 +97,8 @@ static inline int unwind_init_blocked(struct unwind_frame_info *info, · 40 unmodified lines
97	}	97	}
98		98
99	static inline int unwind_init_running(struct unwind_frame_info *info,	99	static inline int unwind_init_running(struct unwind_frame_info *info,
100	asmlinkage void (cb)(struct unwind_frame_info ,	100	asmlinkage int (cb)(struct unwind_frame_info ,
101	void *arg),	101	void *arg),
102	void *arg)	102	void *arg)
103	{	103	{
104	return -ENOSYS;	104	return -ENOSYS;

kernel/unwind.c+3−4

  * Prepare to unwind the currently running thread.
  */
 int unwind_init_running(struct unwind_frame_info *info,
-                        asmlinkage void (*callback)(struct unwind_frame_info *,
+                        asmlinkage int (*callback)(struct unwind_frame_info *,
-                                                    void *arg),
+                                                   void *arg),
                         void *arg)
 {
 	info->task = current;
-	arch_unwind_init_running(info, callback, arg);
-	return 0;
+	return arch_unwind_init_running(info, callback, arg);
 }
 EXPORT_SYMBOL(unwind_init_running);