xref: /openbmc/linux/arch/x86/kernel/stacktrace.c (revision 8594698ebddeef5443b7da8258ae33b3eaca61d5)
1250c2277SThomas Gleixner /*
2250c2277SThomas Gleixner  * Stack trace management functions
3250c2277SThomas Gleixner  *
4250c2277SThomas Gleixner  *  Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
5250c2277SThomas Gleixner  */
6250c2277SThomas Gleixner #include <linux/sched.h>
7250c2277SThomas Gleixner #include <linux/stacktrace.h>
8250c2277SThomas Gleixner #include <linux/module.h>
9250c2277SThomas Gleixner #include <asm/stacktrace.h>
10250c2277SThomas Gleixner 
11250c2277SThomas Gleixner static void save_stack_warning(void *data, char *msg)
12250c2277SThomas Gleixner {
13250c2277SThomas Gleixner }
14250c2277SThomas Gleixner 
15250c2277SThomas Gleixner static void
16250c2277SThomas Gleixner save_stack_warning_symbol(void *data, char *msg, unsigned long symbol)
17250c2277SThomas Gleixner {
18250c2277SThomas Gleixner }
19250c2277SThomas Gleixner 
20250c2277SThomas Gleixner static int save_stack_stack(void *data, char *name)
21250c2277SThomas Gleixner {
22250c2277SThomas Gleixner 	return -1;
23250c2277SThomas Gleixner }
24250c2277SThomas Gleixner 
25bc850d6bSArjan van de Ven static void save_stack_address(void *data, unsigned long addr, int reliable)
26250c2277SThomas Gleixner {
27ade1af77SJan Engelhardt 	struct stack_trace *trace = data;
281650743cSVegard Nossum 	if (!reliable)
291650743cSVegard Nossum 		return;
30250c2277SThomas Gleixner 	if (trace->skip > 0) {
31250c2277SThomas Gleixner 		trace->skip--;
32250c2277SThomas Gleixner 		return;
33250c2277SThomas Gleixner 	}
34250c2277SThomas Gleixner 	if (trace->nr_entries < trace->max_entries)
35250c2277SThomas Gleixner 		trace->entries[trace->nr_entries++] = addr;
36250c2277SThomas Gleixner }
37250c2277SThomas Gleixner 
385bc27dc2SArjan van de Ven static void
395bc27dc2SArjan van de Ven save_stack_address_nosched(void *data, unsigned long addr, int reliable)
409745512cSArjan van de Ven {
419745512cSArjan van de Ven 	struct stack_trace *trace = (struct stack_trace *)data;
421650743cSVegard Nossum 	if (!reliable)
431650743cSVegard Nossum 		return;
449745512cSArjan van de Ven 	if (in_sched_functions(addr))
459745512cSArjan van de Ven 		return;
469745512cSArjan van de Ven 	if (trace->skip > 0) {
479745512cSArjan van de Ven 		trace->skip--;
489745512cSArjan van de Ven 		return;
499745512cSArjan van de Ven 	}
509745512cSArjan van de Ven 	if (trace->nr_entries < trace->max_entries)
519745512cSArjan van de Ven 		trace->entries[trace->nr_entries++] = addr;
529745512cSArjan van de Ven }
539745512cSArjan van de Ven 
549689ba8aSJan Beulich static const struct stacktrace_ops save_stack_ops = {
55250c2277SThomas Gleixner 	.warning = save_stack_warning,
56250c2277SThomas Gleixner 	.warning_symbol = save_stack_warning_symbol,
57250c2277SThomas Gleixner 	.stack = save_stack_stack,
58250c2277SThomas Gleixner 	.address = save_stack_address,
59250c2277SThomas Gleixner };
60250c2277SThomas Gleixner 
619745512cSArjan van de Ven static const struct stacktrace_ops save_stack_ops_nosched = {
629745512cSArjan van de Ven 	.warning = save_stack_warning,
639745512cSArjan van de Ven 	.warning_symbol = save_stack_warning_symbol,
649745512cSArjan van de Ven 	.stack = save_stack_stack,
659745512cSArjan van de Ven 	.address = save_stack_address_nosched,
669745512cSArjan van de Ven };
679745512cSArjan van de Ven 
68250c2277SThomas Gleixner /*
69250c2277SThomas Gleixner  * Save stack-backtrace addresses into a stack_trace buffer.
70250c2277SThomas Gleixner  */
71250c2277SThomas Gleixner void save_stack_trace(struct stack_trace *trace)
72250c2277SThomas Gleixner {
735bc27dc2SArjan van de Ven 	dump_trace(current, NULL, NULL, 0, &save_stack_ops, trace);
74250c2277SThomas Gleixner 	if (trace->nr_entries < trace->max_entries)
75250c2277SThomas Gleixner 		trace->entries[trace->nr_entries++] = ULONG_MAX;
76250c2277SThomas Gleixner }
77*8594698eSIngo Molnar EXPORT_SYMBOL_GPL(save_stack_trace);
789745512cSArjan van de Ven 
799745512cSArjan van de Ven void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
809745512cSArjan van de Ven {
815bc27dc2SArjan van de Ven 	dump_trace(tsk, NULL, NULL, 0, &save_stack_ops_nosched, trace);
829745512cSArjan van de Ven 	if (trace->nr_entries < trace->max_entries)
839745512cSArjan van de Ven 		trace->entries[trace->nr_entries++] = ULONG_MAX;
849745512cSArjan van de Ven }
85*8594698eSIngo Molnar EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
86