2 * Stack trace management functions
4 * Copyright (C) 2006-2009 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
6 #include <linux/sched.h>
7 #include <linux/stacktrace.h>
8 #include <linux/module.h>
9 #include <linux/uaccess.h>
10 #include <asm/stacktrace.h>
12 static void save_stack_warning(void *data, char *msg)
17 save_stack_warning_symbol(void *data, char *msg, unsigned long symbol)
21 static int save_stack_stack(void *data, char *name)
26 static void save_stack_address(void *data, unsigned long addr, int reliable)
28 struct stack_trace *trace = data;
31 if (trace->skip > 0) {
35 if (trace->nr_entries < trace->max_entries)
36 trace->entries[trace->nr_entries++] = addr;
40 save_stack_address_nosched(void *data, unsigned long addr, int reliable)
42 struct stack_trace *trace = (struct stack_trace *)data;
45 if (in_sched_functions(addr))
47 if (trace->skip > 0) {
51 if (trace->nr_entries < trace->max_entries)
52 trace->entries[trace->nr_entries++] = addr;
55 static const struct stacktrace_ops save_stack_ops = {
56 .warning = save_stack_warning,
57 .warning_symbol = save_stack_warning_symbol,
58 .stack = save_stack_stack,
59 .address = save_stack_address,
60 .walk_stack = print_context_stack,
63 static const struct stacktrace_ops save_stack_ops_nosched = {
64 .warning = save_stack_warning,
65 .warning_symbol = save_stack_warning_symbol,
66 .stack = save_stack_stack,
67 .address = save_stack_address_nosched,
68 .walk_stack = print_context_stack,
72 * Save stack-backtrace addresses into a stack_trace buffer.
74 void save_stack_trace(struct stack_trace *trace)
76 dump_trace(current, NULL, NULL, 0, &save_stack_ops, trace);
77 if (trace->nr_entries < trace->max_entries)
78 trace->entries[trace->nr_entries++] = ULONG_MAX;
80 EXPORT_SYMBOL_GPL(save_stack_trace);
82 void save_stack_trace_bp(struct stack_trace *trace, unsigned long bp)
84 dump_trace(current, NULL, NULL, bp, &save_stack_ops, trace);
85 if (trace->nr_entries < trace->max_entries)
86 trace->entries[trace->nr_entries++] = ULONG_MAX;
89 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
91 dump_trace(tsk, NULL, NULL, 0, &save_stack_ops_nosched, trace);
92 if (trace->nr_entries < trace->max_entries)
93 trace->entries[trace->nr_entries++] = ULONG_MAX;
95 EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
97 /* Userspace stacktrace - based on kernel/trace/trace_sysprof.c */
100 const void __user *next_fp;
101 unsigned long ret_addr;
104 static int copy_stack_frame(const void __user *fp, struct stack_frame *frame)
108 if (!access_ok(VERIFY_READ, fp, sizeof(*frame)))
113 if (__copy_from_user_inatomic(frame, fp, sizeof(*frame)))
120 static inline void __save_stack_trace_user(struct stack_trace *trace)
122 const struct pt_regs *regs = task_pt_regs(current);
123 const void __user *fp = (const void __user *)regs->bp;
125 if (trace->nr_entries < trace->max_entries)
126 trace->entries[trace->nr_entries++] = regs->ip;
128 while (trace->nr_entries < trace->max_entries) {
129 struct stack_frame frame;
131 frame.next_fp = NULL;
133 if (!copy_stack_frame(fp, &frame))
135 if ((unsigned long)fp < regs->sp)
137 if (frame.ret_addr) {
138 trace->entries[trace->nr_entries++] =
141 if (fp == frame.next_fp)
147 void save_stack_trace_user(struct stack_trace *trace)
150 * Trace user stack if we are not a kernel thread
153 __save_stack_trace_user(trace);
155 if (trace->nr_entries < trace->max_entries)
156 trace->entries[trace->nr_entries++] = ULONG_MAX;