2 * arch/i386/kernel/stacktrace.c
4 * Stack trace management functions
6 * Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
8 #include <linux/sched.h>
9 #include <linux/stacktrace.h>
11 static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
13 return p > (void *)tinfo &&
14 p < (void *)tinfo + THREAD_SIZE - 3;
18 * Save stack-backtrace addresses into a stack_trace buffer:
20 static inline unsigned long
21 save_context_stack(struct stack_trace *trace, unsigned int skip,
22 struct thread_info *tinfo, unsigned long *stack,
27 #ifdef CONFIG_FRAME_POINTER
28 while (valid_stack_ptr(tinfo, (void *)ebp)) {
29 addr = *(unsigned long *)(ebp + 4);
31 trace->entries[trace->nr_entries++] = addr;
34 if (trace->nr_entries >= trace->max_entries)
37 * break out of recursive entries (such as
38 * end_of_stack_stop_unwind_function):
40 if (ebp == *(unsigned long *)ebp)
43 ebp = *(unsigned long *)ebp;
46 while (valid_stack_ptr(tinfo, stack)) {
48 if (__kernel_text_address(addr)) {
50 trace->entries[trace->nr_entries++] = addr;
53 if (trace->nr_entries >= trace->max_entries)
63 * Save stack-backtrace addresses into a stack_trace buffer.
64 * If all_contexts is set, all contexts (hardirq, softirq and process)
65 * are saved. If not set then only the current context is saved.
67 void save_stack_trace(struct stack_trace *trace,
68 struct task_struct *task, int all_contexts,
72 unsigned long *stack = &ebp;
74 WARN_ON(trace->nr_entries || !trace->max_entries);
76 if (!task || task == current) {
77 /* Grab ebp right from our regs: */
78 asm ("movl %%ebp, %0" : "=r" (ebp));
80 /* ebp is the last reg pushed by switch_to(): */
81 ebp = *(unsigned long *) task->thread.esp;
85 struct thread_info *context = (struct thread_info *)
86 ((unsigned long)stack & (~(THREAD_SIZE - 1)));
88 ebp = save_context_stack(trace, skip, context, stack, ebp);
89 stack = (unsigned long *)context->previous_esp;
90 if (!all_contexts || !stack ||
91 trace->nr_entries >= trace->max_entries)
93 trace->entries[trace->nr_entries++] = ULONG_MAX;
94 if (trace->nr_entries >= trace->max_entries)