99 lines
2.4 KiB
C
99 lines
2.4 KiB
C
/*
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* arch/i386/kernel/stacktrace.c
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*
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* Stack trace management functions
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*
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* Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
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*/
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#include <linux/sched.h>
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#include <linux/stacktrace.h>
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static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
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{
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return p > (void *)tinfo &&
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p < (void *)tinfo + THREAD_SIZE - 3;
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}
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/*
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* Save stack-backtrace addresses into a stack_trace buffer:
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*/
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static inline unsigned long
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save_context_stack(struct stack_trace *trace, unsigned int skip,
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struct thread_info *tinfo, unsigned long *stack,
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unsigned long ebp)
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{
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unsigned long addr;
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#ifdef CONFIG_FRAME_POINTER
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while (valid_stack_ptr(tinfo, (void *)ebp)) {
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addr = *(unsigned long *)(ebp + 4);
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if (!skip)
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trace->entries[trace->nr_entries++] = addr;
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else
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skip--;
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if (trace->nr_entries >= trace->max_entries)
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break;
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/*
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* break out of recursive entries (such as
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* end_of_stack_stop_unwind_function):
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*/
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if (ebp == *(unsigned long *)ebp)
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break;
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ebp = *(unsigned long *)ebp;
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}
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#else
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while (valid_stack_ptr(tinfo, stack)) {
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addr = *stack++;
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if (__kernel_text_address(addr)) {
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if (!skip)
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trace->entries[trace->nr_entries++] = addr;
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else
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skip--;
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if (trace->nr_entries >= trace->max_entries)
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break;
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}
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}
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#endif
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return ebp;
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}
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/*
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* Save stack-backtrace addresses into a stack_trace buffer.
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* If all_contexts is set, all contexts (hardirq, softirq and process)
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* are saved. If not set then only the current context is saved.
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*/
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void save_stack_trace(struct stack_trace *trace,
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struct task_struct *task, int all_contexts,
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unsigned int skip)
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{
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unsigned long ebp;
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unsigned long *stack = &ebp;
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WARN_ON(trace->nr_entries || !trace->max_entries);
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if (!task || task == current) {
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/* Grab ebp right from our regs: */
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asm ("movl %%ebp, %0" : "=r" (ebp));
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} else {
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/* ebp is the last reg pushed by switch_to(): */
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ebp = *(unsigned long *) task->thread.esp;
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}
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while (1) {
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struct thread_info *context = (struct thread_info *)
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((unsigned long)stack & (~(THREAD_SIZE - 1)));
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ebp = save_context_stack(trace, skip, context, stack, ebp);
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stack = (unsigned long *)context->previous_esp;
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if (!all_contexts || !stack ||
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trace->nr_entries >= trace->max_entries)
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break;
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trace->entries[trace->nr_entries++] = ULONG_MAX;
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if (trace->nr_entries >= trace->max_entries)
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break;
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}
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}
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