112 lines
2.6 KiB
C
112 lines
2.6 KiB
C
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/*
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* arch/mips/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 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
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*/
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#include <linux/sched.h>
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#include <linux/stacktrace.h>
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#include <asm/stacktrace.h>
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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 void save_raw_context_stack(struct stack_trace *trace,
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unsigned int skip, unsigned long reg29)
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{
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unsigned long *sp = (unsigned long *)reg29;
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unsigned long addr;
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while (!kstack_end(sp)) {
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addr = *sp++;
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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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}
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static struct pt_regs * save_context_stack(struct stack_trace *trace,
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unsigned int skip, struct task_struct *task, struct pt_regs *regs)
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{
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unsigned long sp = regs->regs[29];
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#ifdef CONFIG_KALLSYMS
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unsigned long ra = regs->regs[31];
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unsigned long pc = regs->cp0_epc;
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extern void ret_from_irq(void);
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if (raw_show_trace || !__kernel_text_address(pc)) {
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save_raw_context_stack(trace, skip, sp);
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return NULL;
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}
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do {
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if (!skip)
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trace->entries[trace->nr_entries++] = pc;
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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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* If we reached the bottom of interrupt context,
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* return saved pt_regs.
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*/
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if (pc == (unsigned long)ret_from_irq) {
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unsigned long stack_page =
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(unsigned long)task_stack_page(task);
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if (!stack_page ||
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sp < stack_page ||
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sp > stack_page + THREAD_SIZE - 32)
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break;
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return (struct pt_regs *)sp;
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}
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pc = unwind_stack(task, &sp, pc, ra);
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ra = 0;
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} while (pc);
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#else
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save_raw_context_stack(sp);
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#endif
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return NULL;
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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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struct pt_regs dummyregs;
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struct pt_regs *regs = &dummyregs;
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WARN_ON(trace->nr_entries || !trace->max_entries);
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if (task && task != current) {
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regs->regs[29] = task->thread.reg29;
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regs->regs[31] = 0;
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regs->cp0_epc = task->thread.reg31;
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} else {
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if (!task)
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task = current;
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prepare_frametrace(regs);
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}
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while (1) {
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regs = save_context_stack(trace, skip, task, regs);
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if (!all_contexts || !regs ||
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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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skip = 0;
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}
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}
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