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1924600cdb
If the PC was ret_from_irq or ret_from_exception, there will be no more normal stackframe. Instead of stopping the unwinding, use PC and RA saved by an exception handler to continue unwinding into the interrupted context. This also simplifies the CONFIG_STACKTRACE code. Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
86 lines
1.9 KiB
C
86 lines
1.9 KiB
C
/*
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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 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 (trace->skip > 0)
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trace->skip--;
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else
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trace->entries[trace->nr_entries++] = addr;
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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 void save_context_stack(struct stack_trace *trace,
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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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if (raw_show_trace || !__kernel_text_address(pc)) {
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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 && sp >= stack_page &&
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sp <= stack_page + THREAD_SIZE - 32)
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save_raw_context_stack(trace, sp);
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return;
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}
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do {
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if (trace->skip > 0)
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trace->skip--;
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else
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trace->entries[trace->nr_entries++] = pc;
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if (trace->nr_entries >= trace->max_entries)
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break;
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pc = unwind_stack(task, &sp, pc, &ra);
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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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}
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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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void save_stack_trace(struct stack_trace *trace, struct task_struct *task)
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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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save_context_stack(trace, task, regs);
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}
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