96 lines
2.4 KiB
C
96 lines
2.4 KiB
C
/*
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* Stack trace management functions
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*
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* Copyright IBM Corp. 2006
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* Author(s): Heiko Carstens <heiko.carstens@de.ibm.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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#include <linux/kallsyms.h>
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#include <linux/module.h>
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static unsigned long save_context_stack(struct stack_trace *trace,
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unsigned long sp,
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unsigned long low,
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unsigned long high,
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int savesched)
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{
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struct stack_frame *sf;
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struct pt_regs *regs;
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unsigned long addr;
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while(1) {
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sp &= PSW_ADDR_INSN;
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if (sp < low || sp > high)
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return sp;
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sf = (struct stack_frame *)sp;
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while(1) {
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addr = sf->gprs[8] & PSW_ADDR_INSN;
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if (!trace->skip)
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trace->entries[trace->nr_entries++] = addr;
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else
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trace->skip--;
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if (trace->nr_entries >= trace->max_entries)
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return sp;
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low = sp;
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sp = sf->back_chain & PSW_ADDR_INSN;
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if (!sp)
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break;
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if (sp <= low || sp > high - sizeof(*sf))
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return sp;
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sf = (struct stack_frame *)sp;
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}
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/* Zero backchain detected, check for interrupt frame. */
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sp = (unsigned long)(sf + 1);
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if (sp <= low || sp > high - sizeof(*regs))
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return sp;
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regs = (struct pt_regs *)sp;
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addr = regs->psw.addr & PSW_ADDR_INSN;
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if (savesched || !in_sched_functions(addr)) {
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if (!trace->skip)
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trace->entries[trace->nr_entries++] = addr;
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else
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trace->skip--;
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}
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if (trace->nr_entries >= trace->max_entries)
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return sp;
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low = sp;
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sp = regs->gprs[15];
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}
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}
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void save_stack_trace(struct stack_trace *trace)
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{
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register unsigned long sp asm ("15");
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unsigned long orig_sp, new_sp;
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orig_sp = sp & PSW_ADDR_INSN;
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new_sp = save_context_stack(trace, orig_sp,
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S390_lowcore.panic_stack - PAGE_SIZE,
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S390_lowcore.panic_stack, 1);
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if (new_sp != orig_sp)
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return;
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new_sp = save_context_stack(trace, new_sp,
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S390_lowcore.async_stack - ASYNC_SIZE,
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S390_lowcore.async_stack, 1);
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if (new_sp != orig_sp)
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return;
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save_context_stack(trace, new_sp,
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S390_lowcore.thread_info,
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S390_lowcore.thread_info + THREAD_SIZE, 1);
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}
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EXPORT_SYMBOL_GPL(save_stack_trace);
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void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
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{
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unsigned long sp, low, high;
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sp = tsk->thread.ksp & PSW_ADDR_INSN;
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low = (unsigned long) task_stack_page(tsk);
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high = (unsigned long) task_pt_regs(tsk);
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save_context_stack(trace, sp, low, high, 0);
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if (trace->nr_entries < trace->max_entries)
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trace->entries[trace->nr_entries++] = ULONG_MAX;
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}
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EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
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