/* * arch/s390/kernel/stacktrace.c * * Stack trace management functions * * Copyright (C) IBM Corp. 2006 * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com> */ #include <linux/sched.h> #include <linux/stacktrace.h> #include <linux/kallsyms.h> #include <linux/module.h> static unsigned long save_context_stack(struct stack_trace *trace, unsigned long sp, unsigned long low, unsigned long high, int savesched) { struct stack_frame *sf; struct pt_regs *regs; unsigned long addr; while(1) { sp &= PSW_ADDR_INSN; if (sp < low || sp > high) return sp; sf = (struct stack_frame *)sp; while(1) { addr = sf->gprs[8] & PSW_ADDR_INSN; if (!trace->skip) trace->entries[trace->nr_entries++] = addr; else trace->skip--; if (trace->nr_entries >= trace->max_entries) return sp; low = sp; sp = sf->back_chain & PSW_ADDR_INSN; if (!sp) break; if (sp <= low || sp > high - sizeof(*sf)) return sp; sf = (struct stack_frame *)sp; } /* Zero backchain detected, check for interrupt frame. */ sp = (unsigned long)(sf + 1); if (sp <= low || sp > high - sizeof(*regs)) return sp; regs = (struct pt_regs *)sp; addr = regs->psw.addr & PSW_ADDR_INSN; if (savesched || !in_sched_functions(addr)) { if (!trace->skip) trace->entries[trace->nr_entries++] = addr; else trace->skip--; } if (trace->nr_entries >= trace->max_entries) return sp; low = sp; sp = regs->gprs[15]; } } void save_stack_trace(struct stack_trace *trace) { register unsigned long sp asm ("15"); unsigned long orig_sp, new_sp; orig_sp = sp & PSW_ADDR_INSN; new_sp = save_context_stack(trace, orig_sp, S390_lowcore.panic_stack - PAGE_SIZE, S390_lowcore.panic_stack, 1); if (new_sp != orig_sp) return; new_sp = save_context_stack(trace, new_sp, S390_lowcore.async_stack - ASYNC_SIZE, S390_lowcore.async_stack, 1); if (new_sp != orig_sp) return; save_context_stack(trace, new_sp, S390_lowcore.thread_info, S390_lowcore.thread_info + THREAD_SIZE, 1); } EXPORT_SYMBOL_GPL(save_stack_trace); void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) { unsigned long sp, low, high; sp = tsk->thread.ksp & PSW_ADDR_INSN; low = (unsigned long) task_stack_page(tsk); high = (unsigned long) task_pt_regs(tsk); save_context_stack(trace, sp, low, high, 0); if (trace->nr_entries < trace->max_entries) trace->entries[trace->nr_entries++] = ULONG_MAX; } EXPORT_SYMBOL_GPL(save_stack_trace_tsk);