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61c1917f47
The current print_context_stack helper that does the stack walking job is good for usual stacktraces as it walks through all the stack and reports even addresses that look unreliable, which is nice when we don't have frame pointers for example. But we have users like perf that only require reliable stacktraces, and those may want a more adapted stack walker, so lets make this function a callback in stacktrace_ops that users can tune for their needs. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1261024834-5336-1-git-send-regression-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
159 lines
3.3 KiB
C
159 lines
3.3 KiB
C
/*
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* Copyright (C) 1991, 1992 Linus Torvalds
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* Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
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*/
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#include <linux/kallsyms.h>
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#include <linux/kprobes.h>
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#include <linux/uaccess.h>
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#include <linux/hardirq.h>
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#include <linux/kdebug.h>
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#include <linux/module.h>
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#include <linux/ptrace.h>
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#include <linux/kexec.h>
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#include <linux/sysfs.h>
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#include <linux/bug.h>
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#include <linux/nmi.h>
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#include <asm/stacktrace.h>
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#include "dumpstack.h"
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/* Just a stub for now */
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int x86_is_stack_id(int id, char *name)
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{
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return 0;
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}
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void dump_trace(struct task_struct *task, struct pt_regs *regs,
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unsigned long *stack, unsigned long bp,
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const struct stacktrace_ops *ops, void *data)
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{
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int graph = 0;
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if (!task)
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task = current;
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if (!stack) {
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unsigned long dummy;
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stack = &dummy;
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if (task && task != current)
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stack = (unsigned long *)task->thread.sp;
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}
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#ifdef CONFIG_FRAME_POINTER
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if (!bp) {
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if (task == current) {
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/* Grab bp right from our regs */
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get_bp(bp);
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} else {
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/* bp is the last reg pushed by switch_to */
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bp = *(unsigned long *) task->thread.sp;
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}
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}
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#endif
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for (;;) {
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struct thread_info *context;
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context = (struct thread_info *)
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((unsigned long)stack & (~(THREAD_SIZE - 1)));
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bp = ops->walk_stack(context, stack, bp, ops, data, NULL, &graph);
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stack = (unsigned long *)context->previous_esp;
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if (!stack)
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break;
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if (ops->stack(data, "IRQ") < 0)
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break;
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touch_nmi_watchdog();
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}
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}
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EXPORT_SYMBOL(dump_trace);
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void
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show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
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unsigned long *sp, unsigned long bp, char *log_lvl)
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{
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unsigned long *stack;
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int i;
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if (sp == NULL) {
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if (task)
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sp = (unsigned long *)task->thread.sp;
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else
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sp = (unsigned long *)&sp;
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}
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stack = sp;
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for (i = 0; i < kstack_depth_to_print; i++) {
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if (kstack_end(stack))
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break;
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if (i && ((i % STACKSLOTS_PER_LINE) == 0))
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printk("\n%s", log_lvl);
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printk(" %08lx", *stack++);
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touch_nmi_watchdog();
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}
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printk("\n");
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show_trace_log_lvl(task, regs, sp, bp, log_lvl);
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}
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void show_registers(struct pt_regs *regs)
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{
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int i;
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print_modules();
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__show_regs(regs, 0);
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printk(KERN_EMERG "Process %.*s (pid: %d, ti=%p task=%p task.ti=%p)\n",
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TASK_COMM_LEN, current->comm, task_pid_nr(current),
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current_thread_info(), current, task_thread_info(current));
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/*
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* When in-kernel, we also print out the stack and code at the
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* time of the fault..
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*/
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if (!user_mode_vm(regs)) {
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unsigned int code_prologue = code_bytes * 43 / 64;
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unsigned int code_len = code_bytes;
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unsigned char c;
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u8 *ip;
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printk(KERN_EMERG "Stack:\n");
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show_stack_log_lvl(NULL, regs, ®s->sp,
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0, KERN_EMERG);
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printk(KERN_EMERG "Code: ");
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ip = (u8 *)regs->ip - code_prologue;
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if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
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/* try starting at IP */
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ip = (u8 *)regs->ip;
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code_len = code_len - code_prologue + 1;
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}
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for (i = 0; i < code_len; i++, ip++) {
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if (ip < (u8 *)PAGE_OFFSET ||
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probe_kernel_address(ip, c)) {
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printk(" Bad EIP value.");
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break;
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}
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if (ip == (u8 *)regs->ip)
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printk("<%02x> ", c);
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else
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printk("%02x ", c);
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}
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}
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printk("\n");
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}
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int is_valid_bugaddr(unsigned long ip)
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{
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unsigned short ud2;
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if (ip < PAGE_OFFSET)
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return 0;
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if (probe_kernel_address((unsigned short *)ip, ud2))
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return 0;
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return ud2 == 0x0b0f;
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}
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