f72c22e45e
As UML uses an alternative signal stack we cannot use the current stack pointer for stack dumping if UML itself dies by SIGSEGV. To bypass this issue we save regs taken from mcontext in our segv handler into thread_struct and use these regs to obtain the stack pointer in show_stack(). Signed-off-by: Richard Weinberger <richard@nod.at>
102 lines
2.5 KiB
C
102 lines
2.5 KiB
C
/*
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* Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
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* Copyright (C) 2013 Richard Weinberger <richrd@nod.at>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/kallsyms.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <asm/sysrq.h>
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#include <os.h>
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struct stack_frame {
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struct stack_frame *next_frame;
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unsigned long return_address;
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};
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static void print_stack_trace(unsigned long *sp, unsigned long bp)
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{
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int reliable;
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unsigned long addr;
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struct stack_frame *frame = (struct stack_frame *)bp;
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printk(KERN_INFO "Call Trace:\n");
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while (((long) sp & (THREAD_SIZE-1)) != 0) {
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addr = *sp;
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if (__kernel_text_address(addr)) {
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reliable = 0;
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if ((unsigned long) sp == bp + sizeof(long)) {
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frame = frame ? frame->next_frame : NULL;
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bp = (unsigned long)frame;
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reliable = 1;
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}
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printk(KERN_INFO " [<%08lx>]", addr);
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printk(KERN_CONT " %s", reliable ? "" : "? ");
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print_symbol(KERN_CONT "%s", addr);
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printk(KERN_CONT "\n");
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}
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sp++;
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}
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printk(KERN_INFO "\n");
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}
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/*Stolen from arch/i386/kernel/traps.c */
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static const int kstack_depth_to_print = 24;
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static unsigned long get_frame_pointer(struct task_struct *task,
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struct pt_regs *segv_regs)
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{
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if (!task || task == current)
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return segv_regs ? PT_REGS_BP(segv_regs) : current_bp();
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else
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return KSTK_EBP(task);
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}
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static unsigned long *get_stack_pointer(struct task_struct *task,
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struct pt_regs *segv_regs)
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{
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if (!task || task == current)
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return segv_regs ? (unsigned long *)PT_REGS_SP(segv_regs) : current_sp();
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else
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return (unsigned long *)KSTK_ESP(task);
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}
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void show_stack(struct task_struct *task, unsigned long *stack)
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{
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unsigned long *sp = stack, bp = 0;
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struct pt_regs *segv_regs = current->thread.segv_regs;
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int i;
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if (!segv_regs && os_is_signal_stack()) {
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printk(KERN_ERR "Received SIGSEGV in SIGSEGV handler,"
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" aborting stack trace!\n");
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return;
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}
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#ifdef CONFIG_FRAME_POINTER
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bp = get_frame_pointer(task, segv_regs);
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#endif
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if (!stack)
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sp = get_stack_pointer(task, segv_regs);
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printk(KERN_INFO "Stack:\n");
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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(KERN_CONT "\n");
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printk(KERN_CONT " %08lx", *stack++);
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}
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printk(KERN_CONT "\n");
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print_stack_trace(sp, bp);
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}
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