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7743a536be
Commit028a690a1e"i386: Remove unneeded test of 'task' in dump_trace()" correctly removed the unneeded 'task != NULL' check because it would be set to current if it was NULL. Commit2bc5f927d4"i386: split out dumpstack code from traps_32.c" moved the code from traps_32.c to its own file dump_stack.c for preparation of the i386 / x86_64 merge. Commit8a541665b9"dumpstack: x86: various small unification steps" worked to make i386 and x86_64 dump_stack logic similar. But this actually reverted the correct change from028a690a1e. Commitd0caf29250"x86/dumpstack: Remove unneeded check in dump_trace()" removed the unneeded "task != NULL" check for x86_64 but left that same unneeded check for i386, that was added because x86_64 had it! This chain of events ironically had i386 add back the unneeded task != NULL check because x86_64 did it, and then the fix for x86_64 was fixed by Dan. And even more ironically, it was Dan's smatch bot that told me that a change to dump_stack_32 I made may be wrong if current can be NULL (it can't), as there was a check for it by assigning task to current, and then checking if task is NULL. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Alexander van Heukelum <heukelum@fastmail.fm> Cc: Jesper Juhl <jesper.juhl@gmail.com> Link: http://lkml.kernel.org/r/20140307105242.79a0befd@gandalf.local.home Signed-off-by: Ingo Molnar <mingo@kernel.org>
139 lines
2.8 KiB
C
139 lines
2.8 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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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 != current)
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stack = (unsigned long *)task->thread.sp;
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}
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if (!bp)
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bp = stack_frame(task, regs);
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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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pr_cont("\n");
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pr_cont(" %08lx", *stack++);
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touch_nmi_watchdog();
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}
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pr_cont("\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_regs(struct pt_regs *regs)
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{
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int i;
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show_regs_print_info(KERN_EMERG);
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__show_regs(regs, !user_mode_vm(regs));
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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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pr_emerg("Stack:\n");
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show_stack_log_lvl(NULL, regs, ®s->sp, 0, KERN_EMERG);
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pr_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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pr_cont(" 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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pr_cont(" <%02x>", c);
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else
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pr_cont(" %02x", c);
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}
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}
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pr_cont("\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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