
x86_64 uses a per_cpu variable kernel_stack to always point to the thread stack of current. This is where the thread_info is stored and is accessed from this location even when the irq or exception stack is in use. This removes the complexity of having to maintain the thread info on the stack when interrupts are running and having to copy the preempt_count and other fields to the interrupt stack. x86_32 uses the old method of copying the thread_info from the thread stack to the exception stack just before executing the exception. Having the two different requires #ifdefs and also the x86_32 way is a bit of a pain to maintain. By converting x86_32 to the same method of x86_64, we can remove #ifdefs, clean up the x86_32 code a little, and remove the overhead of the copy. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Brian Gerst <brgerst@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20110806012354.263834829@goodmis.org Link: http://lkml.kernel.org/r/20140206144321.852942014@goodmis.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
175 lines
3.5 KiB
C
175 lines
3.5 KiB
C
/*
|
|
* Copyright (C) 1991, 1992 Linus Torvalds
|
|
* Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
|
|
*/
|
|
#include <linux/kallsyms.h>
|
|
#include <linux/kprobes.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/hardirq.h>
|
|
#include <linux/kdebug.h>
|
|
#include <linux/module.h>
|
|
#include <linux/ptrace.h>
|
|
#include <linux/kexec.h>
|
|
#include <linux/sysfs.h>
|
|
#include <linux/bug.h>
|
|
#include <linux/nmi.h>
|
|
|
|
#include <asm/stacktrace.h>
|
|
|
|
static void *is_irq_stack(void *p, void *irq)
|
|
{
|
|
if (p < irq || p >= (irq + THREAD_SIZE))
|
|
return NULL;
|
|
return irq + THREAD_SIZE;
|
|
}
|
|
|
|
|
|
static void *is_hardirq_stack(unsigned long *stack, int cpu)
|
|
{
|
|
void *irq = per_cpu(hardirq_stack, cpu);
|
|
|
|
return is_irq_stack(stack, irq);
|
|
}
|
|
|
|
static void *is_softirq_stack(unsigned long *stack, int cpu)
|
|
{
|
|
void *irq = per_cpu(softirq_stack, cpu);
|
|
|
|
return is_irq_stack(stack, irq);
|
|
}
|
|
|
|
void dump_trace(struct task_struct *task, struct pt_regs *regs,
|
|
unsigned long *stack, unsigned long bp,
|
|
const struct stacktrace_ops *ops, void *data)
|
|
{
|
|
const unsigned cpu = get_cpu();
|
|
int graph = 0;
|
|
u32 *prev_esp;
|
|
|
|
if (!task)
|
|
task = current;
|
|
|
|
if (!stack) {
|
|
unsigned long dummy;
|
|
|
|
stack = &dummy;
|
|
if (task && task != current)
|
|
stack = (unsigned long *)task->thread.sp;
|
|
}
|
|
|
|
if (!bp)
|
|
bp = stack_frame(task, regs);
|
|
|
|
for (;;) {
|
|
struct thread_info *context;
|
|
void *end_stack;
|
|
|
|
end_stack = is_hardirq_stack(stack, cpu);
|
|
if (!end_stack)
|
|
end_stack = is_softirq_stack(stack, cpu);
|
|
|
|
context = task_thread_info(task);
|
|
bp = ops->walk_stack(context, stack, bp, ops, data,
|
|
end_stack, &graph);
|
|
|
|
/* Stop if not on irq stack */
|
|
if (!end_stack)
|
|
break;
|
|
|
|
/* The previous esp is saved on the bottom of the stack */
|
|
prev_esp = (u32 *)(end_stack - THREAD_SIZE);
|
|
stack = (unsigned long *)*prev_esp;
|
|
if (!stack)
|
|
break;
|
|
|
|
if (ops->stack(data, "IRQ") < 0)
|
|
break;
|
|
touch_nmi_watchdog();
|
|
}
|
|
put_cpu();
|
|
}
|
|
EXPORT_SYMBOL(dump_trace);
|
|
|
|
void
|
|
show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
|
|
unsigned long *sp, unsigned long bp, char *log_lvl)
|
|
{
|
|
unsigned long *stack;
|
|
int i;
|
|
|
|
if (sp == NULL) {
|
|
if (task)
|
|
sp = (unsigned long *)task->thread.sp;
|
|
else
|
|
sp = (unsigned long *)&sp;
|
|
}
|
|
|
|
stack = sp;
|
|
for (i = 0; i < kstack_depth_to_print; i++) {
|
|
if (kstack_end(stack))
|
|
break;
|
|
if (i && ((i % STACKSLOTS_PER_LINE) == 0))
|
|
pr_cont("\n");
|
|
pr_cont(" %08lx", *stack++);
|
|
touch_nmi_watchdog();
|
|
}
|
|
pr_cont("\n");
|
|
show_trace_log_lvl(task, regs, sp, bp, log_lvl);
|
|
}
|
|
|
|
|
|
void show_regs(struct pt_regs *regs)
|
|
{
|
|
int i;
|
|
|
|
show_regs_print_info(KERN_EMERG);
|
|
__show_regs(regs, !user_mode_vm(regs));
|
|
|
|
/*
|
|
* When in-kernel, we also print out the stack and code at the
|
|
* time of the fault..
|
|
*/
|
|
if (!user_mode_vm(regs)) {
|
|
unsigned int code_prologue = code_bytes * 43 / 64;
|
|
unsigned int code_len = code_bytes;
|
|
unsigned char c;
|
|
u8 *ip;
|
|
|
|
pr_emerg("Stack:\n");
|
|
show_stack_log_lvl(NULL, regs, ®s->sp, 0, KERN_EMERG);
|
|
|
|
pr_emerg("Code:");
|
|
|
|
ip = (u8 *)regs->ip - code_prologue;
|
|
if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
|
|
/* try starting at IP */
|
|
ip = (u8 *)regs->ip;
|
|
code_len = code_len - code_prologue + 1;
|
|
}
|
|
for (i = 0; i < code_len; i++, ip++) {
|
|
if (ip < (u8 *)PAGE_OFFSET ||
|
|
probe_kernel_address(ip, c)) {
|
|
pr_cont(" Bad EIP value.");
|
|
break;
|
|
}
|
|
if (ip == (u8 *)regs->ip)
|
|
pr_cont(" <%02x>", c);
|
|
else
|
|
pr_cont(" %02x", c);
|
|
}
|
|
}
|
|
pr_cont("\n");
|
|
}
|
|
|
|
int is_valid_bugaddr(unsigned long ip)
|
|
{
|
|
unsigned short ud2;
|
|
|
|
if (ip < PAGE_OFFSET)
|
|
return 0;
|
|
if (probe_kernel_address((unsigned short *)ip, ud2))
|
|
return 0;
|
|
|
|
return ud2 == 0x0b0f;
|
|
}
|