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[MIPS] dump_stack() based on prologue code analysis

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Instead of dump all possible address in the stack, unwind the stack frame
based on prologue code analysis, as like as get_wchan() does.  While the
code analysis might fail for some reason, there is a new kernel option
"raw_show_trace" to disable this feature.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Atsushi Nemoto
2006-07-29 23:27:20 +09:00
committed by Ralf Baechle
parent 79495d876c
commit f66686f70a
2 changed files with 141 additions and 23 deletions
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98
arch/mips/kernel/traps.c
View File

@@ -98,24 +98,53 @@ static void show_trace(unsigned long *stack)
printk("\n");
}
#ifdef CONFIG_KALLSYMS
static int raw_show_trace;
static int __init set_raw_show_trace(char *str)
{
raw_show_trace = 1;
return 1;
}
__setup("raw_show_trace", set_raw_show_trace);
extern unsigned long unwind_stack(struct task_struct *task,
unsigned long **sp, unsigned long pc);
static void show_frametrace(struct task_struct *task, struct pt_regs *regs)
{
const int field = 2 * sizeof(unsigned long);
unsigned long *stack = (long *)regs->regs[29];
unsigned long pc = regs->cp0_epc;
int top = 1;
if (raw_show_trace || !__kernel_text_address(pc)) {
show_trace(stack);
return;
}
printk("Call Trace:\n");
while (__kernel_text_address(pc)) {
printk(" [<%0*lx>] ", field, pc);
print_symbol("%s\n", pc);
pc = unwind_stack(task, &stack, pc);
if (top && pc == 0)
pc = regs->regs[31]; /* leaf? */
top = 0;
}
printk("\n");
}
#else
#define show_frametrace(task, r) show_trace((long *)(r)->regs[29]);
#endif
/*
* This routine abuses get_user()/put_user() to reference pointers
* with at least a bit of error checking ...
*/
void show_stack(struct task_struct *task, unsigned long *sp)
static void show_stacktrace(struct task_struct *task, struct pt_regs *regs)
{
const int field = 2 * sizeof(unsigned long);
long stackdata;
int i;
unsigned long *stack;
if (!sp) {
if (task && task != current)
sp = (unsigned long *) task->thread.reg29;
else
sp = (unsigned long *) &sp;
}
stack = sp;
unsigned long *sp = (unsigned long *)regs->regs[29];
printk("Stack :");
i = 0;
@@ -136,7 +165,44 @@ void show_stack(struct task_struct *task, unsigned long *sp)
i++;
}
printk("\n");
show_trace(stack);
show_frametrace(task, regs);
}
static noinline void prepare_frametrace(struct pt_regs *regs)
{
__asm__ __volatile__(
"1: la $2, 1b\n\t"
#ifdef CONFIG_64BIT
"sd $2, %0\n\t"
"sd $29, %1\n\t"
"sd $31, %2\n\t"
#else
"sw $2, %0\n\t"
"sw $29, %1\n\t"
"sw $31, %2\n\t"
#endif
: "=m" (regs->cp0_epc),
"=m" (regs->regs[29]), "=m" (regs->regs[31])
: : "memory");
}
void show_stack(struct task_struct *task, unsigned long *sp)
{
struct pt_regs regs;
if (sp) {
regs.regs[29] = (unsigned long)sp;
regs.regs[31] = 0;
regs.cp0_epc = 0;
} else {
if (task && task != current) {
regs.regs[29] = task->thread.reg29;
regs.regs[31] = 0;
regs.cp0_epc = task->thread.reg31;
} else {
prepare_frametrace(&regs);
}
}
show_stacktrace(task, &regs);
}
/*
@@ -146,6 +212,14 @@ void dump_stack(void)
{
unsigned long stack;
#ifdef CONFIG_KALLSYMS
if (!raw_show_trace) {
struct pt_regs regs;
prepare_frametrace(&regs);
show_frametrace(current, &regs);
return;
}
#endif
show_trace(&stack);
}
@@ -265,7 +339,7 @@ void show_registers(struct pt_regs *regs)
print_modules();
printk("Process %s (pid: %d, threadinfo=%p, task=%p)\n",
current->comm, current->pid, current_thread_info(), current);
show_stack(current, (long *) regs->regs[29]);
show_stacktrace(current, regs);
show_code((unsigned int *) regs->cp0_epc);
printk("\n");
}