linux/arch/mips/kernel/stacktrace.c
Ralf Baechle 49316cbf0a MIPS: Eleminate filenames from comments
They tend to get not updated when files are moved around or copied and
lack any obvious use.  While at it zap some only too obvious comments and
as per Shinya's suggestion, add a copyright header to extable.c.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Acked-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
2009-08-03 17:52:40 +01:00

87 lines
2 KiB
C

/*
* Stack trace management functions
*
* Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
*/
#include <linux/sched.h>
#include <linux/stacktrace.h>
#include <linux/module.h>
#include <asm/stacktrace.h>
/*
* Save stack-backtrace addresses into a stack_trace buffer:
*/
static void save_raw_context_stack(struct stack_trace *trace,
unsigned long reg29)
{
unsigned long *sp = (unsigned long *)reg29;
unsigned long addr;
while (!kstack_end(sp)) {
addr = *sp++;
if (__kernel_text_address(addr)) {
if (trace->skip > 0)
trace->skip--;
else
trace->entries[trace->nr_entries++] = addr;
if (trace->nr_entries >= trace->max_entries)
break;
}
}
}
static void save_context_stack(struct stack_trace *trace,
struct task_struct *tsk, struct pt_regs *regs)
{
unsigned long sp = regs->regs[29];
#ifdef CONFIG_KALLSYMS
unsigned long ra = regs->regs[31];
unsigned long pc = regs->cp0_epc;
if (raw_show_trace || !__kernel_text_address(pc)) {
unsigned long stack_page =
(unsigned long)task_stack_page(tsk);
if (stack_page && sp >= stack_page &&
sp <= stack_page + THREAD_SIZE - 32)
save_raw_context_stack(trace, sp);
return;
}
do {
if (trace->skip > 0)
trace->skip--;
else
trace->entries[trace->nr_entries++] = pc;
if (trace->nr_entries >= trace->max_entries)
break;
pc = unwind_stack(tsk, &sp, pc, &ra);
} while (pc);
#else
save_raw_context_stack(trace, sp);
#endif
}
/*
* Save stack-backtrace addresses into a stack_trace buffer.
*/
void save_stack_trace(struct stack_trace *trace)
{
save_stack_trace_tsk(current, trace);
}
EXPORT_SYMBOL_GPL(save_stack_trace);
void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
{
struct pt_regs dummyregs;
struct pt_regs *regs = &dummyregs;
WARN_ON(trace->nr_entries || !trace->max_entries);
if (tsk != current) {
regs->regs[29] = tsk->thread.reg29;
regs->regs[31] = 0;
regs->cp0_epc = tsk->thread.reg31;
} else
prepare_frametrace(regs);
save_context_stack(trace, tsk, regs);
}
EXPORT_SYMBOL_GPL(save_stack_trace_tsk);