linux/arch/openrisc/kernel/stacktrace.c
Stafford Horne eecac38b04 openrisc: support framepointers and STACKTRACE_SUPPORT
For lockdep support a reliable stack trace mechanism is needed.  This
patch adds support in OpenRISC for the stacktrace framework, implemented
by a simple unwinder api.  The unwinder api supports both framepointer
and basic stack tracing.

The unwinder is now used to replace the stack_dump() implementation as
well. The new traces are inline with other architectures trace format:

 Call trace:
 [<c0004448>] show_stack+0x3c/0x58
 [<c031c940>] dump_stack+0xa8/0xe4
 [<c0008104>] __cpu_up+0x64/0x130
 [<c000d268>] bringup_cpu+0x3c/0x178
 [<c000d038>] cpuhp_invoke_callback+0xa8/0x1fc
 [<c000d680>] cpuhp_up_callbacks+0x44/0x14c
 [<c000e400>] cpu_up+0x14c/0x1bc
 [<c041da60>] smp_init+0x104/0x15c
 [<c033843c>] ? kernel_init+0x0/0x140
 [<c0415e04>] kernel_init_freeable+0xbc/0x25c
 [<c033843c>] ? kernel_init+0x0/0x140
 [<c0338458>] kernel_init+0x1c/0x140
 [<c003a174>] ? schedule_tail+0x18/0xa0
 [<c0006b80>] ret_from_fork+0x1c/0x9c

Signed-off-by: Stafford Horne <shorne@gmail.com>
2017-11-03 14:01:15 +09:00

87 lines
1.9 KiB
C

/*
* Stack trace utility for OpenRISC
*
* Copyright (C) 2017 Stafford Horne <shorne@gmail.com>
*
* This file is licensed under the terms of the GNU General Public License
* version 2. This program is licensed "as is" without any warranty of any
* kind, whether express or implied.
*
* Losely based on work from sh and powerpc.
*/
#include <linux/export.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/stacktrace.h>
#include <asm/processor.h>
#include <asm/unwinder.h>
/*
* Save stack-backtrace addresses into a stack_trace buffer.
*/
static void
save_stack_address(void *data, unsigned long addr, int reliable)
{
struct stack_trace *trace = data;
if (!reliable)
return;
if (trace->skip > 0) {
trace->skip--;
return;
}
if (trace->nr_entries < trace->max_entries)
trace->entries[trace->nr_entries++] = addr;
}
void save_stack_trace(struct stack_trace *trace)
{
unwind_stack(trace, (unsigned long *) &trace, save_stack_address);
}
EXPORT_SYMBOL_GPL(save_stack_trace);
static void
save_stack_address_nosched(void *data, unsigned long addr, int reliable)
{
struct stack_trace *trace = (struct stack_trace *)data;
if (!reliable)
return;
if (in_sched_functions(addr))
return;
if (trace->skip > 0) {
trace->skip--;
return;
}
if (trace->nr_entries < trace->max_entries)
trace->entries[trace->nr_entries++] = addr;
}
void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
{
unsigned long *sp = NULL;
if (tsk == current)
sp = (unsigned long *) &sp;
else
sp = (unsigned long *) KSTK_ESP(tsk);
unwind_stack(trace, sp, save_stack_address_nosched);
}
EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
void
save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
{
unwind_stack(trace, (unsigned long *) regs->sp,
save_stack_address_nosched);
}
EXPORT_SYMBOL_GPL(save_stack_trace_regs);