alistair23-linux/arch/sparc/kernel/stacktrace.c
David S. Miller 667f0cee3e sparc64: Fix stack dumping and tracing when function graph is enabled.
Like x86, when the function graph tracer is enabled, emit the ftrace
stub as well as the program counter it will be transformed back into.

We duplicate a lot of similar stack walking logic in 3 or 4 spots, so
eventually we should consolidate things like x86 does.

Thanks to Frederic Weisbecker for pointing this out.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-21 03:08:11 -07:00

86 lines
2 KiB
C

#include <linux/sched.h>
#include <linux/stacktrace.h>
#include <linux/thread_info.h>
#include <linux/ftrace.h>
#include <linux/module.h>
#include <asm/ptrace.h>
#include <asm/stacktrace.h>
#include "kstack.h"
static void __save_stack_trace(struct thread_info *tp,
struct stack_trace *trace,
bool skip_sched)
{
unsigned long ksp, fp;
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
struct task_struct *t;
int graph = 0;
#endif
if (tp == current_thread_info()) {
stack_trace_flush();
__asm__ __volatile__("mov %%fp, %0" : "=r" (ksp));
} else {
ksp = tp->ksp;
}
fp = ksp + STACK_BIAS;
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
t = tp->task;
#endif
do {
struct sparc_stackf *sf;
struct pt_regs *regs;
unsigned long pc;
if (!kstack_valid(tp, fp))
break;
sf = (struct sparc_stackf *) fp;
regs = (struct pt_regs *) (sf + 1);
if (kstack_is_trap_frame(tp, regs)) {
if (!(regs->tstate & TSTATE_PRIV))
break;
pc = regs->tpc;
fp = regs->u_regs[UREG_I6] + STACK_BIAS;
} else {
pc = sf->callers_pc;
fp = (unsigned long)sf->fp + STACK_BIAS;
}
if (trace->skip > 0)
trace->skip--;
else if (!skip_sched || !in_sched_functions(pc)) {
trace->entries[trace->nr_entries++] = pc;
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
if ((pc + 8UL) == (unsigned long) &return_to_handler) {
int index = t->curr_ret_stack;
if (t->ret_stack && index >= graph) {
pc = t->ret_stack[index - graph].ret;
if (trace->nr_entries <
trace->max_entries)
trace->entries[trace->nr_entries++] = pc;
graph++;
}
}
#endif
}
} while (trace->nr_entries < trace->max_entries);
}
void save_stack_trace(struct stack_trace *trace)
{
__save_stack_trace(current_thread_info(), trace, false);
}
EXPORT_SYMBOL_GPL(save_stack_trace);
void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
{
struct thread_info *tp = task_thread_info(tsk);
__save_stack_trace(tp, trace, true);
}
EXPORT_SYMBOL_GPL(save_stack_trace_tsk);