linux_dsm_epyc7002/arch/csky/kernel/stacktrace.c
Guo Ren 0ea2dc7cd6 csky: stacktrace supported.
The gcc option "-mbacktrace" will push fp(r8),lr into stack and we could
unwind the stack with:
	fp = *fp
	lr = (unsigned int *)fp[1]

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
2018-12-31 23:12:22 +08:00

58 lines
1.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd. */
#include <linux/sched/debug.h>
#include <linux/sched/task_stack.h>
#include <linux/stacktrace.h>
#include <linux/ftrace.h>
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)
{
unsigned long *fp, *stack_start, *stack_end;
unsigned long addr;
int skip = trace->skip;
int savesched;
int graph_idx = 0;
if (tsk == current) {
asm volatile("mov %0, r8\n":"=r"(fp));
savesched = 1;
} else {
fp = (unsigned long *)thread_saved_fp(tsk);
savesched = 0;
}
addr = (unsigned long) fp & THREAD_MASK;
stack_start = (unsigned long *) addr;
stack_end = (unsigned long *) (addr + THREAD_SIZE);
while (fp > stack_start && fp < stack_end) {
unsigned long lpp, fpp;
fpp = fp[0];
lpp = fp[1];
if (!__kernel_text_address(lpp))
break;
else
lpp = ftrace_graph_ret_addr(tsk, &graph_idx, lpp, NULL);
if (savesched || !in_sched_functions(lpp)) {
if (skip) {
skip--;
} else {
trace->entries[trace->nr_entries++] = lpp;
if (trace->nr_entries >= trace->max_entries)
break;
}
}
fp = (unsigned long *)fpp;
}
}
EXPORT_SYMBOL_GPL(save_stack_trace_tsk);