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/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; version 2.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*/
#include <common.h>
#include <asm/stacktrace.h>
#include <asm/unwind.h>
#define THREAD_SIZE 16384
/*
* AArch64 PCS assigns the frame pointer to x29.
*
* A simple function prologue looks like this:
* sub sp, sp, #0x10
* stp x29, x30, [sp]
* mov x29, sp
*
* A simple function epilogue looks like this:
* mov sp, x29
* ldp x29, x30, [sp]
* add sp, sp, #0x10
*/
int unwind_frame(struct stackframe *frame)
{
unsigned long high, low;
unsigned long fp = frame->fp;
low = frame->sp;
high = ALIGN(low, THREAD_SIZE);
if (fp < low || fp > high - 0x18 || fp & 0xf)
return -EINVAL;
frame->sp = fp + 0x10;
frame->fp = *(unsigned long *)(fp);
frame->pc = *(unsigned long *)(fp + 8);
return 0;
}
static void dump_backtrace_entry(unsigned long where, unsigned long from)
{
#ifdef CONFIG_KALLSYMS
printf("[<%08lx>] (%pS) from [<%08lx>] (%pS)\n", where, (void *)where, from, (void *)from);
#else
printf("Function entered at [<%08lx>] from [<%08lx>]\n", where, from);
#endif
}
void unwind_backtrace(struct pt_regs *regs)
{
struct stackframe frame = {};
register unsigned long current_sp asm ("sp");
if (regs) {
frame.fp = regs->regs[29];
frame.pc = regs->elr;
} else {
frame.fp = (unsigned long)__builtin_frame_address(0);
frame.sp = current_sp;
frame.pc = (unsigned long)unwind_backtrace;
}
printf("Call trace:\n");
while (1) {
unsigned long where = frame.pc;
int ret;
ret = unwind_frame(&frame);
if (ret < 0)
break;
dump_backtrace_entry(where, frame.pc);
}
}
void dump_stack(void)
{
unwind_backtrace(NULL);
}
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