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/*
* Copyright (C) 2014 Google, Inc.
* Author: Colin Cross <ccross@android.com>
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* 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 <linux/ptrace.h>
#include <linux/uaccess.h>
#include <asm/stacktrace.h>
#include "fiq_debugger_priv.h"
static char *mode_name(unsigned cpsr)
{
switch (cpsr & MODE_MASK) {
case USR_MODE: return "USR";
case FIQ_MODE: return "FIQ";
case IRQ_MODE: return "IRQ";
case SVC_MODE: return "SVC";
case ABT_MODE: return "ABT";
case UND_MODE: return "UND";
case SYSTEM_MODE: return "SYS";
default: return "???";
}
}
void fiq_debugger_dump_pc(struct fiq_debugger_output *output,
const struct pt_regs *regs)
{
output->printf(output, " pc %08x cpsr %08x mode %s\n",
regs->ARM_pc, regs->ARM_cpsr, mode_name(regs->ARM_cpsr));
}
void fiq_debugger_dump_regs(struct fiq_debugger_output *output,
const struct pt_regs *regs)
{
output->printf(output,
" r0 %08x r1 %08x r2 %08x r3 %08x\n",
regs->ARM_r0, regs->ARM_r1, regs->ARM_r2, regs->ARM_r3);
output->printf(output,
" r4 %08x r5 %08x r6 %08x r7 %08x\n",
regs->ARM_r4, regs->ARM_r5, regs->ARM_r6, regs->ARM_r7);
output->printf(output,
" r8 %08x r9 %08x r10 %08x r11 %08x mode %s\n",
regs->ARM_r8, regs->ARM_r9, regs->ARM_r10, regs->ARM_fp,
mode_name(regs->ARM_cpsr));
output->printf(output,
" ip %08x sp %08x lr %08x pc %08x cpsr %08x\n",
regs->ARM_ip, regs->ARM_sp, regs->ARM_lr, regs->ARM_pc,
regs->ARM_cpsr);
}
struct mode_regs {
unsigned long sp_svc;
unsigned long lr_svc;
unsigned long spsr_svc;
unsigned long sp_abt;
unsigned long lr_abt;
unsigned long spsr_abt;
unsigned long sp_und;
unsigned long lr_und;
unsigned long spsr_und;
unsigned long sp_irq;
unsigned long lr_irq;
unsigned long spsr_irq;
unsigned long r8_fiq;
unsigned long r9_fiq;
unsigned long r10_fiq;
unsigned long r11_fiq;
unsigned long r12_fiq;
unsigned long sp_fiq;
unsigned long lr_fiq;
unsigned long spsr_fiq;
};
static void __naked get_mode_regs(struct mode_regs *regs)
{
asm volatile (
"mrs r1, cpsr\n"
"msr cpsr_c, #0xd3 @(SVC_MODE | PSR_I_BIT | PSR_F_BIT)\n"
"stmia r0!, {r13 - r14}\n"
"mrs r2, spsr\n"
"msr cpsr_c, #0xd7 @(ABT_MODE | PSR_I_BIT | PSR_F_BIT)\n"
"stmia r0!, {r2, r13 - r14}\n"
"mrs r2, spsr\n"
"msr cpsr_c, #0xdb @(UND_MODE | PSR_I_BIT | PSR_F_BIT)\n"
"stmia r0!, {r2, r13 - r14}\n"
"mrs r2, spsr\n"
"msr cpsr_c, #0xd2 @(IRQ_MODE | PSR_I_BIT | PSR_F_BIT)\n"
"stmia r0!, {r2, r13 - r14}\n"
"mrs r2, spsr\n"
"msr cpsr_c, #0xd1 @(FIQ_MODE | PSR_I_BIT | PSR_F_BIT)\n"
"stmia r0!, {r2, r8 - r14}\n"
"mrs r2, spsr\n"
"stmia r0!, {r2}\n"
"msr cpsr_c, r1\n"
"bx lr\n");
}
void fiq_debugger_dump_allregs(struct fiq_debugger_output *output,
const struct pt_regs *regs)
{
struct mode_regs mode_regs;
unsigned long mode = regs->ARM_cpsr & MODE_MASK;
fiq_debugger_dump_regs(output, regs);
get_mode_regs(&mode_regs);
output->printf(output,
"%csvc: sp %08x lr %08x spsr %08x\n",
mode == SVC_MODE ? '*' : ' ',
mode_regs.sp_svc, mode_regs.lr_svc, mode_regs.spsr_svc);
output->printf(output,
"%cabt: sp %08x lr %08x spsr %08x\n",
mode == ABT_MODE ? '*' : ' ',
mode_regs.sp_abt, mode_regs.lr_abt, mode_regs.spsr_abt);
output->printf(output,
"%cund: sp %08x lr %08x spsr %08x\n",
mode == UND_MODE ? '*' : ' ',
mode_regs.sp_und, mode_regs.lr_und, mode_regs.spsr_und);
output->printf(output,
"%cirq: sp %08x lr %08x spsr %08x\n",
mode == IRQ_MODE ? '*' : ' ',
mode_regs.sp_irq, mode_regs.lr_irq, mode_regs.spsr_irq);
output->printf(output,
"%cfiq: r8 %08x r9 %08x r10 %08x r11 %08x r12 %08x\n",
mode == FIQ_MODE ? '*' : ' ',
mode_regs.r8_fiq, mode_regs.r9_fiq, mode_regs.r10_fiq,
mode_regs.r11_fiq, mode_regs.r12_fiq);
output->printf(output,
" fiq: sp %08x lr %08x spsr %08x\n",
mode_regs.sp_fiq, mode_regs.lr_fiq, mode_regs.spsr_fiq);
}
struct stacktrace_state {
struct fiq_debugger_output *output;
unsigned int depth;
};
static int report_trace(struct stackframe *frame, void *d)
{
struct stacktrace_state *sts = d;
if (sts->depth) {
sts->output->printf(sts->output,
" pc: %p (%pF), lr %p (%pF), sp %p, fp %p\n",
frame->pc, frame->pc, frame->lr, frame->lr,
frame->sp, frame->fp);
sts->depth--;
return 0;
}
sts->output->printf(sts->output, " ...\n");
return sts->depth == 0;
}
struct frame_tail {
struct frame_tail *fp;
unsigned long sp;
unsigned long lr;
} __attribute__((packed));
static struct frame_tail *user_backtrace(struct fiq_debugger_output *output,
struct frame_tail *tail)
{
struct frame_tail buftail[2];
/* Also check accessibility of one struct frame_tail beyond */
if (!access_ok(VERIFY_READ, tail, sizeof(buftail))) {
output->printf(output, " invalid frame pointer %p\n",
tail);
return NULL;
}
if (__copy_from_user_inatomic(buftail, tail, sizeof(buftail))) {
output->printf(output,
" failed to copy frame pointer %p\n", tail);
return NULL;
}
output->printf(output, " %p\n", buftail[0].lr);
/* frame pointers should strictly progress back up the stack
* (towards higher addresses) */
if (tail >= buftail[0].fp)
return NULL;
return buftail[0].fp-1;
}
void fiq_debugger_dump_stacktrace(struct fiq_debugger_output *output,
const struct pt_regs *regs, unsigned int depth, void *ssp)
{
struct frame_tail *tail;
struct thread_info *real_thread_info = THREAD_INFO(ssp);
struct stacktrace_state sts;
sts.depth = depth;
sts.output = output;
*current_thread_info() = *real_thread_info;
if (!current)
output->printf(output, "current NULL\n");
else
output->printf(output, "pid: %d comm: %s\n",
current->pid, current->comm);
fiq_debugger_dump_regs(output, regs);
if (!user_mode(regs)) {
struct stackframe frame;
frame.fp = regs->ARM_fp;
frame.sp = regs->ARM_sp;
frame.lr = regs->ARM_lr;
frame.pc = regs->ARM_pc;
output->printf(output,
" pc: %p (%pF), lr %p (%pF), sp %p, fp %p\n",
regs->ARM_pc, regs->ARM_pc, regs->ARM_lr, regs->ARM_lr,
regs->ARM_sp, regs->ARM_fp);
walk_stackframe(&frame, report_trace, &sts);
return;
}
tail = ((struct frame_tail *) regs->ARM_fp) - 1;
while (depth-- && tail && !((unsigned long) tail & 3))
tail = user_backtrace(output, tail);
}
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