/* system/debuggerd/debuggerd.c
**
** Copyright 2006, The Android Open Source Project
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
**
** http://www.apache.org/licenses/LICENSE-2.0
**
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/
#include <stddef.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/ptrace.h>
#include <corkscrew/ptrace.h>
#include <linux/user.h>
#include "../utility.h"
#include "../machine.h"
/* enable to dump memory pointed to by every register */
#define DUMP_MEMORY_FOR_ALL_REGISTERS 1
#ifdef WITH_VFP
#ifdef WITH_VFP_D32
#define NUM_VFP_REGS 32
#else
#define NUM_VFP_REGS 16
#endif
#endif
static void dump_memory(log_t* log, pid_t tid, uintptr_t addr, bool at_fault) {
char code_buffer[64]; /* actual 8+1+((8+1)*4) + 1 == 45 */
char ascii_buffer[32]; /* actual 16 + 1 == 17 */
uintptr_t p, end;
p = addr & ~3;
p -= 32;
if (p > addr) {
/* catch underflow */
p = 0;
}
end = p + 80;
/* catch overflow; 'end - p' has to be multiples of 16 */
while (end < p)
end -= 16;
/* Dump the code around PC as:
* addr contents ascii
* 00008d34 ef000000 e8bd0090 e1b00000 512fff1e ............../Q
* 00008d44 ea00b1f9 e92d0090 e3a070fc ef000000 ......-..p......
*/
while (p < end) {
char* asc_out = ascii_buffer;
sprintf(code_buffer, "%08x ", p);
int i;
for (i = 0; i < 4; i++) {
/*
* If we see (data == -1 && errno != 0), we know that the ptrace
* call failed, probably because we're dumping memory in an
* unmapped or inaccessible page. I don't know if there's
* value in making that explicit in the output -- it likely
* just complicates parsing and clarifies nothing for the
* enlightened reader.
*/
long data = ptrace(PTRACE_PEEKTEXT, tid, (void*)p, NULL);
sprintf(code_buffer + strlen(code_buffer), "%08lx ", data);
int j;
for (j = 0; j < 4; j++) {
/*
* Our isprint() allows high-ASCII characters that display
* differently (often badly) in different viewers, so we
* just use a simpler test.
*/
char val = (data >> (j*8)) & 0xff;
if (val >= 0x20 && val < 0x7f) {
*asc_out++ = val;
} else {
*asc_out++ = '.';
}
}
p += 4;
}
*asc_out = '\0';
_LOG(log, !at_fault, " %s %s\n", code_buffer, ascii_buffer);
}
}
/*
* If configured to do so, dump memory around *all* registers
* for the crashing thread.
*/
void dump_memory_and_code(const ptrace_context_t* context __attribute((unused)),
log_t* log, pid_t tid, bool at_fault) {
struct pt_regs regs;
if(ptrace(PTRACE_GETREGS, tid, 0, ®s)) {
return;
}
if (at_fault && DUMP_MEMORY_FOR_ALL_REGISTERS) {
static const char REG_NAMES[] = "r0r1r2r3r4r5r6r7r8r9slfpipsp";
for (int reg = 0; reg < 14; reg++) {
/* this may not be a valid way to access, but it'll do for now */
uintptr_t addr = regs.uregs[reg];
/*
* Don't bother if it looks like a small int or ~= null, or if
* it's in the kernel area.
*/
if (addr < 4096 || addr >= 0xc0000000) {
continue;
}
_LOG(log, false, "\nmemory near %.2s:\n", ®_NAMES[reg * 2]);
dump_memory(log, tid, addr, at_fault);
}
}
_LOG(log, !at_fault, "\ncode around pc:\n");
dump_memory(log, tid, (uintptr_t)regs.ARM_pc, at_fault);
if (regs.ARM_pc != regs.ARM_lr) {
_LOG(log, !at_fault, "\ncode around lr:\n");
dump_memory(log, tid, (uintptr_t)regs.ARM_lr, at_fault);
}
}
void dump_registers(const ptrace_context_t* context __attribute((unused)),
log_t* log, pid_t tid, bool at_fault)
{
struct pt_regs r;
bool only_in_tombstone = !at_fault;
if(ptrace(PTRACE_GETREGS, tid, 0, &r)) {
_LOG(log, only_in_tombstone, "cannot get registers: %s\n", strerror(errno));
return;
}
_LOG(log, only_in_tombstone, " r0 %08x r1 %08x r2 %08x r3 %08x\n",
(uint32_t)r.ARM_r0, (uint32_t)r.ARM_r1, (uint32_t)r.ARM_r2, (uint32_t)r.ARM_r3);
_LOG(log, only_in_tombstone, " r4 %08x r5 %08x r6 %08x r7 %08x\n",
(uint32_t)r.ARM_r4, (uint32_t)r.ARM_r5, (uint32_t)r.ARM_r6, (uint32_t)r.ARM_r7);
_LOG(log, only_in_tombstone, " r8 %08x r9 %08x sl %08x fp %08x\n",
(uint32_t)r.ARM_r8, (uint32_t)r.ARM_r9, (uint32_t)r.ARM_r10, (uint32_t)r.ARM_fp);
_LOG(log, only_in_tombstone, " ip %08x sp %08x lr %08x pc %08x cpsr %08x\n",
(uint32_t)r.ARM_ip, (uint32_t)r.ARM_sp, (uint32_t)r.ARM_lr,
(uint32_t)r.ARM_pc, (uint32_t)r.ARM_cpsr);
#ifdef WITH_VFP
struct user_vfp vfp_regs;
int i;
if(ptrace(PTRACE_GETVFPREGS, tid, 0, &vfp_regs)) {
_LOG(log, only_in_tombstone, "cannot get registers: %s\n", strerror(errno));
return;
}
for (i = 0; i < NUM_VFP_REGS; i += 2) {
_LOG(log, only_in_tombstone, " d%-2d %016llx d%-2d %016llx\n",
i, vfp_regs.fpregs[i], i+1, vfp_regs.fpregs[i+1]);
}
_LOG(log, only_in_tombstone, " scr %08lx\n", vfp_regs.fpscr);
#endif
}