static void print_backtrace(const intptr_t *bt, unsigned int depth)
{
const mapinfo *mi;
unsigned int cnt;
unsigned int rel_pc;
intptr_t self_bt[MAX_BACKTRACE_DEPTH];
if (!bt) {
depth = get_backtrace(self_bt, MAX_BACKTRACE_DEPTH);
bt = self_bt;
}
log_message("*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***\n");
for (cnt = 0; cnt < depth && cnt < MAX_BACKTRACE_DEPTH; cnt++) {
mi = pc_to_mapinfo(milist, bt[cnt], &rel_pc);
log_message("\t#%02d pc %08x %s\n", cnt,
mi ? (intptr_t)rel_pc : bt[cnt],
mi ? mi->name : "(unknown)");
}
}
/* routine to determine if a word value represents a return address
* This routine checks to see if the word value points to an address that
* immediately follows a branch instruction.
*/
int is_ARM_return_address(int pid, mapinfo *milist, unsigned int value)
{
unsigned int addr;
unsigned int data;
unsigned int rel_addr;
const mapinfo *mi;
/* check 4 bytes before the address */
addr = value-4;
/* FIXTHIS - check map to see if this is in text segment */
rel_addr = addr;
mi = pc_to_mapinfo(milist, addr, &rel_addr);
if (mi == NULL) {
/* address is not in the executable memory map */
/* note that the [stack] map is not executable,
* and has already been filtered from the map list
*/
return 0;
}
DLOG("checking addr=0x%08lx for instruction\n", addr);
data = ptrace(PTRACE_PEEKTEXT, pid, (void*)addr, NULL);
/* detect failure to read data from process memory */
if (data==0xffffffff) {
return 0;
}
DLOG("instruction at %08lx is %08lx\n", addr, data);
if (is_ARM_bl(data)) {
DLOG("this instruction is a branch and link, with offset %d and target 0x%08x\n",
branch_offset(data), branch_target(addr, data));
return 1;
} else {
return 0;
}
}
int unwind_backtrace_with_ptrace_x86(int tfd, pid_t pid, mapinfo *map,
bool at_fault)
{
struct pt_regs_x86 r;
unsigned int stack_level = 0;
unsigned int stack_depth = 0;
unsigned int rel_pc;
unsigned int stack_ptr;
unsigned int stack_content;
if(ptrace(PTRACE_GETREGS, pid, 0, &r)) return 0;
unsigned int eip = (unsigned int)r.eip;
unsigned int ebp = (unsigned int)r.ebp;
unsigned int cur_sp = (unsigned int)r.esp;
const mapinfo *mi;
const struct symbol* sym = 0;
//ebp==0, it indicates that the stack is poped to the bottom or there is no stack at all.
while (ebp) {
mi = pc_to_mapinfo(map, eip, &rel_pc);
/* See if we can determine what symbol this stack frame resides in */
if (mi != 0 && mi->symbols != 0) {
sym = symbol_table_lookup(mi->symbols, rel_pc);
}
if (sym) {
_LOG(tfd, !at_fault, " #%02d eip: %08x %s (%s)\n",
stack_level, eip, mi ? mi->name : "", sym->name);
} else {
_LOG(tfd, !at_fault, " #%02d eip: %08x %s\n",
stack_level, eip, mi ? mi->name : "");
}
stack_level++;
if (stack_level >= STACK_DEPTH || eip == 0)
break;
eip = ptrace(PTRACE_PEEKTEXT, pid, (void*)(ebp + 4), NULL);
ebp = ptrace(PTRACE_PEEKTEXT, pid, (void*)ebp, NULL);
}
ebp = (unsigned int)r.ebp;
stack_depth = stack_level;
stack_level = 0;
if (ebp)
_LOG(tfd, !at_fault, "stack: \n");
while (ebp) {
stack_ptr = cur_sp;
while((int)(ebp - stack_ptr) >= 0) {
stack_content = ptrace(PTRACE_PEEKTEXT, pid, (void*)stack_ptr, NULL);
mi = pc_to_mapinfo(map, stack_content, &rel_pc);
/* See if we can determine what symbol this stack frame resides in */
if (mi != 0 && mi->symbols != 0) {
sym = symbol_table_lookup(mi->symbols, rel_pc);
}
if (sym) {
_LOG(tfd, !at_fault, " #%02d %08x %08x %s (%s)\n",
stack_level, stack_ptr, stack_content, mi ? mi->name : "", sym->name);
} else {
_LOG(tfd, !at_fault, " #%02d %08x %08x %s\n",
stack_level, stack_ptr, stack_content, mi ? mi->name : "");
}
stack_ptr = stack_ptr + 4;
//the stack frame may be very deep.
if((int)(stack_ptr - cur_sp) >= STACK_FRAME_DEPTH) {
_LOG(tfd, !at_fault, " ...... ...... \n");
break;
}
}
cur_sp = ebp + 4;
stack_level++;
if (stack_level >= STACK_DEPTH || stack_level >= stack_depth)
break;
ebp = ptrace(PTRACE_PEEKTEXT, pid, (void*)ebp, NULL);
}
return stack_depth;
}
