char* read_child_str(pid_t pid, long int addr)
{
char *tmp, *str;
int i, idx = 0;
int buffer_size = 256;
str = sys_malloc(buffer_size);
while (1) {
if (idx + READ_SIZE >= buffer_size) {
buffer_size *= 2;
str = realloc(str, buffer_size);
}
tmp = read_child_data_tid(pid, READ_SIZE, addr + idx);
memcpy(str + idx, tmp, READ_SIZE);
sys_free((void**) &tmp);
for (i = 0; i < READ_SIZE; i++) {
if (str[idx + i] == '\0') {
return str;
}
}
idx += READ_SIZE;
}assert(1==0);
return 0;
}
void* read_child_data(struct context *ctx, ssize_t size, uintptr_t addr)
{
void *buf = sys_malloc(size);
/* if pread fails: do the following: echo 0 > /proc/sys/kernel/yama/ptrace_scope */
ssize_t read_bytes = checked_pread(ctx,buf,size,addr);
if (read_bytes != size) {
free(buf);
buf = read_child_data_tid(ctx->child_tid,size,addr);
printf("reading from: %x demanded: %u read %u event: %d\n", addr, size, read_bytes, ctx->event);
perror("warning: reading from child process: ");
printf("try the following: echo 0 > /proc/sys/kernel/yama/ptrace_scope\n");
sleep(5);
}
return buf;
}
void* read_child_data(struct context *ctx, size_t size, uintptr_t addr)
{
size_t bytes_read;
void* data = sys_malloc(size);
/* if pread cannot read all data (for whatever reason) we use ptrace
* primitives to get the rest. */
if ((bytes_read = pread64(ctx->child_mem_fd, data, size, addr)) < size) {
assert(bytes_read >= 0);
void* rest = read_child_data_tid(ctx->child_tid, size - bytes_read, addr + bytes_read);
memcpy(data + bytes_read, rest, size - bytes_read);
sys_free((void**) &rest);
}
/* make sure we no not return more than required */
return data;
}
