user: 请从给定的汇编指令推导出C源代码：

```asm
<get_drives>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x228,%rsp
  mov    %rdi,0x8(%rsp)
  lea    D24(%rip),%rdi
  mov    %fs:0x28,%rax
  mov    %rax,0x218(%rsp)
  xor    %eax,%eax
  call   <opendir@plt>
  mov    %rax,%r12
  test   %rax,%rax
  je     L2
L9:
  xor    %ebp,%ebp
  lea    D30(%rip),%rbx
  lea    D21(%rip),%r15
L19:
  mov    %ebp,0x4(%rsp)
  mov    %ebp,%r14d
  jmp    L21
  xchg   %ax,%ax
L108:
  mov    0x0(%r13),%rdi
  mov    %rbx,%rsi
  call   <strcmp@plt>
  test   %rax,%rax
  jne    L26
L21:
  mov    %r12,%rdi
  call   <readdir@plt>
  mov    %rax,%r13
  test   %rax,%rax
  jne    L108
  mov    %r12,%rdi
  call   <closedir@plt>
  mov    %r14d,%edi
  shl    $0x3,%edi
  call   <malloc@plt>
  mov    %rax,%r12
  mov    0x4(%rsp),%eax
  test   %eax,%eax
  je     L82
  xor    %ebx,%ebx
  lea    0x10(%rsp),%r15
  nopw   0x0(%rax,%rax,1)
L58:
  mov    (%r15,%rbx,8),%r13
  mov    %r13,%rdi
  call   <strlen@plt>
  lea    0x1(%rax),%edi
  call   <malloc@plt>
  mov    %r13,%rdi
  mov    %rax,(%r12,%rbx,8)
  mov    %rax,%r14
  call   <strlen@plt>
  mov    %r13,%rsi
  mov    %r14,%rdi
  mov    %rax,%rdx
  call   <strncpy@plt>
  mov    %r13,%rdi
  call   <strlen@plt>
  mov    (%r12,%rbx,8),%rdx
  add    $0x1,%rbx
  movb   $0x0,(%rdx,%rax,1)
  cmp    %rbx,%rbp
  jne    L58
L82:
  mov    0x8(%rsp),%rax
  mov    0x4(%rsp),%ecx
  mov    %ecx,(%rax)
  mov    0x218(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L78
  add    $0x228,%rsp
  mov    %r12,%rax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopl   0x0(%rax)
L26:
  mov    0x0(%r13),%rdi
  mov    %r15,%rsi
  call   <strcmp@plt>
  test   %rax,%rax
  je     L21
  mov    $0x8,%edi
  call   <malloc@plt>
  mov    0x0(%r13),%rsi
  mov    $0x8,%edx
  mov    %rax,%rdi
  mov    %rax,0x10(%rsp,%rbp,8)
  add    $0x1,%rbp
  call   <strncpy@plt>
  jmp    L19
L2:
  lea    D27(%rip),%rdi
  call   <write_debug@plt>
  lea    D9(%rip),%rdi
  call   <opendir@plt>
  mov    %rax,%r12
  test   %rax,%rax
  jne    L9
  movl   $0x0,0x4(%rsp)
  jmp    L82
L78:
  call   <__stack_chk_fail@plt>
```

tool_calls: name: disassemble_data
arguments: tag: D24
datatype: string
name: disassemble_data
arguments: tag: D30
datatype: string
name: disassemble_data
arguments: tag: D21
datatype: string
name: disassemble_data
arguments: tag: D27
datatype: string
name: disassemble_data
arguments: tag: D9
datatype: string

tool: D24: /sys/class/scsi_generic

tool: D30: .

tool: D21: ..

tool: D27: Cannot open /sys/class/scsi_generic


tool: D9: /sys/block

assistant: ```c
char **get_drives(int *driveNum) {
  DIR *d;
  struct dirent *ent;
  char *tmp[64];
  char **ret;
  int j, jj;
  d = opendir("/sys/class/scsi_generic");
  if (!d) {
    write_debug("Cannot open /sys/class/scsi_generic\n");
    d = opendir("/sys/block");
    if (!d) {
      *driveNum = 0;
      return NULL;
    }
  }
  j = 0;
  while ((ent = readdir(d))) {
    if (strcmp(ent->d_name, ".") != 0 && strcmp(ent->d_name, "..") != 0) {
      tmp[j] = malloc(sizeof(ent->d_name));
      strncpy(tmp[j], ent->d_name, sizeof(ent->d_name));
      ++j;
    }
  }
  closedir(d);
  ret = malloc(j * sizeof(char *));
  for (jj = 0; jj < j; ++jj) {
    ret[jj] = malloc(strlen(tmp[jj]) + 1);
    strncpy(ret[jj], tmp[jj], strlen(tmp[jj]));
    ret[jj][strlen(tmp[jj])] = '\0';
  }
  *driveNum = j;
  return ret;
}
```