源码编译GDB 13.1（RHEL7）无法获取工作目录：权限拒绝

在RHEL7系统上源码编译GDB 13.1成功后，每次启动执行pwd命令都会报错：

Error finding name of working directory: Permission denied

启动gdbserver时也会出现相同错误并立即退出。受企业环境限制，无法以root身份运行GDB，且对运行GDB的目录拥有全部权限。

补充的strace -e file gdb --batch -ex pwd输出如下：

...
openat(AT_FDCWD, "/proc/self/fd", O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_DIRECTORY) = 3
lstat(".", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat("/", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
openat(AT_FDCWD, "..", O_RDONLY)
newfstatat(3, "bin", {st_mode=S_IFDIR|0755, st_size=4096, ...}, AT_SYMLINK_NOFOLLOW) = 0
openat(3, "..", O_RDONLY)
newfstatat(4, "x86_64.linux.2.6.glibc.2.17", {st_mode=S_IFDIR|0755, st_size=4096, ...}, AT_SYMLINK_NOFOLLOW) = 0
openat(4, "..", O_RDONLY)
newfstatat(3, ".exec", {st_mode=S_IFDIR|0755, st_size=4096, ...}, AT_SYMLINK_NOFOLLOW) = 0
openat(3, "..", O_RDONLY)
newfstatat(4, "install", {st_mode=S_IFDIR|0755, st_size=4096, ...}, AT_SYMLINK_NOFOLLOW) = 0
openat(4, "..", O_RDONLY)
newfstatat(3, "13.1", {st_mode=S_IFDIR|0755, st_size=4096, ...}, AT_SYMLINK_NOFOLLOW) = 0
openat(3, "..", O_RDONLY)
newfstatat(4, "gdb", {st_mode=S_IFDIR|0755, st_size=4096, ...}, AT_SYMLINK_NOFOLLOW) = 0
openat(4, "..", O_RDONLY)
newfstatat(3, "fsf", {st_mode=S_IFDIR|0755, st_size=4096, ...}, AT_SYMLINK_NOFOLLOW) = 0
openat(3, "..", O_RDONLY)              = -1 EACCESS (Permission denied)
gdb: warning: error finding working directory: Permission denied
...
lstat(".", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat("/", {st_mode=S_IFDIR|0755, st_size=4096, ...}, AT_SYMLINK_NOFOLLOW) = 0
openat(AT_FDCWD, "..", O_RDONLY)
newfstatat(11, "bin", {st_mode=S_IFDIR|0755, st_size=4096, ...}, AT_SYMLINK_NOFOLLOW) = 0
openat(11, "..", O_RDONLY)
newfstatat(12, "x86_64.linux.2.6.glibc.2.17", {st_mode=S_IFDIR|0755, st_size=4096, ...}, AT_SYMLINK_NOFOLLOW) = 0
openat(12, "..", O_RDONLY)
newfstatat(11, ".exec", {st_mode=S_IFDIR|0755, st_size=4096, ...}, AT_SYMLINK_NOFOLLOW) = 0
openat(11, "..", O_RDONLY)
newfstatat(12, "install", {st_mode=S_IFDIR|0755, st_size=4096, ...}, AT_SYMLINK_NOFOLLOW) = 0
openat(12, "..", O_RDONLY)
newfstatat(11, "13.1", {st_mode=S_IFDIR|0755, st_size=4096, ...}, AT_SYMLINK_NOFOLLOW) = 0
openat(11, "..", O_RDONLY)
newfstatat(12, "gdb", {st_mode=S_IFDIR|0755, st_size=4096, ...}, AT_SYMLINK_NOFOLLOW) = 0
openat(12, "..", O_RDONLY)
newfstatat(11, "fsf", {st_mode=S_IFDIR|0755, st_size=4096, ...}, AT_SYMLINK_NOFOLLOW) = 0
openat(11, "..", O_RDONLY)              = -1 EACCESS (Permission denied)
Error finding name of working directory: Permission denied
open(".gdb_history", O_RDONLY)
+++ exited with 1 +++

从strace输出能明确定位问题：GDB默认通过/proc/self/fd回溯遍历父目录来确定当前工作目录，但路径中某个上级目录没有执行权限（Linux下遍历目录需要x权限），导致最后一步访问被拒绝。即使你对当前运行目录有完全权限，只要父目录缺少x权限就会触发这个错误。

以下是两个可行的解决办法：

• 临时绕过：手动指定PWD环境变量
  GDB会优先读取PWD环境变量来获取当前工作目录，无需遍历父目录。启动GDB前执行：

  export PWD=$(pwd)
  

  或者直接在启动命令中指定：

  PWD=$(pwd) gdb
  

  该方法同样适用于gdbserver：

  PWD=$(pwd) gdbserver <你的参数>
  

• 永久解决：重新编译GDB时禁用procfs依赖
  如果临时方法不够方便，可以在编译GDB时添加配置选项，强制它不依赖/proc来获取工作目录：

  ./configure --disable-procfs --prefix=<你的安装路径>
  make && make install
  

  注意--disable-procfs会关闭部分依赖/proc的功能，但完全满足基本调试和pwd命令的使用需求。

内容的提问来源于stack exchange，提问作者Percee