On Mon, Jun 30, 2014 at 08:53:01AM -0700, Andy Lutomirski wrote: > > Wouldn't it need to be both O_BENEATH_ONLY (for openat()) and > > AT_BENEATH_ONLY (for other *at() functions), like O_NOFOLLOW and > > AT_SYMLINK_NOFOLLOW? (I.e. aren't the AT_* flags in a different > > numbering space than O_* flags?) > > > > Or am I misunderstanding? > > > > Ugh, you're probably right. I wish openat had separate flags and > atflags arguments. Oh well. There's two different AT_* namespaces. The flags that most *at syscalls has, and the the one for the dfd argument, which currently only contains AT_FDCWD, although a new constant has recently been proposed to it. Having an AT_BENEATH magic value for the dfd argument certainly feels elegant to me, but seems to be against the language for openat in Posix: "The openat() function shall be equivalent to the open() function except in the case where path specifies a relative path. In this case the file to be opened is determined relative to the directory associated with the file descriptor fd instead of the current working directory. If the file descriptor was opened without O_SEARCH, the function shall check whether directory searches are permitted using the current permissions of the directory underlying the file descriptor. If the file descriptor was opened with O_SEARCH, the function shall not perform the check. The oflag parameter and the optional fourth parameter correspond exactly to the parameters of open(). If openat() is passed the special value AT_FDCWD in the fd parameter, the current working directory shall be used and the behavior shall be identical to a call to open()." -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
