From: Linus Torvalds <torvalds@linux-foundation.org>
To: Aleksa Sarai <cyphar@cyphar.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>,
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Subject: Re: [PATCH RESEND v14 2/6] namei: LOOKUP_IN_ROOT: chroot-like path resolution
Date: Sun, 27 Oct 2019 08:05:11 -0400 [thread overview]
Message-ID: <CAHk-=wjPPWvm5_eR4uaHJaU1isTUk-4iXQV3Z2Px9A+w6j2nHg@mail.gmail.com> (raw)
In-Reply-To: <20191026185700.10708-3-cyphar@cyphar.com>
On Sat, Oct 26, 2019 at 2:58 PM Aleksa Sarai <cyphar@cyphar.com> wrote:
>
> + /* LOOKUP_IN_ROOT treats absolute paths as being relative-to-dirfd. */
> + if (flags & LOOKUP_IN_ROOT)
> + while (*s == '/')
> + s++;
> +
> /* Figure out the starting path and root (if needed). */
> if (*s == '/') {
> error = nd_jump_root(nd);
So I'm still hung up on this.
I guess I can't help it, but I look at the above, and it makes me go
"whoever wrote those tests wasn't thinking".
It just annoys me how it tests for '/' completely unnecessarily.
If LOOKUP_IN_ROOT is true, we know the subsequent test for '/' is not
going to match, because we just removed it. So I look at that code and
go "that code is doing stupid things".
That's why I suggested moving the LOOKUP_IN_ROOT check inside the '/' test.
Alternatively, just make the logic be
if (flags & LOOKUP_IN_ROOT) {
.. remove '/'s ...
} else if (*s == '/') {
.. handl;e root ..
and remove the next "else" clause
Linus
next prev parent reply other threads:[~2019-10-27 12:05 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-26 18:56 [PATCH RESEND v14 0/6] open: introduce openat2(2) syscall Aleksa Sarai
2019-10-26 18:56 ` [PATCH RESEND v14 1/6] namei: O_BENEATH-style resolution restriction flags Aleksa Sarai
2019-10-26 18:56 ` [PATCH RESEND v14 2/6] namei: LOOKUP_IN_ROOT: chroot-like path resolution Aleksa Sarai
2019-10-27 12:05 ` Linus Torvalds [this message]
2019-10-27 15:41 ` Aleksa Sarai
2019-10-26 18:56 ` [PATCH RESEND v14 3/6] namei: permit ".." resolution with LOOKUP_{IN_ROOT,BENEATH} Aleksa Sarai
2019-10-26 18:56 ` [PATCH RESEND v14 4/6] open: introduce openat2(2) syscall Aleksa Sarai
2019-10-26 18:56 ` [PATCH RESEND v14 5/6] selftests: add openat2(2) selftests Aleksa Sarai
2019-10-26 18:57 ` [PATCH RESEND v14 6/6] Documentation: path-lookup: mention LOOKUP_MAGICLINK_JUMPED Aleksa Sarai
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