From: Linus Torvalds <torvalds@linux-foundation.org>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Michael Schmitz <schmitzmic@gmail.com>,
linux-arch <linux-arch@vger.kernel.org>,
Jens Axboe <axboe@kernel.dk>, Oleg Nesterov <oleg@redhat.com>,
Al Viro <viro@zeniv.linux.org.uk>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Richard Henderson <rth@twiddle.net>,
Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
Matt Turner <mattst88@gmail.com>,
alpha <linux-alpha@vger.kernel.org>,
Geert Uytterhoeven <geert@linux-m68k.org>,
linux-m68k <linux-m68k@lists.linux-m68k.org>,
Arnd Bergmann <arnd@kernel.org>,
Ley Foon Tan <ley.foon.tan@intel.com>, Tejun Heo <tj@kernel.org>,
Kees Cook <keescook@chromium.org>
Subject: Re: [PATCH 1/2] alpha/ptrace: Record and handle the absence of switch_stack
Date: Wed, 16 Jun 2021 14:08:02 -0700 [thread overview]
Message-ID: <CAHk-=whwqjetFoyPLehd0_qGbtmKHjibayFrdKC=g3FWYKzu4Q@mail.gmail.com> (raw)
In-Reply-To: <878s398r4g.fsf@disp2133>
On Wed, Jun 16, 2021 at 1:57 PM Eric W. Biederman <ebiederm@xmission.com> wrote:
>
> Do you know if struct switch_stack or pt_regs is ever exposeed to
> usespace? They are both defined in arch/alpha/include/uapi/asm/ptrace.h
> which makes me think userspace must see those definitions somewhere.
Yeah, that uapi location is a bit unfortunate. It means that user
space _could_ have seen it.
Which probably means that some user space uses it. Not for any kernel
interfaces (the alpha ptrace register offsets are actually sane, and
we have that "regoff[]" array to find them) - but I could see some odd
program having decided to use the kernel pt_regs and switch_stack
structures for their own reasons.
Annoying. Because we don't really expose it as-is in any way, afaik.
Only incidentally - and by mistake - in a uapi header file.
Maybe a flag in thread_info->status (or even a new 32-bit field
entirely in thread_info) is the way to go like Al says.
Linus
next prev parent reply other threads:[~2021-06-16 21:13 UTC|newest]
Thread overview: 112+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-10 20:57 Kernel stack read with PTRACE_EVENT_EXIT and io_uring threads Eric W. Biederman
2021-06-10 22:04 ` Linus Torvalds
2021-06-11 21:39 ` Eric W. Biederman
2021-06-11 23:26 ` Linus Torvalds
2021-06-13 21:54 ` Eric W. Biederman
2021-06-13 22:18 ` Linus Torvalds
2021-06-14 2:05 ` Michael Schmitz
2021-06-14 5:03 ` Michael Schmitz
2021-06-14 16:26 ` Eric W. Biederman
2021-06-14 22:26 ` Michael Schmitz
2021-06-15 19:30 ` Eric W. Biederman
2021-06-15 19:36 ` [PATCH] alpha: Add extra switch_stack frames in exit, exec, and kernel threads Eric W. Biederman
2021-06-15 22:02 ` Linus Torvalds
2021-06-16 16:32 ` Eric W. Biederman
2021-06-16 18:29 ` [PATCH 0/2] alpha/ptrace: Improved switch_stack handling Eric W. Biederman
2021-06-16 18:31 ` [PATCH 1/2] alpha/ptrace: Record and handle the absence of switch_stack Eric W. Biederman
2021-06-16 20:00 ` Linus Torvalds
2021-06-16 20:37 ` Linus Torvalds
2021-06-16 20:57 ` Eric W. Biederman
2021-06-16 21:02 ` Al Viro
2021-06-16 21:08 ` Linus Torvalds [this message]
2021-06-16 20:42 ` Eric W. Biederman
2021-06-16 20:17 ` Al Viro
2021-06-21 2:01 ` Michael Schmitz
2021-06-21 2:17 ` Linus Torvalds
2021-06-21 3:18 ` Michael Schmitz
2021-06-21 3:37 ` Linus Torvalds
2021-06-21 4:08 ` Michael Schmitz
2021-06-21 3:44 ` Al Viro
2021-06-21 5:31 ` Michael Schmitz
2021-06-21 2:27 ` Al Viro
2021-06-21 3:36 ` Michael Schmitz
2021-06-16 18:32 ` [PATCH 2/2] alpha/ptrace: Add missing switch_stack frames Eric W. Biederman
2021-06-16 20:25 ` Al Viro
2021-06-16 20:28 ` Al Viro
2021-06-16 20:49 ` Eric W. Biederman
2021-06-16 20:54 ` Al Viro
2021-06-16 20:47 ` Eric W. Biederman
2021-06-16 20:55 ` Al Viro
2021-06-16 20:50 ` [PATCH] alpha: Add extra switch_stack frames in exit, exec, and kernel threads Al Viro
2021-06-15 20:56 ` Kernel stack read with PTRACE_EVENT_EXIT and io_uring threads Michael Schmitz
2021-06-16 0:23 ` Finn Thain
2021-06-15 21:58 ` Linus Torvalds
2021-06-16 15:06 ` Eric W. Biederman
2021-06-21 13:54 ` Al Viro
2021-06-21 14:16 ` Al Viro
2021-06-21 16:50 ` Eric W. Biederman
2021-06-21 23:05 ` Al Viro
2021-06-22 16:39 ` Eric W. Biederman
2021-06-21 15:38 ` Linus Torvalds
2021-06-21 18:59 ` Al Viro
2021-06-21 19:22 ` Linus Torvalds
2021-06-21 19:45 ` Al Viro
2021-06-21 23:14 ` Linus Torvalds
2021-06-21 23:23 ` Al Viro
2021-06-21 23:36 ` Linus Torvalds
2021-06-22 21:02 ` Eric W. Biederman
2021-06-22 21:48 ` Michael Schmitz
2021-06-23 5:26 ` Michael Schmitz
2021-06-23 14:36 ` Eric W. Biederman
2021-06-22 0:01 ` Michael Schmitz
2021-06-22 20:04 ` Michael Schmitz
2021-06-22 20:18 ` Al Viro
2021-06-22 21:57 ` Michael Schmitz
2021-06-21 20:03 ` Eric W. Biederman
2021-06-21 23:15 ` Linus Torvalds
2021-06-22 20:52 ` Eric W. Biederman
2021-06-23 0:41 ` Linus Torvalds
2021-06-23 14:33 ` Eric W. Biederman
2021-06-24 18:57 ` [PATCH 0/9] Refactoring exit Eric W. Biederman
2021-06-24 18:59 ` [PATCH 1/9] signal/sh: Use force_sig(SIGKILL) instead of do_group_exit(SIGKILL) Eric W. Biederman
2021-06-24 18:59 ` [PATCH 2/9] signal/seccomp: Refactor seccomp signal and coredump generation Eric W. Biederman
2021-06-26 3:17 ` Kees Cook
2021-06-28 19:21 ` Eric W. Biederman
2021-06-28 14:34 ` [signal/seccomp] 3fdd8c68c2: kernel-selftests.seccomp.seccomp_bpf.fail kernel test robot
2021-06-24 19:00 ` [PATCH 3/9] signal/seccomp: Dump core when there is only one live thread Eric W. Biederman
2021-06-26 3:20 ` Kees Cook
2021-06-24 19:01 ` [PATCH 4/9] signal: Factor start_group_exit out of complete_signal Eric W. Biederman
2021-06-24 20:04 ` Linus Torvalds
2021-06-25 8:47 ` kernel test robot
2021-06-26 3:24 ` Kees Cook
2021-06-24 19:01 ` [PATCH 5/9] signal/group_exit: Use start_group_exit in place of do_group_exit Eric W. Biederman
2021-06-26 3:35 ` Kees Cook
2021-06-24 19:02 ` [PATCH 6/9] signal: Fold do_group_exit into get_signal fixing io_uring threads Eric W. Biederman
2021-06-26 3:42 ` Kees Cook
2021-06-28 19:25 ` Eric W. Biederman
2021-06-24 19:02 ` [PATCH 7/9] signal: Make individual tasks exiting a first class concept Eric W. Biederman
2021-06-24 20:11 ` Linus Torvalds
2021-06-24 21:37 ` Eric W. Biederman
2021-06-24 19:03 ` [PATCH 8/9] signal/task_exit: Use start_task_exit in place of do_exit Eric W. Biederman
2021-06-26 5:56 ` Kees Cook
2021-06-24 19:03 ` [PATCH 9/9] signal: Move PTRACE_EVENT_EXIT into get_signal Eric W. Biederman
2021-06-24 22:45 ` [PATCH 0/9] Refactoring exit Al Viro
2021-06-27 22:13 ` Al Viro
2021-06-27 22:59 ` Michael Schmitz
2021-06-28 7:31 ` Geert Uytterhoeven
2021-06-28 16:20 ` Eric W. Biederman
2021-06-28 17:14 ` Michael Schmitz
2021-06-28 19:17 ` Geert Uytterhoeven
2021-06-28 20:13 ` Michael Schmitz
2021-06-28 21:18 ` Geert Uytterhoeven
2021-06-28 23:42 ` Michael Schmitz
2021-06-29 20:28 ` [CFT][PATCH] exit/bdflush: Remove the deprecated bdflush system call Eric W. Biederman
2021-06-29 21:45 ` Michael Schmitz
2021-06-30 8:24 ` Geert Uytterhoeven
2021-06-30 8:37 ` Arnd Bergmann
2021-06-30 12:30 ` Cyril Hrubis
2021-06-28 19:02 ` [PATCH 0/9] Refactoring exit Eric W. Biederman
2021-06-21 19:24 ` Kernel stack read with PTRACE_EVENT_EXIT and io_uring threads Al Viro
2021-06-21 23:24 ` Michael Schmitz
2021-06-16 7:38 ` Geert Uytterhoeven
2021-06-16 19:40 ` Michael Schmitz
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAHk-=whwqjetFoyPLehd0_qGbtmKHjibayFrdKC=g3FWYKzu4Q@mail.gmail.com' \
--to=torvalds@linux-foundation.org \
--cc=arnd@kernel.org \
--cc=axboe@kernel.dk \
--cc=ebiederm@xmission.com \
--cc=geert@linux-m68k.org \
--cc=ink@jurassic.park.msu.ru \
--cc=keescook@chromium.org \
--cc=ley.foon.tan@intel.com \
--cc=linux-alpha@vger.kernel.org \
--cc=linux-arch@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-m68k@lists.linux-m68k.org \
--cc=mattst88@gmail.com \
--cc=oleg@redhat.com \
--cc=rth@twiddle.net \
--cc=schmitzmic@gmail.com \
--cc=tj@kernel.org \
--cc=viro@zeniv.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).