From: Masami Hiramatsu <mhiramat@kernel.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>,
Christoph Hellwig <hch@lst.de>,
"the arch/x86 maintainers" <x86@kernel.org>,
Alexei Starovoitov <ast@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
linux-parisc@vger.kernel.org,
linux-um <linux-um@lists.infradead.org>,
Netdev <netdev@vger.kernel.org>,
bpf@vger.kernel.org, Linux-MM <linux-mm@kvack.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 11/18] maccess: remove strncpy_from_unsafe
Date: Thu, 14 May 2020 10:00:09 +0900 [thread overview]
Message-ID: <20200514100009.a8e6aa001f0ace5553c7904f@kernel.org> (raw)
In-Reply-To: <CAHk-=wjBKGLyf1d53GwfUTZiK_XPdujwh+u2XSpD2HWRV01Afw@mail.gmail.com>
On Wed, 13 May 2020 16:59:40 -0700
Linus Torvalds <torvalds@linux-foundation.org> wrote:
> On Wed, May 13, 2020 at 4:21 PM Masami Hiramatsu <mhiramat@kernel.org> wrote:
> >
> >
> > For trace_kprobe.c current order (kernel -> user fallback) is preferred
> > because it has another function dedicated for user memory.
>
> Well, then it should just use the "strict" kernel-only one for the
> non-user memory.
>
> But yes, if there are legacy interfaces, then we might want to say
> "these continue to work for the legacy case on platforms where we can
> tell which kind of pointer it is from the bit pattern".
Yes, that was why I changed my mind and send reviewed-by last time.
https://lore.kernel.org/bpf/20200511142716.f1ff6fc55220012982c47fec@kernel.org/
> But we should likely at least disallow it entirely on platforms where
> we really can't - or pick one hardcoded choice. On sparc, you really
> _have_ to specify one or the other.
OK. BTW, is there any way to detect the kernel/user space overlap on
memory layout statically? If there, I can do it. (I don't like
"if (CONFIG_X86)" thing....)
Or, maybe we need CONFIG_ARCH_OVERLAP_ADDRESS_SPACE?
Thank you,
--
Masami Hiramatsu <mhiramat@kernel.org>
next prev parent reply other threads:[~2020-05-14 1:00 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-13 16:00 clean up and streamline probe_kernel_* and friends v2 Christoph Hellwig
2020-05-13 16:00 ` [PATCH 01/18] maccess: unexport probe_kernel_write and probe_user_write Christoph Hellwig
2020-05-13 16:00 ` [PATCH 02/18] maccess: remove various unused weak aliases Christoph Hellwig
2020-05-13 16:00 ` [PATCH 03/18] maccess: remove duplicate kerneldoc comments Christoph Hellwig
2020-05-13 16:00 ` [PATCH 04/18] maccess: clarify " Christoph Hellwig
2020-05-13 16:00 ` [PATCH 05/18] maccess: update the top of file comment Christoph Hellwig
2020-05-13 16:00 ` [PATCH 06/18] maccess: rename strncpy_from_unsafe_user to strncpy_from_user_nofault Christoph Hellwig
2020-05-13 16:00 ` [PATCH 07/18] maccess: rename strncpy_from_unsafe_strict to strncpy_from_kernel_nofault Christoph Hellwig
2020-05-13 16:00 ` [PATCH 08/18] maccess: rename strnlen_unsafe_user to strnlen_user_nofault Christoph Hellwig
2020-05-13 16:00 ` [PATCH 09/18] maccess: remove probe_read_common and probe_write_common Christoph Hellwig
2020-05-13 16:00 ` [PATCH 10/18] maccess: unify the probe kernel arch hooks Christoph Hellwig
2020-05-14 1:13 ` Masami Hiramatsu
2020-05-19 5:46 ` Christoph Hellwig
2020-05-13 16:00 ` [PATCH 11/18] maccess: remove strncpy_from_unsafe Christoph Hellwig
2020-05-13 19:11 ` Linus Torvalds
2020-05-13 19:28 ` Christoph Hellwig
2020-05-13 22:36 ` Daniel Borkmann
2020-05-13 23:03 ` Linus Torvalds
2020-05-13 23:24 ` Daniel Borkmann
2020-05-13 23:20 ` Masami Hiramatsu
2020-05-13 23:59 ` Linus Torvalds
2020-05-14 1:00 ` Masami Hiramatsu [this message]
2020-05-14 2:43 ` Linus Torvalds
2020-05-14 9:44 ` Masami Hiramatsu
2020-05-14 10:27 ` Daniel Borkmann
2020-05-13 23:28 ` Al Viro
2020-05-13 23:58 ` Daniel Borkmann
2020-05-14 10:01 ` David Laight
2020-05-14 10:21 ` Daniel Borkmann
2020-05-13 16:00 ` [PATCH 12/18] maccess: always use strict semantics for probe_kernel_read Christoph Hellwig
2020-05-13 16:00 ` [PATCH 13/18] maccess: move user access routines together Christoph Hellwig
2020-05-13 16:00 ` [PATCH 14/18] maccess: allow architectures to provide kernel probing directly Christoph Hellwig
2020-05-13 19:36 ` Linus Torvalds
2020-05-13 19:40 ` Christoph Hellwig
2020-05-13 19:48 ` Linus Torvalds
2020-05-13 19:54 ` Christoph Hellwig
2020-05-16 3:42 ` Masami Hiramatsu
2020-05-18 15:09 ` Christoph Hellwig
2020-05-13 16:00 ` [PATCH 15/18] x86: use non-set_fs based maccess routines Christoph Hellwig
2020-05-13 16:00 ` [PATCH 16/18] maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault Christoph Hellwig
2020-05-13 16:00 ` [PATCH 17/18] maccess: rename probe_user_{read,write} to copy_{from,to}_user_nofault Christoph Hellwig
2020-05-13 16:00 ` [PATCH 18/18] maccess: rename probe_kernel_address to get_kernel_nofault Christoph Hellwig
2020-05-13 19:37 ` clean up and streamline probe_kernel_* and friends v2 Linus Torvalds
2020-05-13 23:04 ` Daniel Borkmann
2020-05-13 23:20 ` Linus Torvalds
2020-05-19 5:50 ` Christoph Hellwig
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