From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Joe Lawrence <joe.lawrence@redhat.com>
Cc: live-patching@vger.kernel.org, linux-kernel@vger.kernel.org,
Peter Zijlstra <peterz@infradead.org>,
Jessica Yu <jeyu@kernel.org>
Subject: Re: [PATCH 0/7] livepatch,module: Remove .klp.arch and module_disable_ro()
Date: Tue, 14 Apr 2020 20:31:17 -0500 [thread overview]
Message-ID: <20200415013117.rc7vlidmo4okzypl@treble> (raw)
In-Reply-To: <187a2ccd-1d04-54db-2fd3-8c4ca6872830@redhat.com>
On Tue, Apr 14, 2020 at 08:57:15PM -0400, Joe Lawrence wrote:
> On 4/14/20 12:28 PM, Josh Poimboeuf wrote:
> > Better late than never, these patches add simplifications and
> > improvements for some issues Peter found six months ago, as part of his
> > non-writable text code (W^X) cleanups.
> >
> > Highlights:
> >
> > - Remove the livepatch arch-specific .klp.arch sections, which were used
> > to do paravirt patching and alternatives patching for livepatch
> > replacement code.
> >
> > - Add support for jump labels in patched code.
>
> Re: jump labels and late-module patching support...
>
> Is there still an issue of a non-exported static key defined in a
> to-be-patched module referenced and resolved via klp-relocation when the
> livepatch module is loaded first? (Basically the same case I asked Petr
> about in his split livepatch module PoC. [1])
>
> Or should we declare this an invalid klp-relocation use case and force the
> livepatch author to use static_key_enabled()?
>
> [1] https://lore.kernel.org/lkml/20200407205740.GA17061@redhat.com/
Right, if the static key lives in a module, then it's still not possible
for a jump label to use it. I added a check in kpatch-build to block
that case and suggest static_key_enabled() instead.
I don't know what the solution is, other than getting rid of late module
patching.
I confess I haven't looked at Petr's patches due to other distractions,
but I plan to soon.
--
Josh
next prev parent reply other threads:[~2020-04-15 1:31 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-14 16:28 [PATCH 0/7] livepatch,module: Remove .klp.arch and module_disable_ro() Josh Poimboeuf
2020-04-14 16:28 ` [PATCH 1/7] livepatch: Apply vmlinux-specific KLP relocations early Josh Poimboeuf
2020-04-14 17:44 ` Peter Zijlstra
2020-04-14 18:01 ` Josh Poimboeuf
2020-04-14 19:31 ` Josh Poimboeuf
2020-04-15 14:30 ` Miroslav Benes
2020-04-15 16:29 ` Josh Poimboeuf
2020-04-15 14:34 ` Miroslav Benes
2020-04-15 16:30 ` Josh Poimboeuf
2020-04-14 16:28 ` [PATCH 2/7] livepatch: Remove .klp.arch Josh Poimboeuf
2020-04-15 15:18 ` Jessica Yu
2020-04-14 16:28 ` [PATCH 3/7] livepatch: Prevent module-specific KLP rela sections from referencing vmlinux symbols Josh Poimboeuf
2020-04-14 16:28 ` [PATCH 4/7] s390/module: Use s390_kernel_write() for relocations Josh Poimboeuf
2020-04-16 8:56 ` Miroslav Benes
2020-04-16 12:06 ` Josh Poimboeuf
2020-04-16 13:16 ` Josh Poimboeuf
2020-04-17 1:37 ` Josh Poimboeuf
2020-04-14 16:28 ` [PATCH 5/7] x86/module: Use text_poke() " Josh Poimboeuf
2020-04-14 16:28 ` [PATCH 6/7] livepatch: Remove module_disable_ro() usage Josh Poimboeuf
2020-04-15 15:02 ` Jessica Yu
2020-04-15 16:33 ` Josh Poimboeuf
2020-04-16 9:28 ` Miroslav Benes
2020-04-16 12:10 ` Josh Poimboeuf
2020-04-14 16:28 ` [PATCH 7/7] module: Remove module_disable_ro() Josh Poimboeuf
2020-04-14 18:27 ` [PATCH 0/7] livepatch,module: Remove .klp.arch and module_disable_ro() Peter Zijlstra
2020-04-14 19:08 ` Josh Poimboeuf
2020-04-15 14:24 ` Peter Zijlstra
2020-04-15 16:17 ` Josh Poimboeuf
2020-04-16 15:31 ` Jessica Yu
2020-04-16 15:45 ` Josh Poimboeuf
2020-04-17 8:27 ` Miroslav Benes
2020-04-17 8:50 ` Jessica Yu
2020-04-16 9:45 ` Miroslav Benes
2020-04-16 12:20 ` Josh Poimboeuf
2020-04-17 9:08 ` Miroslav Benes
2020-04-15 0:57 ` Joe Lawrence
2020-04-15 1:31 ` Josh Poimboeuf [this message]
2020-04-15 1:37 ` Joe Lawrence
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=20200415013117.rc7vlidmo4okzypl@treble \
--to=jpoimboe@redhat.com \
--cc=jeyu@kernel.org \
--cc=joe.lawrence@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=live-patching@vger.kernel.org \
--cc=peterz@infradead.org \
/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).